Clinical evaluation of Er:YAG laser in the treatment of

Clinical evaluation of Er:YAG laser in the

treatment of chronic periodontitis in comparison

with that of hand and ultrasonic treatment

A thesis Submitted to

The College of Dentistry - University of Baghdad

In partial fulfillment of requirements for the Degree of

Master in science in Periodontics

By

Fahad M. Al Dabbagh

B.D.S.

Prof. Dr. Khulood A. Al Safi

B.D.S., M.Sc., Ph.D.

IRAQ – BAGHDAD

1431 A.H. 2010 A.D.

Clinical evaluation of Er:YAG laser in the

treatment of chronic periodontitis in comparison

with that of hand and ultrasonic treatment

A thesis Submitted to

The College of Dentistry - University of Baghdad

In partial fulfillment of requirements for the Degree of

Master in science in Periodontics

By

Fahad M. Al Dabbagh

B. D. S.


B. D. S., M. Sc., Ph. D.

IRAQ – BAGHDAD

1431 A.H. 2010 A.D.

بسم االله الرحمن الرحيم

﴿إن في خلق السـمـوت والأرض وٱختلــف الليل والنهار لأيـــت لأولي

الألبــب﴾ صدق االله العظيم

191- 190 ٱل عمران

Supervisor Declaration

This is to certify that the organization and preparation of this thesis have

been made by the graduate student Fahad Maizar Al Dabbagh under my

supervision in College of Dentistry, University of Baghdad in partial

fulfillment for the degree of Master of Science in Periodontics.

Signature:



College of Dentistry

University of Baghdad

Supervisor

Committee Declaration

We are the examination committee certify that we have read this thesis and

have examine the graduated student Fahad Maizar Al Dabbagh in its

content and that in our opinion, it meets the standard of a thesis for the

degree of Master of Science in Periodontics.

Approval of the dean of the College of Dentistry, University of Baghdad

Signature:

Prof. Dr. Abdullatif A.H. Abbas Aljuboury

B.D.S., M.Sc., Ph.D., Ph.D

Chairman of the examination committee

Signature:

Prof. Dr. Ali H. AlKhafaji

BDS. MSc. D. (UK)

Dean of the College of

Dentistry.

University of Baghdad

Signature:

Assist. Prof. Dr. Kadhem J. Hanau

B.D.S., M.Sc.

Member

Signature:

Lecturer Dr. Aida Z. Khaleel


Member

Dedication To our great messenger Mohammed

(God bless be upon him)

To the persons who give me all they have to be the best,

My Father and my Mother,

To my brothers and sisters in Islam who guide me and

support me,

To everyone how work's hard to get knowledge;

I dedicate this work

Fahad Al Dabbagh

I

ACKNOWLEDGEMENT In the beginning I thank my God for inspiring me with willingness,

strength and patience to finish this work in a good manner, and I pray to

keep me as he will.

Then I would like to express my sincere thanks and deep

appreciation to my supervisor Prof. Dr. Khulood A. Al Safi - Head of

periodontics department in college of dentistry, University of Baghdad -

whom I fortunate to be under her supervision.

Special thank to Dr. Hussain A. Jawad - Dean of laser institution for

postgraduate studies - and institution's staff for helping me to understand

the laser science.

I want to express my appreciation to Dr. Aida F. Zaki for her support

and advices regarding laser aspect of this work.

My grateful thanks and respect to Dr. Sindis Hashim – head of

endodontics and laser unit in al Jumhory dental specialist center - for their

assistance and support especially in practical part of research, also I would

like to thank the staff of center for giving me the permission to conduct my

research in their institution

I would like to thank the seniors of periodontics department, college

of dentistry - University of Baghdad, for their advices and scientific

support; Also those of periodontics unit in college of dentistry - University

of Mosul for their cooperation in collecting research samples.

I want to extend my thanks to my patients, who participated in the

study, follow my instruction carefully and be patience until we complete

the study, so my deep appreciation for them.

II

Finally I would never forget the encouragements and support of my

family, friends and my soul twins, whom their efforts are invaluable, and

thanks for every one helped me in some way or another throughout my

study

III

ABSTRACT UBackgroundU: The use of lasers for treatment of periodontal diseases has

become a topic of much interest and is a promising field in periodontal

therapy, based on its various characteristics, such as tissue ablation,

homeostasis, and sterilization effect; recently an attention has been paid to

the clinical applicability of Erbium-doped: Yttrium-Aluminum- Garnet

(Er: YAG) with a 2.94µm wavelength, as it is capable of ablation in both

soft and hard tissues.

UMaterials and MethodsU: A total of 96 periodontal pockets were first

selected for conducting the initial study. Here the pockets randomly

categorized into six groups. Three energies with two pulse repetition rate

settings of Er:YAG laser were used to determine the most efficient laser

setting for treatment of chronic periodontitis, based on comparison of the

periodontal clinical parameter before treatment (base line) and after three

month of treatment. The results indicate that laser energy setting of 160mJ

and pulse repetition rate of 15Hz is the most efficient setting for this

purpose.

Another 72 periodontal pockets were selected for prime study and

randomly grouped into three groups; the first group treated by Er:YAG

laser (160mJ – 15Hz), the second group treated by ultrasonic scaling device

and the last one treated by hand instruments.

Clinical periodontal assessments (including Plaque Index, Bleeding

on Probing, Probing Pocket Depth and Relative attachment level) were

performed, for three groups, before starting treatment and after three

months. Numerical rating scale (from zero to ten) was used to evaluate the

degree of pain that the patient experience during each type of treatment.

UResultsU: In this study the results show statistically significant (P < 0.05)

reduction in all periodontal clinical parameters at the second visit in all

IV

groups, but the group treated by Er:YAG laser shows most significant

improvement when compared with other two groups, followed by hand

instruments one, while ultrasonic treatment comes at final rank

The results also indicate that less pain was felt during treatment by

Er: YAG laser with a mean of (1.166), followed by ultrasonic instrument

(mean = 4.916), while treatment by hand instruments are regarded as the

most painful one with a mean of (8.166).

UConclusion U: It was concluded that Er:YAG laser of 160mJ energy at 15Hz

pulse repetition rate could be used as an alternative to conventional non

surgical periodontal treatment (ultrasonic and hand instruments) with

significant improvement, regarding periodontal clinical parameters, with

less pain during treatment.

V

LISTS OF CONTENTS

Subject Page No.

ACKNOWLODGEMENTS I

ABSTRACT III

LIST OF CONTENTS V

LIST OF TABLES X

LIST OF FIGURES XII

LIST OF ABBREVIATIONS XIV

LIST OF VOCABULARIES XVI

INTRODUCTION 1

AIMS OF STUDY 3

CHAPTER ONE ( REVIEW OF LITERATURES )

1.1. Periodontal disease 4

1.1.1. Definition 4

1.1.2. Classification of periodontal diseases 4

1.1.3. Etiology of periodontal diseases 4

1.1.3.1. Dental plaque 5

1.1.3.2. Dental calculus 7

1.1.4. Chronic periodontitis 7

1.1.4.1. Definition 7

1.1.4.2. Characteristics 7

VI

1.1.5. Diagnosis of periodontal disease 8

1.1.6. Treatment of periodontal diseases 8

1.1.6.1. Scaling and root planing 8

1.1.6.2. Instruments and instrumentation 9

1.1.6.2.1. Hand instruments 9

1.1.6.2.1.1. Characteristics of hand instruments therapy 10

1.1.6.2.2. Powered instruments 10

1.1.6.2.2.1. Mechanism of action of Powered instruments 11

1.1.6.2.2.2. Characteristics of ultrasonic periodontal therapy 11

1.2. Laser 13

1.2.1. Definition 13

1.2.2. History of laser 13

1.2.3. Electromagnetic radiations 15

1.2.4. Properties of laser 15

1.2.5. Fundamentals of laser 16

1.2.6. Elements of laser device 17

1.2.7. Manner of operation of laser 19

1.2.8. Types of laser 19

1.2.9. Laser tissue interactions 21

1.2.9.1. Light propagation in biological tissues 21

1.2.9.2. Optical processing of tissues 24

1.2.9.3. Mechanism of tissue ablation by Er: YAG laser 25

VII

1.2.10. Laser safety 27

1.2.11. Laser applications in dentistry 29

1.2.12. Laser in nonsurgical periodontics 31

1.2.13. Er:YAG laser 32

1.2.13.1. Characteristics of Er:YAG nonsurgical periodontal therapy 33

1.2.14. Advantages and disadvantages of laser periodontal

therapy 36

CHAPTER TWO ( MATERIALS AND METHODS )

2.1. Materials 38

2.1.1. Sample selection and description 38

2.1.1.1. Inclusion criteria 38

2.1.1.2. Study case sheet 38

2.1.2. Laser equipments 39

2.1.2.1. Laser system 39

2.1.2.2. Hand piece 40

2.1.3. General equipments and instruments 40

2.1.3.1. Ultrasonic device 40

2.1.3.2. Hand instruments 41

2.1.3.3. Other equipments and materials 41

2.2. Methods 43

2.2.1. Study design 43

2.2.2. Study Parameters 43

VIII

2.2.3. Initial study 45

2.2.4. Main study 46

2.2.5. Treatment procedure 47

2.2.5.1. Hand instrument nonsurgical periodontal therapy 47

2.2.5.2. Ultrasonic nonsurgical periodontal therapy 48

2.2.5.3. Er:YAG laser nonsurgical periodontal therapy 48

2.2.6. Post treatment instructions 49

2.2.7. Statistical analysis 49

CHAPTER THREE ( RESULTS )

3.1. Initial study 57

3.1.1. Plaque index 57

3.1.2. Bleeding on probing 57

3.1.3. Probing pocket depth 58

3.1.4. Relative attachment level 58

3.1.5. Conclusion of Initial study results 63

3.2. Main study 63



3.2.3. Probing pocket depth 64

3.2.4. Relative attachment level 65

3.2.5. Pain level (numerical rating scale) 65

3.2.6. Conclusion of main study results 71

IX

CHAPTER FOUR ( DISCUSSION )

4. Discussion 72

4.1. Initial study 73

4.1.1. Energy level 73

4.1.2. Pulse repetition rate 73

4.2. Main study 74



4.2.3. Probing pocket depth & relative attachment level 75

4.2.4. Pain level 76

CHAPTER FIVE ( CONCLUSIONS & SUGGESTIONS)

5.1. Conclusions 77

5.2. Suggestions 78

REFERENCES 79

APPENDIX 90

X

LIST OF TABLES Table Title Page

Chapter one: Review of literatures (1-1) History of laser 14 (1-2) Classification of laser 19 (1-3) Laser types and typical lasing media 21 (1-4) Laser thermal effect on biological tissues 24 (1-5) Types of laser hazards 27 (1-6) Laser safety classes 28 (1-7) Current lasers commonly used in clinical dentistry 30 (1-8) Current application of Erbium lasers 32 (1-9) Advantages and disadvantages of laser periodontal therapy 36

Chapter two: Materials and Methods

(1-1) Basic properties of KaVo Key laser III 39 (2-2) Equipments and instruments used 42 (2-3) Silness and loe plaque index 44 (2-4) Groups and pockets distribution in initial study 46 (2-5) Groups and pockets distribution in main study 47

Chapter three: Results

(3-1) Descriptive statistics of Plaque Index – Initial study 59 (3-2) Paired sample t-test of Plaque Index for six groups at the second

visit – Initial study 59

(3-3) Percentage of Bleeding On Probing at two visits – Initial study 60 (3-4) Chi-Square test of Bleeding On Probing for six groups – Initial

study 60

(3-5) Descriptive statistics of Probing Pocket Depth – Initial study 61 (3-6) Paired sample t-test of pocket depth for six groups at the second

visit – Initial study 61

(3-7) Descriptive statistics of Relative Attachment Level – Initial study 62 (3-8) Paired sample t-test of Relative Attachment Level for six groups at

the second visit – Initial study 62

(3-9) Initial study conclusion 63 (3-10) Descriptive statistics of Plaque Index – Main study 66 (3-11) Paired sample t-test of Plaque Index for three groups at the second

visit – Main study 66

(3-12) Percentage of Bleeding On Probing at two visits – Main study 67 (3-13) Chi-Square test of Bleeding On Probing for six groups – Main

study 67

XI

(3-14) Descriptive statistics of Probing Pocket Depth – Main study 68 (3-15) Paired sample t-test of pocket depth for three groups – Main study 68 (3-16) Descriptive statistics of Relative Attachment Level – Main study 69 (3-17) Paired sample t-test of Relative Attachment Level for three groups

at the second visit 69

(3-18) Mean of pain score for three groups – Main study 70 (3-19) Paired sample t-test of Pain Level for three groups – Main study 70 (3-20) Main study conclusion 71

XII

LIST OF FIGURES Table Title Page

Chapter one: Review of literatures (1-1) Biofilm structure 6 (1-2) Piezoelectric and magnetostrictive scalers 10 (1-3) Electromagnetic Spectrum 15 (1-4) Stimulated absorption, spontaneous emission and stimulated

emission 17

(1-5) Laser device elements 18 (1-6) Laser – tissue interactions 21 (1-7) Absorption spectrum for water of various lasers 23 (1-8) Hard tissue ablation by Er: YAG laser irradiation 26 (1-9) Section of human eye 29

Chapter two: Materials and Methods

(2-1) KaVo Key Laser 51 (2-2) Fibro optic handpiece 51 (2-3) Diagnostic and periodontal instruments 51 (2-4) Gracey and Universal curettes 51 (2-5) Materials used in study 52 (2-6) Materials and devices used in fabrication of stent 52 (2-7) Dental unit 52 (2-8) Ultrasonic scaler device 53 (2-9) Ultrasonic scaler tips 53

(2-10) Laser protective eyeglasses 53 (2-11) Initial and main studies scheme 54 (2-12) Probing pocket depth 55 (2-13) Occlusal stent 55 (2-14) Hand instrumentation 55 (2-15) Ultrasonic instrumentation 56 (2-16) Er:YAG debridement 56

Chapter three: Results

(3-1) Difference of Plaque Index means for six groups between two visits – Initial study

59

(3-2) Difference of Bleeding On Probing percentage for six groups between two visits – Initial study

60

(3-3) Difference of pocket depth mean for six groups between two visits – Initial study

61

(3-4) Difference of Relative Attachment Level mean for six groups 62

XIII

between two visits – Initial study (3-5) Difference of Plaque Index mean for three groups between two

visits – Main study 66

(3-6) Difference of Bleeding On Probing percentage for six groups between two visits – Main study

67

(3-7) Difference of pocket depth mean for three groups between two visits – Main study

68

(3-8) Difference of Relative Attachment Level mean for three groups between two visits – Main study

69

(3-9) Difference of Pain Level for three groups - Main study 70

XIV

LIST OF ABBREVIATIONS No. Abbreviation Word 1 µm Micro Meter 2 ηm Nano Meter 3 ADA American Dental Association 4 BOP Bleeding On Probing 5 C0 Degree centigrade 6 CAL Clinical attachment Level 7 CFUs Colonies Forming Units 8 CO2 Carbon dioxide 9 CW Continuous Wave

10 DL Diode laser 11 EM Electromagnetic 12 Er,Cr:YSGG Erbium-chromium doped: yttrium-scandium-gallium garnet 13 Er:YAG Erbium-doped: Yttrium-Aluminum- Garnet 14 GaAlAs Gallium - Aluminum - Arsenide 15 GaAs Gallium - Arsenide 16 GIC Glass Ionomer Cement 17 GN Gallium - Neodymium 18 HeNe Helium Neon 19 Hz Hertz 20 InGaAsP Indium - Gallium - Arsenide - Phosphid 21 IL-3 Interleukin – three 22 IL-6 Interleukin – six 23 kHz Kilo Hertz 24 Laser Light amplification by stimulated emission of radiation 25 LGAC Laser – generated airborne contaminants 26 mJ Mili Joule 27 mW Mili Watt 28 MMP-8 Matrix Metallo Proteinases – eight 29 Nd:YAG Neodymium-doped: Yttrium-Aluminum- Garnet 30 NRS Numerical Rating Scale 31 P Probability value 32 PI Plaque Index 33 PPD Probing Pocket Depth 34 PRR Pulse Repetition Rate 35 PPS Pulse per second 36 Q Quality 37 RAL Relative Attachment Level

XV

38 S Second 39 SD Standard of Deviation 40 SE Standard of Error 41 SPSS Software Package of Statistical 42 SRP Scaling and Root Planing 43 Ti Titanium 44 t-test Student Paired sample t-test 45 V Volt 46 VUS Vector ultrasonic System 47 W Watt

XVI

LIST OF VOCABULARIES 1 Chronic periodontitis إلتهاب الأنسجة المحيطة بالأسنان المزمن2 Microbial dental plaque الصفيحة السنية الجرثومية 3 Dental calculus الكلس السني 4 Scaling التقليح 5 Root planing (جعله أملس) تسحجة الجذر 6 Curette ( or curet) المجرفة 7 Hand scaler المقلحة اليدوية 8 Ultrasonic scaler المقلحة بالأمواج فوق الصوتية 9 Er:YAG laser ليزر الأيربيوم ياك المشوب بالياتيريوم- ألمنيوم - غارنيت 10 Pulse repetition rate (frequency) (التردد) معدل تكرار النبضة 11 Laser Energy طاقة الليزر

INTRODUCTION

INTRODUCTION

1

INTRODUCTION Periodontal diseases are among the most common infectious diseases

of humans and are characterized by bacterial-induced inflammatory

destruction of tooth supporting tissues including alveolar bone; with

progression of destruction of the tooth supporting tissues, pockets form

between the teeth and the surrounding detached periodontal tissue, and teeth

may become loose and may eventually be lost .(Jin. , 2003)

Scaling and root planing (SRP) is generally the first treatment

employed for periodontitis and it is considered as a nonsurgical procedure,

root planing involves cleaning and smoothing the root surface of an infected

tooth so that the gingival tissue can heal, shrinking the tissue and reducing the

depth of the pocket that had formed, thus making the root surfaces

biologically compatible with optimal healing and reattachment of epithelium

to the root surface, scaling may be performed with hand instruments alone or

with the aid of an ultrasonic scaler. (Bonito et al, 2004)

However, such instrumentation calls for advanced clinical skills and

sometimes, the anatomy of the root often complicates the achievement of the

desired biologically compatible root, also extensive cementum removal may

lead to increased surface roughness in both supra- and sub-gingivally located

areas, which might enhance plaque retention. (Schwarz et al, 2006)

Recently, the use of laser light has been suggested as an alternative to

the conventional mechanical treatment, it was proposed that laser-based root

surface treatment might lead to improved periodontal therapy due to

relatively conservative removal of tooth substance as well as to the

bactericidal effect towards perio-pathogenic bacteria, also it has been

annotated in the literature that application of laser in periodontal treatment

provides a more comfortable patient experience with less trauma and post-

operative complications as well as a decreased healing time. (Kelbauskiene

et al, 2007)

INTRODUCTION

2

The Erbium-doped: Yttrium–Aluminum–Garnet laser (Er: YAG),

emitting at a wavelength of 2940 nm, possesses suitable properties not only

for soft tissue therapy but also for hard tissue treatment due to its

characteristic wavelength that is highly absorbed by water. (Takasaki, 2007)

The erbium laser group has emerged as a promising laser system for

periodontal indications as several in vitro and clinical studies have already

demonstrated an effective application of the Er: YAG laser for calculus

removal and decontamination of the diseased root surface in periodontal non-

surgical and surgical procedures. (Ishikawa, 2008)

AIMS OF THE STUDY

3

AIMS OF THE STUDY: 1- Determination of the most efficient energy and pulse repetition rate (PRR)

(frequency) values for Er:YAG laser for treatment of chronic periodontitis,

based on clinical evaluation of affected teeth before and after treatment, using

clinical measures (Plaque Index (PI), Bleeding On Probing (BOP), Probing

Pocket Depth (PPD) and Relative Attachment Level (RAL).

2- Evaluation of the efficiency of Er:YAG laser in comparison with that of

ultrasonic and hand instruments regarding treatment of chronic periodontitis,

based on clinical evaluation of affected teeth before and after treatment, using

clinical parameters (PI, BOP, PPD and RAL).

3- Evaluation of the pain level that the patient experience during each type of

nonsurgical periodontal treatment (Er:YAG laser, ultrasonic and hand

instruments).

CHAPTER ONE

REVIEW OF LITERATURES

CHAPTER ONE REVIEW OF LITERATURES

4

1.1. Periodontal diseases: 1.1.1. Definition:

The periodontal disease is a chronic, degenerative disease which is

localized in the gingiva, periodontal ligament, cementum and alveolar bone.

(Kesic, 2008)

1.1.2. Classification of periodontal diseases:

The currently used classification of periodontal diseases was introduced

by the 1999 International Work-shop for a classification of periodontal

diseases and conditions and encompasses eight main categories, namely:

I- Gingival diseases

II- Chronic periodontitis

III- Aggressive periodontitis

IV- Periodontitis as a manifestation of systemic diseases

V- Necrotizing periodontal diseases

VI- Abscesses of periodontium

VII- Periodontitis associated with endodontic lesions

VIII- Developmental or acquired deformities and conditions. (American

Academy of Periodontology, 1999)

1.1.3. Etiology of periodontal diseases:

The primary etiologic factor of periodontal disease is the bacterial

biofilm, where gram-positive and gram-negative bacteria possess a plethora of

structural or secreted components that may cause direct destruction to

periodontal tissues or stimulate host cells to activate a wide range of

inflammatory responses, these responses are intended to eliminate the

microbial challenge, but may often cause further tissue damage. (Madianos,

2005)


5

The critical mass of bacteria probably provide triggers that up regulate

inflammatory and degradative processes associated with chronic periodontitis

leading to tissue destruction, possibly by way of three different pathways:

1. Pathogens may release their own proteolytic enzymes that could degrade

periodontal structures directly.

2. Pathogens may elaborate products (e.g. lipopolysaccharide) that could

subsequently trigger host cell populations to express degradative enzymes.

3. Pathogens may stimulate an immune response resulting in release of pro-

inflammatory cytokines such as interleukin 1and 6 (IL-1, IL-6), and tumor

necrosis factor14 that indirectly induce increases in levels of degradative

enzymes which include matrix metalloproteinases such as matrix

metalloproteinases (MMP-8), and elastase, both of which target the principal

connective tissue proteins of the periodontium. (Tenenbaum, 2007)

1.1.3.1 Dental plaque:

Dental plaque can be defined as an organized mass, consisting mainly

of microorganisms that adheres to teeth, prostheses and oral surfaces and is

found in the gingival crevice and periodontal pockets, other components

include an organic, polysaccharide-protein matrix consisting of bacterial by-

products such as enzymes, food debris, desquamated cells and inorganic

components such as calcium and phosphate. (American Academy of

Periodontology, 2001)

This biofilm showed as a thin basal layer on the substratum, in contact

with, and occasionally penetrating, the acquired enamel pellicle, and with

columnar mushroom-shaped multibacterial extensions into the lumen of the

solution, separated by regions “channels” seemingly empty or filled with

extracellular polysaccharide, figure (1-1), the bacteria in a biofilm

communicate with each other by sending out chemical signals, these chemical

signals trigger the bacteria to produce potentially harmful proteins and

enzymes. (Dumitrescu, 2010)


6

Figure (1-1): Biofilm structure

The different regions of plaque are significant to different processes

associated with diseases of the teeth and periodontium, as marginal plaque is

of prime importance in the development of gingivitis, while supragingival

plaque and tooth-associated subgingival plaque are critical in calculus

formation and root caries, whereas tissue-associated subgingival plaque is

important in the soft tissue destruction that characterizes different forms of

periodontitis. (Newman, 2009)

The most important and most prevalent anaerobic gram-negative

bacteria in the subgingival area are Actinobacillus Actinomycetemcomitans,

Porphyromonas gingivalis, Prevotella intermedia, these bacteria play an

important role in the onset and subsequent development of periodontitis,

participating in the formation of the periodontal pocket, connective tissue

destruction, and alveolar bone resorption by means of an immunopathogenic

mechanism and once periodontitis has been established an inflammatory

infiltrate is formed consisting of different kinds of cells, such as macrophages

and lymphocytes that will produce different cytokine subtypes, biological

mediators which are responsible for the immunopathology of different

illnesses. (Bascones and Figuero, 2005)


7

1.1.3.2. Dental calculus:

Calculus is a hard deposit that forms by mineralization of dental plaque

and is generally covered by a layer of unmineralized plaque, hence, does not

directly come into contact with the gingival tissues, therefore calculus is a

secondary etiologic factor for periodontitis. (Newman, 2009)

Supragingivally, calculus can be recognized as a creamy-whitish to

dark yellow or even brownish mass of moderate hardness, while

subgingivally calculus is frequently dark brown or green in color due to the

inclusion of haem, a blood breakdown product (Lindhe, 2008)

Calculus is a local environmental factor for periodontal disease because:

- It has a rough surface always covered with pathogenic bacteria.

- The contour changes produce overhangs and increase plaque retention.

- It is almost impossible to control periodontal disease in the presence of

calculus. (Ireland, 2006)

1.1.4. Chronic periodontitis:

1.1.4.1. Definition:

The chronic periodontitis is defined as inflammation of the gingiva

extending into the adjacent attachment apparatus, the disease is characterized

by loss of clinical attachment due to destruction of the periodontal ligament

and loss of the adjacent supporting bone. (American Academy of

Periodontology, 2000)

Chronic periodontitis is caused by an opportunistic microflora, and this

infection triggers host inflammatory responses resulting in the destruction of

the tooth supporting tissues. (Renvert and Persson 2002)

1.1.4.2. Characteristics:

The main characteristics of chronic periodontitis, according to

classification of periodontal diseases 1999, are:


8

1- Most common in adults, but can occur in children, the prevalence and

severity of the disease increase with age.

2- Slow to moderate rate of progression.

3- Amount of microbial deposits consistent with the severity of

periodontal tissue destruction.

4- Subgingival calculus is frequent finding.

5- Amount of destruction is consistent with the presence of local factors

(e.g., tooth –related or iatrogenic).

6- May be modified by and /or associated with systemic disease (e.g.,

diabetes mellitus).

7- Can be modified by factors other than systemic diseases (e.g., smoking,

emotional stress).

8- Variable distribution of periodontal destruction; no discernible pattern.

9- No marked familial aggregation. (Dumitrescu and Kobayashi, 2010)

1.1.5. Diagnosis of periodontal disease:

To arrive at a periodontal diagnosis, the dentist must rely upon such factors: 1- Presence or absence of clinical signs of inflammation (e.g., bleeding upon

probing).

2- Probing depths.

3- Extent and pattern of loss of clinical attachment and bone.

4- Patient’s medical and dental histories.

5- Presence or absence of miscellaneous signs and symptoms, including pain,

ulceration and amount of observable plaque and calculus. (American

Academy of Periodontology, 2003)

1.1.6. Treatment of periodontal diseases:

1.1.6.1. Scaling and root planing:

Scaling is the process by which plaque and calculus are removed from

both supragingival and subgingival tooth surfaces without any attempt to


9

remove tooth substances along with the calculus; while root planing is the

process by which residual embedded calculus and portion of cementum are

removed from the roots to produce a smooth, hard and clean surface.

(Newman, 2009)

SRP are the bases of non-surgical therapy in the treatment of

periodontitis. (Herrera et al., 2002)

In patients with chronic periodontitis, subgingival debridement (in

conjunction with supragingival plaque control) is an effective treatment in

reducing probing pocket depth and improving the clinical attachment level, In

fact it is more effective than supragingival plaque control alone. (Van der,

2002)

1.1.6.2. Instruments and instrumentation:

The ideal goal of periodontal instrumentation is to effectively remove

plaque and calculus without causing root surface damage; scaling and root

planing are the basis of periodontal therapy and various instruments have

been designed to achieve this goal; ultrasonic scaler and curettes are the

instruments used for surgical and non-surgical periodontal therapy and have

shown similar results as for biological response, plaque/calculus removal and

elimination of endotoxin. (Corrêa, 2009)

1.1.6.2.1. Hand instruments:

Hand instruments are available in various designs, described as

curettes, hoes or scalers; they all have a sharp working tip, which is used to

mechanically break the bond between deposit and tooth. (Walmsley et al.,

2008)

The parts of each instrument, referred to as the working end, shank and

handle. (Newman, 2009)


10

1.1.6.2.1.1. Characteristics of hand instruments therapy: The process is time consuming and physically demanding, but is seen

as the treatment of choice as it is believed that the clinician has direct tactile

control over the hand instrumentation process compared with the use of

powered devices. (Walmsley et al., 2008)

The instruments are cheaper to buy and maintain, also there are no aerosols.

(Ireland, 2006)

1.1.6.2.2. Powered instrument:

Powered instruments are those instruments whose working tip is driven

to oscillate at either sonic (6–8 kHz) or ultrasonic (25–42 kHz) frequencies;

these tip oscillations of sonic devices are generated by the passage of

compressed air over an eccentric rod that vibrates, and these vibrations are

transmitted to the working tip, while the tip vibrations of ultrasonic

instruments may be generated through a process of either piezoelectricity or

magnetostriction, figure (1-2). (Lea and Walmsley, 2009)

Figure (1-2): Piezoelectric (top) and magnetostrictive (bottom) scalers, the working end

for both instruments is similar but the method of vibration generation is quite different.

The nickel-based stack of the magnetostrictive scaler is shown.


11

1.1.6.2.2.1. Mechanism of action of powered instruments:

1- Chipping action: scaling tip of the instrument oscillating in a

longitudinal mode and mechanically removing the deposits by chipping

action.

2- Cavitational activity: encompasses all of the linear oscillatory motions

of gas and/or vapor filled bubbles in an acoustic field, these motions

may vary within one acoustic cycle from cavitation where the bubbles

are oscillating without fragmentation, to transient cavitation, where

there is rapid growth and collapse of the bubble; cavitational activity

will cause fracture of the attached deposits through the resultant shock

waves.

3- Acoustic micro streaming (turbulence): which produced by the

oscillatory action of the ultrasonic scaling tip within water, so the

forces generated by streaming will shear the plaque away from itself

and from the tooth surface. (Laird and Walmsle, 1991)

1.1.6.2.2.2. Characteristics of ultrasonic periodontal therapy:

Currently, the use of the ultrasonic scaler has appeared as an important

alternative for daily clinical use due to its several advantages such as access to

furcation, less operator tiredness, pocket penetration and less time required for

scaling and root planning (Corrêa et al, 2009)

During the use of powered instruments irrigant (normally water) flows

over the working tip, where it helps to reduce the frictional heat generated

during the cleaning process, this water has further benefits which include

helping to clear the treatment site of debris, thus aiding the operator's field of

view; the irrigant may also act as a site for the generation of biophysical

processes commonly associated with ultrasonic powered instruments, namely

cavitation and streaming which may also aid in the cleaning process. (Lea et

al, 2003), (Lea et al, 2005)


12

Powered instruments are believed to provide less sensitive tactile

feedback to the clinician than hand instruments, although recent research has

suggested that the loss of tactile control reported for powered instruments

may only be temporary and that the operator regains sensation with time.

(Tunkel et al, 2002), (Ryan et al, 2005)

In 2000, the Research, Science and Therapy Committee of the

American Academy of Periodontology performed a detailed literature review

to produce a position paper concerning the use of powered instruments in

periodontics and these are conclusions of this paper:

• Sonic and ultrasonic instruments attain similar results to hand instruments in

terms of plaque, calculus and endotoxin removal.

• Instrument width may mean that manual scalers provide less access to

furcations than ultrasonic instruments.

• A disadvantage of powered scalers is the production of contaminated

aerosols. (Drisko et al, 2000)

So when compared with hand scalers, power-driven instruments have

the advantage of being easier to use and may take significantly less time than

hand instruments, also requires minimal stroke pressure; it is not dependent

on permanently sharp instruments and finally precision-thin tips have been

shown to penetrate deeper than hand instruments, but on other hand the

powered instrument has the potential to damage the root surface producing

indentations and unwanted scratches on the hard tissue surface. (Walmsley et

al., 2008) (Ireland, 2006)


13

1.2. LASER: 1.2.1. Definition:

Laser is an acronym for Light Amplification by Stimulated Emission of

Radiation. (Godett, 2009)

A laser system is that one which amplifies light and produces a highly

directional, high intensity beam that most often has a very pure frequency or

wavelength. (Silfvast, 2004)

1.2.2. History of laser:

Table (1-1) summarizes the history of laser. (Silfvast, 2004);

(Bertolotti, 2005); (Gross and Herrmann, 2007)


14

Table (1-1): History of laser

Date Name Achievement 1916 Albert Einstein Theory of light emission. Concept of

stimulated emission

1947 Willis E Lamb

R C Rutherford

Induced emission suspect in hydrogen spectra.

First demonstration of stimulated emission.

1951

Charles H Townes

The inventor of the MASER (Microwave

Amplification of Stimulated Emission of

Radiation) at Columbia University – First

device based on stimulated emission, awarded

Nobel prize 1964.

1957 Gordon Gould First document defining a LASER

1960

Theodore Maiman

Invented first working LASER based on Ruby.

May 16th 1960, Hughes Research

Laboratories.

1960

Ali Javan,

William Bennett

Donald Herriot

First helium-neon LASER at Bell Labs Dec.

1960, First gas laser and first CW laser

1961 Leo F. Johnson,

K. Nassau

First neodymium crystal LASER at Bell Labs

1962 Robert Hall Invention of semi-conductor LASER at

General Electric Labs.

1963 Robert Keyes

Theodore Quist

First diode pumped solid state LASER,

uranium doped calcium fluoride at MIT

Lincoln Labs

1964 Kumar N Patel Inventor of CO2 LASER at Bell Labs.

1965 George Pimentel

J V V Kasper

First chemical LASER at University of

California, Berkley.

1966 Peter Sorokin

John Lankard

First dye LASER action demonstrated at IBM

Labs.


15

1.2.3. Electromagnetic radiations:

Electromagnetic (EM) radiation includes all forms of radio waves,

microwaves, infrared radiation, visible light, ultraviolet radiation, x-rays and

gamma rays. (Csele, 2004)

EM radiation, which is produced by lasers, requires no medium for its

transmission because it can travel through the vacuum of space; it can also

travel through matter in the form of gases, liquids or solids, but the speed and

the direction of the propagation of radiation will be changed upon the

transition from one medium to another in the form of heat. (Berger and Eeg

2006 a)

The EM spectrum is traditionally divided into the seven regions shown

in figure (1-3). (Andrews and Hill, 2009)

Figure (1-3): Electromagnetic Spectrum

1.2.4. Properties of laser:

Laser light has some unique characteristics that don't appear in the light

from other sources, these characteristics are:

1- Directionality: All laser light traveling in very nearly the same

direction, resulting in directionality of laser beam which can be focused

to a very small spot, greatly increasing its intensity.


16

2- Monochromaticity: laser light has far greater purity of color than the

light from other sources.

3- Coherence: monochromaticity and directionality together with the

phase consistency of laser light are combined into a single descriptive

term; coherence makes laser light different from the light produced by

any other source.

4- Intensity (Irradiance): by focusing the laser beams to small spot sizes

one can obtain very high intensities. (Hitz et al., 2001), (Kishen and

Asundi, 2007)

1.2.5. Fundamentals of laser: Stimulated absorption which denotes to process in which an atomic or

a molecular system subjected to an electromagnetic field of frequency (ʋ )

absorbs energy from the photon and as a result of the absorption the atom or

the molecule is raised from lower state (n) to the upper state (m) of higher

energy; this process occurs only when the energy of the photon precisely

matches the energy separation of the participating pair of energy states (where

(En) and (Em) are the energies of the initial state (n) and the final state (m),

(w) is the circular frequency of the incident radiation, and (ħ) is Planck’s

constant). (Abramczyk, 2005)

Light emission takes place by two processes; one is spontaneous

emission wherein an atom in excited state returns to a lower energy state on

its own by emission of a photon with energy equal to the difference of the

energies of the two atomic energy levels; in this process the atoms radiate

randomly and independent of each other leading to incoherent light as in the

light from all conventional sources of it. (Kishen and Asundi, 2007)

When the pumping source is strong, emission can take place not only

spontaneously but also under stimulation by the field, and this kind of

emission is called stimulated emission, so the molecule will already be in an


17

excited state, then an incoming photon, for which the energy is equal to the

energy difference between its present level and the lower level, can

‘‘stimulate’’ a transition to that lower state, which produce a second photon of

the same energy; in contrast to spontaneous emission, stimulated emission

exhibits coherence with the external radiation field; this control on emission

of individual atoms through the control on stimulating photons is the essence

of laser operation, figure (1-4). (Abramczyk, 2005)

Figure (1-4): Scheme of a two-level system illustrating stimulated absorption,

spontaneous emission and stimulated emission phenomena. To produce cascade of identical photons, stimulated emission must be

more likely than absorption, more of the atoms must be in the higher energy

state than are in the lower one, and since this is the reverse of the usual case;

so it is called a population inversion.(Giambattista et al. , 2008)

1.2.6. Elements of laser device:

in its simplest form, a laser consists of a gain or amplifying medium

(where stimulated emission occurs) and a set of mirrors to feed the light back

into the amplifier for continued growth of the developing beam; the three

basic components , as seen in figure (1-5): (Berger and Eeg, 2006 a)


18

A laser always includes the following parts:

1- Energy source (power supply): the types of energy supply depends

on the structure of the medium, thus the energy source may be an

electrical current, optical radiation from flash lamb or another

pumping laser as, radio waves, microwave or chemical reaction;

2- Lasing (amplifying ) medium: it could be either solid , liquid or gas

medium; the lasing medium must be able to store the energy

supplied, by a process of population inversion; the lasing medium is

generally elongated in shape, often in the form of a channel ( gas

laser) or a narrow rod (solid state lasers) or doped channel

(semiconductor lasers);

3- Resonating cavity (mirrors): these mirrors are fitted at both ends of

the medium, one of these mirror is fully reflected while the other is

partially reflected, making the light produced in the lasing medium

reflected back into it several times and stimulates new light

production, thus the resonating cavity is of two fold importance: it

increase the lasing medium's amplification and makes the light

more coherent. (Tuner and Hode, 2004)

Figure (1-5): Laser device elements.


19

1.2.7. Manner of operation of laser:

Lasers operate in one of three different manners:

1- Continuous wave (CW): if the partially transmitting end allows a

fraction of the light energy that strikes it to escape, and if energy can

be pumped into the lasing medium at such a rate that the laser output

can be maintained uninterruptedly then we have a CW laser.

2- Pulsed (long pulse or normal pulse): which occur when the laser

device deliver their output in bursts of light whose duration range from

femtoseconds (10−15

3- Q-switched (or Q-spoiled): is an acousto-optical or electro-optical

device within the optical cavity that is analogous to a shutter; it

prevents laser emission until it is opened, and because of the

combination of high energy and narrow pulse width, very high powers,

on the order of megawatts, are readily attainable with

Q-switched lasers. (Cember and Johnson, 2009)

seconds) to 0.25 seconds.

1.2.8. Types of laser:

Laser systems can be classified using many different criteria, table

(1-2) list most common classifications of laser systems. (Ishikawa et al.,

2004) Table (1-2): Classification of laser.


20

1- Solid state laser:

The oldest technology is that of the optically pumped solid-state

laser, it (not to be confused with semiconductor lasers) consist of a

crystal of glasslike material doped with a small concentration of a

lasing ion such as chromium (in the case of ruby) or neodymium (in the

case of YAG); for many solid state lasers the technology has not

changed much, but in recent years more efficient materials with lower

pumping thresholds have been used, and compact solid-state lasers

have been developed that are pumped by semiconductor laser diodes

instead of lamps. (Csele, 2004)

2- Liquid lasers:

The most common and familiar liquid lasers are those based on

strongly absorbing organic dye molecules in an organic solvent; the

very broad emission and gain spectra of organic dyes lead to tunable

laser output typically over several tens of nanometers, because of this

property, dye lasers are used extensively in wavelength selective

spectroscopy. (Weber, 2001)

3- Gas lasers:

Comprise the largest number of lasing transitions over 12000,

gas lasers may be categorized as neutral atom, ionic, or molecular;

molecular lasers can be further divided or characterized by the nature of

the transitions involved in the stimulated emission process, that is, the

transitions may be between electronic, vibrational, or rotational energy

levels; the output of many lasers may consist of several lines of varying

intensities. Table (1-3). (Cember and Johnson, 2009)


21

Table (1-3): Laser types and typical lasing media. (Weber, 2001)

1.2.9. Laser tissue interactions:

1.2.9.1. Light propagation in biological tissues:

Four basic interactions can take place when laser energy interacts with

a target material or tissue including reflection, scatter, transmission or

absorption, figure (1-4). (Berger and Eeg, 2006 b)

Figure (1-6): Laser – tissue interactions. When it reaches biological tissue, the laser light can be reflected, 1; transmitted to the surrounding tissues, 2; scattered, 3; or be

absorbed, 4. (Schwarz, 2009)

The strength of the individual effect essentially depends on the

wavelength of the incident light, the index of refraction and the attenuation

and scattering coefficients of the tissue, together, they determine the total

transmission of the tissue at a certain wavelength; on the other hand, the

following parameters are given by the laser radiation itself: wavelength,

Laser type Typical lasing medium

Typical excitation methods

Gas He–Ne, CO2 Electrical Semiconductor GaAlAs, GaN Electrical Solid State YAG, Ti:sapphire Optical Dye Rhodamine 6G Optical Metal Vapor Copper Electrical


22

exposure time, applied energy, focal spot size, energy density and power

density. (Haberth"ur, 2002)

a- Reflection and Refraction

Reflection is defined as the returning of electromagnetic

radiation by surfaces upon which it is incident, while reflecting surface

is the physical boundary between two materials of different indices of

refraction such as air and tissue; it originates from a change in speed of

the light wave, changing its wavelength, direction and thus the speed of

light will reduced according to the index of refraction of the medium,

as expressed:

Vm = c / n Where:

Vm

b- Absorption

is the velocity of light in medium

c is the speed of light in space,

n is the index of refraction;

In biological tissue, absorption is mainly due to the presence of

free water molecules, proteins, pigments and other macromolecules;

during absorption, the intensity of an incident electromagnetic wave is

attenuated in passing through a medium; it is due to a partial

conversion of light energy into heat motion or certain vibrations of

molecules of the absorbing material; the absorbance of a medium is

defined as the ratio of absorbed and incident intensities, and the ability

of a medium to absorb electromagnetic radiation depends on a number

of factors, mainly the electronic constitution of its atoms and

molecules, the wavelength of radiation, the thickness of the absorbing

layer and internal parameters such as the temperature or concentration

of absorbing agents. (Niemz, 2007)


23

The process of absorption of laser energy by a tissue is the key to

effective laser to tissue interaction, as this photonic energy is absorbed,

it transfers its energy potential to the target tissue, thus inducing a

change in that tissue; water is the most abundant substance within

tissue and is a strong absorber of light in the near-infrared and

ultraviolet wavelengths, but has highest absorption at mid-infrared

wavelengths; there is negligible absorption of visible light by water,

water absorbs light maximally at 2,940 nm, which is the characteristic

wavelength of the Er: YAG laser. Figure (1-7) (Ishikawa et al., 2009)

Figure (1-7): Absorption spectrum for water of various lasers, such as

Argon, Diode, neodymium-doped yttrium aluminium garnet (Nd: YAG), CO2

Er,Cr:YSGG and erbium-doped yttrium aluminium garnet (Er:YAG). The

Er: YAG laser has the best absorption coefficient of water among these laser

systems.

c- Scattering

When elastically bound charged particles are exposed to

electromagnetic waves, the particles are set into motion by the electric

field; if the frequency of the wave equals the natural frequency of free

vibrations of a particle, resonance occurs being accompanied by a

considerable amount of absorption, while scattering takes place at

frequencies not corresponding to those natural frequencies of particles,

Er: YAG 2.940nm

CO2 10.600nm

Er,Cr: YSGG 2.780nm

Nd: YAG 1.064nm

Argon 488nm

Diod 810nm


24

thus resulting oscillation is determined by forced vibration. (Niemz,

2007)

1.2.9.2. Optical Processing of Tissue

The diagnostic applications of lasers are based on scattered or reemitted

light. Surgical and therapeutic applications depend on absorption of light. The

absorbed laser energy can broadly lead to three effects:

a- Photothermal Effects

Most of the surgical applications of lasers exploit laser induced

photothermal effect that is a rise in tissue temperature subsequent to

absorption of laser radiation, the biological effect depends on the level of rise

in tissue temperature which is determined by two factors, the tissue volume in

which a given laser energy is deposited and the time in which the energy is

deposited via the thermal relaxation time (the inverse of which determines the

rate of flow of heat from heated tissue to the surrounding cold tissue, so if the

rate of deposition of energy is faster than that required for boiling of water,

the tissue is superheated and can be thermally ablated; thermal ablation or

explosive boiling is similar to what happens when cold water is sprinkled on a

very hot iron. Table (1-4) shows the thermal effect on biological tissues.

(Kishen and Asundi, 2007) Table (1-4): Laser thermal effect on biological tissues

Temperature Biological effect 37 oC Normal 45 oC Hyperthermia 50 oC Reduction in enzyme activity, cell immobility 60 oC Denaturation of protein and collagen, coagulation 80 oC Permeabilization of membranes

100 oC Vaporization, thermal decomposition (ablation) > 100 oC Carbonization > 300 oC Melting


25

b- Photomechanical Effects

At high intensities associated with lasers operating in short pulse duration

(nanosecond 10-9, picoseconds 10-12

c- Photochemical Effects

) absorption of laser-radiation may lead to

generation of pressure waves or shock waves; the localized absorption of

intense laser radiation can also lead to very large temperature gradients,

resulting in enormous pressure waves and localized photomechanical

disruption; at high intensities, the electric field strength of radiation is also

very large, the resulting plasma absorbs energy and expands creating shock

waves, which can shear off the tissue, these plasma-mediated shock waves are

used for breaking stones in the kidney or urethra (lithotripsy) and in posterior

capsulotomy for removal of opacified posterior capsule of the eye lens.

(Kishen and Asundi, 2007)

For laser irradiation at power levels where there is no significant rise in

temperature of the tissue, the photothermal and photomechanical effects are

not possible, in such a situation, only photochemical effects can take place

provided the energy of laser photon is adequate to cause electronic excitation

of biomolecules, which can be either endogenous or externally injected; the

photo-excitation of molecules and the resulting biochemical reactions can

lead to either bio-activation exploited in various phototherapies or generation

of some free radicals or toxins, which are harmful for the host tissue and so

there will be a mild rise in the tissue temperature and the tissue removal can

be achieved in an extremely precise manner. (Kishen and Asundi, 2007)

1.2.9.3. Mechanism of tissue ablation by Er:YAG laser:

A mechanism of biological tissue ablation with the Er:YAG laser has

been proposed based on the optical properties of its emission wavelength and

morphologic features of the surface ablated by Er: YAG laser which

concluded that during Er:YAG laser irradiation, the laser energy is absorbed


26

selectively by water molecules and hydrous organic components of biological

tissues causing evaporation of water and organic components and resulting in

thermal effects due to the heat generated by this process ‘photothermal

evaporation’; moreover, in hard tissue procedures, the water vapor production

induces an increase of internal pressure within the tissue, resulting in

explosive expansion called ‘micro explosion’, these dynamic effects cause

mechanical tissue collapse and resulting in a ‘thermo-mechanical’ or

‘photomechanical’ ablation ; this phenomenon has also been referred to as

‘water-mediated explosive ablation’. Figure (1-8). (Aoki et al., 2004)

Figure (1-8): Hard tissue ablation by Er: YAG laser irradiation. W: water molecules. BA: biological apatites. PM: protein matrix. (Sasaki KM et al., 2002)


27

1.2.10. Laser safety:

Lasers and laser systems emit beams of optical radiation (ultraviolet,

visible and infrared which is termed as non-ionizing radiation to distinguish it

from ionizing radiation such as X-rays or gamma rays); eye hazards and/or

skin hazards are the primary concerns associated with optical radiation, table

(1-5). (Western Ontario University, 2006)

Table (1-5) summarizes the possible hazards that laser could cause: Table (1-5): types of laser hazards

Category Type of hazard

Physical

1- Electrical hazards.

2- Collateral and plasma radiation.

3- Noise and mechanical hazards from very high

energy lasers.

4- Cryogenic coolant hazards.

5- X radiation from faulty high-voltage (>15 kV)

power supplies.

6- Explosions from faulty optical pumps and lamps.

7- Fire hazards.

Chemical

1- Laser-generated airborne contaminants (LGAC).

2- Compressed gases, dyes and solvents. (hazardous

and/or contain toxic substances)

3- Biological agents include airborne infectious

materials and microorganisms

The American National Standard for Safe Use of Lasers (ANSL) has

four hazard classifications, which is used to describe the capability of the

laser or laser system to produce injury to personnel; higher-class numbers

indicate greater potential hazards. Brief descriptions of each laser class are as

follows: (U.S. Department of energy, 2005)


28

Table (1-6): laser safety classes

Class Description

Class 1 (Exempt Lasers)

Emit low levels of energy that are not hazardous to the eyes or skin. Class 1 products are safe during normal operation, but may contain higher class lasers (a possible hazard only during service or maintenance). Examples include laser printers and compact disc players.

Class 2a and 2b

(Low-Power Lasers)

Visible lasers that require the use of caution, which can injure the eye if viewed for longer than the aversion response time of 0.25 seconds but will not produce a skin burn. An example is a store barcode scanner.

Class 3a

(Low-Risk Lasers)

Visible lasers that can produce spot blindness and other possible eye injuries under certain conditions. Examples include laser pointers, alignment lasers, survey equipment and laser levels.

Class 3b

(Medium-Power Lasers)

Visible and invisible lasers that cause an eye hazard from direct and specular reflections. Diffuse reflections may be hazardous if the laser is at full power and viewed close to the source. Many Class 3b lasers are used in research settings.

Class 4 (High-Power Lasers)

Always dangerous. These lasers can produce acute skin and eye damage from direct exposure and generate sufficient power to produce serious eye injuries from reflected light. Class 4 lasers are also a fire hazard, igniting flammable material. Examples include medical lasers, research lasers, industrial lasers, and military lasers.


29

Important components of the eye, such as the cornea, lens, and retina,

figure (1-9), are susceptible to damage by laser light. Light enters through the

transparent layers of the cornea and then is focused by the lens onto the retina.

The eye in essence intensifies light energy, particularly the visible and the

near-infrared wavelengths, in some cases as much as 100,000 times.

(Washington University 2007)

Figure (1-9): section of human eye

1.2.11. Laser applications in dentistry:

Lasers were introduced into the field of clinical dentistry with the hope

of overcoming some of the drawbacks posed by the conventional methods of

dental procedures; since its first experiment for dental application in the

1960s, the use of laser has increased rapidly in the last couple of decades; at

present, wide varieties of procedures are carried out using lasers. (Husein,

2006)

A range of lasers is now available for use in dentistry (Walsh, 2003).

Table (1-7) summarizes the lasers of choice for specific indications in laser

dentistry. (Lee, 2007)

Table (1-7): Current lasers commonly used in clinical dentistry

type Active medium Wavelength (nm) Clinical applications company Gas Lasers CO2 10600 Soft tissue incision and ablation

Subgingival curettage

Deka

Lumenis

Diode

Lasers

InGaAsP

GaAlAs

GaAs

655

810

980

Caries and calculus detection

Soft tissue incision and ablation


Bacterial decontamination

Biolase

Elexxion

KaVo

Odyssey, Sirona

Solid-state

Lasers

Nd:YAG 1064 Soft tissue incision and ablation



Deka

Fotona

Periolase

Er:YAG 2940 Soft tissue incision and ablation


Scaling and root debridement

Fotona

Hoya, KaVo

Lumenis, Syneron

Er,Cr:YSGG 2780 Modification of hard tissue surfaces

Hard tissue ablation


Biolase


31

1.2.12. Laser in nonsurgical periodontics:

In the 1990s the neodymium: yttrium-aluminum-garnet (Nd:YAG)

laser was introduced for periodontal treatment, including removal of

subgingival calculus and pocket curettage, but it was not promising due to

profound thermal effects on hard tissues, including cementum and alveolar

bone. (Hakki, 2010)

Based on the results of studies, it appears at present that the carbon

dioxide (CO2) laser is not suitable for nonsurgical pocket applications

because this laser is less effective for root debridement and has the potential

to produce thermal damage in the periodontal pocket and surrounding tissues.

(Schwarz et al., 2009)

Also it was reported that using diode laser was unsuitable for calculus

removal and it altered the root surface in an undesirable manner, the results

showed that this laser may cause damage to periodontal hard tissues if

irradiation parameters are not adequate. (Schwarz et al., 2003 c)

Among the dental lasers, the Er:YAG laser (2.94 mm) has been

considered to be one of the most promising lasers in periodontal therapy,

because of the emission wavelength that is highly absorbed by water, the

Er:YAG laser possesses an excellent capacity for ablating dental hard tissues

including calculus without producing major thermal side-effects such as

carbonization, melting or cracking of the root substance, which are usually

observed following CO2 and Nd:YAG laser irradiation. (Maruyama et al,

2008)

The popularity of the erbium family of lasers has increased in the last

five years, many researchers have examined erbium lasers in the treatment of

periodontal disease; the published literature has shown that erbium lasers can

be an alternative therapy for root surface debridement because the laser can

ablate calculus without producing major thermal side effects to adjacent

tissue. (Glenn, 2004)


32

1.2.13. Er:YAG laser:

Er:YAG laser was introduced in 1974 as a solid-state laser that

generates a light with a wavelength of 2940 nm; of all lasers emitting in the

near- and mid-infrared spectral range, the absorption of the Er:YAG laser in

water is the greatest because its 2940 nm wavelength coincides with the large

absorption band for water, also, as part of the apatite component, OH groups

show a relatively high absorption at 2940 nm, although the maximum

absorption is around 2800 nm. (Featherstone, 2000)

Since the Er:YAG laser is well absorbed by all biological tissue that

contain water molecules, this laser is indicated not only for the treatment of

soft tissues but also for ablation of hard tissues. (Tuner and Hode 2004)

The Er: YAG laser has elemental erbium as dopant; it works in pulsed

mode and the great benefit of this wavelength is that it is not as harmful to the

eyes (unless directly focused on the cornea) as the Nd:YAG laser; compared

to CO2 laser, it is less painful during treatment and healing is somewhat

faster; for avoiding of overheating, a jet of water accompanies the laser beam

in the same way as the conventional drill, application of Er:YAG laser are

listed in table (1-8) (Walsh, 2008)

Table (1-8): Current application of Erbium lasers

Aspect Action

Soft tissue

- Minor soft tissue surgery - Resurfacing of oral mucosa - Removal of gingival melanin pigmentation and gingival

discolourations - Ablative procedures such as gingivoplasty and

peri-implant surgery

Bone

- Cutting bone effectively without burning, melting, or altering the calcium: phosphorus ratio of the irradiated bone.

- Hard tissue crown lengthening - “tunnelling” closed procedure

- Hard tissue crown lengthening - open flap procedure - Milling sites for implant placement15 - Perforating block bone grafts to enhance osseo-induction16


33

- Ablation of bony tori - Preparing bone for block grants, e.g. from the ramus - Selective milling of bone, with the ability to incorporate

autopilot systems18 Enamel

and Dentine

- Caries removal - Surface conditioning (etching) - Removal of resin, composite and GIC restorations

Other hard tissue sites

- Ablation of calculus during closed debridement - Removal of granulation tissue during periodontal or

periapical surgery - Debridement and decontamination of implant surfaces - Disinfection of periodontal pockets and root canals - Removal of smear layer from root canals - Root resection

1.2.13.1 Characteristics of Er:YAG nonsurgical periodontal therapy:

1- Clinical parameters:

In controlled, prospective clinical study for treatment of advanced

periodontal disease with a combination of an Er: YAG laser (KEY II, KaVo,

Germany) and SRP with hand instruments to laser alone, Schwarz et al, 2003

a conclude that

- Non-surgical periodontal therapy with both an Er:YAG laser and SRP

and an Er:YAG laser alone may lead to significant improvements in all

clinical parameters investigated.

- The combined treatment Er:YAG laser and SRP did not seem to

additionally improve the outcome of the therapy compared to Er:YAG

laser alone.

2- Calculus removal and effect on root substance:

Jarjess, 2005 mentioned that best results were obtained from the group

treated by laser of 12.60 J/cm2 with frequency of 10 Hz regarding the least

calculus residues, debris and cracks number on the root surface, and conclude

that the Er:YAG laser subgingival calculus removal was more effective that

the manual instrumentation and the ultrasonic techniques.


34

Another study conducted on root surfaces instrumented with both

Er:YAG in vivo and Diode laser (DL) in vitro by Schwarz et al in 2003 c

exhibited no detectable surface alterations; in contrast, Er:YAG scaling in

vitro and SRP in vivo/in vitro produced superficial micro changes in root

cementum. However, irradiation with DL in vivo caused severe damages to

the root surface (i.e., crater formation). Er:YAG provided subgingival

calculus removal on a level equivalent to that provided by SRP, while DL was

unsuitable for calculus removal, since macroscopic inspection revealed the

presence of large amounts of subgingival calculus.

Eberhard et al, 2003 study the effectiveness of subgingival calculus

removal from periodontally involved root surfaces with an Er:YAG laser and

compared it to hand instrumentation in situ, demonstrate in vivo capability of

the Er:YAG laser to remove calculus from periodontally involved root

surfaces, although the effectiveness did not reach that achieved by hand

instrumentation; the lack of cementum removal in contrast to SRP may

qualify the laser as an alternative approach during supportive periodontal

therapy.

Schwarz et al, 2006 study, for evaluating the effects of fluorescence

controlled Er:YAG laser radiation, an ultrasonic device or hand instruments

on periodontally diseased root surfaces in vivo, conclude within the limits of

their study, that ERL and Vector ultrasonic system (VUS) enabled

- A more effective removal of subgingival calculus.

- A predictable root surface preservation in comparison with SRP.

The results of Folwaczny and Mehl, 2000 study showed that a

substance removal with Er:YAG laser radiation at lower energy densities is

comparable, in effect, to that after conventional root surface instrumentation

with curettes, and results seem to indicate that calculus removal can be

selectively done using lower radiation energies.


35

3- Effect on soft tissue, hard tissues and bactericidal effect:

Ishikawa et al, 2009 have reported in their preclinical report

(Periodontal tissue healing following flap surgery using an Er:YAG laser in

dogs) that degranulation and root debridement were effectively performed

with an Er:YAG laser without major thermal damage and significantly faster

than that with a curet; histologically, the amount of newly formed bone was

significantly greater in the laser group than in the curet group, although both

groups showed similar amounts of cementum formation and connective tissue

attachment.

It was mentioned that Er:YAG laser possesses suitable characteristics

for oral soft and hard tissue ablation, and it has been applied for effective

elimination of granulation tissue, gingival melanin pigmentation, gingival

discoloration and contouring and cutting of bone with minimal damage and

even or faster healing can be performed with this laser; also reported that

irradiation with the Er:YAG laser has a bactericidal effect with reduction of

lipopolysaccharide, high ability of plaque and calculus removal, with the

effect limited to a very thin layer of the surface, and it is effective for implant

maintenance . (Ishikawa et al., 2008)

Bader and Krejci, 2006 reported that the advantages of Er:YAG

applications in periodontology are based on the efficient elimination of

bacteria and endotoxins on root surfaces in combination with the selective

feedback, where the laser arrives to differentiate between calculus and tooth

tissue.

In another study to evaluate the alterations occurring on radicular surfaces

irradiated with the Er:YAG laser, using the rat subcutaneous tissue response

resulting from human dental root specimens implanted at 7, 14, and 28 days

of healing, the results of histological and morphometric analyses showed a

higher number of inflammatory cells in group 4, for the period of 7 days, in

comparison to all the other groups, in groups 1, 2, and 3 some areas showed


36

fiber adherence in the favorable angulation to attachment, denoting more

biocompatibility than that in group 4 suggesting that the Er:YAG laser may

represent an alternative approach in periodontal radicular therapy. (group 1-

Er:YAG laser with 60 mJ, 10 pps, for 15 s; group 2- Er:YAG laser with 100

mJ, 10 pps, for 15 s; group 3- scaling and root planning followed by surface

demineralization with citric acid and tetracycline for 3 min; and group 4-

scaling and root planning). (Jacomino et al., 2005)

4- Pain level and Dentine hypersensitivity:

Birang and Poursamimi, 2006 demonstrated that both Er:YAG and

Nd:YAG lasers have an acceptable therapeutic effect regarding minimizing

the pain and observed that effects seemed to last for at least 6 months, but

they concluded that Nd:YAG laser is more effective than Er:YAG laser in

reduction of patient's pain.

1.2.15. Advantages and disadvantages of laser periodontal therapy:

Table (1-9) summarizes common advantages and disadvantages of laser

therapy. (Lee, 2007) Table (1-9): Advantages and disadvantages of laser periodontal therapy

Advantages

- effective and efficient soft and hard tissue ablation

- greater hemostasis

- bactericidal effect

- Minimal wound contraction

- minimal collateral damages with reduced use of

local analgesia

- the small popping sound of the lasers in action with

Er:YAG seems to produce less stress to patients

than the high pitch vibration sound of most of the

ultrasonic devices


37

Disadvantages

- require precautions to be taken during clinical

application

- Laser irradiation can interact with tissues even in

the non-contact mode

- the cost and size of laser device still constitute an

obstacle for clinical application of the lasers

CHAPTER TWO

MATERIALS AND METHODS

CHAPTER TWO MATERIALS & METHODS

38

2.1. MATERIALS:

2.1.1. Sample selection and description:

This study included a total of 16 patients, attending periodontics unit in

college of Dentistry - University of Mosul, seeking treatment for their

periodontal problem (chronic periodontitis). The subjects were then allocated

randomly and equally into study groups during a period of three months. The

laser treatment was accomplished at Al Jumhouria specialist dental center at

Mosul medical city.

A total of sixteen male patients (with age range from 25-45 years were

asked to participate in this clinical trial. Study goals and Full description of

the entire procedure were explained to each patient and an informed consent

was obtained from each of them (Appendix 1).

2.1.1.1. Inclusion criteria:

1- Male patient (to obtain maximum standardization of sample and exclude any

possible external variables effect) with chronic periodontitis having at least 6

teeth with pockets of ≥ 5mm.

2- The patients shouldn't have:

- Systemic diseases that could affect the periodontal condition.

- Recent (3 months) periodontal treatment.

- Recent (3 months) antibiotics taking.

2.1.1.2. Study case sheet:

A special case sheet was designed and required information was

collected from each patient (Appendix 2).


39

2.1.2. Laser equipments:

2.1.2.1. Laser system:

The KaVo KEY Laser III upgraded is a universally usable erbium laser

for dentistry in the dental environment for oral, jaw and facial surgery. With

its variable pulse lengths, it is appropriate for treating enamel, bone and for

processing soft tissue (mucosa, muscle and connective tissue). Figure (2-1)

It contains two types of laser:

1- A pilot diode laser of 655nm: red light delivering maximum of

1 mW continues laser radiation with class II laser safety used as

guidance.

2- A therapeutic Er:YAG laser. It adjusted in ranges from

10 - 200mJ in 20mJ steps and 200 - 600 mJ in 50 mJ steps. The PRR is

from 2-30 Hz and divergence of laser beam after leaving the laser

contra-angle handpiece is approximately 5-10o. Table below contains

basic properties of KaVo Key laser III

Table (2-1): Basic properties of KaVo Key laser III

Solid-state laser Er: YAG laser class 4

Wavelength 2.94 μm

Pulse energy Up to 600 mJ

Pulse frequency 2 – 30 Hz

Pilot beam 655 nm/1 mW

Power consumption Max. 2.3 KW

Connection 230 V, 50/60 Hz/12 A


40

2.1.2.2. Hand piece:

The hand piece no. 2061 was used with a prism on its exit end which is

rotatable and can thus be adapted to the respective tooth position.

The exit window of the prism tip is rectangular with dimension of

0.5 X 1.65 mm and thus the laser cross sectional area exiting from the prism

tip is 9.12 X10-3 cm 2. Figure (2-2)

The main characteristics of the 2061 handpiece are;

1- Fine spray cooling.

2- Exchangeable sapphire tips.

3- Mountable on laser tube coupling, freely rotatable sapphire tips 360°

with water cooling

4- Sterilisable Up to 135°C in autoclave

The transmission factor of the prism used was 0.72, so that the energy

per pulse exiting the prism is equal to energy per pulse of the laser multiply

by transmission factor.

The energy density of the pulsed laser is described by the following equation:

Energy density = energy per pulse / Area ……….. J/cm2

2.1.3. General equipments and instruments: 2.1.3.1. Ultrasonic device:

Piezoelectric ultrasonic scaler Piezon Master 400, manufactured by

EMS in Switzerland, has been used in this study with supragingival and

subgingival scaling tips. Figure (2-8), (2-9).

In the piezoelectric scalers, electrical energy is converted into

ultrasonic vibrations by a quartz or metal alloy crystal transducer. No

magnetic field is produced, so less heat is generated. Vibrations produced at


41

the working tip of the instrument range from 29,000 to 50,000 cycles per

second in a linear direction; the piezoelectric tip has cutting edges that help

remove tooth deposits. These cutting edges are located along the side of the

working tip. Water is used to cool the heat build-up produced by the friction

between the working tip and the surface of the tooth. (Wilkins, 1971)

2.1.3.2. Hand instruments:

Universal and Gracey curette, Full mouth set, see figure 2-4, were used

for conducting nonsurgical periodontal; instrument with hand instruments.

They manufactured by Hu-friedy in USA.

Universal curet: it is a periodontal instrument used to remove small and

medium sized calculus deposits from the crowns and roots of the teeth; it is

called universal because it can be applied to both anterior and posterior teeth;

it is one of the most frequently used and versatile of all the calculus removal

instruments; universal curet has semicircular cross section and two cutting

edges per working end, with the face at a 900 angle to the lower shank, while

area – specific curet is a periodontal instrument used to remove light calculus

deposits from the crowns and roots of the teeth; its name is signifies that each

instrument is designed for use only on certain teeth and certain tooth surface,

for this reason, several areas – specific currets are required to instrument the

entire mouth; area –specific currets have only one working cutting edge per

working end that is used for periodontal debridement. (Nield-Gehrig, 2000)

2.1.3.3. Other equipments and materials:

Next table list all equipments and instruments used:


42

Table (2-2) Equipments and instruments used No. Item notes

1

Dental diagnostic set / Pakistan

Mirror Tweezer Explorer Kidney dish.

2 Periodontal probes / USA William periodontal probe. WHO probe

3 Metallic ruler / China 4 Dental syringe / Pakistan For emergency 5 Sharpening stone / USA Figure (2-3) 6 Heavy body impression material /

Protesil - Italy

7 Lidocaine dental anesthesia / Spetodent - France

For emergency

8 Dental needle / Denject - Korea For emergency 9 Sucker tips / Italy 10 Face mask / 3ply - China 11 Stone / Italy 12 Disposable cups / Syria 13 Disposable gloves /

Beroglove - Germany

14 Sterile gauze and cotton / Kardelen - Turkey

15 Plastic impression trays / Syria Figure (2-5) 16 Dental engine with carbide fissure bur /

Strong - China

17 Readymade Light cure acrylic / Megadent - Germany

18 Acrylic light curing device / Megadent - Germany

Figure (2-6)

19 Dental unit / Belmont – Japan Figure (2-7) 20 Laser Protective eyeglasses /

KaVo - Germany Figure (2-10)

21 Digital camera / Sony - Japan 22 Autoclave sterilization device


43

2.2. METHODS:

2.2.1. Study design: The design of this study is an experimental comparative randomized

clinical trial. The entire patients were diagnosed and treated by the same

operator (the researcher) under the supervision of specialist dentist qualified

in using laser for dental treatment, also the operator takes courses in laser

sciences at laser institution for postgraduate studies – university of Baghdad

and he passed examinations of courses and become qualified to use dental

laser.

The treatment procedure included three appointments for each patient

(after explaining the study procedure, the purposes from it and obtaining the

informed consent from him). The first one was for diagnosis, recording the

required information; the second was for giving planned treatment, while the

third one, after three months later, is for recording the final result.

Intra examiner calibration was done and each record was obtained three

times from the same patient, same site and by the same examiner

(regarding PPD and RAL).

2.2.2. Study parameters:

a- Plaque Index (Silness and loe. 1964):

A dental mirror and a periodontal probe or dental explorer were

used after drying of the teeth included in the study to assess plaque

amount; the selected teeth were examined for plaque using a

periodontal probe which was gently passed along the gingival crevice.

Amount of plaque were scored into four scoring, these are:


44

Table (2-3): Silness and loe plaque index

Score 0 no plaque Score 1 A film of plaque adhering to the free gingival margin and

adjacent area of the tooth. The plaque may be seen in situ only after application of disclosing solution or by using the probe on the tooth surface.

Score 2 Moderate accumulation of soft deposits within the gingival pocket, or on the tooth and gingival margin, which can be seen with the naked eye.

Score 3 Abundance of soft matter within the gingival pocket and/or on the tooth and gingival margin

b- Bleeding on Probing:

The selected sites were gently probed with a WHO periodontal

probe to the deepest point. If bleeding occurs within 30 seconds after

probing, the site was given a positive score, while a negative score is

given for non bleeding sites.

c- Clinical Probing Pocket Depth:

The distance from gingival margin to the most apical extent of

the probe inserted into the gingival crevice as close as to the long axis

of the tooth was recorded to the nearest half millimeter; the probe had

been allowed to fall without exerting excessive pressure. Each tooth

was probed at four sites, and each site was probed for three times to

ensure the accurate assessment, mean of three records is dependant as

the final score for that site. Figure (2-12).

d- Relative Attachment Level:

An occlusal stents were fabricated for each patient, then these

stents adjusted to fit on teeth. Vertical grooves corresponding to the

probing direction for each site were made by using a fine fissure dental

stone bur, these grooves provided a reproducible reference points for

the paths of insertion and the angulations of probing at each site. Figure

(2-13).


45

The distance from the base of the pocket to the lower periphery

of the stent was considered as a relative attachment level. Measurement

made to the nearest half millimeter and done three times by the same

operator in different time interval (15minute), to ensure the accuracy of

assessment, then the mean of records dependent as final score for the

site.

PI, PPD and RAL were assessed by using a periodontal probe

having William's graduations, with 0.4 mm tip diameter, which

modified to increase its graduation to 14mm.

e- Pain level:

In this study, NRS was used (see Appendix 3) to evaluate pain

intensity during each type of treatment for each patient, were each one

learned carefully how to use this scale. In this scale the 0 represent no

pain, while 10 represent the maximum pain, then the patient asked to

record the corresponding value for pain that he felt immediately after

each treatment type. (Ali, 2008)

2.2.3. Initial study: Before conducting main study, a three months initial one was

conducted on four patients (having the criteria of study that mentioned before)

in order to be familial with working and to determine the most efficient

energy and frequency of Er:YAG laser for the treatment of chronic

periodontitis.

Three energy settings (120mJ, 140mJ, 160mJ) and two of frequency

(10Hz, 15Hz) were tested. The selection of these settings was done by

analysis the data of previous researches.


46

In each patient (each one having twenty four periodontal pocket ≥

5mm), the affected teeth are randomly categorized into six groups and treated

by using Er:YAG laser but each one treated at different setting.

The periodontal clinical parameters (PI, BOP, PPD and RAL) were

recorded for each patient before starting treatment and then after 3 months

from the treatment visit. Table (2-4).

Table (2-4): Groups and pockets distribution in initial study

Initial study Energy 120 mJ 140 mJ 160 mJ Total

Frequency 10 Hz 15 Hz 10 Hz 15 Hz 10 Hz 15 Hz No. of

pockets/patient 4 4 4 4 4 4 24

No. of patients 4 4 4 4 4 4 4 Total No. of

pockets treated 16 16 16 16 16 16 96

2.2.4. Main study:

Twelve patients have been participated in the Main study; whose have

the study criteria of having periodontal pockets ≥ 5 affecting at least six sites.

The affected teeth for each patient are randomly categorized into three groups.

The first one received nonsurgical Er:YAG laser treatment of (160mJ, 15Hz)

settings, the second received ultrasonic non surgical periodontal treatment,

while the third one treated by hand instruments. Periodontal clinical

parameters were recorded for each patient before starting treatment and after

three months from treatment. Table (2-5); Figure (2-11).


47

Table (2-5): Groups and pockets distribution in main study

Main study Periodontal nonsurgical treatment

Hand

instrument

Ultrasonic

LASER

(160mJ, 15Hz)

Total

No. of pockets / patient

2 2 2 6

No. of patients 12 12 12 12

Total No. of pockets treated

24 24 24 72

2.2.5. Treatment procedure: 2.2.5.1. Hand instrument nonsurgical periodontal therapy:

Hand instrumentation was done by using universal curette with

G5 - G6 used for posterior teeth while Gracey curette G3 - G4 was used for

anterior teeth. The hand curettes were sharpened before instrumentation each

tooth. Although the dental anesthesia is provided, the instrumentation was

performed without local anesthesia to evaluate the pain level during treatment

and the anesthesia kept for emergency.

The curette was held in a pen like grasp. The cutting edge is slightly

adapted in the tooth, with the lower shank kept parallel to tooth surface. Then

it moved toward the tooth and inserted below the gingiva and advanced to the

base of the pocket by light stroke. At pocket base a working angulations of

45o and 90o is established and pressure is applied laterally against the tooth

surface. Calculus is removed by a series of controlled overlapping short

powerful strokes primarily using wrist-arm motion. Longer, lighter root

planing strokes are then activated with less lateral pressure until the root

surface is completely smooth and hard. The tooth surface is instrumented until

it is visually and tactilely free of all deposits. Figure (2-14).


48

2.2.5.2. Ultrasonic nonsurgical periodontal therapy:

Ultrasonic instrumentation is accomplished by using EMS - Piezon

Master 400 ultrasonic scaler. Water irrigation was used according to the

operator preference

Ultrasonic nonsurgical periodontal therapy is accomplished by applying

a light touch and light pressure. Keeping the tip of scaler parallel to tooth

surface and constantly in motion, the working tip kept in contact with all

aspects of the root surface to ensure thorough removal of deposits and toxins,

and this was achieved by a series of focused, overlapped strokes which ensure

complete root coverage. The debridement was performed until the operator

felt that the root surfaces are smooth and hard by mean of dental explorer.

Figure (2-15).

2.2.5.3. Er: YAG laser nonsurgical periodontal therapy:

Before starting laser therapy a protective eyeglasses were wearied by

operator and patient for safety from laser hazard. Er :YAG laser device was

adjusted on 160mJ as energy level and 15Hz as frequency (based on the result

of pilot study), while water irrigation was used according to the operator

preference .

The instrumentation performed from coronal to apical in parallel paths,

with an inclination of the fiber tip of 150 to 200 to the root surface.

Consequently, the energy density of the laser light reaching the root surface

(Folwaczny et al. 2001). The debridement was performed until the operator

felt that the root surfaces are smooth and hard by mean of dental explorer.

Figure (2-16).


49

2.2.6. Post treatment instructions: All the patients were instructed not to use any type of antibiotics or

mouth rinse during the research period (to exclude their effect on research

results), also they instructed to use the same method of brushing (Modified

Bass technique).

2.2.7. Statistical analysis: The SPSS version 11 was used for analysis of data collected and to obtain

both descriptive and inferential statistics.

I- Descriptive statistics:

The following values were included in the analysis of data

representing clinical parameters collected:

a- Mean.

b- Standard of error.

c- Standard deviation.

d- Minimum value.

e- Maximum value.

Bleeding on probing assigned as either present (1) or absent (0) and

expressed as a ratio.

Descriptive statistics also include statistical tables and graphic

presentation such as bars

II- Inferential statistics:

Statistical analysis of difference between mean scores before

treatment and their value after three months from treatment were

undertaken using the paired sample Student t-test (Intra group

comparison), also differences between the groups (inter group

comparison) was assessed using the same test.


50

Chi-square test was used for comparing the percentage of bleeding

on probing. The comparison was done at a 5% significant level.


51

Figure (2-1): KaVo Key Laser Figure (2-2): Fibro optic handpiece

Figure (2-3): Diagnostic and periodontal instruments

Figure (2-4): Gracey and Universal curettes


52

Figure (2-5): Materials used in study

Figure (2-6): Materials and devices used in fabrication of stent

Figure (2-7): Dental unit


53

Figure (2-8): Ultrasonic scaler device

Figure (2-9): Ultrasonic scaler tips

Figure (2-10): Laser protective eyeglasses


54

Figure (2-11): Initial and main studies scheme


55

Figure (2-12): Probing pocket depth

Figure (2-13): Occlusal stent

Figure (2-14): Hand instrumentation


56

Figure (2-15): Ultrasonic instrumentation

Figure (2-16): Er:YAG debridement

CHAPTER THREE

RESULTS

CHAPTER THREE RESULTS

57

3. RESULTS: Sixteen patients were participated in this study, four in initial study and

twelve in main one. All patients have completed this trail, attended all

required visits and followed the instructions that given to them, all as initially

designed for this clinical study.

3.1. Initial study: In this part six groups of ninety six periodontal pockets were treated by

Er:YAG laser, but each group treated at certain laser energy and PRR

(frequency) setting.

Study variables are recorded before starting the treatment and after

three months from it, and they are listed below:

3.1.1. Plaque Index:

The comparison of means of six groups at baseline visit and second visit

(after three months) revealed a very highly significant reduction in the PI

score between two visits. The group treated by laser at setting of 160mJ-15Hz

shows the greatest reduction. Figure (3-1) represents the difference in PI mean

for the six groups between two visits. Table (3-1) represents the descriptive

statistics of PI for the six groups at two visits.

Results in table (3-2) represent the difference between PI means for all

six groups at the second visit

3.1.2. Bleeding On Probing:

All the examined periodontal pockets show BOP at the baseline visit.

Group treated by using (160mJ-15Hz) setting show highly significant

reduction in percentage of bleeding pockets (sites) on probing, followed by

group treated by using (120mJ-15Hz) setting which show significant

reduction, while rest four group show nonsignificant reduction in bleeding


58

sites, see figure (3-2); table (3-3). Table (3-4) represents Chi-square test

results for sixth groups.

3.1.3. Probing Pocket Depth:

Intra-group comparison of PPD for all groups shows very highly

significant reduction in the pocket depth between the baseline visit and

second recall visit. Figure (3-3); Table (3-5).

Inter-group comparison between the six groups, regarding means of

PPD at the second visit, is listed in table (3-6).

3.1.4: Relative Attachment Level:

Comparison of RAL for the same group at two visits shows very highly

significant reduction in the attachment level. The greatest reduction is

obtained in the group treated by the (160mJ-15Hz) followed by (140mJ-

10Hz) same as that observed in PPD. Figure (3-4); Table (3-7).

Table (3-8) represents inter-group comparison at the second visit,

regarding the mean of RAL.

0

1

2

3

123456

Plaque indexscore

Groupbaseline visit second visit

Group

Setting

1st visit 2nd visit Sign. Mean SE SD Min. Max. Mean SE SD Min. Max.

6 160mJ-15Hz 2.125 0.085 0.341 2 3 0.250 0.144 0.577 0 2 VHS 5 160mJ-10Hz 2.250 0.111 0.447 2 3 0.500 0.158 0.632 0 2 VHS 3 140mJ-10Hz 2.400 0.130 0.507 2 3 0.666 0.210 0.816 0 2 VHS

2 120mJ-15Hz 2.312 0.119 0.478 2 3 0.750 0.170 0.683 0 2 VHS 4 140mJ-15Hz 2.466 0.133 0.516 2 3 0.933 0.248 0.961 0 3 VHS 1 120mJ-10Hz 2.375 0.125 0.500 2 3 0.875 0.221 0.885 0 3 VHS

Group 1 2 3 4 5 6

1 2 0.333 3 0.458 0.792 4 0.751 0.424 0.301 5 0.211 0.333 0.458 0.110 6 0.036 0.041 0.048 0.010 0.104

HS: Highly Significant P < 0.01 S: Significant P < 0.05 NS: Non Significant P > 0.05

VHS: Very Highly Significant P < 0.001


NS: Non Significant P > 0.05

S: Significant P < 0.05

HS: Highly Significant P < 0.01

Table (3-2): Paired sample t-test of Plaque Index for six groups at the second visit – Initial study

Figure (3-1): difference of Plaque Index means for six groups between two visits – Initial study

Table (3-1): descriptive statistics of Plaque Index – Initial study

0

20

40

60

80

100

123456

BOP(%)

Group

bleeding sites at baseline visit

non bleeding sites at second visit

bleeding sites at second visit

Group

Setting

1st visit 2nd visit Sign. Bleeding sites (%) Bleeding sites (%)

6 160mJ-15Hz 100 12.5 HS 2 120mJ-15Hz 100 18.75 S 1 120mJ-10Hz 100 37.5 NS

3 140mJ-10Hz 100 37.5 NS 5 160mJ-10Hz 100 37.5 NS 4 140mJ-15Hz 100 43.75 NS

Group 1 2 3 4 5 6

Chi -Square

1.000 6.250 1.000 0.250 1.000 9.000

Sign.

0.317 0.012 0.317 0.617 0.317 0.003







Table (3-4): Chi-Square test of Bleeding On Probing for six groups – Initial study

Figure (3-2): difference of Bleeding On Probing percentage for six groups between two visits – Initial study

Table (3-3): Percentage of Bleeding On Probing at two visits – Initial study

0

1

2

3

4

5

6

123456

PPD(mm)


Group

Setting


6 160mJ-15Hz 5.458 0.180 0.723 5 7.33 3.447 0.139 0.556 3 4.83 VHS 3 140mJ-10Hz 5.611 0.136 0.529 5 6.83 3.744 0.228 0.883 2.66 5.50 VHS 5 160mJ-10Hz 5.552 0.160 0.640 5 6.83 3.822 0.175 0.703 3 5 VHS

1 120mJ-10Hz 5.552 0.112 0.450 5 6 3.958 0.220 0.882 3 5.83 VHS 2 120mJ-15Hz 5.572 0.113 0.455 5 6.16 3.989 0.150 0.603 3 5.16 VHS 4 140mJ-15Hz 5.566 0.120 0.466 4.83 6.166 4.122 0.245 0.952 3 6 VHS

Group 1 2 3 4 5 6

1 2 0.867 3 0.538 0.366 4 0.383 0.506 0.133 5 0.621 0.483 0.939 0.254 6 0.045 0.014 0.240 0.020 0.083







Table (3-6): Paired sample t-test of pocket depth for six groups at the second visit – Initial study

Figure (3-3): difference of pocket depth mean for six groups between two visits – Initial study

Table (3-5): descriptive statistics of Probing Pocket Depth – Initial study

0123456789

101112

123456

RAL(mm)


Group

Setting


6 160mJ-15Hz 11.84 0.197 0.789 11 13.5 8.468 0.132 0.531 8 9.5 VHS 3 140mJ-10Hz 11.76 0.206 0.798 10.5 13 8.666 0.199 0.771 8 10 VHS 4 140mJ-15Hz 11.70 0.095 0.368 11 12 8.800 0.205 0.797 8 10 VHS

5 160mJ-10Hz 11.62 0.216 0.866 10 13 8.937 0.187 0.750 8 10 VHS 2 120mJ-15Hz 11.34 0.134 0.539 10.5 12 9.093 0.145 0.583 8 10 VHS 1 120mJ-10Hz 11.09 0.122 0.490 10.5 12 9.156 0.248 0.995 8 11 VHS

Group 1 2 3 4 5 6

1 2 0.751 3 0.084 0.048 4 0.339 0.225 0.639 5 0.424 0.463 0.492 0.806 6 0.034 0.003 0.354 0.119 0.043







Table (3-3): Paired sample t-test of pocket depth for six groups at the second visit

Figure (3-1): difference of pocket depth mean for six groups between two visits

Table (3-2): descriptive statistics of Probing Pocket Depth – Pilot study

Table (3-8): Paired sample t-test of Relative Attachment Level for six groups at the second visit

Figure (3-4): difference of Relative Attachment Level mean for six groups between two visits – Initial study

Table (3-7): descriptive statistics of Relative Attachment Level – Initial study


63

3.1.5. Conclusion of Initial study results:

From the results mentioned before, it obvious that the treatment of

chronic periodontitis with Er:YAG best done when the laser energy setting at

160mJ and PRR (frequency) at 15Hz. Table (3-9) summarize groups sequence

in each study clinical criteria

Table (3-9): Initial study conclusion

PI BOP PPD RAL 6 6 6 6 5 2 3 3 3 1,3,5 5 4 2 4 1 5 4 2 2 1 4 1

We can observe that the best settings following (160mJ-15Hz) is

(140mJ-10Hz) then (160mJ-10Hz).

3.2. Main study: Here seventy two periodontal pocket equal or larger than (5 mm), of

twelve patients, were carefully examined and randomly grouped into three

groups. The first one treated by Er:YAG laser at setting (160mJ-15Hz), the

second group treated by ultrasonic instruments, while the third group is

treated by using hand instruments. The study periodontal clinical parameters

are recorded for each group before treatment and after three months later.

Pain level is recoded for each patient, immediately after each type of

treatment by using NRS.


64

3.2.1. Plaque Index:

Intra-group comparison of mean at baseline visit and second visit

revealed very high significance reduction for all groups. Figure (3-5); Table

(3-10).

Inter-group comparison of mean for the three method show significant

differences between groups treated by Er:YAG laser and the other two

groups. The difference was insignificance between group treated by ultrasonic

instrument and that treated by hand instruments. Table (3-11).

3.2.2. Bleeding On Probing:

All three groups show BOP at the baseline visit. Groups treated by laser

and hand instruments show very highly significant reduction in the bleeding

sites, while group treated by ultrasonic instrument comes in next by 63.63%

reduction in bleeding sites, which is non significant one. Figure (3-6); Tables

(3-12), (3-13).

3.2.3. Probing Pocket Depth:

The values of pocket depth show very high significant reduction in

means between two visits for all groups. The highest reduction is recorded in

the group treated by Er:YAG laser followed by group treated by hand

instruments, group treaded by ultrasonic instrument fall in the last place by

minimum reduction in pocket depth. Figure (3-7) show the difference of

pocket depth means for three groups at two visits, table (3-14) list the

descriptive analysis for the three groups at the two visits. The difference

between Er:YAG laser group and hand instrument treated group was not

significant, but it is significant with ultrasonic group. Table (3-15).


65

3.2.4. Relative Attachment Level:

Intra-group comparison of mean values for all groups between visits

reveals very high significant reduction in RAL. Again the Er:YAG treated

group success in achieving the greatest reduction, followed by hand

instrument treated group and finally ultrasonic treated one. Figure (3-8);

Table (3-16).

Inter-group comparison reveals no significant difference in the values of

mean for three groups at the second visit, Table (3-17) declares that.

3.2.5 Pain level (by NRS):

At the baseline visit, and after finishing each type of treatment, the

patient asked to chose the most appropriate value that correspond pain level

that he felt during treatment, the recorded data proved that sites treated by

Er:YAG laser show the minimum amount of pain as compared to those

treated by ultrasonic instrument or hand instruments. Figure (3-9); Table

(3-18).

The difference between three groups was very highly significant

regarding pain level during treatment, Table (3-19).

0

0.5

1

1.5

2

2.5

3

123

PIScore


Group

Setting


1 Er: YAG 2.18 0.084 0.394 2 3 0.22 0.091 0.428 0 1 VHS 2 Ultrasonic 2.45 0.108 0.509 2 3 0.72 0.149 0.702 0 2 VHS 3 Hand ins. 2.22 0.091 0.428 2 3 0.54 0.108 0.509 0 1 VHS

Group Er: YAG Ultrasonic Hand

Er: YAG Ultrasonic 0.013

Hand 0.031 0.383







Table (3-11): Paired sample t-test of Plaque Index for three groups at the second visit – Main study

Figure (3-5): difference of Plaque Index mean for three groups between two visits – Main study

Table (3-10): descriptive statistics of Plaque Index – Main study

0

20

40

60

80

100

123

BOP(%)

Groupbleeding sites at baseline visitnon bleeding site at second visitbleeding site at second visit

Group

Setting

1st visit 2nd visit Sign. Bleeding sites (%) Bleeding sites (%)

1 Er: YAG 100 9.09 VHS 3 Hand ins. 100 9.09 VHS 2 Ultrasonic 100 36.36 NS


Chi -Square

14.747 1.636 14.747

Sign.

0.000 0.201 0.000







Table (3-13): Chi-Square test of Bleeding On Probing for six groups – Main study

Figure (3-6): difference of Bleeding On Probing percentage for six groups between two visits – Main study

Table (3-12): Percentage of Bleeding On Probing at two visits – Main study

1

2

3

4

5

6

7

123

PPD(MM)


Group

Setting


1 Er: YAG 5.52 0.158 0.742 4.66 7 3.48 0.130 0.612 3 5 VHS 3 Hand ins. 5.41 0.090 0.426 5 6 3.81 0.176 0.827 2.83 5.66 VHS 2 Ultrasonic 5.45 0.104 0.488 4.8 6 4.07 0.186 0.873 3 6 VHS



Hand 0.185 0.423







Table (3-14): descriptive statistics of Probing Pocket Depth – Main study

Table (3-15): Paired sample t-test of pocket depth for three groups – Main study

Figure (3-7): difference of pocket depth mean for three groups between two visits – Main study

1

3

5

7

9

11

13

123

RAL(mm)


Group

Setting


1 Er: YAG 11.54 0.160 0.754 11 13 9.63 0.165 0.774 9 11 VHS 3 Hand ins. 11.38 0.092 0.434 11 12 9.84 0.192 0.904 8.5 11.5 VHS 2 Ultrasonic 11.52 0.101 0.475 11 12 10.13 0.186 0.875 9 12 VHS



Hand 0.480 0.371







Table (3-17): Paired sample t-test of Relative Attachment Level for three groups at the second visit

Figure (3-8): difference of Relative Attachment Level mean for three groups between two visits – Main study

Table (3-16): descriptive statistics of Relative Attachment Level – Main study

0123456789

10

123456789101112

Pain Score

PatientEr: YAG laser ultrasonic ins. Hand ins.

Group

Setting Pain Level (0 - 10) Mean Min. Max.

1 Er: YAG 1.166 0 3 2 Ultrasonic Ins. 4.916 2 8 3 Hand Ins. 8.166 6 10



Hand 0.0001 0.0001





Table (3-19): Paired sample t-test of Pain Level for three groups – Main study

Figure (3-9): difference of Pain Level for three groups - Main study

Table (3-18): mean of pain level for three groups – Main study


71

3.2.6. Conclusion of main study results:

Table (3-20) summarize results of three groups in all study criteria

Table (3-20): Main study conclusion

PI BOP PPD RAL NRS 1 1,3 1 1 1 3 2 3 3 2 2 2 2 3

CHAPTER FIVE

DISCUSSION

CHAPTER FOUR DISCUSSION

72

4. Discussion: The present study is aiming to evaluate the most efficient setting for

Er:YAG in the treatment of chronic periodontitis, also comparing the clinical

periodontal parameters following nonsurgical periodontal treatment with an

Er:YAG dental laser with that done by using ultrasonic or hand instruments.

The results have demonstrated that non-surgical periodontal treatment

with the three treatment modalities results in significant reductions in all

study clinical parameters (PI, BOP, PPD and RAL) after three months period.

This come in accordance with numerous periodontal studies which

demonstrate that achieving root surface free from plaque and calculus is the

most important step for healing of chronic periodontitis. (Wennstro¨m and

Tomasi, 2006)

In fact, hand or ultrasonic Instrumentation is regarded as mechanical

means for pathological deposits removal, while Er:YAG laser therapy

removes these deposits by photothermal mechanism; the rapid subsurface

expansion of the interstitially trapped water within the mineral substrate

causes a massive volume expansion, and this expansion causes the

surrounding material to be exploded away; due to the water spray and the

short pulse duration, there is a minimal amount of heat transferred to the

remaining and adjacent tooth structure. (Freiberg and Cozean, 2002)

Also the erbium wavelength (2940 nm) is absorbed by water in the

bacterial cells, and the cells undergo the same liquid-to-steam vaporization

that is seen during ablation of hard tissue, this destruction of bacteria is one of

the additional advantages of using lasers for soft or hard tissue dental

procedures.(Bornstein and Lomke, 2003)


73

4.1. Initial study: The explanations of initial study results could be categorized into two

categories, these are:

4.1.1. Energy level:

Regarding energy, when the laser energy is increased, it lowers the

ablation threshold and, in turn, accelerates the ablation process to certain

limit; another consideration is that when the energy is increased, the pressure

and velocity of the ejected material increases which results in a more intense

impact on the target site. (Hibst, 2002)

The energy causes the water molecules to be heated into steam, which

in turn strains and fractures the collagen matrix in the extracellular

environment. In addition, the near infrared wavelengths are much more

selective for the removal of soft tissue and, therefore, able to ablate the

chronically inflamed soft tissue on the inner wall of the periodontal pocket

with very minimal damage to adjacent tissues (bone, cementum, dentin).

(Glenn, 2004)

4.1.2. Pulse repetition rate:

Statistical analysis of data collected indicates that the ability of

Er:YAG laser in improvement clinical parameters is proportional to the rise in

the pulse repetition rates employed, this outcome may be explained that when

pulse repetition rate increase it will leads to an increment of the energy

density that achieves the target surface per unit of time during irradiation, as a

consequence, more water molecules micro explosions occur in the same time

interval, and therefore more hard substance is expected to be removed.

(Ortolan et al, 2009)


74

4.2. Main study: 4.2.1. Plaque Index:

The statistical analysis of data collected at the end of study show

significant reduction in plaque index for all treatment groups.

The highest reduction is reported in group treated by Er:YAG laser

with mean (2.181) at beginning, which inclined to (0.227) at the end;

followed by ultrasonic instrument and finally hand instrumentation, despite

that the difference between the groups was not statistically significant.

As mentioned by Gronqvist et al. (2000), thermal evaporation of water

and organic components would be the major process in the ablation of

bacterial biofilms with the Er:YAG laser, as with other hard lasers.

Also Er:YAG laser shows antimicrobial effects against

periodontopathic bacteria and the removal of lipopolysaccharides.

(Folwaczny et al., 2002)

4.2.2. Bleeding on Probing:

The percentage of sites that shown bleeding on probing at the first visit

are 100% which reduced dramatically to be 9.090% after treatment by

Er:YAG laser and hand instrumentation, while the reduction in bleeding sites

treated by ultrasonic instruments comes in the second rank and here the

reduction is from 100% at the first visit to 36.36% after treatment.

The favorable short-term (three months) improvement as assessed by

clinical parameters could be a reflection of a reduction of the bacterial load

after laser treatment. (Eberhard, 2003)

Other study revealed that the Er:YAG laser had a significant

decontamination effect on periodontally diseased root surfaces and also had a

significantly better decontamination effect than that of the ultrasonic scaler

with respect to the total numbers of Colony forming units (CFUs) of aerobic

and anaerobic microbes, these bacteria would be devitalized and detoxified by


75

thermal denaturation of the bacterial substances, study also shows that the

remaining biofilms on the boundary of treated areas of ultrasonically scaled

root surface completely retained their original form of bacterial flora, whereas

the remaining biofilms at the marginal region on the laser-treated surface

showed a zone with a denatured appearance in the SEM examination.

(Akiyama et al., 2010)

4.2.3. Probing Pocket Depth and Relative Attachment Level:

The data which analyzed after three months following treatment shows

significant improvement in both probing pocket depth and relative attachment

level in all groups.

Again the group treated by Er: YAG laser become at the top of list by

achieving the greatest reduction in PDD an RAL as indices score was 5.522,

11.545 mm respectively before starting treatment to be after it 3.484, 9.636

mm respectively. Whereas the group treated by hand instrumentation shows

lesser reduction in both PPD and RAL, followed by group treated by

ultrasonic instrument.

Pourzarandian et at. , (2005) was shown that Er:YAG laser induces

cyclooxygenase-2 expression to produce prostaglandin E2 in a laser-energy-

dependent manner, suggesting that cyclooxygenase-2-dependent

prostaglandin E2

Present study findings comes in accordance with results from previous

studies which have shown that conventional SRP alone cannot totally

eliminate the etiological contaminants; In particular, the production of a

smear layer after mechanical root surface debridement with hand instruments

has been reported to be detrimental to periodontal tissue healing as it may

inhibit cell migration and attachment. (Schwarz et al, 2003 b).

by Er: YAG laser irradiation may play an important role in

the acceleration of gingival fibroblast proliferation; this probably explain, at

least in part, the successful healing following Er:YAG non-surgical

periodontal treatment as described in numerous clinical studies.


76

Rossa et al. (2002) reported that root surfaces subjected exclusively to

conventional SRP were not conductive to cellular adhesion and proliferation.

Another study shown that predominantly flat cells were found on laser

and ultrasonically instrumented root surfaces; In contrast, the scaled and root

planed specimens exhibited considerable fewer attached and more round cells,

these findings may be supported by the results from controlled clinical trials,

which have shown that nonsurgical periodontal treatment with an Er: YAG

laser resulted in a statistically significant higher gain of clinical attachment

than SRP with hand instruments. (Schwarz et al, 2003 d).

4.2.4. Pain level:

The records obtained by using NRS for assessing pain level reveal a

significance reduction in pain level during Er:YAG laser treatment. More pain

is experienced by patient during treatment by ultrasonic instruments.

The most painful treatment was felt during hand instrumentation. An

explanation for pain reduction during Er:YAG treatment might be the

disruption of nerve terminals in the dentin tubules, combined with a

degeneration of nerve terminals between the odontoblasts, which were

demonstrated by using transmission electron microscopy. (Inoue et al., 2004)

The advantages of Er: YAG applications in periodontology are based

on the efficient elimination of bacteria and endotoxins on root surfaces in

combination with the selective feedback, where the laser arrives to

differentiate between calculus and tooth tissue. (Bader and Krejci, 2006)

All these findings come in accordance with that of Schwarz et al. (2001

a) how concluded that these reasons why Er:YAG laser seems to be an

efficient alternative for non-surgical periodontal treatment as Er:YAG laser

treatment significantly reduces PPD, BOP and improves clinical attachment

level (CAL) when compared to the classical treatment strategy with SRP.

CHAPTER FIVE

CONCLUSSIONS

And

SUGGESTIONS

CHAPTER FIVE CONCLUSIONS & SUGGESTIONS

77

5.1. CONCLUSIONS:

1- Based on clinical findings, Er:YAG laser can be used for treatment of

chronic periodontitis, and the most efficient energy and frequency settings for

this purpose is 160mJ and 15Hz respectively.

2- Er:YAG laser at (160mJ - 15Hz) setting shows greatest improvement in the

clinical findings (PI, BOP, PPD and RAL) when compared with ultrasonic

and hand instruments.

3- Patients treated with Er:YAG laser, experience the lesser amount of pain

during treatment, while those treated by ultrasonic instruments felt more pain

and those treated by hand instruments shows the maximum level of pain

during the treatment.

4- Treatment by hand instruments shows best improvement in clinical

periodontal parameters than that of ultrasonic one, but regarding pain level,

the ultrasonic instrument was better to use than hand instruments.

CHAPTER FIVE CONCLUSIONS & SUGGESTIONS

78

5.2. SUGGESTIONS:

1- A long term prospective in vivo study is needed to evaluate and compare

the efficiency of Er:YAG with that of ultrasonic and hand instruments

regarding treatment of chronic periodontitis.

2- Further in vivo studies are needed to estimate time required for that with

each of three treatment methods.

3- Microbiological Researches are needed to evaluate the effects of

Er:YAG laser on periodontal pathogens and compare the results with that of

ultrasonic and hand instruments.

4- More in vitro and vivo studies are required to evaluate the efficiency of

using Er:YAG laser in surgical periodontal therapy.

5- Further in vitro and vivo studies are needed to determine the efficiency of

Er:YAG laser in the treatment of peri implantitis.

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APPENDIX

APPENDIX

90

1. Consent form:

إقرار

أني .............................. , أوافق على المشاركة في البحث الخاص برسالة الماجستير للطالب

, والتي تهدف الى تحديد الفعالية السريرية لليزر الأريبيوم ياك في ( فهد ميزر عبد الجبار الدباغ )

علاج التهاب اللثة ومقارنتها مع العلاج بالأمواج فوق الصوتية والأدوات اليدوية. هذا وقد تم شرح

تفاصيل العلاج كاملة لي وبينت كافة الآثار الجانبية التي قد تحدث خلال او بعد تطبيق طرق العلاج

المذكورة. ولهذا أوافق على تزويد الباحث بكل المعلومات المطلوبة وأن اخضع لكافة الإجراءات

والفحوصات التي يتطلبها الأمر ولأجله وقعت.

أسم المريــــض:

التوقيــــــــــــــع:

التاريــــــــــــــخ:

APPENDIX

91

2. Research Case sheet:

d- UResearch criteria:

No. Type of debridement

Research criteria

1ry visit record Reading 1st 2nd 3rd

2ry visit record Reading 1st 2nd 3rd

1

Er: YAG laser (120mJ, 10Hz)

Plaque index

BOP

PPD

RAL

2


Plaque index

BOP

PPD

RAL

a- Basic information:

Patient Name: Age Sex :

Occupation: Address: Mobile:

Date of starting visit:

Date of 1ry observation visit: Date of 2ry observation visit:

b- Medical history: Renal failure, dialysis Acquired or congenital heart diseases Organ transplantation Prosthetics heart valve Infection diseases Chronic hypertension Angina/ M .I. Chronic hypotension epilepsy Diabetes mellitus Others: Recent Drug history:

c- Habits and signs of stress: Bruxism Smoking

Clenching Ulcers

APPENDIX

92

3


Plaque index

BOP

PPD

RAL

4


Plaque index

BOP

PPD

RAL

5


Plaque index

BOP

PPD

RAL

6


Plaque index

BOP

PPD

RAL

7

Hand instrument

Plaque index

BOP

PPD

RAL

8

Ultrasonic scaler

Plaque index

BOP

PPD

RAL

APPENDIX

93

3. Numerical Rating Scale: مدرج التقييم العددي لمستوى الألم

10 ألم شديد 9 8 7 6 5 4 3 2 1

0 لا يوجد ألم

لب

Page 1 س

Uالخلاصة إن استخدام الليزر لعلاج أمراض الأنسجة المحيطة بالأسنان أصبح من المواضيع ذات

الاهتمام الكبير ويمثل مجالا واعدا في علاج الأنسجة المحيطة بالأسنان, يعود ذلك للخصائص

المختلفة التي يتمتع بها الليزر مثل أمكانية استئصال الأنسجة و إيقاف النزف و التعقيم. وقد تم التوجه

مايكروميتر,وذلك للفعالية التطبيقية 2.94 مؤخرا لليزر الأيربيوم ياك ذو الطول ألموجي البالغ

السريرية لهذا الليزر حيث يمتلك هذا النوع القدرة على استئصال الأنسجة الرخوة و القاسية معا.

جيب محيط بالأسنان لأجراء الدراسة الأولية أولا, حيث تم 96في هذه الدراسة تم اختيار

توزيع هذا العدد عشوائيا إلى ست مجموعات وتم استخدام ثلاثة قيم للطاقة وقيمتان لمعدل إعادة

النبضة (التردد) لجهاز الأيربيوم ياك ليزر, وذلك لتحديد أكثر قيمة طاقة وقيمة تردد ملائمة لعلاج

التهاب الأنسجة المحيطة بالأسنان المزمن,اعتمادا على مقارنة العلامات السريرية لما حول الأسنان

قبل العلاج (في الزيارة الابتدائية) وبعد ثلاثة أشهر من العلاج,وأظهرت النتائج أن قيمة الطاقة

هرتز معا هي أكثر القيم فعالية لهذا الغرض. 15ملي جول وقيمة التردد 160

جيب أخر محيط بالأسنان لغرض الدراسة الرئيسية وتم توزيع هذه 72كما تم اختيار

الجيوب عشوائيا إلى ثلاث مجموعات, الأولى تم علاجها باستخدام جهاز الأيربيوم ياك بالقيم

هرتز), أما الثانية فقد تم علاجها باستخدام جهاز التقليح بالأمواج فوق 15 –ملي جول 160(

الصوتية وتم علاج المجموعة الأخيرة باستخدام أدوات التقليح اليدوية.

تم إجراء تقييم سريري لأنسجة ما حول الأسنان للمجموعات الثلاث قبل وبعد العلاج,

وتضمن التقييم (مؤشر الصفيحة الجرثومية, اختبار النزف عند التسبير, عمق الجيوب المحيطة

بالأسنان لدى التسبير و مستوى الارتباط النسبي).كما استخدم مدرج التقييم العددي (مكون من

عشرعلامات) لتقييم درجة الألم التي يشعر بها المريض لدى كل طريقة علاج.

) 0.05 <في هذه الدراسة أثبتت النتائج وجود فرق إحصائي معنوي (عند قيمة معنوية

وتحسن في كل المؤشرات السريرية للأنسجة المحيطة بالأسنان في الزيارة التالية للعلاج بثلاثة أشهر

في المجموعات الثلاث, ولكن أظهرت المجموعة التي تم علاجها بجهاز ليزر اليربيوم ياك التحسن

الأكبر وبفرق إحصائي معنوي واضح, تبعتها المجموعة التي تم علاجها بأدوات التقليح اليدوية وجاء

العلاج بجهاز التقليح بالأمواج فوق الصوتية بالمركز الأخير.

لب

Page 2 س

كذلك دلت النتائج أن أقل مستوى للألم سجل خلال العلاج بجهاز ليزر الأيربيوم ياك بمعدل بلغ

), بينما كان العلاج بأدوات التقليح 4.916), ومن ثم العلاج بالأمواج فوق الصوتية بمعدل ((1.166

).(8.166اليدوية هو الأكثر ألما وبمعدل بلغ

هرتز) 15والتردد ملي جول160نستنتج من هذه الدراسة أن ليزر الأيربيوم ياك (ذو الطاقة

ممكن أن يستخدم كبديل للعلاج التقليدي الغير جراحي لالتهاب الأنسجة المحيطة بالأسنان (العلاج

بأدوات التقليح اليدوية وأدوات التقليح بالأمواج فوق الصوتية), و بدرجة تحسن ملحوظة , فيما يتعلق

بالعلامات السريرية للأنسجة المحيطة بالأسنان, مع مستوى ألم أقل خلال العلاج.

التقييم السريري لليزرالأيربيوم ياك في علاج إلتهاب الأنسجة المحيطة بالأسنان المزمن ومقارنته بالعلاج بالأدوات اليدوية

والأمواج فوق الصوتية

رسالة مقدمة إلى

مجلس كلية طب الأسنان - جامعة بغداد

كجزء من متطلبات نيل درجة الماجستير في

أمراض وجراحة ماحول الأسنان

مقدمة من قبل

فهد ميزر عبد الجبار الدباغ

بكالوريوس طب وجراحة الفم والأسنان

بإشراف الأستاذ

د.خلود عبد الهادي الصافي

دكتوراه أمراض وجراحة ماحول الأسنان

العراق - بغداد

ه1431 م 2010

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Clinical evaluation of Er:YAG laser in the treatment of