RUBBER DAM

INTRODUCTION

HISTORY

ADVANTAGES OF RUBBER DAM

DISADVANTAGES OF RUBBER DAM

MATERIAL AND INSTRUMENTS

o Rubber dam material

o Rubber dam punch

o Rubber dam forcep

o Rubber dam frame

o Rubber dam clamp

o Rubber dam -Napkin

o Lubricant

o Holo positioning guide

o Anchor (other than clamps)

GUIDELINES FOR POSITIONING THE HOLE

APPLICATION TECHNIQUE

MULTIPLE TOOTH ISOLATION

REMOVAL OF RUBBER DAM

RUBBER DAM IN CLINICAL RESTORATIVE PROCEDURE

ERROR IN APPLICATION AND REMOVAL

WASHED FIELD APPARATUS

CONCLUSION

REFERENCES

RUBBER DAM

INTRODUCTION:

There are many ways to isolate an area of the mouth or a tooth so that

restorative services can be performed without interference from soft tissues,

tongue, saliva or other fluids. Various tongue and cheek retruding devices and

suction methods are used. By far the most complete method of obtaining field

isolation is rubber dam.

HISTORY:

It is not realized that the rubber dam was first described over 120 years ago

when in March 1864 Dr. Sanford Barnum first explained its use at meeting of

Connecticut Valley Dental Society in New York. He described his delight in

finding such a simple means of saliva control at a time when saliva control was

sedimentary.

By the following year, the use of rubber dam was warmly recommended to

profession as an indispensable aid to dental practice and 5 years later in 1870 Dr.

J.F.P. Hodson described in detail the methods then in current use. Several aspects

of the technique have not changed greatly from that time. The main difference

from current practice being that rubber dam clamps were not developed and

retention of rubber dam was exclusively by means of wedges and floss silk

ligatures. Rubber dam frames were not used and the edges of rubber were retracted

by neck harness and weights suspended from floss silk ligatures looped around the

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tooth. Hodson’s article in 1870 details the construction of seven types of clamps

which were designed solely to achieve improved gingival retraction and were

placed without the aid of clamp forceps.

In 1879 the Ainsworth Rubber dam punch was patented the design of which

has changed little in more than a century.

Dr. W. ST Geo Elliotts in 1878 described clamp forceps gripped the jaws of

he clamp rather than the bow. This arrangement allowed the hole in the rubber

dam to be retained on the forcep tips, thus earliest forerunners of idea of carrying

the rubber dam and clamp to mouth simultaneously.

About the same time (1880) the Hickmann “Lipped” clamp was in use in

which the rubber dam sheet was retained on the clamp between two lips on each

jaw. These were earliest forerunner of present day winged design.

Most of the other design of early clamps and forceps were designed to

tension the clamp by engaging the clamp bow. By 1890 some clamps were being

made with holes in jaws to allow the use of forceps similar to stokes pattern of

today.

A few of early designs have remained popular to the present day e.g. “Tees

Festooned Clamp” designed in 1870. The only feature lacking when compared to

modern version being holes in each jaw. This design was only one of the first

feature jaw which were directed gingivally or “festooned” a forerunner of the

retentive jaw design today.

Colyer gave a detailed account of techniques in use by 1890 and his

description would be quite familiar to today’s practitioner.

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Rubber dam frames were described in early 20 th century as Metal

Fernauld’s design. More recent designs have taken advantages of developments in

plastics to produce frames which are radiolucent.

By the time G.V. Black produced his seminal text “Operative Dentistry” in

1908, the use of rubber dam was firmly established. He strongly advocated its use

stating “the rubber dam should be in place for all amalgam fillings, the same as for

gold…. It is as impossible to make a good amalgam filling as it is a gold (foil)

filling with any moisture present”.

The American Dental Association Council on Dental Materials and

Equipments has acknowledged the use of rubber dam stating in 1986 that “The use

of rubber dam to maintain dry field is essential”.

ADVANTAGES OF RUBBER DAM:

The advantages of rubber dam isolation are:-

1) Dry clean operating field:- The operator can best perform procedures such as

caries removal, cavity preparation, restorative procedure in dry field. Teeth

prepared and restored using rubber dam isolation are less prone to post-

operative problems related to contamination from oral fluid.

2) Access and visibility:- Rubber dam provides maximal access and visibility. It

act as physical barrier to moisture and retracts the soft tissues. Rubber dam

retracts the gingival tissue, lips, tongue and cheek. Rubber dam provides a

dark, non-reflective background in contrast to operating site thus enhances the

visibility.

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3) Improved properties of dental materials by preventing the moisture

contamination of restorative materials during insertion and promotes improved

properties of dental materials.

4) Protection of patient and operator:- The rubber dam protects both patient and

operator. It protects the patient from aspirating or swallowing small

instruments and debris associated with operative procedures. It controls the

soft tissues and their protection from injury. The importance of physical barrier

(which rubber dam provides) between patient and operator and patient’s oral

fluids, has recently become more widely recognized due to risk of treating

undiagnosed carriers of HIV and hepatitis B virus. Thus it provides a pleasant

controlled operating environment. (Operative Dentistry 1986; 11:159)

5) Operating Efficiency:- Use of rubber dam enhances operating efficiency and

increased productivity. Patient management is simplified by avoiding need to

rinse the mouth of debris, improving access to operating area, gingival

retraction and control of gingival haemorrhage and surgically clean field.

DISADVANTAGES:

1) Time consumption and patient objection are most frequently quoted

disadvantages of rubber dam.

2) Minor damages can occur to marginal gingival and cervical cemetnum.

3) Damage to the restorations such as metal crown margins show microscopic

defects following clamp removal and ceramic crown may fracture at margins

if clamps are allowed to grip the porcelain.

4) Accidental aspiration of the clamps

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5) Certain conditions which preclude the use of rubber dam

a. Malpositioned teeth

b. Teeth that have not erupted fully to support retain

c. Third molars

d. Excessive coronal tissue loss

6) Patient suffering from respiratory diseases such as asthma may not tolerate

rubber dam if the breathing through nose is difficult.

7) Contact allergy to latex rubber dam sheet. Two cases of contact allergy to

rubber dam have been reported during last 20 years. One manifesting as

angioneurotic oedema with systemic symptoms and other as contact

dermatitis.

MATERIALS AND INSTRUMENTS:

1. Rubber Dam:

Rubber dam material is made from natural latex rubber. They are

manufactured as,

a) Continuous rolls available in two widths (125 mm or 150 mm)

b) Pre-cut form available in 5 x 5 inch (12.5 x 12.5 mm) or 6 x 6 (15 x 15

mm) square sheets.

Rubber dam material available in assay of colours. Traditionally black

rubber dam was available but now four alternative colour such as green, blue, grey

and natural (translucent) are there.

Thickness: Rubber dam is manufactured in range of five thicknesses.

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Grade ThicknessMm Inch

Thin 0.15 0.006Medium 0.20 0.008Heavy 0.25 0.010Extra heavy 0.30 0.012Special heavy 0.35 0.014

Shelf life:- Rubber dam material has shelf life of about 9 months at room

temperature. Shelf life will be reduced in warm storage conditions and so a

refrigerator or freezer is best used if prolonged storage is anticipated.

2. Rubber Dam Punch:

Precision instrument with rotating metal table. These instrument are used to

produce the clean cut holes in the rubber sheet through which the teeth can be

isolated.

Two types of holes are made:-

1) Single hole

2) Multihole

1) Single hole:- Available in two sizes. Single hole punches are used mainly for

endodontic isolation and have the advantage of accurate and consistent punch

point to avail alignment. E.g. Dentsply single hold punch.

2) Multihole:- More versatile and preferred by authors. They allow holes to be

punched in a range of sizes from 0.5 to 2.5mm in diameter by rotation of axil.

E.g. Ivory pattern (Heraeus Kulzer) punch. E.g. Ash or Ainsworth pattern

punch.

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Rubber dam punches should be regularly checked for wear and tear. Three main

problems can arise:-

1) Blunting of the sharp cutting edge to the anvil holes, usually due to prolong

use.

2) Damage to the punch point and anvil, as a result of incorrect alignment.

Punching of holes:- The size of hole punched for each tooth depends on several

factors.

a) Whether the tooth is to be clamped or not

b) Cervical diameter of the tooth

c) The elasticity of rubber dam being used

3. Rubber Dam Forceps:

Rubber dam forceps are needed to stretch the jaws of clamp open in a

controlled manner during placement and removal. Several designs of forceps are

available. Three widely used designs are:-

a) ash or stokes pattern

b) Ivory pattern

c) University of Washington pattern

All three have a sliding ring between the hinge and forceps handles which

can hold the forcep open and so hold the clamp under tension. These three forcep

differ in their tip design.

University of Washington pattern design provide a definite stop which

positively prevent jamming of instrument tip in the hole in clamp jaw.

It also resists tilting of clamp while held in the forceps.

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Stokes and ivory pattern have both notched and pointed tips which engages

the holes in clamp jaws.

Ivory pattern forceps (Heraeus Kulzer) have stabilizers that prevent the

clamp from rotating on the beaks.

Stokes type which have notches near the tips of their beaks in which to

locate the holes of rubber dam clamp allow a range of rotation for the clamp so

that it may be positioned on teeth that are mesially or distally angled.

4. Rubber Dam Frame:

Rubber dam frames support the edges of rubber dam and so retract the soft

tissue and improve access to isolated teeth. It can be metal or plastic. Fernauld’s

frame made of metal was first widely used rubber dam frame.

The metal frames available now are versions of Young’s design. It is ‘U’

shaped open at the top and this allows the upper edge of rubber to fall slightly

forward away from tip of nose.

Young’s frame design also available in plastic preferred particularly for

endodontic radiographs since radiolucent. The rubber dam is retained by series of

pegs around the edges over which the rubber sheet is stretched. Shape of pegs can

be fine spike with relatively sharp points (young’s) or broad pegs with blunt type

(Hygienic or Fernauld’s).

One type of plastic frame (Nygaard Ostby) is a complete circle supporting

the upper edge of rubber.

Rubber dam harnesses retract only the sides of rubber dam. The harness is

attached to vertical edges of rubber sheet by metal clips from which elastic pass

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around the back of the head and apply traction to edges of rubber sheet. E.g.

Woodbury retractor.

Dry dam an alternative to frame and harness which consists of small sheet

of rubber set into the centre of an absorbent paper sheet with light elastic on either

side to pass over the ears. This is useful for quickly isolating anterior teeth but not

suitable for molars bleaching due to absorbent nature of paper surround.

5. Rubber Dam Clamp:

Rubber dam clamp (retainer) is used to anchor the dam to the tooth to be

isolated. The clamp consists of four prongs and two jaws connected by a bow.

Clamps can be divided into two main groups according to jaw design:-

Bland

o Winged

o Wingless

Retentive

o Winged

o Wingless

Bland: Bland clamps are recognized by the jaws which are flat and points directly

towards each other and are designed to grasp the tooth at or above the gingival

margin and thus causing minimum gingival damage.

Retentive: Retentive clamps have jaws which are directed more gingivally so that

they can grasp the tooth well below the gingival margin.

Winged: The wings are the small flanges on the outer edges of clamp jaws which

are provided to allow the clamp to be retained in dam during placement.

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Clamps are made from metal and non-metal

Metal clamps have traditionally been made from tempered carbon steel

plated to resist corrosion and more recently from stainless steel. Dentsply is

producing gold coloured clamp with diamond grit on jaws. Diamond coating is

said to improve retention on the tooth.

Non-metal clamps made from polycarbonate plastic (Endo Technic).

Advantage of these clamps is that they are radiolucent. Disadvantage – do not fit

the tooth well and are bulky.

To be secure a clamp must fit around the tooth below the level of maximum

crown width (maximum coronal diameter). The points of the jaws of the clamps

must all contact the crown below this level in four areas. Two on facial surface

and two on lingual surface. This is called ‘Four Point Contact’. The four point

contact prevents rocking and tilting of retainer. This is most easily achieved by

selecting those clamps in which the length of clamp jaws relate to the mesodistal

width of the root.

The jaws should not extend the mesial and distal line angles of tooth because,

1) They may interfere with the placement of matrix and wedge

2) Gingival trauma is more likely to occur

3) Complete seal around the anchor tooth is more difficult to achieve

Correct placement of clamp on an anchor tooth is achieved when:-

1) When the bow is to the distal

2) All four points of jaws are in contact with the anchor tooth.

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3) The clamp is gripping the crown of the tooth below its maximum coronal

diameter.

Clamp placement:

Before a clamp is placed on any tooth, the dental floss should be tied. The

dental floss should be 12 inches (30.5 cm) in length. The floss allows

retrival of retainer or its broken parts if they are accidentally swallowed or

aspirated.

The clamp is carried to the tooth using clamp forceps.

The clamp engaged in the beaks of forcep by means of holes in the jaws.

The clamp is oriented in the forcep, so that bow will lie to the distal on the

tooth.

Sufficient pressure is used to tension the clamp and retain it on the forcep.

The handle lock maintains the tension in the clamp.

The clamp is placed on the tooth by opening it sufficiently to pass over the

maximum coronal diameter.

The lingual (or palatal) jaw is placed first in contact with lingual surface of

the anchor tooth. Then the clamp tilted bucally until buccal jaw below

maxillary coronal diameter.

The tension of clamp is released slowly as the buccal jaw is placed.

6. Rubber Dam Napkin:

Rubber dam napkin placed between the rubber dam and patient’s skin and

has following advantages:-

a) It prevents skin contact with rubber to reduce the possibility of allergies

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b) Absorbs saliva seeping at the corners of mouth

c) Act as cushion

d) Provides a convenient method of wiping the patient’s lips on removal of

dam

7. Lubricant:

A water soluble lubricant applied in the area of punched holes facilitates the

passing of dam septae through the proximal contacts. Rubber dam lubricant is

commercially available but other lubricant such as shaving cream or soap slurry

are satisfactory cocoa butter or petroleum jelly may be applied at the coroners of

patient’s mouth to prevent irritation. These 2 materials are not satisfactory rubber

dam lubricant because both are oil based and cannot be easily rinsed from dam

once the dam is placed.

8. Hole-Positioning Guides:

a) Teeth as a guide:- The teeth themselves or stone cast of teeth can be used in

marking the dam. The cusp tips of posterior teeth and incisal edges of anterior

teeth can be visualized through the dam, and centers of teeth are marked on the

dam with pen.

b) Template:- Templates are available to guide the marking of dam. These

template are approximately the same size and shape as the unstretched dam

itself.

c) Rubber dam stamp:- Provides a convenient and efficient way of marking the

dam for punching.

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9. Anchors (other than clamps):

Alternatives to clamps are of two types –

a) Employs the area beneath the interdental contacts for retention. These include

interdental wedges or wood sticks inserted below the contact point or rubber

strip passed under tension through contact point and released to lie beneath the

contact area.

b) When the tapering crown/ root surface beneath the maxillary crown diameter,

the rubber dam in this case is retained by ligatures of dental floss tied around

the neck of the tooth or elastic rings which are stretched through the contact

points and released to grip the neck of the tooth.

GUIDELINES FOR POSITIONING THE HOLES:

1) Punch an identification hole in upper left (patient’s left) corner of the rubber

dam for ease of location when applying the rubber dam holder.

2) When operating on incisors or mesial of canine isolate from first premolar to 1st

premolar. Metal retainer are not required for this isolation.

3) When operating on canine, it is preferable to isolate from 1st molar to opposite

lateral incisor.

4) To treat a class V lesion on canine, isolate posteriorly to include first molar to

provide access for cervical retainer placement on canine.

5) When operating posterior teeth, isolate anteriorly to lateral incisor of opposite

side. Anterior teeth included in isolation provide better access and visibility to

operator and finger rest.

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6) When operating premolar punch holes to include two teeth distally and extend

anterior up to opposite lateral incisor.

7) When operating molars, punch holes as far distally as possible and extend

anteriorly to include opposite lateral incisors.

8) Isolation of minimum of three teeth recommended except in endodotnic

therapy in which the tooth to be treated is isolated.

9) The distance between holes is equal to the distance from the center of one tooth

to the center of adjacent tooth measured at the level of gingival tissue. It is

generally ¼ inch (6.3 mm).

10)When the rubber dam is applied to the maxillary teeth the first holes are

punched of central incisors which are placed approximately 1 inch (25 mm)

from the upper border so that sufficient material to cover upper lip.

11)When the rubber dam is applied to mandibular tooth, the first hole punched is

for the post anchor tooth that receives the retainer. To determine the proper

location mentally divide the rubber dam into three vertical sections : left,

middle and right.

12)When a cervical retainer is applied to isolate a class V lesion, a heavier rubber

dam is usually recommended for better tissue retraction and the hole should be

punched slightly facially to the arch form to compensate for the extension of

the dam to the cervical area. The farther gignivally the lesion extends, the

further the hole must be positioned from the arch form. In addition the holes

should be larger and distance between it and holes for adjacent teeth should be

slightly increased.

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13)When a thinner dam is used, smaller holes must be punched to achieve an

adequate seal around the teeth because the thin dam greatly elastic.

APPLICATION TECHNIQUES:

Preoperative Procedures:

Patient’s mouth is examined carefully for calculus deposits, and sharp

edges on restoration.

All contact points in operating field are checked with dental floss.

All roughness and deposits present interdentally must be removed to allow

free passage of rubber dam and prevent tearing.

Anaesthetize the gingiva when indicated

Rinse an dry the operating field.

Before rubber dam is applied to a patient a clear decision has to be made

about teeth should be isolated. Whether a single tooth or a group of teeth is

to be brought through the rubber dam will depend on the procedure to be

undertaken.

When a clamp is to be placed, three techniques of rubber dam application

are commonly used. The clamp can be applied before, after or along with the

rubber dam sheet.

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Technique 1: Clamp placement prior to rubber dam

Step 1:- Testing and lubricating the proximal contacts:- Passing the floss through

the contacts identifies any sharp edges of restorations or enamel that must be

smooth or removed from the teeth to be isolated. Waxed dental tape may lubricate

tight contacts to facilitate dam placement.

Step 2:- Punching the holes:- It is recommended that assistant punch the holes

after assessing the arch form and tooth alignment. Holes can be marked by using

template or rubber dam stamp.

Step 3:- Lubricating the dam:- Lubrication of both the sides of rubber dam in the

area of punched holes using cotton roll or gloved fingertips. The lips and corners

are lubricated with petroleum jelly or cocoa butter.

Step 4:- Selecting the retainer:- Try the retainer on tooth to verify retainers

stability and tie the floss.

Step 5:- Testing retainer stability and retention:- If during trial placement the

retainer seem to be acceptable, remove the forcep and check for stability and

retention.

Step 6:- Positioning the dam over the retainer:- With the forefinger stretch the

anchor hole of dam over the retainer bow first and then under jaw. The forefingers

may thin out to single thickness, the septal dam for the mesial contact of retainer

tooth and attempts to it through the contact lip of the hole first.

Step 7: Applying the Napkin:- The operator now gather the rubber dam in left

hand and inserts the right hand through the napkin opening and grasps the bunched

dam held by operator.

Step 8:- Positioning of Napkin

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Step 9:- Attaching the frame: The operator unfolds the dam and stretches over the

rubber dam frame.

Step 10:- Attaching the neck strap: (optional) Neck straps attached to the frame

and its tension is adjusted to stabilize the frame and hold the frame.

Step 11:- Passing the tooth to distal contact: If there is tooth distal to the retainer

the distal edge of post anchor hole should be passed through the contact.

Step 12:- Applying compound (optional): If stability of retainer is questionable,

low fusing modeling compound may be applied.

Step 13:- Applying the anterior anchor (if needed): The operator passes the dam

over the anterior anchor tooth anchoring anterior portion of rubber dam.

Step 14:- Passing the septa through contacts without taper. The operator passes the

septa through as many contacts as possible without the use of dental tape by

stretching the septal dam faciogingivally and linguogingivally with the forefingers.

Pressure from a blunt hand instrument (e.g. beaver-tail burnisher) applied in the

facial embrasure gingival to the contact usually is sufficient to obtain enough

separation to permit the septum to pass through contact.

Step 15:- Passing the septa through the contacts with tape. Use waxed dental tape

to pass the dam through the remaining contacts. Tape is preferred over floss

because its wider dimension more effectively carries the rubber septae through the

contact. The waxed variety makes passage easier and decreases the chances for

cutting holes in the septa or tearing the edges of holes.

Step 16:- Technique for using tape (optional):- Often several passes with dental

tape are required to carry a reluctant septum through a tight contact, when this

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happen previously passed tape should be left in the gingival embrasure until the

entire septum has been placed successfully with passage of time.

Step 17:- Inverting the dam interproximally: Invert the dam into the gingival

sulcus to complete the seal around the tooth and prevent leakage.

Step 18:- Inverting the dam faciolingually: Complete the inversion facially and

lingually using an explorer or beaver-tail burnisher while the assistant directs a

stream of air onto the tooth. This is done by moving the explore around the neck

of the tooth facially and lingually with tip. The tooth surface or directed slightly

gingivally.

Step 19:- Using a saliva ejector

Step 20:- Confirming a properly applied rubber dam

Step 21:- Checking for access and visibility

Step 22:- Inserting the wedges

Technique 2: Applying dam and retainer simultaneously

Winged/ clamps are used in this technique. The retainer and dam may be

placed simultaneously to reduce the risk of retainer being swallowed or aspirated

before the dam is placed.

In this method first apply the posterior retainer to verify the stable fit.

Remove the retainer and with the forceps still holding the clamps, pass the bow

through the proper hole from the underside of dam.

When using retainer with lateral wings, place the retainer in hole punched

for the anchor tooth by stretching the dam to engage these wings. The operator

conveys the retainer (with dam) into the mouth and positions it on anchor tooth.

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Technique 3: Applying dam before the retainer

The dam may be stretched over the anchor tooth before the retainer is

placed. It is recommended for anterior teeth perhaps including first premolar.

Preferred technique when double bow or butterfly clamps are selected.

Multiple tooth isolation:

Multiple restorations and quadrant dentistry may require much larger

number of teeth to be isolated.

- Whenever possible clamps should not be placed on the tooth which requires

restoration of proximal surfaces. The clamp is placed on the next tooth distal to

it. If tooth is narrow mesiodistally the second tooth to the distal is preferable to

provide optimum access.

- When several teeth require treatment the operating field is extended mesially

or across the arch to provide clear access to all the teeth and maximize

retention.

- The more teeth included the better the retraction of lips, cheek and tongue and

better the access.

- The minimum operating field for one tooth to be restored proximally will

therefore include teeth, one distal which will usually be clamped, and one

mesial which is often not clamped.

- As the rubber is passed through each of remaining contacts in operating field,

care must be taken to allow only one edge of the interdental web of rubber dam

i.e. leading edge to be carried initially into each contact area. This process is

referred to as “Knifing the rubber dam through the contacts”, accomplished by

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stretching the rubber dam between the fingers to form a thin “knife edge”

aimed at contact point. Knife edge of the rubber dam can be often “sawn” past

the contact pulling it gingivally.

- The edge of rubber dam is inverted proximally first and then faciolingually. A

ligature of dental floss can be placed around the neck of tooth to hold the

rubber dam inverted.

REMOVAL OF RUBBER DAM:

Before removal of rubber dam, rinse and suction away any debris that may

have collected to prevent its falling into the floor of mouth during the removal

procedures.

Step 1: Cutting the septa: Stretch the dam facially pulling the septal rubber away

from gingival tissues and tooth. Clip each septum with blunted tip scissors, freeing

the dam from the inter proximal space, but the dam is left over the anterior and

posterior anchor teeth.

Step 2:- Removing the retainer: Remove the retainer by engaging it to the forceps.

Step 3: Removing the dam: Once the retainer is removed, release the dam from

anterior anchor tooth and remove the dam and frame simultaneously.

Step 4:- Wiping the lips: Wipe the lips with napkin immediately after the removal

of dam and frame.

Step 5:- Rinsing the mouth and managing the tissue

Step 6:- Extracting the dam

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RUBBER DAM IN CLINICAL RESTORATIVE PROCEDURES:

1) Endodontics: Rubber dam application in endodontics is essential to ensure the

patient’s safety during treatment. Aspiration or swallowing of root canal

instruments makes its use an integral part of endodontic practice.

2) Soft tissue control:- Control of lips, cheek and tongue can prove difficult with

some patient generally the young patient or patients who find hard to cooperate

during restorative procedure. The use of rubber dam enables fast and efficient

treatment in such cases.

3) Cavity preparation:- Rubber dam provides a controlled pleasant operating

environment. The enhanced contrast of cavity margins with rubber sheet,

improved access and safety, moisture control recompense for extra effort.

4) Specialized clamps / retainer:-

a. Clamps with the extended bows i.e. the bows lies more distally than the

standard clamp. E.g. Dentsply HW pattern and Ash AD pattern. They

can be used if the preparation distal surface of clamped tooth is

necessary.

b. Modified bow clamps designed to deal with problems encountered

when clamp has to be placed on the third molar. Standard clamp bow

interfere with the ramus of mandible. Modified bow clamps are so

designed that bow lies offset to one side i.e. palatal side and thus not

interfere with ramus.

The standard clamps can be modified by heat treatment and bending the

bow distally.

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Modification of rubber dam clamp increases access to distal surface of

anchor teeth.

c. Cervical retainer:- The use of cervical retainer for restoration of class V

cavity was recommended by Markley. E.g. of cervical retainer Ferrier

212 or Dentsply C. Teeth with cervical cavities which extend

subgingivally usually requires soft tissue at the gingival margin to be

retracted. The retraction force and retention of these clamps on the tooth

is provided mainly by impression compound which is softened and

moulded around the clamp bows and onto adjacent teeth. While the

impression compound is hardening, pressure is applied to the clamp to

press it gingivally and so reflect the soft tissue margins. As a rule the

facial jaw of the clamp should be 0.5 to 1 mm gingival to anticipated

location of gingival margin of completed tooth preparation.

5) Fixed bridge isolation:- It is sometimes necessary to isolate one or more

abutment teeth of a fixed bridge. Indications for fixed bridge isolation include

restoration of an adjacent proximal surface and cervical restoration of an

abutment teeth.

The rubber dam is punched as usual except for providing one large hole for

each unit in the bridge. Fixed bridge isolation is accomplished after the

remaining dam is applied.

A blunted curved suture needle with dental floss attached is threaded from the

facial aspect through the hole from the anterior abutment and bask through the

same hole on lingual side. The needle direction is then reviewed as it is passed

from the lingual side through the hole for the second bridge unit, then under

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the same anterior connector and through the hole of second bridge unit on

facial side. A square knot is then tied with the two ends of floss thereby pulling

the dam material smugly around the connector and into gingival embrasure.

6) Rubber dam in Pedodontics:- The age of the patient often dictates changes in

the procedures of rubber dam application. Because young patient have small

dental arches than adult patient holes should be punched accordingly. For primary

teeth isolation is usually from most post tooth to canine as the same side. Rubber

dam sheet is smaller 5 x 5 inch (12.5 x 12.5 cm).

The unpunched rubber dam is attached to the frame, the holes are punched,

the dam with frame is applied over the anchor tooth, and retainer is applied. The

jaws of the retainers should be directed more gingivally because of short clinical

crowns or because the anchor tooth’s height of contour is below the crest of

gingival tissue.

SS White No.27 recommended for primary and Ivory No.214 retainer for

young permanent teeth.

Isolated teeth with short clinical crowns (other than anchor tooth) may

require ligation to hold the dam position. Rubber dam described as “Rubber Rain

Coat” for young children.

ERRORS IN APPLICATION AND REMOVAL:

Certain errors in application and removal can prevent adequate moisture

control, reduce access and visibility or cause injury to the patient.

1) Off center arch form:- A rubber dam punched off center may not

adequately shield the patient’s oral cavity, allowing the foreign matter to

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escape down the patient’s throat. It can result in excess of material

superiorly that may occlude the patient’s nasal airway.

2) Inappropriate distance between the holes:- Too little distance precludes

adequate isolation because holes of rubber dam are stretched and will not fit

smugly around the necks of the teeth. Conversely too much distance causes

wrinkles between the teeth.

3) Incorrect arch form of holes:- If the punched arch form is tooth small, the

holes will be stretched open around the teeth, permitting leakage.

4) Inappropriate retainers:-

a. If too small, resulting in occasional breakage when jaws are

overspread.

b. Unstable on anchor tooth

c. Impinge on soft tissue

d. Impede wedge placement.

5) Retainer pinched tissue: Jaws and prongs of rubber dam retainer usually

depress the tissue but should not impinge on it.

6) Incorrect location of hole for class V lesion:- If there is an incorrect

location of hole for class V lesion and hole is not punched facial to arch

form, circulation of interproximal tissue will be diminished.

7) Sharp tips on No.212 retainer:- Sharp tips on retainer No.212 is dulled to

prevent damaging the cementum.

8) Incorrect technique for cutting septa:- During removal of rubber dam an

incorrect technique for cutting the septa may result in cut tissue or a torn

septa.

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WASHED FIELD APPARATUS:

This method employs inexpensive plastic tubing that is attached to saliva

ejector hose at one end and to the clamp or rubber dam itself at the other. Childers

and Marshall’s have recommended the use of clear vinyl tubing with inside

diameter of 0.0625 inch and an outside diameter of 0.125 inch. As connector for

saliva ejector hose recommended clear vinyl tubing with an inside diameter of

0.125 inch and outside diameter of 0.025 inch. The end of smaller diameter tube is

carried under the rubber dam frame and tucked under the bow o a wing of rubber

dam clamp in back of dam tubing may be attached to rubber dam by cyanoacrylate

adhesive. The washed field apparatus is used for evacuation of fluids from dam

when no assistant is available.

CONCLUSION:

When rubber dam is applied skillfully and thoughtfully any minor

drawbacks to patient are completely outweighed by outstanding benefits of this

excellent method of tooth isolation and patient protection. There are very few

situation in which one cannot have complete confidence that its use will enhance

the quality of dental treatment.

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REFERENCES:

1) Sturdwent’s Art and Science of Operative Dentistry. 4th edition.

2) Rubber Dam in clinical Practice.

3) Atlas of Operative Dentistry. 2nd edition.

4) Principles and Practice of Operative Dentistry. 3rd edition.

5) Operative Dentistry Modern Theory and Practice. 1st edition.

6) Fundamentals of Operative Dentistry by James B. Summit. 2nd edition.

7) Operative Dentistry 1986; 11:42-45.

8) Journal of Endodontics 1986; 12:183-186.

9) British Dental Journal 1984; 156:402-403.

10) Journal of Endodontics 1984; 10: 544-545.

11) Journal of Endodontics 1984; 10: 452-454.

12) Quintessence International 2003 Nov-Dec 34(10)

13) Journal of Endodontics 2003 Oct. 29(10)

14) Journal of Prosthetic Dentistry 1983; (5): 797-799.

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