1 Fluid Control

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

Fixed Partial Denture 5


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



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



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



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.



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



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



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



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



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.



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)



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.



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%



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



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



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.



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.



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



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



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



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



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



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.



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



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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