ISOLATION IN RESTORATIVE DENTISTRY

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Contents

• Introduction
• History
• Goals of isolation
• Advantage of moisture control
• Methods of isolation
• Direct method :
• Rubber dam
• Cotton rolls
• cellulose wafers
• Dri-angle
• Gauze piece
• Suction devices
• Mouth props

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• Isolation of soft tissues
• Retraction of cheeks ,lips and tongue
• Retraction of gingiva

-Mechanical

-Mechanical chemical

-Chemical

-Surgical

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• Recent advances
• Conclusion

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Introduction

• Isolation is a technique to protect a tooth against contamination from oral fluids during a surgical or restorative procedure, usually through the application of a rubberdam or various other measures.

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• Good isolation is required for the success of any restorative treatment

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• Isolation is necessary for easy manipulation and insertion of restorative materials

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History

• Rubber dam developed by SC Barnum – 1864
• 1870, Dr. J.F.P. Hodson,7 types of clamps & no forceps used
• 1870, Dr. Tees festooned clamps
• 1878,Dr.Elliot design clamp forceps
• 1879, Ainsworth rubber dam punch
• 1880, Dr.Hickman’s lipped clamps
• 1890, clamps with holes
• Early 20th century –Rubber dam frame introduced(metal Fernauld’s frame)

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Goals of isolation

• Moisture control
• Retraction and access
• Harm prevention

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Advantages of moisture control

Patient related:

• Provides comfort
• Protect from swallowing or aspirating foreign bodies
• Protect soft tissues by retracting them

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Operator related:

• dry clean operative field
• Infection control
• Increased accessibility to operative site
• Improved properties of restorative materials
• Improved visibility & less fogging of mirror
• Prevents contamination of tooth preparation

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Rubber dam

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• One of the most effective means of isolating teeth
• Developed by SC Barnum in 1864

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• ABCD’s of rubber dam
• Adequate access and visibility in the operating field
• Better patient protection and management
• Control of moisture in the operating field
• Decreased operating time

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Equipment

• Rubber dam sheet
• Rubber dam frame
• Rubber dam retainer
• Rubber dam template
• Rubber dam punch
• Rubber dam forceps
• Rubber dam napkin
• Waxed dental floss
• Lubricants

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Rubber dam sheet�

• latex or non-latex.
• Available as rolls/sheets
• Available in 2 sizes-

5” X 5”( pediatric)

6” X 6”( Adult)

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• Colour – Green and blue are preferred –good contrast

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• Has a shiny and dull surface, dull side will be face the operator

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Rubber dam frame�

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• maintains the border of the dam in position
• Support the edges of the rubber dam
• Available in metal and plastic

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• Young frame

U-shaped metal frame with small metal projections for securing borders of the rubber dam.

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• Nygard-Ostby frame

Also known as shark mouth

• U-shaped frame made of plastic
• Because of its shape, exerts less tension on the dam
• Easier to use
• Stands away from face

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Rubber dam retainer

• consists of a bow & 2 jaws , each jaw -2 prongs
• Aid in anchoring the dam to the tooth & in soft tissue retraction

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Material used- Metallic

Nonmetallic/plastic

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Based on flange – Winged

Wingless

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• 4 point contact
• Jaws should not extend beyond the angle of the tooth
• interfere with the wedge placement ,matrix band
• cause gingival trauma
• complete seal around anchor tooth difficult

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Rubber dam punch

It is a precision instrument with rotating metal table with six holes of varying sizes and a tapered sharp pointed plunger.

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• Types

Ivory pattern

Ash /Ainsworth pattern

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• Errors in punching holes

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• Holes punched too close together – dam to stretch,space around teeth, causing leakage
• Holes punched too far apart– dam bunches up between teeth
• Holes position too low on the dam – dam covers patient’s eyes or nose
• Holes position too high on dam – dam does not extend over upper lip

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• Hole positioning guides

-Teeth as a guide – teeth themselves/stone cast

- Template

- Rubber dam stamp

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Rubber dam clamp forceps�

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• Used for placement and removal of retainer from the tooth.

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Lubricants�

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• Water soluble lubricant is preferred
• Velvachol

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• Lubricants for lip – petroleum based like Vaseline,cocoa butter ,silicate lubricant,lip balm

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Rubber dam napkins

• Prevent direct contact between the rubber sheet & patient’s cheek

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• Absorb saliva that accumulate beneath the dam

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• Indicated in cases of allergy to the rubber dam
• Provides a convenient method of wiping the patient’s lip on removal of the dam

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Dental floss

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• 12 inch dental floss tied on the bow of the clamp

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• aid in retrieval of the clamp if it is dislodged

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Rubber dam application

• When operating on central and lateral incisor,mesial aspect of canine isolation done – 1^st pm to 1^st pm

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• Canine- 1 molar to opposite lateral incisor

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• Premolars – 2 tooth distally – lateral incisor

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• Molars – isolate till posterior most tooth on the same side and till lateral incisor on the opposite side.

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Preparation of the mouth

• Teeth should be cleaned if necessary

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• Contacts checked with floss

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• Rough contacts smoothened- interproximal contact disk

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• Restorative procedure involving occlusal surface – maximum intercuspation contacts marked with articulating paper /tape prior to dam

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• Centric occlusion markings coated with light cured resin/varnish

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• Lips to be lubricated done prior to dam placement

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Methods of rubber dam placement

1. Clampfirst technique
2. Dam first technique
3. Clamp and the dam together

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Clamp first technique

• Testing and lubricating the proximal contacts

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• Punching the holes

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• Lubricating the dam

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• Selecting the retainer

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• Testing the retainer’s stability and retention

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• Positioning the dam over the retainer

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• Applying the napkin

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• Attaching the frame

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• Passing the septa throught the contacts

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• Invert the rubber dam interproximally

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• Invert the rubber dam faciolingually

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• Confirming a properly placed rubber dam

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Checking for access and visibility

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Dam first technique

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Clamp and the dam together

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Removal of rubber dam

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Cutting the septa

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Remove the clamps

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• Remove the dam

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• Wiping the lips

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• Massage the tissue

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• Examine the dam

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Split dam technique

• Rubber dam is placed to isolate the tooth without the use of clamp
• 2 overlapping holes punched in the dam
• Dam stretched over tooth to be treated and adjacent tooth on each side

Indication – isolate anterior teeth

insufficient crown structure

isolation of teeth with porcelain crown required

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• Advantages of rubber dam

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• Increases visibility & accessibility
• Provides a dry field
• Effectively retracts tongue, cheeks away from the field of operation
• Improved properties of dental materials
• Improves the efficiency of treatment
• Reduces the chances of injury to soft tissues
• Protects against bad taste of the materials used
• Prevents any aspiration or ingestion of dental instruments

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• Disadvantages of rubber dam

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• Takes time to be applied
• Communication with the patient can be difficult
• Incorrect use may damage porcelain crowns/gingival tissues
• Insecure clamps can be swallowed or aspirated

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• Contraindications

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• Asthmatic patients
• Presence of some fixed orthodontic appliances
• Third molars(in some cases)
• allergy to latex
• Mouth breathers
• Psychological reasons

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Recent advances

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Recent Accessory to Rubber Dam�1. Cushees�

• These are soft thermoplastic cashew shaped nodules which are grooved on their inner surface and act as rubber dam clamp cushions.
• It is slipped over the tooth attachment blade of clamp prior to clamp application.
• It increases patient comfort.��

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2. Wedjets (Hygenic)�

• These are stretchable elastic stabilizing cords made from natural latex rubber and used as a rubber dam retainer

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• These are a faster and easier method of retaining the rubber�dam than using conventional clamps.

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• placed like dental floss over the rubber dam in the�interproximal areas of the teeth

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• especially used in the isolation of anterior teeth.������

• Cotton rolls

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• Available in different diameters, cut to variant lengths & have plain or woven surfaces

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• Stabilized & held sublingually with specific holders or with an anchoring rubber dam clamp

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- manually rolled

- prefabricated - smooth

- woven

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• Can be applied without holders, over or lateral to salivary gland orifices

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Cellulose wafers

• Absorbent pads made of cellulose
• Most commonly used inside cheek covering parotid ducts
• Available in various shapes and sizes
• Adv- absorbency more than cotton rolls

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• Dri – angle
• A thin, absorbent, cellulose triangle

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• Covers the parotid or Stensen's duct and effectively restricts the flow of saliva
• Provides the required Dri-Field for
• Composites
• Bonding
• Cementing

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• Comes in two types:  plain and silver coated

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• Advantage – Slight retraction of cheeks aiding in visibility & access
• Disadva- Absorbents can be used for short period of time only

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• Precaution:
• Moisten the cotton rolls & cellulose wafers while removing to prevent inadvertent removal of epithelium from cheeks, floor of mouth or lips

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• Gauze piece or throat shields

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• Indicated when there is danger of aspirating or swallowing small objects, when rubber dam is not being used

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• Used in pieces of 2”x2” or larger

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• Particularly important when treating teeth in maxillary arch

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• Gauze sponge unfolded & spread over the tongue& posterior part of the mouth

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• Advantage –
• Better tolerated by delicate tissues
• Less adherence to dry tissues compared to cotton

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Evacuation system

• 2 types

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High vacuum evacuation system

Low vacuum evacuation system

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• High vacuum suction

Powerful suction equipment used with an assistant

May also used to retract lip simultaneously

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• Low vacuum suction ( saliva ejector)

Fluid removal during cemntation and impression procedure

Can be used during tooth preparation

Used without any assistance

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Saliva ejector

High volume evacuator

• Types of saliva ejectors :
• Metallic –
• Autoclavable
• Rubber tip to avoid irritating delicate tissues

on floor of the mouth

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• Plastic – Disposable & inexpensive

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Metallic saliva ejector

Plastic saliva ejector

• Requirements :

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• Tip should always be molded to face backwards with a slight upward curvature
• Floor of the mouth under the tip should be covered with gauze to prevent injury to soft tissues
• Should not interfere with instrumentation

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• Mouth props

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• Can be potential aid for lengthy appointment on posterior teeth

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• Should maintain suitable mouth opening

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• Types –
• Block
• Ratchet

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Block type

Ratchet type

• Ideal characteristics -
• Should be adaptable to all mouths
• Should be easily positioned & removed with no patient discomfort
• Should be stable once applied
• Should be either sterilizable or disposable

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Svedopter

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• Flange type of saliva ejector made of metal
• Fluid removal and tongue retraction during tooth preparation on mandibular arch and isolatioin during impression and cementation
• Can be used without assistance

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• Indirect methods :
• Comfortable position of patient
• Local anaesthesia
• Drugs –
• Anti sialogogues
• Anti anxiety ( Diazepam/barbiturate 24 hr before appoinment)

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Local anaesthesia

• Reduce salivation as patient Is more comfortable ,less anxious and less sensitive to oral stimuli reducing salivary flow

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• Mechanism of action :by blocking nerve impulses from pdl that regulate salivary flow

Vasoconstrictor- reduce blood flow – control haemorrhage at the opening site

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• Antisialogogue
• Anticholinergics - Atropine ,Dicyclominne ,Propantheline – 1hr before procedure
• C/I – hypersensitivity to drug, glaucoma,asthma,obstructive conditions of GIT ,CCF

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• Clonidine - antihypertensive drug

Dosages

Atropine- 0.4 mg

Dicyclomine HCl – 10-20 mg

Propantheline bromide - 7.5 -15 mg

Clonidine – 0.2 mg

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• Gingival tissue management

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The procedure of temporary eversion or resection of gingiva away from the tooth surface or deepening of gingival sulcus to expose the cervical portion of tooth in order to have proper marginal finish to the restoration or by establishing a good cervical cavosurface margin to the tooth preparation.

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��Retraction of gingiva

• Mechanical

Copper band

Rubber dam

Cotton thread

Magic foam

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• Mechanical chemical- retraction cord
• Chemical
• Surgical

Rotary curettage( gingettage)

Electoro surgery

Soft tissue lasers

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Mechanical method

Physically displaces the gingiva

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Copper band

• Oversized copper bands are contoured to the gingiva and restricted towards the cavity margin when gently seated over the tooth.

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• The band should be about 2 mm wider than the MD width of tooth

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Cotton threads

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• Use of Rolled Cotton TWILLS which are forcibly introduced into the gingival sulcus

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Results are seen within 30 minutes

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Magic foam

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It consisit of comprecap- a hollow cotton and magic foamcord- poly vinyl siloxane material

Prior to impression making – desired size of comprecap selected

• Magic foamcord injected around the preparation and inside comprecap
• Pt instructed to gently bite to hold the comprecap

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Adv- Easy to use with less trauma

Disadv- Less retraction than cord

Prior Haemostasis must be established

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Mechanical chemical

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A retraction cord is used for mechanically separating the tissue from prepared margin and is impregnated with chemicals for astringent action and / haemostasis as impressions are made.

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Ideal requirements

• Dark in colour.
• Made of absorbent material
• Strong enough to resist placement and should not snap.
• Available in different diameters to accommodate the gingival sulcus

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D] Depending on number strands

• Single
• Double-string

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E] Depending on surface finish

• Waxed
• Unwaxed

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A] based on material

• Ready made cotton
• Synthetic woven cords

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B] based on medication

• Medicated
• Non-medicated

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C] based on presence of adrenaline

• Adrenaline containing
• Adrenaline free

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F] based on configuration

Braided

Knitted

Twisted

Flattened

Plain

G] based on the thickness (color coded)

black 000

yellow 00

purple 0

blue 1

green 2

red 3

• Chemicals used

Ferric sulphate 20-25%, aluminium chloride 15-29%

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Cord supplied impregnated with chemical/ cord dipped in specific chemical agents .

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Transient ischemia

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shrinking of tissue

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control gingival fluids

haemostasis

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Instrument for packing the cord – Fischer’s cord packer

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Displacement techniques

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• Single cord technique
• Double cord technique

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The packing instrument should be blunt, with definite corners, latchet or hoe-shaped preferably with serrations.

• Single cord technique

Making impression of one to three prepared teeth with healthy gingiva tissues

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• Retraction cord dipped in appropriate chemical

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• Loop of retraction cord formed around the tooth

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• Cord grasped from lingual side

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• Placement of retraction cord begun by pushing into sulcus on mesial surface

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• Instrument angled slightly toward the root

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• Excess cord cut off in mesial interproximal area

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• Application of ferric sulphate to arrest bleeding

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• Double cord technique

Deep sulcus

tissues health is slightly compromised with more than normal bleeding anticipated

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Chemical

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• Aluminium chloride containing paste(Expasyl) injected into sulcus
• Left 3-4 min
• Good hemostasis with less trauma
• Disadv: retraction less compared to cord

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Gingifoam

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• It’s a 2 paste system
• Base paste: poly dimethyl siloxane
• Catalyst paste: tin

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• On mixing the 2 pastes, H2 gas is released 🡪 formation of foam 🡪 gingival retraction

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Merocel

a synthetic material that is specifically chemically extracted by a biocompatible polymer (hydroxylate polyvinyl acetate).

• Available as strips.
• Used for gingival retraction.

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Surgery

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Rotary curettage(gingettage)

• Amsterdam in 1954
• Troughing technique
• Epithelial tissue in the sulcus is removed by rotary instrument while finish line is being created,
• Should be used

Absence of bop

sulcus depth < 3 mm

Adequate keratinized gingiva

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• Disadv

Poor tactile sensation

Potential for destruction of periodontium with inexperienced hands

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Electrosurgery

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Controlled tissue destruction to achieve a surgical result.

Mechanism

• High density current from a small cutting electrode produces a rapid rise of temperature at the point of contact with tissue .the cells in contact with the electrode are destroyed by this temperature rise

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• An unmodulated alternative current recommended

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Indication

• Gingival sulcus enlargement and hemostasis
• Gingivectomy
• Crown lengthing

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Contraindication

• Pt with electronic medical device- cardiac pacemaker,insulin pump
• Pt with delayed healing
• Thin attached gingiva
• Not used with metal instrument in contact with them
• Not used in presence of flammable agents- topical anaesthetics- ethyl chloride/aerosols,nitrous oxide analgesia

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Soft tissue lasers

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Types

�Neodymium: Yttrium – Aluminum - Garnet (Nd-YAG)�Lasers�The use of this type is contraindicated near tooth surface as they tend to absorb energy and heat. This heat can be�transmitted to bone and may result in bone loss.�

Erbium: Yttrium – Aluminum - Garnet (Er:YAG)�Lasers�These minimally penetrate the soft tissues, so they are fairly�safe to use.�

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CO2 laser

CO2 lasers absorb little energy near tissue surfaces, with only small temperature increases (<3ºC) and minimal collateral damage. Also, these lasers do not alter the structure of the tissues.�

Advantages�- Excellent haemostasis is provided by CO2 laser.�- There is reduced tissue shrinkage.�- It is relatively painless procedure and sterilizes the�sulcus.��

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• Recent advances in isolation

�1. Kool dam (Pulpdent Corporation)

• It is a light cured material applied to the gingiva or tooth surfaces prior to power bleaching, sand blasting or other procedures requiring intraoral protection or isolation.
• also used to block out undercuts prior to taking impressions.
• Also called as liquid rubber dam
• It remains flexible after curing and has good tear resistance.������

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Fast dam

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• It can be used in place of cotton rolls to retract the cheek and

tongue while maintaining a dry field.

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• Continuous aspiration is achieved by means of 17 suction holes along the perimeter, eliminating the need to change saturated cotton rolls while retracting the cheek and tongue.

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Isolite

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• simultaneously delivers continuous throat�protection, illumination, retraction and isolation �
• It can be particularly useful in young people with incompletely erupted teeth. ���

Conclusion

A thorough knowledge of the isolation techniques is required for the success in restorative dentistry.

It is imperative that there should be proper moisture control ,good accessibility and visibility as well as adequate room for instrumentation around working area.

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THANK YOU

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