4. INTRODUCTION
Gingival Retraction is deflection of the marginal gingiva away from a
tooth.
Its is a process of exposing margins when making impression of
prepared teeth.
Impression making is technique sensitive because accurate reproduction
of the finish line is essential for the fabrication of the cast restoration
Hence it is necessary to retract the gingival sulcus prior to impression
making
5. NEED FOR GINGIVAL RETRACTION
Contour of the future restoration
Patient’s comfort
Efficiency of impression material
Operators access and visibility
6. “RETRACTION” is the downward and outward
movement of the free gingival margin
“RELAPSE” is the tendency of the gingival
cuff to go back to its original position.
“DISPLACEMENT” is a downward
movement of the gingival cuff that is caused by heavy-
consistency impression material bearing down on
unsupported retracted gingival tissues.
“COLLAPSE” is the tendency of the
gingival cuff to flatten under forces associated with the
use of closely adapted customized impression trays
Gingival Retraction Techniques for Implants vs Teeth.
Bennani V, Schwass D, Chandler N. J Am Dent Assoc.2008;139:1354-63.
7. VARIOUS PHASES IN GINGIVAL DISPLACEMENT
During tooth preparation (Preparatory phase ) :-
plan the position of the cervical finish line in relation to the gingiva prior to tooth
preparation.
The gingiva must be displaced to give a clear view of the cervical area
During impression making ( working phase ) :-
An adequate access to the finish line should be obtained after tooth preparation is
done.
This displaces the gingiva apically and laterally to provide space for the impression
material to flow and record details.
During Cementation of Restoration (Maintenance phase ):-
The gingiva adjacent to the finish line must be displaced prior to cementation to
evaluate marginal fit and also to remove excess cement after cementation
8. CRITERIA FOR SELECTION OF A GINGIVAL
RETRACTION MATERIAL
According to Milford B.Reiman (1976), the gingival retraction material must
be effective enough to create a trough, free of blood and fluids and there must
be no damage to the gingiva in terms of inflammation or bleeding.
The resulting contours of the tissues must be predictable and tissue must
recover in a considerable period of time with minimal systemic or localized
effects.
9. There are three criteria that must be satisfied by a gingival retraction
material:
- It should be effective in gingival retraction and achieve hemostasis
if necessary.
- There should be absence of systemic effects.
- No irreversible damage to gingival tissues with the material selected.
Shillinburg HT. Fundamentals of Tooth Preparation. 3rd Edition
12. Biological width
About 2.04mm ---- 1.07
con.tissue & 0.97 epth.attach
Placement of restoration should
not encroach this space.
13. Evaluation of biological width
Clinically - distance between
bone and restorative margin
Probe is pushed through the
anesthetised attachments
< 2mm - violation of biological
width
15. Margin placement guidelines
Should be placed in the sulcus not in the attachment
Shallow probing depth (1-1.5mm) - preparation should extend only
0.5mm
> 1.5mm - 1/5th the depth of the sulcus below the crest
> 2mm - perform gingivectomy
Deeper the gingival sulcus - greater the risk of gingival recession
19. 1.Rubber dam
It was introduced by S. C. Barnum (1864) , it produces retraction by
compression and is used when a limited number of teeth in one quadrant have
been prepared.
• Heavy weight rubber dams were used..
• Advantages
control of seepage and hemorrhage.
ease of application.
• Disadvantages
full arch models cannot be made.
severe cervical extension preparations.
20. Limitations :
Should not be used with polyvinyl siloxane impression material,
because the rubber dam will inhibit its polymerization.
Cannot be used to record subgingival preparation.
Shillinburg HT. Fundamentals of Tooth Preparation. 3rd Edition
21. 2.Copper Band
The copper band acts as a means of
carrying the impression material and a
mechanism for gingival retraction.
Disadvantage :
Incisional injuries to gingival tissues
Shillinburg HT. Fundamentals of Tooth Preparation. 3rd Edition
22. Technique:-
Selection of copper band.
One surface of band may be perforated.
Cervical end of the band may be trimmed in accordance with the
finish line.
The band is filed with soft wax and seated on the tooth.
The wax is chilled and impression is removed.
The impression indicates over extension of the band.
Adjustments if required may be made and second trial impression is made.
23. The wax is melted and modelling compound is introduced.
Incisal or occlusal end gingival end
Seat the band securely into its position.
Pressure is applied on the compound directly.
Chill the impression.
A towel clamp may be used to remove the impression.
24.
25. 3. Cotton Twills With ZnoE Cement
• Employs gentle pressure over a period of time.
• ZnoE mixed into creamy consistency, Cotton twills are rolled into
this mass and then on a towel to gain compactness.
• This Prevents sticking of pack to the instruments and gives ease
in handling.
• Should reflect the tissue laterally.
• Pack held in place with fast setting ZnOE cement.
26. 4.GINGIVAL CORD TECHNIQUE
It physically pushes the gingiva away from the finish line.
Its effectiveness is limited because pressure alone will not control sulcular
haemorrhage.
27. CLASSIFICATION OF CHORDS
Depending on the configuration
Plain
Twisted
Braided or Knitted
Depending on the surface finish
Waxed
Unwaxed
Depending on the chemical treatment
Plain
Impregnated
29. Depending on the number of strands
• Single
• Double
Depending on the thickness (colour coded)
o Black 000
o Yellow 00
o Purple 0
o Blue 1
o Green 2
o Red 3
30. OTHER MATERIALS USED FOR PLAIN CORD TECHNIQUE
Nylon and polyester can be used for plain cord gingival retraction technique.
Cotton can also be used in conjunction with nylon and polyester.
Plain cotton cord yields maximum absorption capacity amongst all. The
diameter of these cords can range from 0.58-1.17mm.
32. FORCE REQUIRED WHILE PLACING THE CORD INTO THE
GINGIVAL SULCUS
Epithelial attachment resistance:1 N/mm²
Pressure exerted in periodontal probing:1.31- 2.41N/mm²
Pressure exerted to insert the cord: 2.5-5 N/mm²
Hence for a marginal gingival opening of 0.5 mm in adults, requiers a
pressure of 0.1 N/mm² .
Barendregt DS. Van Der Velden U. Reiker L. Loos BG.
Journal of Clinical Periodontology 2001
34. SINGLE CORD TECHNIQUE
••Simplest & least traumatic technique
••Indications
- when gingival tissue are healthy & do not bleed.
- For making impressions for 1 to 3 prepared teeth.
Procedure :-
Isolate the quadrant
Suitable length / diameter of cord selected.
Dip the cord in astringent solution and squeeze out the excess with gauze square
Push cord between tooth & gingiva on mesial aspect
Continue packing on lingual, distal & buccal aspects.
Leave 2 mm of cord in excess
Kept in place for 10 min
Krammer et al;DCNA 2004
35.
36.
37. DOUBLE CORD TECHNIQUE
Indication - gingival inflammation, increased hemorrhage.
Disadvantage - healing & re-attachment - unpredictable.
Procedure :
• An extra thin esp. # 00 size (0.3 mm dm) - placed
0.5 mm below finish line for 5 min;
• 2nd larger diameter impregnated cord is placed above
it for 8-10 mins for hemostasis.
• The 2nd cord is removed just before the impression is injected.
• 1St cord removed after temporization & cementation- to remove any
residual impression material in sulcus.
Krammer et al;DCNA 2004
38.
39.
40. Advantages:
Accurate and precise impression can be achieved showing the finish line clearly.
No chemical substances added to the sulcus.
Drawbacks of Retraction Cord technique
Risk of epithelial attachment injury.
Painful procedure requiring preventive anaesthesia.
It is technique sensitive.
Bleeding and seepage may occur.
Risk of irreversible gingival retraction.
41. CHEMICO-MECHANICAL TECHNIQUE
Combining chemical action with pressure packing of the retraction cord.
Enlargement of gingival sulcus as well as control of fluids seeping from the walls
of the gingival sulcus cab be achieved.
Caustic Chemicals tried earlier:
Sulfuric acid
Trichloroacetic acid
Negatol (45% condensation product of meta cresol sulfonic acid and formaldehyde)
Zinc Chloride
Shillinburg HT. Fundamentals of Tooth Preparation. 3rd Edition
42. EFFECT OF THESE MEDICAMENTS:
Effective in shrinking the gingival tissues.
Zinc chloride is caustic and prolonged application or high concentrations
cauterizes the tissue.
Negatol is highly acid and decalcifies the teeth.
An evaluation of the drugs used for gingival retraction. Woycheshin FF.
J of Prosthet Dent. 1964;14: 769-76
43. CHEMICALS USED ALONG WITH CORD
Hemostatic agents
ferric sulphate
Astringents { cause tissue contraction }
aluminium chloride
Aluminium sulphate
Vasoconstrictor
Epinephrine
44. EPINEPHRINE
Epinephrine (8%) has been documented as gingival retraction agent in 1980s
Shillinburg HT. Fundamentals of Tooth Preparation. 3rd
Edition.
45. Advantages of epinephrine :
Effectiveness in gingival displacement
Haemostasis
Absence of irreversible damage to gingiva
Disadvantages of epinephrine :
‘Epinephrine Syndrome’
Tachycardia
Rapid respiration
Elevated blood pressure
Anxiety
Postoperative depression
46. Contraindications of Epinephrine :
CVS Disease
Hypertension
Diabetes
Hyperthyroidism
Known Hypersensitivity to epinephrine
Patients on, Ganglionic Blockers or Epinephrine potentiating drugs
48. STAT GEL
15% ferric sulphate
Aids in hemostasis & tissue retraction
49. INFUSION TECHNIQUE
specialized instrument called a dento infusor is used to apply 15% or 20% ferric
sulphate in the sulcular area.
done with firm pressure with burnishing action.
cord is dipped in the ferric sulphate solution and packed into the sulcus.
left in the sulcus for 1 to 3 minutes
52. AMOUNT OF ABSORPTION OF MEDICAMENT
DEPENDS ON:
Exposure of the vascular bed
Length and concentration of the impregnated cord
Length of time of application
Donovan TE, Gandara BK, Nemetz H.
Review and survey of medicaments used with gingival retraction cords. J Prosthet
Dent. 1985;53:525-31.
54. ROTARY GINGIVAL CURETTAGE
“Gingitage” or “Denttage”
Concept put forward by Amsterdam (1954)
Developed by Hansing and Ingraham
“Troughing technique”, the purpose of which is to produce limited removal
of epithelial tissue in the sulcus while a chamfer finish line is being created
in tooth structure
Shillinburg HT. Fundamentals of Tooth Preparation. 3rd Edition.
56. CRITERIA FOR GINGIVAL CURETTAGE:
Must be done on healthy and inflammation free tissue to prevent tissue
shrinkage that occurs when diseased tissue heals.
Absence of bleeding on probing.
Sulcus depth less than 3.0 mm.
Presence of adequate keratinized gingiva.
Shillinburg HT. Fundamentals of Tooth Preparation. 3rd Edition.
57. Procedure
In conjunction with axial reduction, a shoulder finish line is prepared at
the level of the gingival crest with a flat end tapered diamond.
Then a tapered diamond of 150 – 180 grit is used to extend the finish
line apically, one half to two thirds the depth of the sulcus converting the
finish line to a chamfer. Cord impregnated with aluminium chloride or alum is
gently placed to control hemorrhage and is removed after 4 – 8 minutes.
Disadvantages:
Poor tactile sensation when using diamonds in sulcular walls, can cause
deepening of the sulcus.
The technique also has the potential for destruction of periodontium if used
incorrectly.
Shillinburg HT. Fundamentals of Tooth Preparation. 3rd Edition.
58. ELECTROSURGERY (OR) SURGICAL DIATHERMY
Electrosurgery unit is a high frequency oscillator or radio transmitter
that uses either vaccum tube or a transistor to deliver a high
frequency electrical current of at least 1.0MHz.
History:
1891- Arsonval and Telsa: found that electricity at high
frequency can be passed through a body without producing a shock
or muscular response .
1924- William Clark: used dessication current for removal of
carcinomatous growths. He was known as father of American
Electrosurgery.
59. Principle:
Experiments of d’Arsonvol (1891) demonstrated that
electricity at high frequency can pass through a body without
producing a shock (pain or muscle spasm), producing instead an
increase in the internal temperature of the tissue.
This discovery was used as the basis for eventual
development of electrosurgery. It is also known as Surgical
Diathermy.
60. Mechanism of Action:
Controlled tissue destruction
Current flows through a small cutting electrode
Producing high current density and rapid temperature rise
Cells directly adjacent to electrode are destroyed due to temperature increase
The circuit is completed by contact between the patient and a ground
electrode
61.
62. TYPES OF CURRENT
Fully Rectified current (modulated)
continuous flow of current
good cutting characteristics
enlargement of gingival sulcus
Fully Rectified current (filtered)
continuous current wave
excellent cutting characteristics
less injury than modulated current
63. Partially rectified current (damped)
Considerable tissue destruction
Slow healing.
Used for spot coagulation
Unrectified current (damped)
Recurring peaks of current that rapidly diminish
Causes intense dehydration and necrosis
Slow and painful healing
Not used in dental surgery
64. SURGICAL ELECTRODES
Similar to a probe
Designed to produce intense heat during surgical procedure
and it can fit into the electro surgical hand piece.
This heat helps to vaporize the target tissue.
It comprises of the shank and cutting edge
65. Cutting Edge Designs Are:-
A) Coagulating probe
B) Diamond loop
C) Round loop
D) Small straight probe
E) Small loop
66. TISSUE CONSIDERATIONS
Keep electrode in motion & free of tissue fragments
Appropriate current setting
Tissue must be moist
67. ELECTRO SURGERY TECHNIQUE
STEPS:
Anesthetize the area
Apply peppermint oil, at the vermilion border of lip
Check the equipment setting
Cutting electrode should be applied with very light pressure and quick, deft strokes
Electrode should move at a speed of no less than 7mm/second
68. If it is necessary to retrace the path of a previous cut, 8 – 10 seconds
should be allowed to elapse before repeating the stroke.
Proper technique with the cutting electrode can be summed up in three
points:
Proper power setting
Quick passes with the electrode
Adequate time intervals between strokes
69. Advantages:
Clear operating area without or no bleeding.
Healing by primary intension.
Lack of pressure to incise tissue.
less tissue loss after healing
Disadvantages:
Unpleasant odour.
Slight loss of crestal bone
Burn mark on the root surface.
Not suitable for thin gingiva.
70. Adverse healing response
Heat is generated in tissues adjacent to electrosurgical incision
Alveolar bone is extremely sensitive to heat
Greater injury occurred after heating to 530C for a minute
Heating to 600C or more resulted in obvious bone tissue necrosis
Theoretical upper limit is 560C, since alkaline phosphatase is known to denature at
this temperature.
Heat generated depends on
Waveform of the electrical current
Duration of current application
Power of the active tip electrode
Electrode size
Depth of electrode penetration
71. Contraindications
Should not be employed on patients with cardiac pace maker
Should not be used in the presence of flammable agents
There is slight danger with the use of nitrous oxide with electrosurgery.
Shillinburg HT. Fundamentals of Tooth Preparation. 3rd Edition
72. GINGIVAL SULCUS ENLARGEMENT
To enlarge gingival sulcus, a small, straight or J-shaped electrode is selected. It is
used with wire parallel to the long axis of the tooth.
If the electrode is maintained in this direction the loss of gingival height will be
about 0.1mm.
Probe is run at a speed of 7mm per second to avoid lateral heat dissipation
75. REMOVAL OF AN EDENTULOUS CUFF
Frequently the remnants of the interdental papilla adjacent to an edentulous
space will form a roll or cuff that will make it difficult to fabricate a pontic
with cleanable embrasure and strong connectors.
A large loop electrode is used for planning away the large roll of tissues.
76. CROWN LENGTHENING
There are circumstances in which it may be desirable to have a longer
clinical crown on a tooth than is present.
If there is sufficiently wide band of attached gingiva surrounding the tooth,
this can be accomplished with a clinical crown lengthening (gingivectomy)
using a diamond electrode.
When surgery leaves an extensive post-operative wound as in this case, it is
necessary to place a periodontal dressing, which should be changed in about
7 days.
79. LASER RETRACTION
Compared with other retraction techniques, diode lasers with a wavelength of
980 nanometers and neodymium: yttrium-aluminum-garnet(Nd:YAG) lasers
with a wavelength of 1,064 nm are less aggressive, cause less bleeding and
result in less recession around natural teeth (2.2% vs 10.0%)
80.
81. Application of Nd: YAG laser provides faster healing with less haemorrhage
and less inflammatory reaction.
In conclusion it was evident that pulsed laser is a surgical device increasingly
important to dentistry.
83. CHEMICALS WITH AN INJECTIONABLE
MATRIX : EXPASYL TECHNIQUE
Non-cord gingival retraction system
Green colored paste in glass cartridges similar to anesthetic cartridges
Metal dispenser is used to express the paste through a disposable metal dispensing tip
into the gingival sulcus prior to impression making or cementation
84. Visco-plastic product calculated to exert a stabilized pressure of
0.1N/mm².
The pressure depends on the viscosity of the product and on the speed
of the injection.
It is left in the place for 1-2 minutes and removed by rinsing.
Hemostasis is achieved by aluminum chloride.
Body is provided by kaolin and clay.
85. Principle of Expasyl Technique:
A paste product injected into the sulcus exerts a pressure of 0.1N/mm².
This pressure is too low to damage the epithelial attachment, but
sufficient to obtain a sulcus opening of 0.5mm for 2 minutes.
88. Advantages:
Effectively achieves hemostasis
Little pressure – atraumatic
Less time consuming
Color makes easy to see
Easy removal
Easy to dispense with the gun
Disadvantages:
Expensive
Thickness of the paste makes it difficult to express into the sulcus.
Metal tips too big for interproximal areas
Tissue should be dried before placement
89. MAGIC FOAM CORD
non-hemostatic gingival retraction system Coltène/Whaledent.
expanding vinyl polysiloxane material
less time-consuming
90. Magic Foam Cord
Magic FoamCord is reportedly the first expanding vinyl polysiloxane material
designed for retraction of the gingival sulcus without the potentially traumatic
and time-consuming packing of retraction cord.
It is a non-traumatic method of temporary gingival retraction with easy and fast
application directly to the sulcus .It is not aimed to achieve hemostasis.
91. Procedure
Magic FoamCord material is syringed around the crown preparation margins
and a cap (Comprecap) is placed to reportedly maintain pressure.
After five minutes, the cap and foam are removed and the tooth is ready for the
final impression.
95. Clinical significance
When the cavity preparation extends into the subgingival area as in
class II and class V cavity preparartion.
Aesthetics, while placing crown it should stay 0.5mm into ginigival
sulcus.
Enhancing the retention: if crown is smaller, restoration is to be placed
after increasing crown length after gingival surgery.
Gingival overgrowth hindering operative procedure.
Control gingival hemorrhage during operative procedure
96. CONCLUSION
The accuracy of the impression taken in the prosthetic area
is extremely important both for the health and the aesthetics
of the treated patients. The offered techniques should be
patient-based and applied whenever the individual treatment
necessitates, or allows it.