IsolationIntroduction

The production of absorbed dryness by the exclusion of mouth sections

and humidity from the operative field is essential to the correct performances of

most operative procedures.

The term oral environment refers to the following items which require

proper control to prevent them. From interfering with the execution of any

restorative procedures

1. Saliva

2. Moving organs, ie tongue

3. Lips & Check

4. The periodontium

5. The contacting teeth and restoration

6. The sulci, floor of the mouth and palate

7. Respiratory moisture

With six major salivary glands producing saliva there must be a way to

evacuate it either mechanically by the patient own swallowing mechanism or

by chemically reducing its secretion.

All these procedures are important because saliva may obstruct proper

vision and access interfere with and detrimentally affect the setting and

adaptability of restorative materials, modify or regale the effect of medicaments

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and may be sprayed with rotary instruments to propagate infection in the office

atmosphere.

1. Moisture Control

Moisture control refers to excluding sulcular fluid, saliva and gingival

bleeding from the operative field.

It also refers to preventing the handpiece spray and restorative debris

from being swallowed or aspirated.

The advantages of isolation are

1. Dry clean operating field

2. Access and visibility

3. Improved properties of dental materials

4. Protection of patient and operator

5. Operating efficiency

Isolation of the operative fields involves several conceptual elements

1. Moisture control

2. Retraction

3. Harm prevention

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2. Retraction and Access

The details of the restorative procedures cannot be managed without

proper retraction and access. Thus provides maximal exposure of the operative

site. It involves maintaining mouth opening and depressing or retracting the

gingival tissue tongue lips and check.

The rubber dam, mouth props, high volume evacuators, absorbants and

retraction cord are used.

Harm prevention

An axiom taught to every member of the health profession is do not

harm. An important consideration of isolating the operating field is preventing

the patient from being harmed during the operation. Excessive saliva and hand

piece spray can alarm the patient. Small instruments or debris can be

swallowed. As with moisture control and retraction. The dam, section devices

and absorbants play a role in harm prevention. Harm prevention is provided as

such by the nannee in which these devices are used as by the devices

themselves.

Absorbants and Throat shield

Absorbants such as cotton rolls and cellulose wafer are useful for short

periods of isolation example for examination, polishing etc. and also for topical

fluoride application. Absorbants are isolation alternative in cases where rubber

dam application may not be possible.

Especially along with profound anesthesia absorbants provide

acceptable dryness for procedure such as impression taking and cementation.

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The dental assistant mostly has the job of keeping dry cotton rolls in the mouth.

They should be changed when saturated.

Several commercial devices for holding cotton rolls in position are

available. It is generally necessary to remove the holding appliance from the

mouth to change the cotton rolls. This may be inconvenient and time

consuming.

An advantage of cotton roll holders is that the cheeks and tongues are

slightly retracted from the teeth which enhances access and visibility,

For maxillary teeth

A medium sized cotton roll is placed in the adjacent vestibule.

For the mandibular teeth

One medium sized roll in the vestibule and a larger one

between the teeth and tongue.

The teeth are then dried by short blasts from the air syringe.

Cellulose wafers may be used to retract the check and provide

absorbancy.

While removing these absorbants it may be necessary to moisten them

using the all water syringe to prevent removal of the epithelium from the

cheeks, floor of mouth and lips.

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Throat Shields

These are indicated when small instruments are being used or indirect

restoration placed. This is to prevent aspiration or swallowing of restoration.

High volume evacuators and saliva ejectors

When a high speed hand piece is used air water spray is supplied

through the head of the hand piece to wash the operating site and to act as a

coolant for the bur and the tooth. High volume evacuators are perferred for

suctioning water and debris from the mouth because saliva ejectors remove

water slowly and have little capacity for picking up solids.

McWhecter in 1957 showed that evacuators generally would remove 5L

of water in 2 seconds had 75% to 95% pickup of air and water and would

remove 100% of solids during cavity cutting procedures.

A practical test for the efficacy of the evacuator would be to keep it in

150ml of water it should suck it in 1 seconds.

The tips for these may be

1. Plastic Disposable

2. Metallic auto cleavable

The combined use of water spray and high volume evacuator has the

following advantages.

1. Restorative and tooth debris are removed from the operating site.

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2. Access and visibility are improved.

3. No dehydration of oral tissues.

4. Time is saved as the pauses required for patient to spit and wash are

eliminated.

5. Precious metals are readily salvaged.

6. Quadrant dentistry is facilitated.

Precautions

1. The tip should be as near as possible to the tooth to be operated upon

just distal to it.

2. It should not obstruct the operators view.

3. It should not be so close as to direct the water spray away from the

rotary instrument.

Saliva ejectors

Most patient do not require saliva ejectors as salivary flow is greatly

reduced when the operating site is profoundly anesthetized.

The saliva ejector removes saliva that collects on the floor of the mouth.

It is used in conjunctions with sponges cotton rolls and the rubber dam. It

should be placed in an area least likely to interfere with the operators

movements.

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The tip of the ejector must be smooth and made from a non-irritating

material. Disposable inexpensive plastic ejectors that may be shaped by

bending with the fingers are available. The ejector should be placed to prevent

occluding its tip with tissue from the floor of mouth.

Advantages can be summarized as the

A – adequate access and visibility

B – better patient protection and management

C – control of moisture in operating field

D – decreased operating time of rubber dam i.e.

The Rubber Dam

In 1864 S.C. Barmem a New York city dentist introduced the rubber

dam into dentistry. Use of the rubber dam ensures appropriate dryness of the

teeth and improves the quality of clinical restorative dentistry.

The rubber dam is used to define the operating field by isolating one or

more teeth from the oral environment. The dam eliminator saliva from the

operating site and retracts the soft tissues.

The advantages can be summarized as the

Adequate access and visibility

Better patient proportion and management

Control of moisturing operating field

Decreased operating time

of rubber dam i.e.

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Advantages

1. Dry clean operating field rubber dam isolation is the preferred method of

obtaining appropriate dryness. The time saved by operating in a clean

contamination fill field with the good visibility more than compensate

for the time spend in applying rubber dam.

2. Access and Visibility the rubber dam controls moisture and retracts lips

cheek and tongue. It is dark coloured so it provides a dark non reflective

background so access and visibility are greatly improved.

The rubber dam prevents the agents from contacting the tissues. The

teeth are in a dry field so there is a greater surface area to which solutions like

fluoride etc. may be applied. The teeth become some what dehydrated has their

permeability increases so fluoride uptake is more.

The rubber dam protects the patient from aspirating or swallowing small

instruments or debris associated with operative procedures. Immediate

recovery of these materials is facilitated by the rubber dam. A properly applied

rubber dam protects the soft tissue from irritating or distaste feel medicaments

such as etchants.

The dam also offers some protection from rotating burs and stones in

addition the operator is protected from infections present in the patients mouth.

The time required for patient to expectorate and rinse is saved. A certain

amount of mouth opening is provided.

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Disadvantages

1. It cannot be used in

a. Partially erupted teeth

b. Some third molars

c. Extremely malpositioned teeth.

2. In patient suffering with asthma it cant be used or if patient has

preaching problems in such eases a hole may be cut in the palatal area

thus facilitating breathing through the mouth.

3. Some patients may not be open to the idea of rubber dam if they are

allergic to latex or if they have had an experience previously with an

awkward or inept dental team.

Armamentarium

1. Rubber dam sheets

2. Rubber dam holder

3. Rubber dam retainer

4. Rubber dam punch

5. Forceps

6. Napkin

7. Lubricant

Rubber dam material

It is available in rolls or sheets

The advantage of material in rolls is that it can be cut to the desired

shape whereas rolls are time saving.

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The sheets may be 5x5 inch or 6x6 for Pedo.

Sterile dam material is also available packed as individual sheets. The

thickness available are :

Thin - .006 inch .15mm

Med - .008 inch .2mm

Heavy - .010 inch .25mm

Extra heavy - .012 inch .3mm

Special heavy - .014 inch .35mm

Rubber dam material has a shiny and dull side

The thicker dam is available to retract the tissue its more resistant to

tearing and especially recommended for Class V cavities in conjunction with a

cervical retainers. The thinner materials have the advantage of passing through

the contacts easier which is particularly helpful when they are tight.

Rubber dam clamps

Each clamp consists of

1. A jaw – on each side carrying the tooth attachment blades and wings.

2. A bow - which connects the 2 jaws and which should be elastically

stainable and resistant enough to import a gripping force on the

attaching blades against the teeth.

According to the type and shape of the attaching blades clamps may be

1. 4 point contact blades i.e. blade portions of the jaw point inwards at

each corner so that gripping forces are applied only on these dam points

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usually they contact the axial angles of the tooth and the attachments are

very secure.

Indications

1. Newly erupting teeth.

Disadvantages

Its possible traumatic effect or weakened undermined tooth structure.

2. Circum furencial contact blades

The blade portion has noprojections and will contact the tooth surface

evenly throughout its length. This type is less retentive but may also be less

traumatic.

It is used 1. When axial angles are lost or do not coincide with the corners of

the 4patient contact damps.

2. When axial convexity of the tooth surface is sufficient for

anchorage.

Winged

Clamps may also be classified as

Wingless

Those having wings can be attached to the rubber dam before

application so the dam may be released after the clamp has engaged the tooth.

Those are bulky and cannot be used in 3rd molars. The various clamps

area Retracting anchoring clamps.

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These are clamps especially designed to other functions besides

anchoring the dam to the tooth.

Examples:

The No 212 S.S. White clamp was designed by Rew I Ferrier to isolate

the gingival carious lesion.

It is an effective gingival retractor and is especially used for cohesive

gold restorations as the gingiva does not interfere with polishing of the

restoration.

The No 212 clamp is a double bow hatch type design that is also used

for endodontic treatment of anterior teeth. The lingual opening is facilitated by

the clamp design and there are finger rests on the compound lock that stabilizes

the clamp before the clamp is used the grooves for the forceps should be

deepened with a bur to prevent any movement. When it is placed because

instability could cause damage to the gingiva or cementum. This damp can be

modified to specifically fit narrow teeth lesions located more gingivally than

normal and rotated teeth.

They may also be sectioned and used for gingival isolation.

The Schultz clamp series resembles the 212 clamp but are split in half

facio lingually making it a gingivally retracting clamp with one bow only.

Their use and attachment is very similar to that of 212 clamps but they are

specially useful. Where a second bow cannot be accommodated due to a lack of

space or limited accesses.

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Cervical retracting clamps may be single or double bowed, but the jaws

and their blades are movable even after attaching the clamp to the tooth by

moving these blades apically the gingiva can be retracted more apically and

vice versa.

Modified Clamps

Clamps such as No W8A can be reshaped and adapted to almost any

type of tooth and easily secured below the height of contour.

The clamps most commonly modified are the ivory no W8A and the

S.S. White No. 212. Ferrier clamps. These have broad application and can be

fitted to the majority of operative cases.

To expediate placing on rotated teeth the jaws may be modified by

grinding suitable contour to the tip edge. The jaws may be bent for use on teeth

where gingival access to lesions is difficult. This is done by heating the jaws to

cherry red in a flame and then grasping the entire facial jaw and slightly

bending it apically the procedure is repeated for the lingual jaw bending it

occlusally.

It is then carried and placed on the tooth. Next a ball burnisher is hooked

onto one of the retainer notches and used to move the facial jaw gingivally to

final position .5 to 1mm apical of the expected gingival margin care should be

taken that the epithelial attachment is not harmed. The retainer is supported and

locked into this position with red stick modeling compound which is placed

between the bows and gingival embrasures placed between the bows and

gingival embrasures.

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Anchors other than retainers

1. A piece of cut rubber dam if wedged between contacting teeth can be

used to anchor the dam especially proximal to the most anteriors isolated

tooth.

2. Inter ceptal rubber if it is of sufficient dimensions and is placed between

intact teeth or properly restored teeth will be a very effective locking

mechanism.

3. Compound is used for immobilization of certain clamps by engaging

their bows with adjacent teeth.

4. Wooden wedges placed between teeth can be used to immobilize the

interceptal rubber or alone to anchor the dam at its most anterior end. They

are also used in isolating bridge pontics and abutments.

5. A dental floss tape tied around a piece of cylindrical rubber, can be

wrapped or tied around the axial surface to lock the dam apical to the rubber

cylinder. This could be used when these are no apical convexities on the

axial surfaces of a terminal anchoring tooth.

6. Rental tape or floss is tied around the neck of the tooth to retain the dam

apically it the gingival clest is at the same level on all tooth surfaces and

will be in contact with dental floss or tape.

Rubber Dam Punch

The punch is apricision instrument having a rotating metal table with 6

holes of varying sizes and a tapered sharp pointed plunger call should be

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exercised when changing from one hole to another the plunger should be

centered in the cutting hole and the tip of the plunger should not be allowed to

drag over the edges of the holes, otherwise the cutting quality of the punch will

be ruined as evidenced by in completely cut holes which will tear open easily

when spread during application over the retainer or tooth.

Forceps

Forceps all used to seat the cleanup around the tooth to hold the rubber

dam in the mouth and tolerance the clamp. Cleanup placement requires good

observation to prevent injury to the soft tissue and this is accomplished with

contoured and fitted rubber dam forceps. The nose of the forceps can be refined

to aid in securing the cleanup maintenance includes only lubrication and

sterilization.

Rubber dam holders

There are a variety of holders for the rubber dam but their main

objective is to keep the peripheries of the dam out of the mouth others

objectives mouth.

Others objectives are

1. To stretch the dam in 4 directions.

2. To retract check and lips.

3. To clear the field for further procedures

They are classified as

1. Strap type

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Which depends on the back of patient head for anchorage it should be

attached to the dam at its corners and sides. From these attachments come belts

which stretch and pull the rubber towards the occipital parts of the head

eg. Wood burry holder.

They may used an attached weight to keep the dam from wrinkling.

2. Hanging frame holders may be Metallic

Plastic

3. U shaped or ellipitical or rectangular with multiple prongs at their

peripheries these prongs will equal the rubber dam, thus retracting both the

dam and the musculature engaged by the dam. These are the most popular

holders.

Advantages

1. Ease of application

2. Minimal contact of rubber with skin

Disadvantage is that they may decrease the access.

Napkins

These are absorbant materials that are placed between the skin and

rubber dam and has the following advantages.

1. Prevents contact of skin with rubber so reduces the allergic action is

sensitive patients.

2. Absorbs saliva at the corners of the mouth. This prevents irritation and

cracked facial tissue which results from prolonged moisture contact.

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3. Acts as a cusion.

4. Provides a convenient method of wiping the patients lips on removal of

the dam.

It ads to the comfort of the patient especially on long appointments.

Lubricant

A water soluble lubricant is applied in the areas of the punched holes.

This facilitates the passing of the dam through proximal contacts.

The lubricant may be commercially available but shaving cream or soap

sherry are satisfactory substitutes.

All of these agents are easily removable from the enamel surfaces after

the dam application in order to prevent contamination and adaptation problems.

Petroleum jelly is also used by some but leaves an in removable film, so

it is not recommended.

Template

1. A template may be used to mark the location of the holes. These

templates may only serve as guide lines as the teeth may not be in their

ideal places in all mouths.

Another method is to place the area on the rubber dam to be marked on

study models and mark them directly for punching.

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A this method is, the patient is asked to bite an a short of base plate wax

which is then chilled and applied over the area to be punched and the teeth are

marked with a pin penetrating the wax.

Guidelines

2. Always isolate a minimum of 3 teeth except for root canal treatment

where only one tooth should be isolated.

3. The distance between 2 holes is equal to the distance between center of

one tooth to center of another measured at the level of gingival tissue.

It the distance is more the dam wrinkles and causes folds if it is less it

stretches and causes seepage.

4. For operations on anterior teeth canine to canine isolation is sufficient

wedges may be placed distal to the canine and are adequate to retain the

dam.

5. For class V lesions and usage of 212 clamp. The hole should be deviated

2-3mm away from the normal arch line facially or lingually depending

on weather it is a facial or lingual lesion.

6. For a person with large upper lip the holes for anterior teeth should be

more than an inch from the edge and vice versa.

7. For mandibular teeth the further posteriorly the anchor tooth the more

dam material is required to come from behind the retainer over the upper

lip.

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8. Heavier dams are used to isolate a class V lesion.

9. Thinner dams have greater elasticity so they require smaller holes.

Attaching the dam to the teeth

There are 4 ways

1. Winged clamps attach the dam to the dam engaging projection the

forceps are engaged in the dam holes. The clamp is placed on the tooth and

pushed apically over the height of contour there, the clamp is then released

from the forceps and the forceps is removed in an occlusal direction. After

making sure of the stability of the clamp the dam holes are disengaged from

the clamp wings and directed apical to the clamp components.

2. A wingless clamp is attached to the anchor tooth. The hole for the

anchor tooth in the rubber is then stretched on both sides laterally and

slipped over the bow and jaws of the clamp and anchored apical to the

clamp jaws.

3. The dam hole is stretched over the tooth to be anchored and kept in

place with finger pressure and then the clamp is placed.

4. The dam can be attached to the bow of a wingless clamp by the edges of

its anchor tooth hole then the clamp is placed and rubber is slipped apical to

its jaws

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.

Rubber dam application

Special rubber dam application

1. Fixed bridge isolation

Indications

1. Restoration of an adjacent proximal surface.

2. Cervical restoration of an abutment tooth.

Methods

1. This type is done with no holes in place of the pontic. The dam is seated

so that the rubber will actually be located occtusal to the abutment. Wedges

are inserted interproximally between the pontics and the abutment tooth to

retain the rubber apically softened compound is added to stabilize these

wedges.

2. This is similar to the first except a piece of pipe cleaner is used instead

of wedges.

3. The dam is stretched onto the teeth. A blunt curved suture needle with

floss is threaded the hole for the anterior abutment and then under the

anterior connector and back through the same hole on the lingual side.

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The needles direction is then reversed and it is passed from the lingual

side through the hole for 2nd bridge unit then under the same anterior connector

and then through the hole of the 2nd bridge unit on the facial side.

A square knot is tied with the free ends of the floss thereby pulling the

dam material simply around the connector and into the gingival embreasure.

Substitution of a retainer with a matrix

A matrix can be applied instead of retainer to hold the rubber dam in

place.

The operator obtains access and visibility for insection of the alloy by

reflecting the dam distally and occlusally over the mirror.

Care must be taken not to stretch the dam so much that it is pulled away

from the matrix permitting leakage around the tooth or slippage over the

matrix.

The matrix unlike the retainer has neither jaws or bow so the dam may

slip unless dryness is maintained.

Removal of Rubber dam

Errors in application and removal

1. Off center arch form this may obstruct the patients nasal airway and may

not even shield the complete oral cavity so foreign material may escape

down the throat.

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2. In appropriate distance between the holes

a. Too small distance will lead to leakup.

b. Too great distance will leads to

a. Wrinkling

b. Inadequate access and tissue retraction

3. In appropriate retainer

Retainer may be in appropriate by

1. Being two small when jaws are stretched it may break.

2. Being unstable on the anchor tooth.

3. Impinging on soft tissue.

4. Impinging on dam material.

4. Sharp tips of a 212 retainer should be

sufficiently dulled to prevent damaging the cementum in Class V

lesions.

5. Shredding or tearing dam should be

avoided as this will lead to incomplete isolation.

Alternative isolation aids

Retraction cord when properly applied can be used for isolation and

retraction in the direct procedures of treatment of cervical lesions in facial

veneering as well as in indirect veneers.

The gingival retraction when moistened with a non caustic styptic may

be placed in gingival sulcus to control sulailar seepage and or hemorrhage.

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Most brands are available with and without the voso constrictor

epinephrine which acts to control sulculae fluids.

A properly applied retraction cord, will improve access and visibility

and help prevent abrasion of gingival tissue during cavity preparation.

Antisalivary drugs

The use of drugs in restorative dentistry to control salivation is rarely

indicated and generally limited to atropine.

Is with any drug the operator should be familiar with its indications

contra indications and side effects. It is important to remember that atropine is

contra indicated for nursing mothers and for patients with glaucoma.

Some Anti histaminics like Hi receptor antagonists also cause dryness of

mouth due to anti cholinergic action but they inhibit the action of local

anesthesia so are contra indicated.

Although several methods and devices are available to create a dry

working field. The rubber dam is one of the most ideal the working field that is

produced is in principle.

In medicine, surgical procedures are done with controller operating

field’s surrounded by aseptic environment. An attempt should be made in

restorative dentistry to work only on clean teeth and on a patient who is under

control. Control should mean not only the elimination of moisture but the

elimination of humidity as well utilizing all the above mentioned measures.

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Reference:

*Studevant’s Art & Science of Operative Dentistry / forth edition

Theodore M.Roberson, Herold O. Heymann, Edward J.Swift. JR

Atlas of Operative Dentistry / Third edition

William W.Howard, Richard C. Moller

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Contents

1. Introduction

2. Methods of Isolation

3. Rubber Dam

4. Drugs

5. Conclusion

6. Reference

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Isolation

Seminar byDr. N.Upendra Natha Reddy

Postgraduate Student2004-2007

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