ABSTRACT PhD THESIS - UMF Iasi. „GRIGORE T. POPA” IAŞI FACULTY OF DENTAL MEDICINE ABSTRACT PhD THESIS Scientific coordinator PROF.UNIV.DR. ANDRIAN SORIN PhD Student MOLDOVANU

U.M.F. „GRIGORE T. POPA” IAŞI

FACULTY OF DENTAL MEDICINE

ABSTRACT

PhD THESIS

Scientific coordinator

PROF.UNIV.DR. ANDRIAN SORIN

PhD Student

MOLDOVANU ANTONIA

2014

U.M.F. „GRIGORE T. POPA” IAŞI

FACULTY OF DENTAL MEDICINE

PhD THESIS

CLINICAL, LABORATORY AND EXPERIMENTAL

STUDIES ON THE DIAGNOSTIC AND

THERAPY OF ROOT DENTAL CARIES

Scientific coordinator

PROF.UNIV.DR. ANDRIAN SORIN

PhD Student

MOLDOVANU ANTONIA

2014

1

SUMMARY OF PhD THESIS

GENERAL PART

I.Root surface dental caries. Generalities...................................................................................1

II.Epidemiological data of root dental caries.............................................................................5

III.Root dental caries ethiopathogeny......................................................................................11

III.1.Pathogeny of root dental caries........................................................................................11

III.2.Root dental caries microbiology.......................................................................................15

III.3.Favourising factors...........................................................................................................17

IV.Clinical and morphological factors:

IV.1.Morphological structure of dental tissues........................................................................25

IV.2.Clinical and morphological aspects.................................................................................29

V.Clinical-therapeutical management of root dental caries.....................................................35

V.1.Positive and differential diagnosis of root dental caries....................................................35

V.2.Therapeutical options:

V.2.A.Therapeutical and preventive measures.........................................................................37

V.2.B.Restorative approaches..................................................................................................55

PERSONAL RESEARCHES

VI.Reasons forthe choice of research theme. Methodology....................................................63

VII.Epidemiological and clinical study....................................................................................75

VIII.Research on the assessment of organic component changes following the treatment with

Carisolv....................................................................................................................................99

IX.Anatomical and clinical features of enamel-dentine junction – SEM study.....................129

X.The assessment of cario-preventive effect of some food supplied before the action of acid

beverages on exposed dental root surfaces.............................................................................151

XI.The assessment of status of giomer and resin-modified glass ionomer restorations used in

the treatment of root dental caries..........................................................................................171

XII.Conclusions......................................................................................................................209

References

2

KEY WORDS: root cement, root dental caries, prevalence, enamel-dentine junction

PhD Thesis is structured as follows:

General part – five chapters (62 pages)

Personal researches – seven chapters (150 pages, 127 tables, 45 graphs, 5 images, 84 figures)

Note: the PhD abstract presents selective references and images

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I. ROOT DENTAL SURFACES. GENERAL ASPECTS.

The root dental caries is a major issue of oral health for old-aged

individuals. Three arguments support this assertion: life hope increased

significantly in developed countries, high prevalence of periodontal

diseases at old-aged patients, the preservation of high number of teeth

related to high number of root surfaces susceptible to dental caries.

The oral status of old-aged individuals has improved because of

high availability to oral health education, oral care improvement and large

scale use of fluoride toothpastes.

The number of old-aged patients with high number of natural teeth is significantly

higher comparing with past years and records a progressive increase.

The root dental caries dental caries are associated with exposed root surfaces

following gingival recession. Sumney et al. consider root dental caries as cavitated lesion

localised below enamel-cement junction and characterised by colour changes and reduced

consistency of cement and dentine (373, 167). Many authors proposed distinct criteria

regarding root dental caries, like localisation at the level of enamel-cement junction or root

cement (29), undermining of adjacent enamel (215), or extension to more than half of cement

surface (389).

The individual behaviour related to oral health is strictly correlated to age, with higher

effects for old-aged individuals. There is a direct relation between age and risk factors. The

use of sugar in tea or coffee associated with unregulated dental checking doubles the risk of

root dental caries for old-aged individuals.

The ethiology of root dental caries is complex, with bacterial factor as most important

risk factor. The old persons are most exposed to root dental caries because associated

systemic diseases. Many old-aged persons use medication that reduces salivary rate and

produces dry mouth.

The cavitary root dental caries can be easily diagnosed in clinical examen.

Despite many studies were performed regarding prevalence and associated factors,

our knowledges are limited. This should stimulate future researches focused on the ethiology,

treatment and prevention of root dental caries.

Each individual has a characteristic way of carious attack, influenced by different

factors, including number of type of natural teeth and their association with gingival

recessions. For old-aged persons, many missing teeth are, in fact, those teeth prediposed to

root dental caries. Katz et al. demonstrated that most root dental caries are localised on

mandibular molars, followed by premolars and incisives (215). Anterior maxillary teeth are

more affected of root dental caries than mandibular teeth. Both buccal and proximal surfaces

are affected by root dental caries, followed by oral surfaces. There are undefined specific oral

factors that can determine cariogenic attack patterns.

The bacteria implied in the ethiology of root dental caries are anaerobic facultative-

gram bacteria (streptococci, lactobacilli, actinomycetes) and anaerobic-gram bacteria

(Bacteroides, Prevotela, Saelenomonas, Fusobacterium, Leptotrichi, Capnocytophaga). Also

are implied favourising factors like bone alveolar recessions contributing to the exposure of

root surfaces to oral environment.

The enamel-cement junction is most vulnerable to dental caries because of thin and

weak mineralized cement layer covering the root dentine. This cement layer offers weak

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protection for the pulp-dentine complex and retention conditions for bacterial biofilm; more,

most areas are not accessible to the artificial self-cleaning especially when associated with

gingival inflammations and gingival hypertrophy.

The anatomy of enamel-cement junction is different as follows: cement covers enamel

for 60% individuals, cement in tight junction with cervical enamel for 30% individuals, thin

space between cement and cervical enamel for 10% individuals (overlap, meet, gap).

Most protective factors against cariogenic agents are localized in saliva and sulcular

fluid. The decrease of salivary secretion conducts to the increase of bacterial biofilm and

cariogenic bacteria. Patients with xerostomia present rampant dental caries also at the level of

root dental surfaces. If RFR is decreased and RFS is normal, salivary glands have a normal

response to external stimulus but do not produce adequate saliva during rest. In this situation,

teeth are covered by rest saliva for 14 hours daily and cariogenic activity significantly

increases.

The risk factors are as follows: low salivary flux, xerostomia, exposure of root

surfaces, chronic diseases, radiotherapy, manual ability limitation because of heart stroke,

artritis, or Parkinson, diseases like Alzheimer, Sjogren syndrom, diabetes, poor oral hygiene,

xerostomic medication. Potential risk factor is represented by previous carious experience

(treated or untreated root surfaces).

Old-aged individuals are associated with significant presence of systemic diseases.

Infections, autoimmune diseases, neoplasia can change normal response of immune system.

Also the salivary glands function must be considered as an important risk factor implied in

the assessment of old-aged patients.

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I.CLINICAL AND EPIDEMIOLOGICAL STUDY REGARDING ROOT SURFACE

DENTAL CARIES

The root dental caries represent a frequent pathology in old-aged

individuals (9). Proximal and buccal exposed root surfaces represent

risk areas for root dental caries (194). Despite low prevalence of root

dental caries for persons under age 60, this can increase to over 80%

for persons over age 60 (133). The root dental caries are related

especially to molars and bicusps for all age groups (23). The patients

with healthy periodontal tissues have low prevalence of root dental caries (4%), while

patients with gingivitis (15%) and patients with periodontal pockets (17%) have much higher

prevalence of root dental caries (389).

The epidemiological studies relate root dental caries with next factors: aged

population, high number of natural teeth, the increase of prevalence and severity of

periodontal disease, the increase of susceptibility for root dental caries of patients under

periodontal treatments (316).

THE AIMS OF STUDY:

The aims of study:

assessment of prevalence and distributions of root dental caries related to environment

factors, behavior factors and biological factors for patients included in study group

analisys of factors implied in the etiology of root dental caries and the assessment of

cariogenic risk for patients included in study group

data statistical analysis and establishment of possible correlation between the presence of

root dental caries and environment factors, behavior factors and biological factors

MATERIALS AND METHODS

The study group included patients with age between 45-85 years, selected from

patients treated in Clinical Base of Dental Learning „Mihail Kogălniceanu” and private dental

office in 2011-2012.

The research activities performed according to laws related to deontological norms of

research. The clinical examination was performed according to Law no.46, 21 januar 2003

related to patient rights. Written consent was obtained from patients included in study group.

The clinical examen used clasical probe and mirror associated with magnification means

(lens UK Loupes, x 3,5). The objectives were as follows:

1. Assessment of DMFT index

2. Assessment of root carious disease using Indices ICDAS II and CARS for root

surfaces (Pits&Ismail 2005)

3. Plaque index (Silness&Loe), cariogenic index of bacterial plaque (test Hardwick

J.L., Manly E.B.)

4. Root dental caries index Katze

5. Salivary function (buffer capacity (Dentobuff), RFR, RFS, saliva viscosity (Leus

P.A., Beliasov L.V), colorimetric test Snyder

6. The assessment of Mutans Streptococcus (Dentocult SM) and Lactobacilus

(Dentocult LB), 7. The assessment of cariogenic risk (educational level, systemic diseases, medication,

quest regarding foods type and content, carbohydrates consume frequency).

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RESULTS:

Regarding sex, the distribution was as follows: males 53%, females 47% (graph 7.1).

Regarding residence, 67% patients are from urban environment (graph 7.2.). In graph 7.3. is

presented the structure of study group related to age and sex. In study group the mean age is

63,17 years. Test Kolmogorov-Smirnov established the distribution related to age of study

group.

Table 7.I. Test Kolmogorov-Smirnov

Tests of Normality

Kolmogorov-Smirnova Shapiro-Wilk

Statistic df p. Statistic df p.

age .116 192 .000 .954 192 .000

a. Lilliefors Significance Correction

The distribution is symetric and abnormal. The correlation between residence and age

was established using Pearson test. Chi-square was 42,928, freedom degrees were 3 and

significance two-tailed is 0,0001, (<0,05). The results validate a significant correlation

between age and residence.

Table 7.II. Pearson test (correlation between residence and age)

Chi-Square Tests

Value df

Asymp. Sig. (2-

sided)

Pearson Chi-Square 41.928a 3 .000

Likelihood Ratio 42.254 3 .000

Linear-by-Linear Association 7.153 1 .007

N of Valid Cases 192

a. 0 cells (.0%) have expected count less than 5. The minimum expected

count is 6.33.

The coefficient chi-square was 88,992, freedom degrees 3. The significance two-

tailed is 0,0001, less than 0.05 shows a significant correlation between age and sex (table

7.III).

Table 7.III. Pearson test (correlation between sex and age)

Chi-Square Tests

Value df

Asymp. Sig. (2-

sided)



Linear-by-Linear Association .589 1 .443


a. 0 cells (.0%) have expected count less than 5. The minimum expected

count is 7.92.

The age group 55-64 years was most affected by root dental caries with ICDAS 01.

The test Pearson showed the existence of significant correlation between root dental caries

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with ICDAS 01 and age group (chi-square 87,085, freedom degree 6 and significance two-

tailed 0,0001<0,05) (table 7.IV).

Table 7.IV. Pearson test (correlation between ICDAS 01 and age group )

Chi-Square Tests

Value df

Asymp. Sig. (2-

sided)





a. 3 cells (25.0%) have expected count less than 5. The minimum

expected count is 2.25.

The age group 55-64 years was most affected by root dental caries with ICDAS 02.

The test Pearson showed the existence of significant correlation between root dental caries

with ICDAS 01 and age group (chi-square 124,856, freedom degrees 9 and significance two-

tailed 0,0001<0,05) (table 7.V).

Table 7.V. Pearson test (correlation between ICDAS 02 and age group)

Chi-Square Tests

Value df

Asymp. Sig. (2-

sided)







Regarding root dental caries adjacent to composite resins fillings, 33,3% root dental

caries were incipient and 33,5% were deep caries. Regarding root dental caries adjacent to

amalgam fillings, 25% were deep root caries and 16,7% were incipient root caries (table

7.VI).

Tabelul 7. VI. Root dental caries adjacent to amalgam and composite resins fillings

Case Processing Summary

Cases

Valid Missing Total

N Percent N Percent N Percent

Age *filling .30 64 33.3% 128 66.7% 192 100.0%

Age * satisfactory amalgam

filling40

32 16.7% 160 83.3% 192 100.0%

Age *incipient adjacent root

dental caries 31

64 33.3% 128 66.7% 192 100.0%

Age * incipient root dental

caries adjacent to amalgam41

32 16.7% 160 83.3% 192 100.0%

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Age *incipient root dental

caries adjacent to composite

resin filling 32

64 33.3% 128 66.7% 192 100.0%

Age *deep root dental caries

adjacent to amalgam filling

42

48 25.0% 144 75.0% 192 100.0%

Regarding the distribution of incipient root dental caries adjacent to composite resins

fillings (CARS 31) related to age group, most affected were patients with age between 55-64

years, followed by age groups 45-54 and 74-85. Pearson test showed the existence of

significant correlation between incipient root dental caries adjacent to composite resins

fillings (CARS 31) and age group (chi-square 22,710, freedom degrees 3, significance two-

tailed 0,0001<0,05) (table 7.VII).

Table 7.VII. Pearson test (correlation between CARS 31 and age group.

Chi-Square Tests

Value df

Asymp. Sig. (2-

sided)



Linear-by-Linear Association .725 1 .395

N of Valid Cases 64

a. 4 cells (50.0%) have expected count less than 5. The minimum expected

count is .25.






tailed 0,0001<0,05) (table 7.VIII).

Table 7.VIII. Pearson test (correlation between CARS 32 and age group

Chi-Square Tests

Value df

Asymp. Sig. (2-

sided)




N of Valid Cases 64


expected count is .25.






tailed 0,0001<0,05) (table 7.IX).

Table 7.IX. Pearson test (correlation between CARS 42 and age group)

Chi-Square Tests

Value df

Asymp. Sig. (2-

sided)


9



N of Valid Cases 48


expected count is .67.

The results of the assessment of cariogenic risk using Snyder test showed that all

patients from age group 45-54 have high cariogenic risk. For age group 55-64 high cariogenic

risk was associated with 50,5% patients, and for age group 75-84 high cariogenic risk was

associated with 84,2% patients. Pearson test showed the existence of significant correlation

between cariogenic risk and age group (chi-square 96,351, freedom degrees 6 and

significance two-tailed 0,0001<0,05) (table 7.X).

Tabelul 7.X. Pearson test (correlation between cariogenic risk and age group)

Chi-Square Tests

Value df

Asymp. Sig. (2-

sided)







The analysis of saliva viscosity showed that patients with root dental caries from age

group 45-54 years had good viscosity. Low viscosity was recorded for 50,5% patients in age

group 55-64 years , 64,6% patients from age group 65-74 years and 94,7% patients from age

group 75-84 years. Pearson test showed significant correlation between saliva viscosity and

age group (chi-square 73,461, freedom degrees 6, significance two-tailed 0,0001<0,05) (table

7.XI).

Table 7.XI. Pearson test (correlation between saliva viscosity and age group)

Chi-Square Tests

Value df

Asymp. Sig. (2-

sided)







Regarding biologic parameters, all patients from age group 45-54 years were

associated with cariogenic biofilm, 82,8% from patients in age group 55-64 years were

associated with cariogenic biofilm, 68,8% from patients in age group 65-74 years and only

10,5% ffrom patients in age group 75-84 years were associated with cariogenic biofilm.

Pearson test showed significant correlation between cariogenic biofilm and age group (chi-

square 56,804, freedom degrees 3, significance two-tailed 0,0001<0,05) (table 7.XII).

Table 7.XII. Pearson test (correlation between cariogenic biofilm and age group)

Chi-Square Tests

Value df

Asymp. Sig. (2-

sided)


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For age group 45-54 years, half of patients were associated with low levels of

Streptococcus mutans, for the other half levels raised up to 100000 ufc\mL. For age group

55-64 years 33,3% from patients were associated with levels of Streptococcus mutans close

to 1000000 ufc\mL. For age group 65-74 years 64,6% from patients were associated with

levels of Streptococcus mutans close to 1000000 ufc\mL. 89,5% from patients in age group

75-84 years were associated with low levels of Streptococcus mutans in saliva. Pearson test

showed significant correlation between Streptococcus mutans in saliva and age group (chi-

square 126,355, freedom degrees 9, significance two-tailed 0,0001<0,05) (table 7.XIII).

Table 7.XIII. Pearson test (correlation between levels of Streptococus mutans in

saliva and age group)

Chi-Square Tests

Value df

Asymp. Sig. (2-

sided)







For age group 45-54 years, half of patients were associated with low levels of

Streptococcus mutans, for the other half levels raised up to 100000 ufc\mL. For age group

55-64 years 66,7% from patients were associated with low levels of Lactobacillus. For age

group 65-74 years 64,6% from patients were associated with levels of Lactobacillus had

mean levels. 84,2% from patients in age group 75-84 years were associated with low levels of

Lactobacillus in saliva, and only 10,5% had mean levels of Lactobacillus. Pearson test

showed significant correlation between Lactobacillus in saliva and age group (chi-square

185,174, freedom degrees 9, significance two-tailed 0,0001<0,05) (table 7.XIV).

Tabelul 7.XIV. Pearson test (correlation between levels of Lactobacillus in saliva and

age group)

Chi-Square Tests

Value df

Asymp. Sig. (2-

sided)







Regarding the assessment of nutritional factor, all patients in age group 45-54 years

has score 15. Same result was obtained for age group 65-74 years. For age group 55-64 years,

82,8% patients and 15,8% patients from age group 75-84 had score over 15. Pearson test

showed significant correlation between cariogenic level of nutritional factor and age group

(chi-square 78,430, freedom degrees 3, significance two-tailed 0,0001<0,05) (table 7.XV).

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Table 7.XV. Pearson test (correlation between cariogenic level of nutritional level

and age group)

Chi-Square Tests

Value df

Asymp. Sig. (2-

sided)







The assessment of systemic diseases were showed that most patients were affected by

hepatitis and articular diseases (13,64%), followed by hypertension and diabitis (9,09%),

heart stroke (8,81%)(graph 7.5).Most consumed xerostomic drugs was nitroglycerine and

diuretic drugs(13,1%), followed by antidepressants and beta-blockers(8,7%), digoxin (8,2%).

Pearson test showed significant correlation between xerostomic drugs consume and

age group (chi-square 277,316, freedom degree 24, significance two-tailed 0,0001<0,05)

(table VI.15).

Table 7.XVI. Pearson test (correlation between xerostomic drugs consume and age group)

Chi-Square Tests

Value df

Asymp. Sig. (2-

sided)







DISCUSSIONS

The epidemiological studies show a large range of root dental caries prevalence

depending on the diagnostic criteria, studied population, aim of study. The probability that a

patient under 40 years have root dental caries is with 20% lower than age (96). Index RCI is

most used in epidemiological studies, with incidence rates: 1,5 – 4,3 root dental

caries/patient/year or 0.87 – 8,2 root dental caries/100 risk surfaces/year (32). The

epidemiological studies show the lack of consensus regarding definition and diagnostic

criteria of root dental caries. Only microbiological studies validate as single criteria the

consistency of cement (soft for active lesions, hard for inactive lesions).

The actual data show that root dental caries represents a real problem for old-aged

individuals, especially for those with systemic diseases. Regarding the composition of

bacterial biofilm localized on dental root surfaces, Van Houte J.et al. show that Streptococci,

Actinomyces, Veillonela represent 84,2%, 57,8%, 65,7% (388). Streptococus mutans and

Lactobacillus are not always present in bacterial biofilm from root dental surfaces.

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Poor oral hygiene of old-aged individuals is a risk factor for the development of root

dental caries. The retraction of periodontal tissues is associated with interdental areas hard to

be cleaned using classical means. Also the ability to learn new adequate tooth cleaning

methods is very low.

Vehkalalahti M. M. Et al. associated root dental caries with poor oral hygiene (OR

3,), low number of teeth (OR 2,3-2,7), old age (OR 2,1) (390).

The dental practice must insist on education and motivation regarding adequate oral

hygiene of patients.

Most protective factors against cariogenic agents are present inside saliva and sulcular

fluid. The decrease of salivary secretion conducts to the increase of bacterial biofilm and

microbial flora changes. Patients with xerostomia are associated with rampant dental caries,

especially on root dental surfaces. Gastroesophageal reflux disease (GERD) maintains pH

under critical pH for many hours, submitting dental cement to demineralisation and

disolution followed by cavitary dental caries. Liver diseases influence immune system and

conduct to the lack of specific defensive agents like Ig A, M, G and determine the

development of cariogenic flora.

The correlation between diabetes and root dental caries can be explained by continous

elimination of glucose in saliva and development of cariogenic flora (especially

Streptococcus Mutans).

The xerostomic drugs and Parkinson disease can also affect the ability for adequate

hygiene of old-aged individuals. More, xerostomic drugs diminishes the rate of salivary flux

and reduces the protective effect of saliva.

CONCLUSIONS:

Prevalence of root dental caries is 68,7%.

Incipient root dental caries affect especially age group 55-64 years, followed by age

groups 45-54 years, 65-74 years, 75-84 years.

Age group 55-64 years was most affected by deep root dental caries, followed by age

groups 65-74 years, 45-54 years, 75-84 years.

Age group 55-64 years was most affected by root dental caries adjacent to composite

resins and amalgam fillings.

Most incipient and deep root dental caries, were adjacent to composite resins fillings,

followed by deep root dental caries adjacent to amalgam fillings.

Significant statistical correlations between salivary factors (rest and stimulated salivary

flux, buffer capacity, saliva viscosity) as well as biological microbial parameters (levels

of Streptococcus mutans and Lactobacillus, cariogenity of bacterial biofilm), nutritional

factor, systemic diseases, xerostomic drugs and root dental caries for old-aged patients.

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II. STUDY REGARDING THE ASSESSMENT OF CHANGES

RELATED TO ANORGANIC COMPONENT OF ROOT

DENTINE AFTER TREATMENT WITH CARISOLV

INTRODUCTION: Root dental caries represent an interesting issues for many dental

researches (167, 133,134, 214, 248, 283) as many individuals maintain their natural teeth at

advanced ages. Some controversial aspects are considered by many authors regarding the

development mechanisms and efficiency of preventive and therapeutical

methods.

An important objective of root dental caries therapy is the removal of

carious dentine. The chemo-mechanical method Carisolv is a viable solution

for this therapeutical stage.

Various methods and devices can offer qualitative and quantitative

informations regarding chemical elements and distributions of atoms and ions. Some

methods can offer only qualitative informations, other methods can offer both qualitative and

quantitative informations regarding type of chemical elements and concentrations. For

researches investigating surface status, analysis depth must be considered. There are

differences between methods that can analyse 100μm depth and methods that analyse 2μm

depth. Some features like porosity and hardness can influence accuracy of depth analysis.

Also an improper samples preparation can affect the results of chemical analysis.

THE AIM OF STUDY:

The aim of study was to assess the quantitative and qualitative chemical

composition (Ca, P ions) of root dental surfaces, following treatment with Carisolv.

MATERIALS AND METHOD:

The study group included 12 teeth extracted for periodontal reasons, with root dental

caries, associated with minimum one healthy surface. Teeth were stored in distilled water at

4°C. Teeth were divided in 2 halves using diamond discs (Komet Dental, Brasseler

GmbH&Co, Germania), under water cooling ; section plan separated the healthy root surface

from carious root surface. For each toot were performed two samples, one with carious root

surface (study group) and the other with healthy dentine surface (control group).

For each sample in study group, infected dentine was removed with Carisolv by a

single practitioner, accordingly to working protocol recommended by producer. Carisolv gel

covered carious dentine for 30 seconds; the softened dentine was removed using hand

instrument. The procedure was repeated until total removal of carious dentine, confirmed

with a probe touching hard dentine.

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Figure 8.10-8.13. Removal of carious dentine using Carisolv

The checking was performed using a dye Caries indicator (Vladmiva). The samples

with healthy dentine were considered control group.

The processed dentine samples were investigated by EDX method, using QUANTAX

QX2 ROENTEC (Bruker AXS Microanalysis GmbH, Germania):

assessment of qualitative and quantitative chemical composition,

mapping of chemical elements.

SEM microscope had the next parameters: resolution 3nm-30 KV, magnification 13-

1.000.000 X; 200 V, 30kV, scanning speed 200 ns-10 ms pixel-1.

RESULTS:

Using EDX analysis, spectrum of chemical elements was obtained from all dentine

samples allowing mapping of these elements on investigated dental surfaces. Also, EDX

method allowed quantitative analysis, expressing chemical composition as wt%.

An example is presented in graph 8.I, with higher percentages for oxygen, calcium and

phosphorus ions and lower percentages for Na, Mg, K (graph 8.I).

Graph. 8.I. Spectrum of chemical elements for a sample (group study) after removal of

carious dentine using Carisolv

Chemical composition (same tooth sample) is as follows: 58,01% wt% oxygen, 28,18 %

wt% calcium, P 13,22% wt%, K 1,03% wt%, Na 0,45% wt%, Mg 0,06% wt% (table 8.I.).

Table 8.I. Chemical composition for a sample (study group) after removal of carious

dentine using Carisolv

Element series [wt.-%] [norm. wt.-

%]

[norm. at.-%] Error in %

Calcium K-series 28,18901 28,47998 14,98967 0,882531

Phosphorus K-series 13,22548 12,99325 8,848761 0,563728

Sodium K-series 0,454188 0,446213 0,409417 0,072871

Potassium K-series 1,038483 1,020248 0,550435 0,063034

Magnesium K-series 0,063055 0,061947 0,053763 0,034233

Oxygen K-series 58,01711 56,99836 75,14795 8,960411

Sum: 101,7873 100 100

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Figures 8.21-8.22. Mapping of chemical elements of analysed surfaces for samples in

study group a) calcium ions b) phosphorus ions

Chemical elements spectrum for control sample is presented in graph 8.II. Higher

percentages are observed for oxygen, calcium, phosphorus (graph 8.II).

Graph 8.II. Chemical elements of sample in control group

Chemical composition (same tooth sample) is as follows: 39,91% wt% oxygen, 28,42 %

wt% calcium, P 14,59% wt%, K 1,11% wt%, Na 1,02% wt%, Mg 0,42% wt% (table 8.I.).

Table 8.II. Chemical elements of sample in control group

(carious dentine removal using Carisolv)

For all investigated samples, only levels of calcium and phosphorus were considered,

as predominant chemical elements of dentine anorganic component. The results show levels

of calcium for samples with root dental caries between 23,09-28,18, and for control samples

between 23,18-28,42. The results show levels of phosphorus for samples with root dental

caries between 9,76-13,22, and for control samples between 9,88-14,59.

The mean of calcium ions was higher in control group (25,23), comparing with study

group (24,61). Same tendency was recorded for phosphorus ions, with a mean 10,84 in

control group and 10,52 in study group (table 8.IV).

Element series [wt.-%] [norm. wt.-

%]

[norm. at.-%] Error in %

Calcium K-series 28,42801 25,18514 13,62272 0,878865

Phosphorus K-series 14,59191 12,92737 9,047769 0,634063

Sodium K-series 1,025756 0,908745 0,856905 0,141928

Potassium K-series 1,112692 0,985764 0,546563 0,073081

Magnesium K-series 0,42306 0,3748 0,334294 0,072792

Oxygen K-series 39,91758 35,36405 47,91635 7,47444

Sum: 112,8761 100 100

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Table 8.IV. Descriptive statistics. Mean values and standard deviations for Ca and P

levels in control group and study group

Descriptive Statistics

N Minimum Maximum Mean Std. Deviation Skewness Kurtosis

Statistic Statistic Statistic Statistic Statistic Statistic Std. Error Statistic Std. Error

Ca

study group

12 23.09 28.18 24.6167 1.35850 1.657 .637 3.963 1.232

Ca

control group

12 23.18 28.42 25.2325 1.41168 .712 .637 1.201 1.232

P

study group

12 9.76 13.22 10.5208 .95997 2.262 .637 6.058 1.232

P

control group

12 9.88 14.59 10.8467 1.25067 2.787 .637 8.754 1.232

Valid N (listwise) 12

The analysis of graph 8.V. shows that distribution of calcium ions in study group

deviates from normal curve and do not allow the use of parametrical test for statistical

comparisons.In graph 8.VI the distribution of calcium ions in control group deviates from

normal curve and do not allow the use of parametrical test for statistical comparisons.

The analysis of graph 8.VII. shows that distribution of phosphorus ions in study group

deviates from normal curve and do not allow the use of parametrical test for statistical

comparisons.In graph 8.VIII the distribution of phosphorus ions in control group deviates

from normal curve and do not allow the use of parametrical test for statistical comparisons.

The results of Mann-Whitney test (for the assessment of statistical differences)

showed the lack of significant statistical difference between the study groups and control

group regarding the levels of calcium and phosphorus ions (Mann-Whitney U = 48,500, z =

1.357, p = 0.175, respectiv Mann-Whitney U = 49,500, z = 1.300, p = 0.194) (tables 8.VI-

8.IX).

Tables 8.VI,8.VII. Mann-Whitney test (comparison between Ca ions levels)

Ranks

lot N

Mean

Rank

Sum of

Ranks

Ca Study

group

12 10.54 126.50

Control

group

12 14.46 173.50

Total 24

17

Mann-Whitney test shows the absence of significant statistical difference between the

scores of study group and control group, related to calcium ions levels (Mann-Whitney U =

48,500, z = 1.357, p = 0.175).

Mann-Whitney test shows the absence of significant statistical difference between the

scores of study group and control group, related to phosphorus ions levels (Mann-Whitney U

= 49,500, z = 1.300, p = 0.194).

DISCUSSIONS: The application of Carisolv gel facilitates the removal of carious dentine. The

chemical agents contain chloramines (NaOCl and aminoacids) with minimal adverse effects

on oral tissues and hard dental tissues. The final effects on dentine are not yet completely

explained.

Carisolv system removes the infected carious tissues due to the proteolitic action of an

organic complex (NaOCl 0,5% and three aminoacids: leucine, lisine, glutamic acid). Many in

vitro studies analyses the aspects, roughness, bacterial infiltrate degree, microhardness,

smear-layer, adhesion.

The aim of our study is to analyse the changes in mineral component of root dental

tissues after chemo-mechanical removal of carious dentine with Carisolv system. Because the

changes of mineral content can affect significantly the preventive and therapeutic strategy

addressed to root dental caries, some researchers are focused on the assessment of these

changes comparing carious dentine with healthy dentine (368, 370). Also Hamama HH et al.

(2013) assessed the changes of mineral content in carious lesions (159).

The quantitative methods can be invasive or non-invasive. Each method has a certain

correlation between measured parameters and mineral loss as well as reproductibility.

Our samples were examined under microscope SEM VEGA II LSH. The possibility to

use EDX system, QUANTAX QX2, allowed the mapping of the examined surfaces to

establish quantitative and qualitative chemical composition.

In a similar in vitro study (183) Hossain et al. assessed microhardness of dentine after

carious dentine removal using Carisolv, levels of Ca and P and repport CA/P, both on healthy

dentine adjacent to root dental caries and restant dentine. The authors concluded the lack of

significant statistical differences regarding (Ca%) and (P%), as well as the repport Ca/P

(p<0,01). SEM analysis revealed unregulated surface , roughness surface, covered on some

areas by smear-layer and other areas with open dentinal tubuli. The results indicated that

Carisolv do not produces adverse effects on treated dental surfaces, regarding dentine

composition in the examined carious cavities.

Also our results did not revealed significant statistical difference regarding chemical

composition of dentine before and after removal of carious dentine with Carisolv. However

further studies using higher number of samples are requested.

The results of our study and literature data show the absence of Carisolv

disadvantages, excepting a significant decrease of adhesion to healthy dentine, if separate

etching and dual composite resins are used for coronal restoration (132).

For cervical and root dental caries it is difficult to obtain minimal excavation

(restricted to carious infected dentine) due to difficulties in moisture control and location of

pulp room. For this category of dental caries, chemo-mechanical methods as well as air-

abrasion and laser have are advantageos alternatives to classical mechanical method for the

removal of carious dentine. More, root dental caries are accessible for Carisolv system. Our

results sustain conclusions expressed by Ericson et al. (1999) (114). The mean time for the

removal of carious dentine was 6,9±2,8 minutes for Carisolv and 3,8±2,0 minutes for

mechanical method. In another study, 78% patients treated with Carisolv perceived equal or

18

less time for Carisolv comparing with mechanical method (115). Even the disadvantage of

longer working time is balanced by the lack of anesthesia and higher patient comfort.

The use of NaOCl 10% improves the potential of remineralisation due to proteolitic

action of NaOCl. Literature data show the increase of root dentine permeability to fluor ions

after treatment with NaOCl.

The anorganic content of cement (45-50%) is lower comparing to bone (65%),

enamel (96%) or dentine (70%). This composition makes high susceptibility of cement to

demineralization. The lack of uniform percentages for calcium and phosphorus ions

complicates the use of laboratory methods for the investigation of chemical structure.

For our study, microanalysis of chemical composition for healthy and affected

dentine after Carisolv, did not highlighted any significant changes of anorganic structure.

CONCLUSIONS:

1. The chemical elements microanalysis by EDX, regarding changes induced in vitro in

the structure of healthy dentine and restant dentine after treatment with chemo-

mechanical method Carisolv, offers orientative informations regarding potential for

structural changes of mineral component of root dental tissues after the action of

Carisolv.

2. The method Carisolv did not conducted to significant quantitative and qualitative

changes of anorganic component of root restant dentine comparing with healthy

dentine surfaces.

3. În restant dentine after the action of Carisolv, values of Calcium ions varied between

23.09 and 28.18, values for Phosphorus ions varied between 9.81 and 13.22.

4. For healthy dentine, Calcium ions varied between 23.18-28.42, Phosphorus ions

varied between 9.88 -14.59.

19

III. SEM STUDY REGARDING THE FEATURES OF

ENAMEL/CEMENT/DENTINE JUNCTION

INTRODUCTION: Old-aged patients have a significant problem with exposed

dental surfaces thar are vulnerable to root dental caries, especially if these patients have

systemic diseases that affect protective salivary environment (391, 389). Literature data (82,

218) demonstrate direct correlation between depth of periodontal pocket and quantity of

bacterial biofilm and calculus. ECJ (enamel-cement junction) is area associated with high

quantity of bacterial biofilm and calculus. However this issue remains controversial both for

periodontists and general dentists (314).

This study aimed to assess the various anatomical relations between enamel, dentine,

cement at the level of ECJ, on different dental groups, buccal, oral, proximal surfaces. The

ECJ anatomy influences the bacterial biofilm and calculus retention as well as possible

biological and clinical implications. The specific morphology of root carious areas constitutes

a factor that favourises the localization of root carious lesions on these surfaces, when patient

presents high cariogenic risk related to diverse ethiological factors.

The presence of enamel-cement junction exposed to oral cavity cariogenic factors on

patients with gingival recession, is considered as most susceptible cariogenic area. The

cement layer has less thickness than enamel, less mineralization degree than enamel and

dentine. The root cement offers weak protection for pulp-dentine complex; also offers

retention conditions for bacterial biofilm considering the lack of accesibility and artificial

cleaning due to gingival hypertrophia and gingival inflammations.

The relation between root cement and enamel in ECJ was approached in many studies

using polarized light microscopy, SEM microscopy, nanoindentation technique,

prophylometry, electronic probe analysis, morphopatological studies (81, 37). The issue

remains incompletely understood due to numerous variables that interfere.

Choquet (1899) published first study about ECJ, further studies showed great

variability regarding relation between enamel and cement near to ECJ (81).

The issue related to ECJ anatomy became an important issue due to high prevalence

of cervical and root dental caries as well as noncariogenic lesions (erosion, abfraction,

cervical abrasion) and periodontal diseases.

In our study we proposed to interpret the result as to highlight some useful

conclusions for practitioner regarding prevention and treatment of root surface

carious lesions.

THE AIM OF STUDY:

The study aimed to identify anatomical and pathological features of tissues relations

of ECJ, by SEM microscopy as well as the changes following diverse therapeutical

procedures applied at the level of ECJ.

Objectives:

1. Description of ECJ tissue repports;

2. Identification of ECJ potential for accumulation of bacterial biofilm and calculus.


The study group included 16 extracted teeth (IC, IL, C, PM1, PM2, M1, M2, M3)

with healthy cervical area. The teeth were stored in distilled water at 4°C The teeth were

divided in 4 halves (buccal, oral, mesial, distal), and sectioned using diamond discs (Komet

20

Dental, Brasseler GmbH&Co, Germania), under water cooling. The section plan was selected

as to preserve ECJ. For each tooth were performed 4 samples.

The dental samples were analysed regarding morphology with SEM microscope

VEGA II LSH (TESCAN, Cehia). The parameters of microscope were as follows: resolution

3nm-30KV, magnification 30-1.000.000 X, acceleration tension 200 V-30 kV, scanning

speed 200 ns-10 ms per pixel.

The types of ECJ were analysed regarding morphological aspects and retention degree

for bacterial biofilm and calculus.

RESULTS:

The results are presented in figures 1 and 2:

- maxillary teeth, on surfaces as follows: buccal(B), oral(O), mesial(M), distal(D).

central incisive: highest frequency for “head-to-head” ECJ (B,D), followed bu

exposed dentine (O) and ECJ with cement covering enamel (M).

lateral incisive: highest frequency for exposed dentine (B, D), followed by cement

covering enamel (O), and enamel covering cement (M).

canins: highest frequency for exposed dentine (B,O), followed by “head-to-head”

ECJ (M), enamel covering cement (D).

bicusps:

PM 1: distribution similar to canines

PM2: highest frequency for exposed dentine (O,M), followed by

cement covering enamel (D) and “head-to-head” ECJ (V).

molars:

M1: highest frequency for cement covering enamel (B,O,D), followed by

“head-to-head” (M).

M2, highest frequency for cement covering enamel (B,O), followed by

exposed dentine (D)

M3, highest frequency for cement covering enamel (B,O), followed by

exposed dentine (M), and enamel covering cement (D).

- Mandibular teeth on surfaces as follows: buccal (B), oral (O), mesial (M) şi

distal (D).

central incisives: highest frequency for cement covering enamel (O, D), followed

by “head-to-head” (B), and enamel covering cement (M).

lateral incisives: highest frequency for „head-to-head” (B, M), followed by cement

covering enamel (O) and enamel covering cement (D).

canines: similar results with central incisives.

bicusps:

PM1, highest frequency for „head-to-head” (B, M), followed by cement

covering enamel (O), and enamel covering cement (D).

PM2, highest frequency for „head-to-head” (B, D), followed by cement

covering enamel (M), and enamel covering cement (O).

molars,

M1 highest frequency for „head-to-head” (B, M), followed by cement

covering enamel (O), and enamel covering cement (D).

M2, highest frequency for cement covering enamel (B), followed by “head-to-

head” (D), and enamel covering cement (O).

M3 highest frequency for „head-to-head” (B,M), followed by cement covering

enamel (O), and enamel covering cement (D).

21

There are various situations regarding surface patterns of enamel, exposed dentine and

cement as well as structure of ECJ seems to contribute to the attachment of bacterial biofilm

and calculus (Fig. 9.1-9.19). The unregulated topography allows the development of bacterial

biofilm as to request significant scaling to eliminate all residual deposits. CEJ is frequently

located near to restorations that hinder adequate action of scaling instruments. The borders of

restorations present retention areas with bacterial biofilm and even calculus. Highest retention

degree was associated to ECJ with exposed dentine between enamel and cement.

Figures 9.1-9.3.Aspects of ECJ “head-to-head”.

The aspects of ECJ “head-to-head” are presented in SEM images 9.1.-9.3. with

enamel in tight contact with cement.

Figures 9.4-9.6. Aspects of ECJ with thin space between enamel and cement exposing dentine

The aspects of ECJ with spaces between cement and enamel are presented in SEM

images 9.4-9.6, with exposed dentine.

Figures 9.7-9.8. Aspects of ECJ with cement covering cement.

The aspects of ECJ with cement covering enamel are presented in SEM images 9.7-

9.8., with absence of space between enamel and cement.

22

Figure 9.9-9.11. Aspects of ECJ with enamel covering cement.

Figure 9.12. Deposits of bacterial biofilm and calculus near to ECJ.

Statistical analysis: I. Results for maxillary teeth:

The correlation coefficient is – 0,4530, with significance level 0,009. There is a

significant negative correlation between „cement covering enamel” and „ECJ with exposed

dentine” (Table 9. IV). Table 9.IV. Results of correlation coefficient between ECJ for maxillary teeth

Correlations

Cement

covering enamel

ECH “head-

to-head”

ECJ with

exposed dentine

Enamel

covering cement

Spearman's

rho

Cement

covering enamel

Correlation

Coefficient

1.000 -.237 -.453**

-.236

Sig. (2-tailed) . .192 .009 .193

N 32 32 32 32

“Head-to-head” Correlation

Coefficient

-.237 1.000 -.160 -.026

Sig. (2-tailed) .192 . .382 .887

N 32 32 32 32

Exposed dentine Correlation

Coefficient

-.453**

-.160 1.000 -.274

Sig. (2-tailed) .009 .382 . .130

N 32 32 32 32

Enamel

covering cement

Correlation

Coefficient

-.236 -.026 -.274 1.000

Sig. (2-tailed) .193 .887 .130 .

N 32 32 32 32

**. Correlation is significant at the 0.01 level (2-tailed).

23

Statistical analysis was performed related to ECJ category, tooth category, surface

category. The non-parametrical Kruskal-Wallis test was performed.

1.a).ECJ category: Table 9.V. Kruskal-Wallis, related to ECJ category (maxillary teeth)

Ranks

ECJ N Mean Rank

Variable Cement covering enamel 32 66.00

ECJ “head-to-head” 32 66.00

ECJ with exposed dentine 32 70.00

ECJ with enamel covering dentine 32 56.00

Total 128

Table 9.VI. Kruskal-Wallis test for maxillary teeth (ECJ category).

Test Statisticsa,b

Variable

Chi-Square 4.335

df 3

Asymp.

Sig.

.228

a. Kruskal Wallis Test

b. Grouping Variable:

joncţiune

The results of statistical test is expressed as chi-square (4,335) with 3 freedom degrees

and p = 0.228 > 0.05; the results show lack of significant statistical difference (Table 9.VI).

1.b. Teeth category Table 9.VII. Kruskal-Wallis test for maxillary teeth (teeth category)

Ranks

Tooth type N Mean Rank

Variabile central incisive 16 64.00

lateral incisive 16 64.00

canine 16 64.00

bicusp1 16 64.00

bicusp2 16 64.00

molar1 16 64.00

molar2 16 68.00

molar3 16 64.00

Total 128

24

Table 9.VIII. presents the results regarding the presence or absence of significant

statistical differences.

Table 9.VIII. Kruskal-Wallis test for maxillary (teeth category).

Test Statisticsa,b

Variable

Chi-Square .284

df 7

Asymp. Sig. 1.000


b. Grouping Variable: tipul dintelui

The results of statistical test are as follows: chi-square (0,284) with 7 freedom degree,

p = 1.000 > 0.05; the results show the absence of significant statistical differences (Table

9.VIII).

1.c).Surface category:

Table 9.IX. Kruskal-Wallis test for maxillary teeth (surface category).

Ranks

Surface category N Mean Rank

Variable Buccal 32 62.00

Oral 32 66.00

Mesial 32 64.00

Distal 32 66.00

Total 128

.

Table 9.X. Kruskal-Wallis test for maxillary teeth (tooth surface).

Test Statisticsa,b

Variable

Chi-Square .446

df 3

Asymp. Sig. .931


b. Grouping Variable: tipulsuprafetei

The results of statistical test are as follows: chi-square (0,446) with 3 freedom

degrees, p = 0.931 > 0.05; the results show significant statistical differences (Tabel 9.X).

1. Results for mandibular teeth:

Correlation coefficient between ECJ (Table 9.XI):

- 0,558, significance level 0,001. Significant negative correlation between „head-to-

head” and „cement covering enamel”. Significant statistical correlation.

– 0,3578, significance level 0,045. Significant negative correlation between „enamel

covering cement” and „cement covering enamel”. Significant statistical correlation.

–0,438, significance level 0,012. Significant negative correlation between „head-to-

head” and „enamel covering cement”. Significant statistical correlation.

25

Table 9.XI . Results of correlation coefficient between ECJ for mandibular teeth

Correlations

Cement

covering enamel

Head-to-

head

Exposed

dentine

Enamel

covering

cement

Spearman's

rho

Cement

covering

enamel

Correlation

Coefficient

1.000 -.558**

-.174 -.357*

Sig. (2-tailed) . .001 .341 .045

N 32 32 32 32

“Head-to-head” Correlation

Coefficient

-.558**

1.000 -.214 -.438*

Sig. (2-tailed) .001 . .241 .012

N 32 32 32 32

Exposed

dentine

Correlation

Coefficient

-.174 -.214 1.000 -.137

Sig. (2-tailed) .341 .241 . .456

N 32 32 32 32

Enamel

covering

cement

Correlation

Coefficient

-.357* -.438

* -.137 1.000

Sig. (2-tailed) .045 .012 .456 .

N 32 32 32 32

**. Correlation is significant at the 0.01 level (2-tailed).

*. Correlation is significant at the 0.05 level (2-tailed).

The statistical analysis (non-parametrical test Kruskal-Wallis) regarding ECJ category,

tooth category, surface category

2.a). ECJ category (mandibular teeth).

Table 9.XII. Kruskal-Wallis test related to ECJ (mandibular teeth).

Ranks

ECJ N Mean Rank

Variabile Cement covering enamel 32 68.50

“head-to-head” 32 74.50

Exposed dentine 32 52.50

Enamel covering cement 32 62.50

Total 128

Table 9.XIII. Kruskal-Wallis test for mandibular teeth related to ECJ.

Test Statisticsa,b

Variable

Chi-Square 10.914

Df 3

Asymp. Sig. .012



ECJ

26


degrees, p = 0.012 < 0.05; results show significant statistical difference.

There are significant statistical differences between the investigated ECJ (Table

9.XIII.).

2.B). Teeth category

Table 9.XIV. Kruskal-Wallis test for mandibular teeth (teeth category).

Ranks

Teeth category N Mean Rank

Variable central incisive 16 64.50

lateral incisive 16 64.50

canine 16 64.50

bicusp1 16 64.50

bicusp2 16 64.50

molar1 16 64.50

molar2 16 64.50

molar3 16 64.50

Total 128

Table 9.XV. Kruskal-Wallis test for mandibular teeth (teeth category).

Test Statisticsa,b

Variable

Chi-Square .000

df 7

Asymp. Sig. 1.000



tipuldintelui


degrees, p = 1.000 > 0.05; results show the lack of significant statistical difference (Table

9.XV).

2.c). Surface category

Table 9.XVI. Kruskal-Wallis test for mandibular teeth (surface category).

Ranks

Surface

category N Mean Rank

Variable buccal 32 64.50

oral 32 64.50

mesial 32 64.50

distal 32 64.50

Total 128

27

Table 9.XVII. Kruskal-Wallis test for mandibular teeth (surface category).

Test Statisticsa,b

Variable

Chi-Square .000

df 3

Asymp. Sig. 1.000



tipulsuprafetei


degrees, p = 1.000 > 0.05; results show the lack of significant statistical difference (Table

9.XVII).

DISCUSSIONS:

The ECJ morphology represents an area with high clinical and therapeutical

significance due to the association with tooth hypersensibility and susceptibility to cervical

dental caries and non-cariogenical lesions.

Most root dental caries are localised on exposed surfaces, but 10-20% are localised

subgingivally (362). Banting et al. (30) consider that most root dental caries are localised near

to gingival margins, but Ravald et al. (315) identify as risk areas the borders of direct

restorations (51%), ECJ (25%) for patients under periodontal therapy (315). Katz et al.

repport the localisation of root dental caries at the level of buccal and interdental surfaces of

posterior mandibular teeth, followed by interdental surfaces of maxillary posterior teeth and

interdental surfaces of anterior mandibular teeth (215). Heegard et al.(168) repported that

most root dental caries are localised on buccal surface teeth. Imazato et al. (192) consider that

canines and first bicusps are most affected by root dental caries, while Kularatne et al. (230)

prove that molars are most frequently associated with root dental caries.

In our study ECJ of teeth before extraction were covered by gingival tissues, but

further exposure to oral environment is expected with age. From that moment, ECJ will be

exposed to various chemical and physical factors that will alter its morphology.

Our study proved that most encountered ECJ category is „head-to-head”, result that is

sustained by other literature data. The presence of space between enamel and cement is most

frequent to maxillary teeth, most predisposed to pathological changes following therapeutical

periodontal sessions or bleaching techniques.

Our results show that distribution of enamel, dentine and cement in cervical area is

unregulated and non-predictible. Preventive or therapeutical acts can generate dental or

periodontal damage with negative results in future (87).

The attachment of bacterial biofilm to the cervical enamel or root surface represent

key elements in initiation of periodontal disease or root dental caries. However subgingival

biofilm can present significant variations regarding quantity and accumulation rate, due to

host factors like xerostomia, surface nature, host genetics, oral hygiene variation and bacterial

composition (360,156). The adherence of bacterial biofilm is significantly influenced by

texture and composition of dental surface.

Quirynen M. et al.. prove that surface roughness facilitates the bacterial adhesion and

is correlated with free surface energy. The dental surfaces with higher roughness have higher

surface energy that facilitate the bacterial adherence.

Many researches confirmed (87) that, despite the efficiency of scaling and root

planning, they do not eliminate completely the bacterial biofilm and calculus from

subgingival root dental surfaces.

28

CONCLUSIONS:

There are four ECJ categories as follows: cement covering enamel (32.8%), urmată de

“head-to-head” (29,68%), exposed dentine due to space between cement and enamel

(20,31%) and enamel covering cement (17,1%).

Each tooth can have variations of ECJ on different surfaces (buccal, oral, mesial,

distal).

JSC represents a significant clinical challenge influencing the initiation and

development of root dental caries

The unregulated margins between enamel and cement, the presence of development

defects, enamel hypoplasia, represent retentive areas with risk for the accumulation of

biofilm and calculus.

Unregulated topography of ECJ can influence the results of scaling and root planning,

but overinstrumentation can produce enamel fracture associated with more retentive

ECJ and higher accumulation of bacterial biofilm and calculus.

29

IV. ASSESSMENT OF CARIOPREVENTIVE EFFECT OF FOODS

SUPPLIED PREVIOUS TO THE ACTION OF BEVERAGE

DRINKS ON THE EXPOSED ROOT SURFACES

INTRODUCTION: The literature data show high prevalence of cervical and

root dental caries of old-aged patients. This pathology is favourised by the systemic

diseases associated with old-aged individuals. Most implied factors are food acids

(253, 255) and intrinsic acids (36, 338).

Many clinical and epidemiological researches confirmed relation between

carbohydrates and dental caries (169, 267, 409, 203). The etiopathogeny of dental

caries is influenced by mineral elements. 100 mineral elements are divided in two

categories: macroelements (C, H, O, N, P, S, Na, K, Cl, Ca, Mg) and microelements

(Zn, Fe, Cu, Ca, I, F, Cr, Mn, Mo, Se, V, etc.). Calcium is in highest quantity in

organism (1100-1400 g), 95% in bones and teeth. Old-aged individuals have lower

adsorption of calcium. There are food factors that increase the adsorption of calcium

(vitamins C and D, lactose, lactic acid excess of proteins) and food factors that

decrease the calcium adsorption (oxalic acid from chocolate, cacao, excess of fats

and phosphaţis, food fibres).

Milk and milk products offer high levels of calcium

(57,225,200). Milk has 120 mg/l calcium, cow cheese has 250

mg/100g, 900-1000mg/100g in cheeses type Olanda and

Schweitzer and 1300mg/100g. In Parmezan.

Vegetables (broccoli, cabbage) and fruits contain low

quantities of calcium. Meat has very low levels of calcium as

well as grains. High levels of calcium have oceanic fish and marine algae (ex:

wakame algae, 1380mg/100g).

Gedalia (42) et al. and Lewinstein et al. (243) researched in situ efectele the

effects of milk and cheese on enamel demineralisation following consume of acidic

beverages (cola). Kato, Sales-Peres and Buzalaf proved the role of iron ions in

cervical dental erosions (280, 105, 211, 212). As liver is an important source of iron

(224) also broccoli is rich in iron (272); thus the consume of broccoli can have a

protective effect on dental demineralisation. The studies mentioned previously

demonstrate the existence of remineralisation processes associated with consume of

milk, cheese, broccoli, on demineralised dental surfaces.

The potential of milk and some foods to protect teeth against demineralisation

is an issue that worth more attention from the research groups.

AIM OF STUDY:

Our study aimed to assess the cariopreventive effect of milk, cheese and algae

after the action of acid beverage on exposed root dentine.


The study group included 20 healthy extracted teeth, for orthodontic reasons.

The teeth were sectioned with diamond discs (Extec Corp, Enfield, CT, Statele Unite

ale Americii), under water cooling. The study group included 40 sections of buccal

and oral root surfaces with lenght 4 mm, width de 4 mm and grossness 3 mm.

The research was performed by assessment of prepared dental surfaces and

prophilometry of acidic erosion degree following the action of acidic beverage

(Sprite).

30

The samples were divided in four groups:

I – milk action

II –cheese extract action

Lot III –algae Wakame action

Lot IV –control group, no protective action following the effect of acidic

beverage (Sprite).

The samples were covered on half of surface with varnish resistent to acid

(Farmec ultrarezistent, Farmec S.A. România.) that was applied in two layers; the

uncovered half was submitted to the action of investigated protective foods. The

samples were immersed in cheese extract (Forgrana, Parmezan Grana Padano, Italia),

algae Wakame Flakes (ClearSpring, Japonia), milk (Zuzu, S.C.Albalact S.A.,

România) for 5 minute (32 ml/sample) previously to the immersion in Sprite (pH

3,4). Between erosive cycles the samples were immersed in artificial saliva

Fusayama - Mayer (pH 7) (32 ml/sample) at room temperature.

În control group, the samples were submitted for 72 hours to 9 cycles (3 cycles in

24 hours) of demineralisation by immersion in Sprite, (Coca Cola, Romania), for 5

minutes (32 ml/sample). In periodes between immersions the samples were

maintained in artificial saliva. The wear of root surfaces submitted to acidic cycles

was determined by prophilometric method with rugosimeter TAYLOR HOBSON-

Surtronic25.

RESULTS:

For all the investigated samples roughness profiles were recorded for root dental

surfaces. It was recorded mean value of profile deviation related to mean line (Ra).

The results for all samples from study groups and control group are presented in

table 9. II.

Table 10.II. Erosions values related to food categories Suprafeţe radiculare

Milk Cheese Algae Control

1 0,787 0,512 0,424 1,370

2 0,581 0,483 0,479 1,110

3 0,770 0,415 0,462 1,714

4 0,641 0,509 0,501 1,298

5 0,512 0,498 0,521 1,684

6 0,591 0,531 0,439 1,433

7 0,589 0,547 0,547 1,786

8 0,627 0,469 0,487 1,769

9 0,659 0,509 0,533 1,862

10 0,574 0,545 0,499 1,674

31

I. Study group I (Milk)

Table 10. III. Values of surface erosions for study group Milk

Graph 10.1. Values of surface erosions for study group Milk

II. Study group II (Cheese)

Table 10. IV. Values of surface erosions for study group Cheese

Graph 10.2. Values of surface erosions for study group Cheese

III. Study group III (Algae)

Tabel 10.V. Values of surface erosions for study group Algae.

Graph 10.3. Values of surface erosions for study group Algae

IV. Control group

Table 10.VI. Values of surface erosions for control group

Graph 10.4. Variations of surface erosions for control group

32

Results for statistical analysis:

Table 10.VII. Descriptive statistics

milk cheese algae control

N Valid 10 10 10 10

Miss 0 0 0 0

Mean .63310 .50180 .48920 1.57000

standard errors of mean .027444 .012449 .012528 .078911

Standard deviation .086786 .039367 .039617 .249538

Mean value of „algae” study group (0.48920) is lower than mean value of

erosion for „cheese” study group (0.50180), but lower than mean value of „milk” study group

(0.63310), that is lower than mean value of „control” group (1.57000).

Graph 10.5. Variations of mean values for erosion in all study groups

Frequencies distribution

The results of homogeneity analysis of distributions for the study groups are presented in

table 10.VIII.

Test Shapiro-Wilk has p (sig.) >0,05 for all groups, resulting normal distributions.

Table 10.VIII. Results of homogenity analysis for all study groups (Shapiro-Wilk).

Tests of Normality


Statistic df Sig. Statistic df Sig.

Milk .186 10 .200* .899 10 .211

Cheese .173 10 .200* .911 10 .290

Algae .098 10 .200* .974 10 .928

Control .262 10 .051 .906 10 .252


*. This is a lower bound of the true significance.

Table 10. IX.Results of Levene for all study groups

Test of Homogeneity of Variances

Erosion

Levene Statistic df1 df2 Sig.

19.901 3 36 .000

Test Mann-Whitney is used to determine the presence or absence of significant

statistical differences between study groups.

33

Study groups „Milk” versus „Cheese”

Table 10. X . Comparison of erosion between „Milk” and „Cheese”.

Ranks

lot N Mean Rank Sum of Ranks

erosion Milk 10 15.15 151.50

Cheese 10 5.85 58.50

Total 20

Table 10. XI . Mann-Whitney test for study groups „Milk” versus „Cheese”.

Test Statisticsb

eroziune

Mann-Whitney U 3.500

Wilcoxon W 58.500

Z -3.518

Asymp. Sig. (2-tailed) .000

Exact Sig. [2*(1-tailed Sig.)] .000a

a. Not corrected for ties.

b. Grouping Variable: lot

Mann-Whitney test shows value U 3.5000, p = 0.001 < 0.05. There are significant

statistical differences between the values of erosions for „milk” and „cheese” study groups.

Study groups „Milk” versus „Algae”

Table 10. XII . Comparison of erosion between study groups „Milk” and „Algae”

Ranks


Erosion milk 10 15.20 152.00

algae 10 5.80 58.00

Total 20

Table 10. XIII . Mann-Whitney test for study groups „Milk” versus „Algae”

Test Statisticsb

eroziune


Wilcoxon W 58.000

Z -3.553






statistical differences between the values of erosions for „milk” and „algae” study groups.

34

Study groups „Milk” vs „Control” Table 10.XIV . Comparison of erosion between study groups „Milk” and „Control”

Ranks

N Mean Rank Sum of Ranks

erosion Milk 10 5.50 55.00

Control 10 15.50 155.00

Total 20

Table 10.XV. Mann-Whitney test for study groups „Milk” versus „Control”

Test Statisticsb

eroziune

Mann-Whitney U .000

Wilcoxon W 55.000

Z -3.780







statistical differences between the values of erosions for „milk” and „control”.

Study groups „Cheese” vs „Algae”

Table 10. XVI . Comparison between study groups„Cheese” versus „Algae”

Ranks


eroziune branza 10 11.45 114.50

alge 10 9.55 95.50

Total 20

Table 10. XVII . Mann-Whitney test for study groups „Cheese” versus „Algae”

Test Statisticsb

eroziune


Wilcoxon W 95.500

Z -.719





Mann-Whitney test shows value U 40.500, p = 0.472 > 0.05. There are not significant

statistical differences between the values of erosions for „cheese” and „algae”.

Study groups „Cheese” versus „Control”

Table 10. XVIII. Comparison of erosion between study groups „Cheese” versus „Control”

Ranks


erosion cheese 10 5.50 55.00

control 10 15.50 155.00

Total 20

35

Table 10.XIX. Mann-Whitney test for study groups „Cheese” versus „Control”.

Test Statisticsb

erosion

Mann-Whitney U .000

Wilcoxon W 55.000

Z -3.781





Mann-Whitney test shows value U 0.0001, p = 0.001 <0.05. There are significant

statistical differences between the values of erosions for „cheese” and „control”.

Study groups „Algae” versus „Control”

Table 10. XX . Comparison of erosion between study groups „Algae” versus „Control”

Ranks


erosion algae 10 5.50 55.00

control 10 15.50 155.00

Total 20

Table 10. XXI . Mann-Whitney test for study groups „Algae” versus „Control”.

Test Statisticsb

eroziune

Mann-Whitney U .000

Wilcoxon W 55.000

Z -3.780





Mann-Whitney test shows value U 0.0001, p = 0.001 <0.05. There are significant

statistical differences between the values of erosions for „algae” and „control”.

DISCUSSIONS:

The demineralization and remineralisation cycles are complex processes that alternate

daily and represent a natural component of dynamic behavior of dental tissues under the

action of a local factors complex (saliva, anatomy and mineral content of teeth, food factor,

pH of bacterial biofilm, fluor bioavailability).

Our study aimed to study the erosive potential on root surface to understand better the

ultrastructural surface changes of root dental caries.

The control group is associated with high levels of minerals loss in the cement areas,

comparing with minerals loss in coronal areas, recorded by other studies. This phenomenon is

explained by the lower mineralization and hardness of cement. This explains faster evolution

of root dental caries comparing with coronal carious lesions.

Heitor Marques Honório et al. (2010) and other studies researched erosive processes

in cervical enamel and root tissues on animals teeth. (177). In our study we preffered human

36

teeth because animals teeth are more porous and more susceptible to erosive processes. The

assessment included three cycles of acidic pH to simulate the daily consume of acidic

beverages and foods.

For acidic beverages the time needed for saliva to buffer the acids will increase. The

content of calcium and phosphates influences the local environment at the level of dental

surface; thus, the addition of calcium and phosphates is an efficient anti-erosive strategy.

West Nx. et al. (2003) compared, by prophilometry, the effects of acidulated drinks

with high content of calcium with the effect of orange juice, after 20 days of consuming 250

ml, four times daily (399). The conclusions was that consume of acidic drinks with content of

calcium reduced significantly the minerals loss, comparing with orange juice.

The consume of milk protects the enamel due to calcium and phosphate ions, despite

the possible low pH.

The immersion of dentine samples in remineralisation solutions (250 ppm, 2000 ppm)

for one minute, showed an increase of resistance to erosion in direct relation with content of

fluor (18). The immersion of enamel samples in AMF gels presents a significant protective

effect against erosions and abrasion (18).

In conditions of neutral pH, hydroxiapatite is in chemical balance with saliva rich in

calcium and phosphate ions; as pH decreases under the action of external and internal acids,

the saturation degree decreases till critical pH associated with unsaturated saliva. The

demineralisation provoked by acidulated beverages, is influenced by remineralisation of

acquired pellicle. Remineralisation is slowly and can take a few hours. The acidic drinks and

foods increase the level of H+ ions, level that can be measured only for disociated ions.

However undisociated form has an important role in the initiation of erosive processes. The

total acidic level is important as determine the quantity of (H+) ions that interact with dental

surface. pH indicates only the initial values of (H+) ions.

In our study the loss of dental tissues by acidic demineralisation was used as response

variable as is able to measure the dental tissues loss following pH cycles. Even if probe used

in prophilometric tests, would deteriorate the dental surface, this phenomenon appears on all

samples and could not influence the results of the statistical tests. The resolution of

prophilometer is 0,4 um, allowing accurate measurements by erosion, as mean values of

erosion depth is higher than error limit of device.

CONCLUSIONS:

The cariopreventive effect of foods must be considered in analysis regarding

risk of root dental caries..

Root dental surfaces can benefit by the protective action of foods rich in

minerals (calciumCa, P).

Milk, cheese and algae consumed before acidic beverages, have the possibility

to protect and reduce the erosive potential of root dental surfaces.

The surface roughness of root cement is lower if protective foods are

consumed before the action of acidic beverages.

The surface roughness of root cement had lower value for „algae” (0.48920),

followe by „cheese” (0.50180) and „milk” (0.63310); all study groups values

mean values are lower than mean value of „control” (1.57000).

37

VI. ASSESSMENT OF GIOMER AND RESIN-MODIFIED

GLASSIONOMER IN ROOT DENTAL CARIES THERAPY

INTRODUCTION: The prevalence of root dental caries is high, especially for old-

aged persons. Remains incompletely known both etiological factors and possibilities to stop

these carious lesions. The morphological and structural particularities of ECJ area represent a

challenge dor dental practitioner. Both techniques and materials contribute to the success of

direct restorations in this area. The ideal material must be resistant, esthetic, biocompatible

and must have ability to prevent marginal secondary caries. One new material produced for

these types of restorations is giomer (Beautifil, Shofu, Japan).Many studies analyse and

propose optimal solutions, but cervical and root surfaces restorations remains an questionable

issue.

Giomers are hybrid materials that combine resin with prepolymerized glassionomer

particles (Prereacted Glass Ionomer). Producers claim that giomers have superior properties

comparing with resin-modified glassionomer cements (RMGC). Giomers have both the

advantages of composite resins (esthetics, resistance) and glassionomer cements

(biocompatible, fluor release, good adhesion in cervical area).

The cervical and root dental areas raise problems related to adhesion due to cervical

margins of restorations close to gingival tissues and hypersensitivity to thermic, chemical,

mechanical stimulus.The choice of an optimal materials is critical to obtain restoration

longevity. The adhesion of ECJ area is inferior to adhesion to enamel. The materials used for

these type of restorations are glassionomer cements (CGI), resin-modified glassionomer

cements (RMGC), giomers (G) and composite resins (RC). Conclusions of studies that

assessed the behavior of these materials in ECJ area are various, some supporting composite

resins (58), other supporting RMGC (276). Some studies highlight the culour alterations for

RMGC (127, 411). Data literature offer informations regarding behavior on periodes of 1-8

years (148,149, 403). A few studies compared the qualities of composite resins and giomers

used in the treatment of cervical and root dental caries.

AIM OF STUDY:

Scopul acestui studiu este de a evalua longitudinal performanţele clinice de restaurare

a cariilor radiculare pe o perioadă de 24 luni, a două materiale din categoria cimenturilor

glassionomere modificate cu răşini (CGMR) şi Giomeri (G).


The study group included 30 patients (18 women, 12 males) , selected from patients

treated in Clinical Base of Dental Learning „Mihail Kogălniceanu” and

private dental office in 2011-2012.The research activities performed

according to laws related to deontological norms of research. The clinical

examination was performed according to Law no.46, 21 januar 2003 related

to patient rights. Written consent was obtained from patients included in

study group. The clinical assessment and treatment were performed by a

single pratitioner to avoid inter-examinators errors. Before treatment all patients were

submitted to professional teethbrushing and scaling. The study group included Fuji II LC,

GC (Japonia) and Beautifil II, Shofu (Japonia). 40 cavities were prepared, that were divided

randomly in two study groups (n=20).The culour choice was performed using Vita SYSTEM

3D-MASTER and isolation was performed with Ultrapac (ULTRADENT).After 24 hours the

restorations were finished with diamond burs (Micro Diamond Technologies) and finishing

discs (3M ESPE) and polishing paste Super Polish (KERR).The assessment of qualities

parameters was performed after 1, 12, 24 months by a single examinators with mirror and

probe. The assessment was performed using assessment criteria FDI 2010 (Tables 11.II-

11.IV). Three categories of criteria were used: A. esthetics, B. funcţional, B. biologic.

38

Table 11.II. FDI Assessment criteria for direct restorations.

A. Estethic criteria 1. Surface status; Roughness

2. Colour: a) surface b) marginal.

3. Culour correspondence and translucency

4. Anatomic form (estethics)

B. Functional criteria

5. Restoration fracture and retention

6. Marginal adaptation 7. Occlusal contour.

8. Proximal contact point

9. Radiographic examen

10. Patient opinion: a) esthetics, b) function

C. Biological criteria 11. Reccurence of carious lesions

12. Tooth fracture; retention

13. Effect on periodontal tissues

In statistical analysis were included next criteria::

1. Surface status; Roughness

2. Colour: a) surface b) marginal.


4. Marginal adaptation 5. Patient opinion: a) esthetics, b) function

6. Effect on periodontal tissues

RESULTS:

All 30 patients were assessed after 1, 12, 24 months. The results of the criteria

assessment were noted as clinically excellent (CE), clinically acceptable (CA), clinically

satisfactory (CS), clinically unsatisfactory (CUS), clinically unacceptable (CUA).

Figure 11.4-11.7. Giomer restorations (before, after, after 12 months, after 24 months)

39

Figure 11.8 -11.11. Glassionomer cement restorations (before, after, after 12 months,

after 24 months)

1. Surface status; Roughness:

The results after 1 years are presented in tables 11.VII, 11.IX:

Giomer 85% score 1 (clinically excellent), 10% score 2 (clinically acceptable), 5% score

3 (clinically satisfactory)

RMGC: 75% score 1 (clinically excellent), 10% score 2 (clinically acceptable), 10%

score 3 (clinically satisfactory), 5% score 4 (clinically unsatisfactory).

The results after 2 years are presented in tables 11.VII, 11.X:

Giomer 80% score 1 (clinically excellent), 15% score 2 (clinically acceptable), 5% score

3 (clinically satisfactory)

RMGC 70% score 1 (clinically excellent), 15% score 2 (clinically acceptable), 10% score

3 (clinically satisfactory), 5% score 4 (clinically unsatisfactory).

The result of homogenity analysis is presented in table 11.XI. Test Kolmogorov-Smirnov has

p (sig.) <0,05 and do not sustain normal distribution for the two study groups.The test Mann-

Whitney will be applied for significant statistical differences after 12 and 24 months.

Table 11.XI. Results of homogenity analysis for distributions in study groups G vs. RMGC

for roughness and surface status

Tests of Normalityb,c



G12months .499 20 .000 .447 20 .000

G24months .475 20 .000 .522 20 .000

RMGC12months .444 20 .000 .583 20 .000

RMGC24months .413 20 .000 .635 20 .000


b. G1month is constant. It has been omitted.

c. RMGC1lmonth is constant. It has been omitted.

Table 11.XII. Mann-Whitney test for surface status and roughness.

Ranks

cement N Mean Rank Sum of Ranks

12months G 20 19.38 387.50

RMGC 20 21.63 432.50

Total 40

24months G 20 19.33 386.50

RMGC 20 21.68 433.50

Total 40

40

Table 11.XIII. Mann-Whitney test for surface status and roughness

Test Statisticsb

luna12 luna24

Mann-Whitney U 177.500 176.500

Wilcoxon W 387.500 386.500

Z -.872 -.839

Asymp. Sig. (2-tailed) .383 .402

Exact Sig. [2*(1-tailed Sig.)] .547a .529

a


b. Grouping Variable: ciment

12 months, U 177,5, p = 0.383 > 0.05.

24 months U 176,5, p = 0.402 > 0.05.

Scores for study groups „G” and „CGMIR” do not present significant statistical

differences.

2. Colour: a) surface; b) margins

After one year:

Giomer: 85% score 1 (clinically excellent), 10% score 2 (clinically acceptable),

5% score 3 (clinically satisfactory),

RMGC: 80% score 1 (clinically excellent), 10% score 2 (clinically acceptable),

10% score 3 (clinically satisfactory), 2% score 2 (clinically non-satisfactory).

After 2 years:

Giomer: 80% score 1 (clinically excellent), 10% score 2 (clinically acceptablel),

10% score 3 (clinically satisfactory),

RMGC: 75% score 1 (clinically excellent), 10% score 2 (clinically acceptable),


The results of homogenity analysis of distributions for study groups are presented in table

11.XIX. Kolmogorov-Smirnov test has p (sig.)<0,05 for both study groups and distribution is

abnormal. Test Mann-Whitney will be applied to analyse if there are significant statistical

differences between study groups.

Table 11.XIX. Homogenity analysis for distributions related to colour: a) surface b)

margins.




G12months .499 20 .000 .447 20 .000

G24months .476 20 .000 .515 20 .000

RMGC12months .476 20 .000 .515 20 .000

RMGC24months .441 20 .000 .564 20 .000




41

Table 11.XX. Mann-Whitney test for colour: a) surface; b) margins.

Ranks

cement N

Mean

Rank

Sum of

Ranks

12

mont

hs

G 20 19.95 399.00

RMGC 20 21.05 421.00

Total 40

24

mont

hs

G 20 19.85 397.00

RMGC 20 21.15 423.00

Total 40

Table 11.XXI. Mann-Whitney test for colour: a) surface; b) margins.

Test Statisticsb

luna12 luna24


0

187.000

Wilcoxon W 399.00

0

397.000

Z -.450 -.482


Exact Sig. [2*(1-tailed

Sig.)]

.779a .738

a



The results of Mann-Whitney test (Table 11. XXL):

12 months U 189, p = 0.653 > 0.05,

24 months U 187, p = 0.630 > 0.05.

The scores for study groups „G” and „RMGC” do not present significant statistical

differences.


After 1 year:

Giomer: 80% score 1 (clinically excellent), 5% score 2 (clinically acceptable),


After 2 years:

RMGC: 75% score 1 (clinically excellent), 10% score 2 (clinically

acceptable), 10% score 3 (clinically satisfactory), 5% score 4 (clinically non-

satisfactory).


11.XXV. Kolmogorov-Smirnov test has p (sig.)<0,05 for both study groups and distribution

is abnormal. Test Mann-Whitney will be applied to analyse if there are significant statistical


42

Table 11.XXV. Homogenity analysis of distributions for study groups G and RMGC

after 12 and 24 months, for restoration fracture and retention

Table 11.XXVI. Mann-Whitney test for study groups G and RMGC after 12 and 24

months, for restoration fracture and retention.

.

Table 11.XXVII. Mann-Whitney test for study groups G and RMGC after 12 şi 24

luni, for restoration fracture and retention.

Test Statistics

b

12months 24months


Wilcoxon W 408.500 408.500

Z -.058 -.058



a



The results of Mann-Whitney test:

12 monthsU 198,5, p = 0.954 > 0.05.

24 monthsU 198,5, p = 0.954 > 0.05.

The score for study group „G” and „RMGC” do not present significant statistical

differences.


Kolmogorov-Smirnov

a Shapiro-Wilk


G12months .475 20 .000 .523 20 .000

G24months .475 20 .000 .523 20 .000

RMGC12months .467 20 .000 .509 20 .000

RMGC24months .467 20 .000 .509 20 .000



c. RMGC1month is constant. It has been omitted.

Ranks

ciment N Mean Rank Sum of Ranks

month12 G 20 20.58 411.50

RMGC 20 20.43 408.50

Total 40

month24 G 20 20.58 411.50

RMGC 20 20.43 408.50

Total 40

43

4. Marginal adaptation

After 1 year:

Giomer: 85% score 1 (clinically excellent), 10% score 2 (clinically

acceptable), 5% score 3 (clinically satisfactory),


acceptable), 10% score 3 (clinically satisfactory), 2% score 4

(clinically non-satisfactory).

After 2 years:

Giomer: 80% score 1 (clinically excellent), 10% score 2

(clinically acceptable), 10% score 3 (clinically satisfactory),

RMGC: 75% score 1 (clinically excellent), 10% score 2

(clinically acceptable), 5% score 3 (clinically satisfăctory), 10% score

4 (clinically non-satisfactory).

The results of homogenity analysis of distributions for study groups are

presented in table 11.XXXIII. Kolmogorov-Smirnov test has p (sig.)<0,05 for both study

groups and distribution is abnormal. Test Mann-Whitney will be applied to analyse if

there are significant statistical differences between study groups.

Table 11. XXXIII. Homogenity analysis of distributions for marginal adaptation.

Kolmogorov-Smirnov test.




G12months .499 20 .000 .447 20 .000

G24months .476 20 .000 .515 20 .000

RMGC12months .476 20

.000 .515 20 .000

RMGC24months .441 20 .000 .564 20 .000


b. G1lmonth is constant. It has been omitted.


Table 11. XXXIV. Mann-Whitney test for marginal adaptation.

Ranks


12months G 20 19.95 399.00

RMGC 20 21.05 421.00

Total 40

24months G 20 19.85 397.00

RMGC 20 21.15 423.00

Total 40

44

Table 11. XXXV. Mann-Whitney test for marginal adaptation. Test Statisticsb

12months 24months


Wilcoxon W 399.000 397.000

Z -.450 -.482


Exact Sig. [2*(1-tailed Sig.)] .779a .738a



The results of Mann-Whitney test:

12 months, U 189, p =0.653 > 0.05.

24 months, U 187, p = 0.630 > 0.05.


differences.

5. Patient opinion

After 1 year:

Giomer: 90% score 1 (clinically excellent), 10% score 2 (clinically

acceptable).


acceptable), 5% score 3 (clinically satisfactory), 5% score 4 (clinically

non-satisfactory).

After 2 years:

Giomer: 85% score 1 (clinically excellent), 5% score 2

(clinically acceptable), 10% score 3 (clinically satisfactory),

RMGC: 75% score 1 (clinically excellent), 5% score 2

(clinically acceptable), 15% score 3 (clinically satisfactory), 5% score

4 (clinically non-satisfactory).


11.XIX. Kolmogorov-Smirnov test has p (sig.)<0,05 for both study groups and distribution is

abnormal. Test Mann-Whitney will be applied to analyse if there are significant statistical


Table 11.XLI. Homogenity analysis of distributions for patient opinion.

Kolmogorov-Smirnov test.




G12months .527 20 .000 .351 20 .000

G24lmonth .502 20 .000 .440 20 .000

RMGC12months .496 20 .000 .441 20 .000

RMGC24months .451 20 .000 .587 20 .000



c. CGIMR1month is constant. It has been omitted.

45

Table 11.XLII. Mann-Whitney test for patient opinion Ranks


12months G 20 19.90 398.00

RMGC 20 21.10 422.00

Total 40

24months G 20 19.40 388.00

RMGC 20 21.60 432.00

Total 40

Table 11.XLIII. Mann-Whitney test for patient opinion. Test Statisticsb

luna12 luna24


Wilcoxon W 398.000 388.000

Z -.565 -.853


Exact Sig. [2*(1-tailed Sig.)] .758a .565a



The results for Mann-Whitney test:

12 months, U 188, p = 0.572 > 0.05.

24 months, U 178, p = 0.393 > 0.05.


differences.

6. The effect of restoration on periodontal tissues

After 1 year:

Giomer: 85% score 1 (clinically excellent), 10% score 2 (clinically acceptable), 5%

score 3 (clinically satisfactory),


score 3 (clinically satisfactory), 5% score 4 (clinically non-satisfactory).

After 2 years:

Giomer: 85% score 1 (clinically excellent), 5% score 2 (clinically acceptable), 10%

score 3 (clinically satisfactory),


score 3 (clinically satisfactory), 5% score 4 (clinically non-satisfactory).

The results of homogenity analysis of distributions for study groups are presented in

table 11.XIX. Kolmogorov-Smirnov test has p (sig.)<0,05 for both study groups and

distribution is abnormal. Test Mann-Whitney will be applied to analyse if there are

significant statistical differences between study groups.

46

Table 11.XLIX. Homogenity analysis for distributions for effect of restoration on

periodontal tissues. Kolmogorov-Smirnov test. Tests of Normalityb,c



G12months .499 20 .000 .447 20 .000

G24months .502 20 .000 .440 20 .000

CGIMR12months .496 20 .000 .441 20 .000

CGIMR24months .467 20 .000 .509 20 .000



c. RMGC1month is constant. It has been omitted.

Table 11.L. Mann-Whitney test for effect of restoration on periodontal tissues

Ranks


12months G 20 20.40 408.00

RMGC 20 20.60 412.00

Total 40

24months G 20 20.00 400.00

RMGC 20 21.00 420.00

Total 40

Table LI. Mann-Whitney test for effect of restoration on periodontal tissues.

Test Statisticsb

luna12 luna24


Wilcoxon W 408.000 400.000

Z -.087 -.409



a



The results of Mann-Whitney test (table LI):

12 months, U 198, p = 0.931> 0.05.

24 months, U 190, p = 0.683> 0.05.

The scores for study groups „G” and „CGMIR” do not present significant statistical

differences.

DISCUSSIONS:

The clinical studies indicate that success of material is related to clinical performance

in oral cavity and longevity. ADA indicates a minimal retention of 95% after 6 months, and

90% after 18 months, to accept a dental material or adhesive system.

The retention of adhesive materials (composite resins, giomers, compomers) depends

on the strenght of their adhesive systems that confront with compressive stress (in restoration

mass) and breaking stress (to the adhesive interface).The lost of marginal adaptation is main

reason that produces the replacement of cervical restorations. RMGC materials avoid

adsorption and lost of “free water” and major changes during setting reaction acid/base.

RMGC has the advantage of hydric balance due to setting reaction acid-base and to HEMA

47

polimerisation by photosensible activators. Thus, for RMGC materials despite the limits of

photoactivation, chemical setting reaction will continue for complete setting of restoration

mass. The link of HEMA to poliacrilic acid allows protection of restoration during setting

reaction. The adsorption of water will be hindered after photoactivation. It can be a difference

regarding physical differences between areas completely photopolimerized and some areas

with residual HEMA, incompletely photopolimerized. luminoasã. These incompletely

photopolimerized areas benefit by the chemical polimerisation. However HEMA is hidrophil

and can adsorp some low quantitis of water and contribute to the restoration expansion and

lower resistance to abrasion and erosion as well as colour changes for patients with poor oral

hygiene. RRMGC materials include Fuji II LC, Photac-fil, Vitremer. For Fuji II LC (GC) and

Vitremer (3M/ESPE), ionic changes with dentine and additional chemical setting reaction

improve physical properties and chemical adhesion to the dentinal tissues (204). The limits of

these materials are represented by culour changes and vulnerability to erosion and abrasion

for patients with frequent consume of acidic beverages and patients with high cariogenic risk.

However the absence of secondary marginal caries at the margins of RMGC restorations is

highlighted in studies. Sunico et al. observed a 80% success rate after 2 years for cervical

restorations with S-PRG 80%, and only 71% for F-PRG (374).Giomers have the advantages

of high resistance to abrasion and erosion,fluor release and high esthetics. Yap et al. observed

that giomers release low levels of fluor ions both on short and long term (412.). Our study assessed RMGC and giomer root-cervical restorations , after 1, 12 and 24

months, using FDI criteria (2010). Or results are similar with other studies (374, 150). The

result regarding retention after 24 months is rather disappointing, due to 8% restorations with

non-acceptable score, result that is similar for RMGC and giomers. Regarding esthetic

criteria, giomer restorations do not suffer significant changes after 12 months and most are

acceptable after 24 months, due to surface status. The esthetic changes of RMGC restorations

are important after 24 months for smokers or those patients consuming tea or coffee, but

without significant statistical differences. Good adhesion to dental tissues is proved by the

absence of posttreatment hypersensitivity for those teeth presenting cervical hypersensitivity

before treatment. Adhesive system of giomers (FL Bond II LC) has satisfactory marginal

adaptation, while RMGC have chemical adhsesion to dentine.

CONCLUSIONS:

Resin-modified glassionomer cements (RMGC) and Giomers (G) used in the

therapy of cervical and root dental caries have retention rates over 90% if

adequate technique is applied and cariogenic risk is controlled as well as the

traumatic occlusal contacts are removed.

After 24 months, most giomer restorations present clinically excellent scores for

functional and biological criteria; poor scores were associated with marginal

adaptation.

After 24 months, most of resin-modified glassionomer cement restorations present

acceptable clinical scores regarding esthetic and biologic criteria and satisfactory

scores regarding functional criteria.

The status of surfaces is superior for giomer comparing with RMGC restoartions.

Giomer and RMGC are not susceptible to surface coloration, marginal coloration

or dental hypersensitivity.

RMGC is inferior to giomer regarding marginal adaptation, but no significant

statistical differences were recorded between the investigated materials.

The retention rates are similar for both materials after similar periodes of time.

Surface status is similar for giomer and RMGC, despite the superiority to giomer

related to behaviour to finishing sessions.

48

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ABSTRACT PhD THESIS - UMF Iasi. „GRIGORE T. POPA” IAŞI FACULTY OF DENTAL MEDICINE ABSTRACT PhD THESIS Scientific coordinator PROF.UNIV.DR. ANDRIAN SORIN PhD Student MOLDOVANU