gingival tissue retraction

GINGIVAL TISSUE DISPLACEMENT IN FPD

Deepak K Gupta

facebook.com/notesdental

• Definition

• Importance, criteria

• Classification and types:

- Mechanical

- Mechanico-chemical

- Rotary gingival curettage

- Electrosurgery

- other methods and new materials


GPT : Gingival retraction or displacement is the deflection of the marginal gingiva away from the tooth. ‘tissue dilation’


NEED AND IMPORTANCE OF DISPLACEMENT

1. Adequate access to the prepared tooth.

2. Reproduction of the finish line.

3. For accurate duplicating the sub-gingival margins.

4. Providing the best possible condition for the impression material, fluid control.

5. Precision of the restoration for prevention of periodontal disease.


CRITERIA FOR SELECTION :

• Effectiveness in gingival displacement and hemostasis

• Absence of irreversible damage to the gingiva

• Paucity of untoward systemic effect


TYPES OF DISPLACEMENT

• LATERAL: displaces the tissue so that adequate bulk of the impression material can be interfaced with the prepared tooth.

• APICAL/VERTICAL: exposes the uncut portion of the tooth apical to the finish line. May cause trauma of the gingival tissues followed by recession.


CLASSIFICATION

• MECHANICAL

• CHEMICO-MECHANICAL

• ROTARY GINGIVAL CURETTAGE ‘GINGETTAGE’

• ELECTROSURGERY

• OTHER METHODS/COMBINATION


MECHANICAL TISSUE DILATION

One of the first and earliest methods used for physically displacing the gingiva.

1. Impression material filled copper band/tube

2. Rubber dam

3. Temporary acrylic resin coping

4. Temporary metal crown filled with thermoplastic stopping material

5. Strings or fibers


Impression material filled copper band/tube


VARIOUS IMPRESSION MATERIALS USED:

Impression compound,elastomeric material,

Gutta-percha or auto polymerizing resin.

DISADVANTAGES:

• Incisional injuries to the gingival tissues

• Excess pressure tends to stripple the tissue from the tooth

ADVANTAGE:

• Good method to confirm gingival margins e.g. in multiple abutments


RUBBER DAM

ADVANTAGES• Asset during tooth preparation as it exposes

the finish line.• Excellent impressions are obtained due to

fluid controlDISADVANTAGES• Useful only when limited number of teeth in

one quadrant are being restored.• Used in simple preparations with minimal

Sub-gingival preparations.


TEMPORARY ACRYLIC RESIN COPING

1. A Temporary acrylic resin coping is constructed and the inside is relieved by 1 mm.

2. Adhesive is applied and elastomeric impression material is placed and reseated

3. The tissue is displaced when the material mechanically fills into the sulcus.

4. A complete arch impression is subsequently made over the coping and it becomes an integral part of the impression


TEMPORARY METAL CROWN FILLED WITH THERMO-PLASTIC STOPPING MATERIAL

1. Correct size is selected, trimmed to confirm to the gingival contour and the margins are smoothened.

2. Fill it with compound or gutta percha. Under occlusal pressure it is forced into the predetermined position.

3. The excess material from gingival end will displace the free gingiva.

4. The excess material is trimmed without excessive pressure (blanching).

5. Cement it with temporary cement for 24 hours6. Final impression made in the next appointment


STRINGS OR FIBERS

e.g. - Plain cotton thread

- Un-waxed floss

- Cotton cord

- 2/0 untreated Surgical Silk

- Elastic retraction rings

Types- plain, braided, knitted or other type

- can be used wet or dry


MECHANICO-CHEMICAL METHODS

• The Mechanical aspect involves placement of a string into the gingival sulcus to displace the tissues.

• The Chemical aspect involves treatment of the string with one or more number of chemical compounds that will induce

i) Temporary shrinkage of the tissues &

ii) Control the hemorrhage & fluid seepage


STERILE TWILLS OF COTTON IMPREGNATED WITH SLOW SETTING ZINC-OXIDE EUGENOL CEMENT

PROCEDURE:

1. Cotton twills the size of floss are rolled in a creamy mixture of ZnOE cement

2. Several twills are placed in the sulcus. Min of 48hrs is recommended for placement but not more than 5-7 days.

DISADVANTAGE:

• Sulcular hemorrhage during packing


RETRACTION CORD DESIGNS

• Twisted,

• Knitted

• Braided

– does not separate when inserted into the sulcus and much easy to use.

– larger sizes should be avoided as they tend to double up and leads to traumatic placement


RETRACTION CORD DIAMETER

The cord that can be atraumatically placed into the sulcus should be used.

• SMALL- to be used in anterior teeth, where thin firmly tissue is present

• MEDIUM- indicated where greater bulk is encountered e.g. posterior teeth

• LARGE- should be used with caution as can produce soft tissue trauma


CHEMICALLY IMPREGNATED CORDS

• The cords are used to keep the chemicals in contact with the tissue and confine them to the application site.

• By combining chemical action with pressure packing, enlargement of the gingival sulcus as well as fluid control is more readily accomplished.


VARIOUS DRUGS USED FOR GINGIVAL DISPLACEMENT

CHEMICAL BRAND

0.1-0.8% Racemic epinephrine RACORD, GINGI-PAK,

SIL-TRAX,SULPAK

100% Alum sol. POT. ALUM. SULFATERASTRINGENT II,FLEXI-BRAID,GINGI YARN

5%-25% Aluminum chloride sol. HEMODENT,GINGI-AID,

GINGI-GEL

Ferric Sub-sulfate MONSEL’S SOL.-

13.3% Ferric sulfate sol. ASTRINGEDENT,

VISCOSTAT

8%-40% Zinc chloride sol. -

20%-100% Tannic acid -

45% Negatol sol. NEGATANfacebook.com/notesdental

COMBINATIONS BRAND

EPINEPHRINE + ALUM R-44, 45-46 ASPETICO

EPINEPHRINE + ZINC PHENOL SULPHONATE

RACORD

4% EPINEPHRINE +ALUM SULPAK, ULTRAX

0.1% EPINEPHRINE+ COCAINE

-

ZINC CHLORIDE+ 8% EPINEPHRINE

-

ALUM + ALUMINIUM CHLORIDE

-


EPINEPHRINE

• A catecholamine hormone secreted by the adrenal medulla and a CNS neurotransmitter released by some neurons

• It appears to act primarily on the walls of small arterioles and to a lesser degree on the walls of capillaries venules and large arterioles, thus epinephrine is not very effective in controlling gingival bleeding


ALUM (POTASSIUM ALUMINUM SULFATE)

• ACTION- Astringent, transient ischemia

• Used in 100% concentration, efficacy slightly less than Eph.

• Very few systemic effects, used in place of epinephrine

ADVANTAGES:

1. Good tissue recovery(10 days)

2. Minimal tissue loss(0.1mm)

3. Extended working time.(can be safely left for 20 min)

DISADVANTAGE:

1. Less hemostasis and displacement compared to epinephrine


ALUMINUM CHLORIDE 5% - 25%

• Most commonly used

• 25% solution approx. doubles the haemostatic effect of other chemicals

ADVANTAGES:

1. No known contraindications and minimal side effects.

2. Considered most effective chemical to control bleeding and displace tissue with minimal damage

DISADVANTAGE:

1. <10% causes local tissue destruction


FERRIC SUBSULFATE – MONSEL’S SOL.

• Slightly more effective than Eph.

• Tissue recovery is good but messy to use

• Recommended time of use is 3 min.

• Literature infers that ferric or ferrous salts are corrosive, injurious to soft tissues and stain the enamel. this is due to their high acidity = 72% of sol.


FERRIC SULFATE 13.3%

• It does not traumatize the tissue as noticeably, healing is more rapid than aluminum chloride.

• It is compatible with aluminum chloride, not epinephrine.

• When used with Eph. It develops a massive blue precipitate.

• Coagulates blood very quickly.

• Time of use 1-3 min and 10-20 min max.

• Tissue displacement is maintained for at least 30 min.

• Corrosive effect absent, unpleasant taste, tissue discoloration.


ZINC CHLORIDE (bitartarate) 8% - 40%

• 8% =displacement = epinephrine. it can cause severe necrosis of the tissues that did not heal in 60 days

• 40% =displacement > epinephrine. Is very caustic and is termed as a chemical cauteryagent.

• These sol. are not recommended for use as they are Eschariotic and cause permanent injury to soft tissue and even bone


TANNIC ACID 20% - 100%

• Astringent

• Good tissue recovery

• Less effective than epinephrine

• Haemostatic effect is minimal

• Time of usage- 10 min


NEGATOL SOL.

• 45% condensation product of meta cresol sulphonic acid and formaldehyde.

• Better retraction than epinephrine

• Tissue recovery is poor

• Highly acidic and decalcifies teeth in 10% and 100% sol.

• Classified as a chemical cautery agent and not recommended for gingival displacement.


TIME OF PLACEMENT OF RETRACTION CORDS

• Untreated string/cord is safe for placement for periods from 5-30 min, when bleeding and seepage not a problem.>30 mins, causes permanent soft tissue changes.

• Strings saturated with chemicals are recommended for use from 5 – 10 min , <20 min.

• After 30 min, impregnated cords caused injury to the sulcular epithelium, these healed with in 10 days.


TECHNIQUES FOR GINGIVAL DISPLACEMENT USING RETRACTION CORDS

1. Single cord technique

2. Double cord technique

3. Infusion technique of gingival displacement

4. The ‘every other tooth’ technique


SINGLE CORD TECHNIQUE

1. Loop of retraction cord is

Formed around the tooth

and held with the thumb

and forefinger

2. Placement of the cord is begun

By pushing it in the sulcus on the

mesial surface of the tooth (A)

it should also be tacked into the distal

crevice to hold the cord in place (B)


3. As the cord is placed subgingivally

the instrument must be pushed slightly

towards the area already tucked into

place (A)

if the force is directed away from the

area previously packed the cord

will be pulled out (B)

4. It may be needed to hold the cord

with another instrument.

5.The instrument should be slightly

angled towards the root to facilitate

subgingival placement.


6. Excess cord is cut at the mesial

Interproximal area.

7. Placement of the distal end of the

cord is continued till it overlaps

the mesial.


• CORD PACKING INSTRUMENTS:

Angled

Circlet® Packing Plain

Circlet® Packing Serrated

Standard Packing Serrated

Standard Packing

Plain

PASCAL Cord Packing Instrument

Fischer’s ULTRAPAKPackers


THE DOUBLE CORD TECHNIQUE

Indications:

-impression of multiple

prepared Teeth.

-when tissue health is

compromised.

-excess gingival fluid exudates.

-can be used routinely.


1. A smaller diameter cord is placed in

sulcus.

2. A second cord (largest diameter that

can be placed) is placed above the first.

3.After waiting for 8-10 min it is soaked

in water and removed, dried,and

impression is made with the

first cord in place facebook.com/notesdental

THE INFUSION TECHNIQUE

Steps:1. After preparation of the margins, hemorrhage

is controlled Using a special dental Infusor with

Ferric sulfate medicament 15% 0r 20%.

2. The infusor is used with a burnishing

Action, 360 deg. Around the sulcus.

3. Recommended time 1-3 mins.

4. Cord is removed

and impression

made.


THE ‘EVERY OTHER TOOTH’ TECHNIQUE:

Indications:

1. Multiple anterior teeth impression, where any damage to the gingival tissue will lead to recession.

2. Teeth with root proximity- placing cords around all the teeth simultaneously will cause strangulation of the gingival papilla, leading to unaesthetic black triangles


ROTARY GINGIVAL CURETTAGE

• Also called as ‘Gingettage’ and ‘Troughing’

• A technique of using rotary diamond instruments to enlarge the sulcus. It involves preparation of the tooth sub-gingivally while simultaneously curetting the inner lining of the gingival sulcus.

• The goal is to eliminate the trauma from pressure packing and the need for electrosurgical procedures


SUITABILITY OF THE GINGIVA FOR GINGETTAGE

• Absence of bleeding from probing.

• Sulcus depth less than 3 mm.

• Presence of adequate keratinized gingiva.


ELECTROSURGERY

• Also called ‘Troughing’ and ‘Gingival dilation’• A trough is created that extends from the crestal height

of the gingiva to a point 0.3-0.4mm apical to the finish line using a fully rectified current.


INDICATIONS

1. Areas of inflammation and granulation tissue around tooth.

2. In cases where it is impossible to retract the gingiva.

3. To enlarge the sulcus and also to control hemorrhage.

4. To remove irritated tissue

that has proliferated over

the finish line.


5. Removal of edentulous cuff.6. Crown lengthening.

CONTRAINDICATIONS:1. Patients with cardiac pace makers, TENS, Insulin

pump.2. Very fine marginal gingiva with little or no attached

gingiva.3. Presence of inflammable anesthetics or agents.4. Delayed healing due to debilitating disease, radiation

therapy.facebook.com/notesdental

TECHNIQUE:


• ELECTRODES:

A-COAGULATING

B-DIAMOND LOOP

C-ROUND LOOP

D-SMALL STRAIGHT

E-SMALL LOOP

Oringer recommends that the

grounding electrode be placed

under the thigh rather than back,

as contact with a small bony

protuberance, vertebra etc could

produce high current density

to cause a burn.


RECENT ADVANCES IN GINGIVAL TISSUE RETRACTION


GINGIFOAM


Crown preparation prior to retraction

Pre-fit one Comprecapper crown preparation

Apply Magic FoamCord

have the patient bite and maintain pressure

Remove after 5 minutes

result is a wide open sulcus multiple preparations facebook.com/notesdental

• Comprecap / Comprecap anatomic


• Gel Cord® or Stat Gel®

Apply gel to sulcus

Hemostasis occurs in as little as 2 minutes

Pack cord through gelGel works into cord

After removing cord,rinse & dry

Clean, dry site

Final impressionfacebook.com/notesdental

GingiTrac™

1) Make Matrix

2) Dispense GingiTrac

into the matrix

3) Bite down & wait 4) Ready forimpressionin less than 5 minutes


MEROCEL (Merocel Co., Mystic)

Synthetic materialthat is specifically

chemically extracted from a biocompatible

polymer (Hydroxylate polyvinyl acetate)


• Stay-put

Stay-put is so pliable that it stays where you put it. Stay-put is a unique combination of softly braided retraction cord and an ultra fine copper filament

• GINGI-LOOPS


LASER:

• DIODE AND ND:YAG LASER channels laser through a fiber optic light bundle which incises and cauterizes tissue simultaneously creating haemostasisas well as a retracted field.

PULSED ND = YAG LASER IRRADIATION.

The present histological findings revealed that with the application of PULSED ND: YAG LASER the gingival tissues showed faster healing with less hemorrhage and less inflammatory reaction in comparison with the Ferric sulphate (13.3%).


gingival tissue retraction

Health & Medicine