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tissue management
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Fluid Control and Soft Tissue Management
INTRODUCTION
Complete control of the environment of the operative site is
essential during restorative dental procedures for the patients
comfort and safety and for the operator’s access and clear visibility
Control of the oral environment extends to the gingiva
surrounding the teeth being restored. The gingiva must be displaced
to make a complete impression, preparation and cementation of the
restoration. Sometimes it is necessary to alter the contours of the
gingival tissues around the teeth or edentulous ridge.
Need for fluid control
It depends upon the task being performed.
During preparation of teeth – it is necessary to remove large
volumes of water produced by the hand piece spray and to
control the tongue to prevent accidental injury.
During impression making and cementation of restoration – in
these stages much smaller volume of fluid to be removed, but
a greater degree of dryness is required.
METHODS
1. Rubber dam
is the most effective of all isolation devices utilized in
restorative dentistry
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Fluid Control and Soft Tissue Management
Uses
Valuable in the removal of old restorations
Excavation of caries when exposure of pulp is a possibility.
For pin retained amalgam or composite resin core is required
For Dowel core preparation
Pattern fabrication
Cementation especially acid etched bridges
Rubber Dam HVE Suction
Limitations
Should not be used with polyvinyl siloxane impression
material, because the rubber dam will inhibit its
polymerization.
2. High volume vacuum suction
Used during preparation phase.
It can also be used to retract the lip and the tongue by the
assistant
Not critical during impression and cementation period
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Fluid Control and Soft Tissue Management
3. Saliva ejector
Useful adjunct to high volume evacuation
Saliva ejector is placed in the corner of the mouth opposite
the quadrant being operated and the patient’s head is turned
towards it .
4. Svedopter
For isolation and evacuation of the mandibular teeth, the
metal saliva ejector with attached tongue deflector.
It can be used for preparation, cementation and impression
making.
It is most effective when it is used with the patient in a nearly
upright position
Drawbacks
Access to the lingual surface of the mandibular teeth is
limited.
Presence of mandibular tori precludes its use
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Fluid Control and Soft Tissue Management
Selection of oversized reflector could trigger gag reflux by
touching the palate.
Use is limited if the patient is positioned in a supine position.
5. Cotton rolls
Useful in impression making and cementation phase
Maxillary arch – single cotton roll in the buccal vestibule will
suffice.
For maxillary 2 n d and 3 r d molar it is necessary to place
multiple cotton rolls in order to block the stenson’s duct.
In mandibular arch, it is usually necessary to place additional
cotton rolls to block off the sublingual and submandibular
salivary ducts.
Rolls on the buccal and lingual sides of the prepared teeth
will help with soft tissue retraction.
An alternative to use multiple cotton rolls is to place one long
roll of ‘horse shoe fashion’ in the maxillary and mandibular
buccal half.
Disadvantage
When part of the cotton is saturated the entire roll must be
replaced
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Fluid Control and Soft Tissue Management
6. Moisture absorbing cards
These are pressed paper wafers covered on one side with a
reflective foil.
Paper side is placed against the dried buccal tissue and
adheres to it .
In addition to it , two cotton rolls are placed in the mandibular
and maxillary vestibules to control saliva and displace the
cheek laterally.
7. Local anesthesia
Mechanism of action
Nerve impulses from the periodontal ligament form part of the
mechanism that regulates saliva flow. When they are blocked
by anesthetic, saliva production is considerably reduced.
Dentine hypersensitivity during preparation also triggers
increased salivary flow, which is blocked by the local
anesthesia.
8. Antisialagogues
It is given for the patients who salivate excessively.
1. Anticholinergics
Gastro intestinal anticholinergics that act on the smooth
muscles of the gastrointestinal, urinary and biliary tracts
produce dry mouth as a side effect.
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Fluid Control and Soft Tissue Management
They are
Methantheline bromide (Banthine) – 50mg tablet taken 1
hour before appointment.
Propantheline bromide (pro-banthine) – 15mg tablet taken
1 hour before appointment.
Duration – 1.5 hours .Action within 5 to 10 mins.
Side effects
Drowsiness
Blurred vision
Unpleasant taste
Contraindications
Drug hypersensitivity
Glaucoma and asthma
Obstructive condition of the gastrointestinal or
urinary tracts
Congestive heart failure.
2. Clonidine hydrochloride
It is an antihypertensive agent
Dose 0.2mg/hour before appointment
Should be given cautiously in patients who receive other
antihypertensive drugs
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Fluid Control and Soft Tissue Management
Because of the sedative effect of the drug, someone should
accompany the patient to do any driving.
MANAGEMENT OF GINGIVAL TISSUE (OR) FINISH LINE
EXPOSURE
Prerequisite
It is essential that gingival tissue be healthy and free of
inflammation before cast restorations are begun
Untreated gingivitis makes the task more difficult and
seriously compromises the chances for success.
Need for finish line exposure
Because the marginal fit of a restoration is essential in
preventing recurrent caries and gingival irritation, the finish
line of the tooth preparation must be reproduced in the
impression.
When the preparation margin extends subgingivally, the
adjacent gingival tissues must be displaced laterally to allow
access and to provide adequate thickness of the impression
materials.
Methods
Mechanical
Chemico mechanical
Surgical
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Fluid Control and Soft Tissue Management
I. MECHANICAL
Physically displacing the gingiva was one of the first methods
used for insuring adequate reproduction of the preparation finish
line.
a. Copper band and tube
Copper band can both serve as a mean of carrying impression
material and mechanism for displacing the gingiva.
Can cause incisional injuries of gingival tissues.
Useful for situation in which several teeth have been
prepared.
b. Rubber dam
Can also accomplish the exposure of the finish line needed.
Used when a limited number of teeth in one quadrant are
being restored and in situation in which preparation do not
have to be extended very far subgingivally.
c. Plain cotton cord
Used with elastic impression materials
Physically pushing away the gingiva from the finish line
Does not control hemorrhage
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Fluid Control and Soft Tissue Management
d. UAB gingival retraction cord
The retraction cord is left in the sulcus and the impression
material is applied over it .
After the impression material is set it becomes the part of the
finished impression.
Advantages
Accurate and precise impression showing the finish line
clearly.
No need to remove the cord from the sulcus or impression
Easy procedure
No new equipment required
No chemical substances added to the sulcus
e. Expa-syl temporary gingival retraction system (Kerr)
Non-cord gingival retraction system
Green colored paste in glass cartridges similar to anesthetic
cartridges
Metal dispenser is used to express the paste through a
disposable metal dispensing tip into the gingival sulcus prior
to impression making or cementation
It is left in the place for 1-2 minutes and removed by rinsing
Hemostasis is achieved by aluminium chloride
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Fluid Control and Soft Tissue Management
Body is provided by kaolin and clay
Advantages
Effectively achieves hemostasis
Little pressure – atraumatic
Less time consuming
Color makes easy to see
Easy removal
Easy to dispense with the gun
Available as
20 – 1gm capsules of retraction paste
(Application gun + 40 applicator tips)
Disadvantages
Expensive
Thickness of the paste makes it difficult to express into the
sulcus.
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Fluid Control and Soft Tissue Management
Metal tips too big for interproximal areas
Precautions
Tissue should be dried before placement
f. Temporary crown
Oversized temporary crowns with slight extension cervically
can also be used to displace the gingiva physically.
II. CHEMICO MECHANICAL
Retraction cord impregnated with chemicals.
Criteria
Effectiveness in gingival displacement and hemostasis
Absence of irreversible damage to the gingiva
Paucity of untoward systemic effects
Advantages
Enlargement of the gingival sulcus
Control of fluid seeping from the walls of the gingival sulcus
is more readily accomplished.
Chemicals used
Sulfuric acid, trichloro acetic acid, negatol (45% metacresol
sulfonic acid + formaldehyde)
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Fluid Control and Soft Tissue Management
8% racemic epihephrine
8% racemic epihephrine
Advantages of epinephrine
Effectiveness in gingival displacement
Haemostasis
Absence of irreversible damage to gingiva
Disadvantages of epinephrine
Can be absorbed into systemic circulation through the exposed
gingival capillaries and produces ‘epinephrine syndrome’
Elevation of blood pressure and increases the heart rate
Contraindicated in patients with cardiovascular disease,
hypertension, diabetes, hyperthyroidism or a known
hypersensitivity to epinephrine.
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Fluid Control and Soft Tissue Management
Can cause epinephrine syndrome characterized by increased
blood pressure, increased heart rate, rapid respiration, anxiety
and post operative depression.
Commercial products
Sil-trax plus – racemic epinephrine hydrochloride with zinc
phenol sulfonate
Aluminium chloride
Alum (aluminium potassium sulfate), aluminium sulfate and
ferric sulfate – these are astringents.
Clinical trial by Jokstad revealed that aluminium sulfate cords
performed clinically well similar to cords containing
epinephrine.
Martinez et al revealed that ferric sulfate impregnated cotton
cords had lowered tensile strengths than aluminum sulfate
impregnated cords.
Hydrated cords had higher tensile strength than dry
specimens.
Nasal and ophthalmic decongestants
Phenylephrine hydrochloride – 0.25%
Oxymetazoline hydrochloride – 0.05%
Tetrahydrozolin hydrochloride – 0.05%
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Fluid Control and Soft Tissue Management
Bowels et al (1991) found that Visine and Afrin provided
superior clinical results than any of the other agents.
Woody et al (1993) found that Visine and Afrin had more
acceptable pH that any other agents.
V. Tissue hemorrhage can also be controlled indirectly by
adjunctive use of antimicrobial rinse . 0.12%
chlorhexidine gluconate 2 weeks before teeth preparation.
Types of gingival retraction cord
a. Twisted
b. Woven
(i) Braided
(ii) Knitted
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Fluid Control and Soft Tissue Management
Step-by-step procedure
Isolate the prepared teeth with cotton rolls. Place saliva
evacuators as required, and dry the field with air.
Cut the length of cord sufficient to encircle the tooth.
It has been postulated that handling the cord with latex gloves
may indirectly inhibit polymerization of polyvinyl siloxane.
Teeth must not be over desiccated since this may lead to
postoperative sensitivity.
Dip the cord in astringent solution and squeeze out the excess
with gauze square.
An impregnated cord can be placed dry but should be
moistened in situ to prevent the thin sulcular epithelium from
sticking to it and tearing when it is removed.
Form the cord into ‘u’ and loop it around the prepared tooth.
Gently slip the cord between the tooth and the gingiva in the
mesial interproximal area with a ‘Fischer packing instrument’
Cord placement is a fineness move not a power play
The instrument should be analyzed toward the tooth so the
cord is pushed directly into the area.
It should also be angled slightly toward any cord already
packed
A second instrument may aid placement
Over packing should be avoided
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Fluid Control and Soft Tissue Management
Double cord technique
For low crest situations in the anterior sextant, extra-light
pressure used to place #00 cord followed by either #0 or #1
cord.
The cords must remain visible at the sulcus crest
With normal or high crest, first lightly place a #00 braided
cord followed by #0 braided cord. Be careful that cord does
not overlap each other.
The two cords when placed are undistorted should measure
1.5mm height and with the connective tissue attachment of
1mm should create a space of 2 to 2.5mm from the alveolar
crest. A radio surgery is performed to expose the second cord.
Evaluation
When looking at the tooth preparation from the occlusal
aspect, one should be able to see the preparation margin
circumferentially and the uninterrupted cord, with no soft tissue
folded over it , in contact with the tooth.
III. SURGICAL
A. Rotary curettage - Gingettage
“Troughing technique”, the purpose of which is to produce
limited removal of epithelial tissue in the sulcus while a
chamfer finish line is being created in tooth structure.
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Fluid Control and Soft Tissue Management
Concept of using rotary curettage was described by
Amsterdam in 1954.
Requirements
Absence of bleeding upon probing
Sulcus depth less than 3.0mm
Presence of adequate keratinized gingiva
Procedure
In conjunction with axial reduction, a shoulder finish line is
prepared at the level of the gingival crest with a flat end tapered
diamond.
Then a tapered diamond of 150 – 180 grit is used to extend
the finish line apically, one half to two thirds the depth of the
sulcus converting the finish line to a chamfer.
Cord impregnated with aluminium chloride or alum is gently
placed to control hemorrhage
Cord is removed after 4 – 8 minutes
Disadvantages
Poor tactile sensation when using diamonds in sulcular walls,
can cause deepening of the sulcus.
The technique also has the potential for destruction of
periodontium if used incorrectly.
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Fluid Control and Soft Tissue Management
B. Electrosurgery or Surgical diathermy
Electrosurgery unit is a high frequency oscillator or radio
transmitter that uses either vaccum tube or a transistor to
deliver a high frequency electrical current at least 1.0MHz.
History
1891 - Arsonval and Telsa found that high frequency
oscillating can be passed through the body without muscular
response (Shock).
1924 - William Clark used dessication current for removal
of carcinomatous growths. He was known as father of American
Electrosurgery.
1924 - Wyeth introduced endothermic knife which is the
protype of many instruments used today.
Terminology
Rectification
Process of transforming alternating current and directing
current
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Fluid Control and Soft Tissue Management
Partial rectification
Process of rectification in which only one half of each
alternating current cycle is been converted to direct current.
Full rectification
Process of rectification in which both that of the alternating
cycle is converted to direct current
Filtration
Process by which current variations are inherently smoothed
out to produce an unmodulated waveform
Two types of electrodes
Based upon the mechanism
1. Unipolar
Electrosurgical arrangement in which high frequency current
passed over the patients body between a large, passive
electrode which is placed at a distance from a smaller, single
active electrode at which the energy becomes concentrative.
2. Bipolar
Utilizes two wire electrodes of equal sizes positioned in close
approximation thereby eliminating the large passive electrode
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Fluid Control and Soft Tissue Management
Procedures used in FPDs
Elecrocoagulation
Electrosection
Mechanism
Produces controlled tissue destruction
Current flows from a small cutting electrode that produces a
high current density and a rapid temperature rise at its point
of contact with the tissues.
The cells directly adjacent to the electrode are destroyed by
this temperature increase
The current concentrates at sharp bends
The circuit is completed by contact between the patient and a
ground electrode that will not generate heat in the tissue
Fixed Partial Denture 24
Fluid Control and Soft Tissue Management
because its large surface area produces a low current density,
even though the same amount of current passes through it .
Types of current
There are different forms of currents than be generated for
electrosurgical use. There currents exhibit different wave form when
viewed on as oscilloscope.
Unrectified damped current
Partially rectified damped current
Fully rectified current
Fully rectified, filtered current
Stages of healing of electrosurgical incision
Latent period – 0 to 18 hours
Epithelial migration and wound closure – 18 to 48 hours
Epithelial maturation and connective tissue activity – 30 to 48
hours
Adverse healing response
Heat is generated in tissues adjacent to electrosurgical
incision
Alveolar bone is extremely sensitive to heat
Greater injury occurred after heating to 53 0C for a minute
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Fluid Control and Soft Tissue Management
Heating to 60 0C or more resulted in obvious bone tissue
necrosis
Theoretical upper limit 56 0C since alkaline phosphatase is
known to denature at this temperature.
Heat generated depends on
Waveform of the electrical current
Duration of current application
Power of the active tip electrode
Electrode size
Depth of electrode penetration
Contraindications
Should not be employed on patients with cardiac pace maker
Should not be used in the presence of flammable agents
There is slight danger with the use of nitrous oxide with electro
surgery.
Electro surgery technique
Steps
Anesthetise the area
Apply peppermint oil, at the vermilion border of lip
Check the equipment setting
Fixed Partial Denture 26
Fluid Control and Soft Tissue Management
Proper use of electrosurgery requires that the cutting
electrode be applied with very light pressure and quick, deft
strokes
Electrode should move at a speed of no less than 7mm/second
If it is necessary to replace the path of a previous cut, 8 – 10
seconds should be allowed to elapse before repeating the
stroke.
Proper technique with the cutting electrode can be summed up
in three points
Proper power setting
Quick passes with the electrode
Adequate time intervals between strokes
Gingival sulcus enlargement
It is important to assess the width of attached before electro
surgery
To enlarge gingival sulcus, a small, straight or J-shaped
electrode is selected. It is used with wire parallel to the long
axis of the tooth.
If the electrode is maintained in this direction the loss of
gingival height will be about 0.1mm.
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Fluid Control and Soft Tissue Management
Removal of an edentulous cuff
Frequently the remnants of the interdental papilla adjacent to
an edentulous space will form a roll or cuff that will make it
difficult to fabricate a pontic with cleanable embrasure and
strong connectors.
A large loop electrode is used for planning away the large
roll of tissues.
Crown lengthening
There are circumstances in which it may be desirable to have
a longer clinical crown on a tooth than is present.
If there is sufficiently wide band of attached gingiva
surrounding the tooth, this can be accomplished with a
gingivectomy using a diamond electrode.
When surgery leaves an extensive post operative wound as in
this case, it is necessary to place a periodontal dressing,
which should be changed in about 7 days.
Effect of electrosurgery on metallic restorations
Wisser et al studied the effects of incidental electrosurgical
contacts with metallic restorations such as silver amalgam. It was
found that
Contact less than 0.4 seconds no histological changes in the
pulp
Fixed Partial Denture 28
Fluid Control and Soft Tissue Management
Contact greater than 0.4 seconds histological changes
occurred in the pulp
Reference
1. Herbert. T Shillingburg JR, Sumiya Hobo: Fundamentals of
fixed Prosthodontics; 3 r d Edition
2. Stephen. F Rosentiel, Martin F. Land, Fujimoto:
Contemporary Fixed Prosthodontics; 3 r d Edition
3. William F.P Malone, David L Koth: Tylmans Theory and
Practise of Fixed Prosthodontics;8 t h Edition
4. Woody RD, Miller A, Staffanou RS: Review of the pH of
hemostatic agents used in tissue displacement ; J prosthet
Dent. 1993 Aug; 70(2): 191-2.
5. Azzi R, Tsao TF, Carranza FA Jr, Kenney EB: Comparative
study of gingival retraction methods. J Prosthet Dent. 1983
Oct; 50(4): 561-5.
6. Bowles WH , Tardy SJ, Vahadi A: Evaluation of new gingival
retraction agents. J Dent Res. 1991 Nov; 70(11): 1447-9.
7. Jokstad A. Clinical trial of gingival retraction cords.
J Prosthet Dent. 1999 Mar; 81(3):258-61.
8. Schoenrock GA: The laminar impression technique. J Prosthet
Dent. 1989 Oct; 62(4): 392-5.
9. Patel MG. Electrosurgical management of hyperplastic tissue.
J Prosthet dent. 1986 Aug; 56(2):145-7.
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