INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com

www.indiandentalacademy.com
Fluid Control and Soft tissue
Management
 Introduction

 1)Complete control

of the environment of the
operative site is...
Introduction……


)Sometimes it is necessary to permanently
alter the contours of the gingival tissue
around the teeth or ...
FLUID CONTROL


Need for removal of fluids varies and
depends on the task that is carried out:
1)Preparation of teeth – L...
RUBBER DAM
 1)Most

effective of all isolation devices
 2)It plays a major role in conservative dentistry
procedures
 3...
High volume Vacuum
 1)Extremely useful

during the preparation

phase.
 2)Excellent Lip Retractor while the operator
use...
Saliva Ejector


1)Adjunct to high Volume evacuation – but can
be used alone for the maxillary arch



2)Placed in the c...
Svedopter


1)For isolation and evacuation of the mandibular
teeth,the metal saliva ejector with attached
tongue deflecto...
Antisialagogues


1)Drugs used to create a dry zone in the oral cavity,

Methantheline bromide (Banthine)
Propanthaline b...


Side Effects
 1)Drowsiness,blurred vision,bitter taste


Contraindications
 1)Hypersensitivity,
 2)Eye problems , G...


Drug interactions



1)Potentiated by antihistamines
,tranquilizers, and narcotic analgesics



Alternatives
 1)Prop...
FINISH LINE EXPOSURE


1.Tooth preparations in the presence of
untreated gingivitis makes task more
difficult and comprom...
Techniques for exposure of finish line


1)Complete impression is complicated when
some or all of the finish line lies at...
Mechanical Methods


1)Physically displacing the gingiva was one of the method
for finish line exposure
 2)Copper band o...
MEDICAMENTS FOR CORD
IMPREGNATION



Epinephrine (8%)



Alum (Aluminium Potassium Sulphate)

www.indiandentalacademy.co...


Epinephrine



1)causes local vasoconstriction ,which
results in transitory gingival shrinkage.



2)should not be us...


Alum

Used in patients with cardiovascular
diseases or hyperthyroidism or a known
hypersensitivity to adrenaline.

www....
Gingival Retraction -Procedure


1)2 inch piece of
retraction cord is
cut off



2)Cord is twisted to
make it as ight an...
3)Loop of retraction
cord is formed around
the tooth and and held
taut with the thumb
and the forefinger
4)Placement is st...


5)As the cord is placed
subgingivally the
instrument must be
pushed slightly toward
the area already tucked
into place....




6)Occasionally it is
necessary to hold the
cord with one
instrument while
packing with the
second

7)Instrument is
s...


8)If the instrument is
held parallel to the
long axis of the
tooth,the cord will be
pushed against the
wall of the ging...


10)The placement of the
distal end is finished
until it overlaps the mesial .
It is made sure that the
force of the ins...


Placement of the cord in the sulcus
 A)Correct
 B)Incorrect
www.indiandentalacademy.com
Usage of ferric Sulphate Solution


Cord removal is done after made damp
 If bleeding persists,Electro coagulation and f...
Rotary Curettage


1)It is a troughing technique
 2)Purpose is to produce limited removal of
epithelial tissue in the su...


1)A shoulder is formed at the level of the gingival
crest prior to rotary curettage
 2)A Torpedo tipped diamond bur si...
Electrosurgery


1)Employed in situations where gingiva cannot be
handled with retraction cord alone.

(Ex – Areas of in...




1)Typical electrosurgery
unit with active electrode
(A) and ground electrode
(B)

2)Five commonly used
electrodes –
...
Electro surgery – Mode of Action


1)Unit generates heat in a way similar to
microwave heating oven or a diathermy
machin...
Types of current



1)unrectified damped
 2)partially rectified,damped(Half wave
modulated)
 3)fully rectified(Full wav...
Electrosurgery - Contraindications


1)Patients with Cardiac Pacemakers



2)Should not be used in the presence of
infla...
Electro surgery Technique


1)Anesthesia is verified in the site of surgery
 2)Aromatic oil (Peppermint) is placed on th...
Contd……


7)Moist tissue will cut best
 8)High volume vacuum tip(Plastic tip used
– to avoid burns when contact is made ...
Gingival Sulcus Enlargement



1.Small ,straight or j shaped electrode is
selected for this purpose.

www.indiandentalaca...
Cuts for
gingival crevice
enlargement are
made with a
small straight
electrode ,
Facial,mesial ,
lingual and
distal
www.in...


Debris are cleaned
from the enlarged
sulcus with
hydrogen peroxide
on a cotton pellet

www.indiandentalacademy.com
Removal of Edentulous Cuff




1.Remnants of interdental
papilla adjacent to an
edentulous space will form a
hypertrophi...
Crown Lengthening procedure


1)If there is a sufficiently wide band of
attached gingiva surrounding a tooth,its
removal ...
Impressions


Impression – Definition



A negative likeness or copy in reverse
of the surface of an object;an imprint o...
www.indiandentalacademy.com
Requirements of a good
impression


1.Exact duplication of the prepared tooth(all
of the preparation and enough undercut
...
Requirements……..


2.Teeth and tissue adjacent to the prepared
tooth must be accurately reproduced to
permit accurate art...
Impressions procedures

www.indiandentalacademy.com
Reversible hydrocolloid








1)Packaged as a semisolid gel in polyethylene tubes
2)Liquefied in a hydrocolloid con...
6)Distortion problem is inherent – since can
lose or absorb water (Syneresis or
imbibition),Hence have to be poured immd.
...
8)Two impressions are usually made –
Sectional (Quadrant) impression for making
a die and a full arch impression for the
w...
Custom Resin trays


1.These trays are used in elastomeric impression
techniques because these materials are more
accurat...


4)Aluminum foil piece is adapted over the wax
and stone cast to provide separation(Prevents
wax from impregnating the s...
Polysulphide impression


1)Also known as as Mercaptan,Thiokol .
 2)The material is packaged into 2 tubes – a
base and a...


5)Dimensionally more stable than hydrocolloid .
But contract as curing occurs(Hence have to be
poured within 1 hour
 6...


1)Anesthesia is checked.
 2)Custom tray tried,Retraction cord placed
 3)On disposable pad squeeze out – 1.5 inches
ea...


7)Cord is removed after damping.
 8)Syringe material is injected into the
sulcus,around the entire circumference of th...
Polyvinyl Siloxane


1)Also known as addition silicones
 2)Dimensional stability of this group is much
better than that ...
5)Least affected by pouring delays –
accurate even when poured after one week
after removal from the mouth.
 6)Earlier fo...


8)Two pastes can be packaged in separate
tubes(Mixed on a pad) or placed in twin
barelled cartridge(dispenser or gun is...


1.Paint the custom tray with adhesive at least 15
minutes before the impression is to be made
 2)Using a tube dispense...
5)After mixing the ,cord is removed and
Impression material is injected starting in
one interproximal area
6)Operator appl...
Polyether


1)1)It is a copolymer of 1,2 epoxyetane and
tetrahydofuran that is reacted with an
alpha,beta unsaturated aci...


4)Highly accurate
 5)Improved dimensional stability(Can be
poured even after 1 week)
 6)hydrophilic material and henc...


1)7.5 inches each of base and accelerator
are dispensed onto a mixing pad.
 2)Mixed for 1 minute
 3)Syringe and tray ...
Conventional Silicone Rubber Base


1.Also known as condensation silicones.
 2.Base paste
a)Is a liquid silicone polymer...


4.Two are mixed –materials are mixed by a
cross reaction between terminal hydroxyl
groups and ethyl orthosilicate



5...


Technique
 1)2 inches of base are mixed with two
drops of accelerator to provide the material
used in the syringe.
 2...


Preliminary impression is made with a
heavily filled stock tray with putty material.
 Preliminary impression serves as...


Tray preparation (Done before tooth
preparation is begun) and impression making
 1)Stock tray is selected
 2)Tray adh...


7)Tray is removed from mouth,excess
removed with sharp knife,set aside.
 8)After tooth prep,Gingival retraction
proced...


12)Gingival retraction cord is removed after
made damp,and tooth is dried.
 13)Syringe material is injected into the
s...
Thank you
For more details please visit
www.indiandentalacademy.com

www.indiandentalacademy.com
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Tissue management /certified fixed orthodontic courses by Indian dental academy

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The Indian Dental Academy is the Leader in

continuing dental education , training dentists

in all aspects of dentistry and offering a wide

range of dental certified courses in different

formats.

Indian dental academy provides dental crown &

Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit

www.indiandentalacademy.com ,or call
0091-9248678078

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Transcript of "Tissue management /certified fixed orthodontic courses by Indian dental academy "

  1. 1. INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  2. 2. Fluid Control and Soft tissue Management  Introduction  1)Complete control of the environment of the operative site is essential during restorative dental procedures (Fluid control procedures)  2)Control of the oral environment extends to the gingiva surrounding the tooth being restored(Gingival retraction procedures) www.indiandentalacademy.com
  3. 3. Introduction……  )Sometimes it is necessary to permanently alter the contours of the gingival tissue around the teeth or edentulous ridge for long lasting,better restorations(Electrosurgery procedures) www.indiandentalacademy.com
  4. 4. FLUID CONTROL  Need for removal of fluids varies and depends on the task that is carried out: 1)Preparation of teeth – Large volumes of water and saliva has to be removed 2)Cementation of Restoration & Impression making - Smaller volumes of fluid has to be removed .  Several types of attachment are used with Low Volume (saliva ejector) or high volume vacuum outlets to remove fluids www.indiandentalacademy.com
  5. 5. RUBBER DAM  1)Most effective of all isolation devices  2)It plays a major role in conservative dentistry procedures  3)Limited role in the area of cast restorations  4)Can be used during tooth preparation for inlays and onlays, for making impressions and cementing the same.  5)In Impression making - not to be used with polyvinylsiloxane material as it inhibits polymerization www.indiandentalacademy.com
  6. 6. High volume Vacuum  1)Extremely useful during the preparation phase.  2)Excellent Lip Retractor while the operator uses a mirror to retract and protect the tongue  3)Not useful while making impressions or cementation phases www.indiandentalacademy.com
  7. 7. Saliva Ejector  1)Adjunct to high Volume evacuation – but can be used alone for the maxillary arch  2)Placed in the corner of the mouth ,opposite the quadrant being operated,and the patients head is turned towards it.  3)Very effectively used in the maxillary arch for impressions and cementation  4)Can be used on the mandibular arch also. www.indiandentalacademy.com
  8. 8. Svedopter  1)For isolation and evacuation of the mandibular teeth,the metal saliva ejector with attached tongue deflector is excellent.  2)Most effective when used with the patient in upright position.  3)Access to the lingual surfaces of the mandibular teeth is a drawback  4)Presence of mandibular tori precludes its use.  5)The anterior part of the Svedopter should be placed in the incisor region,with the tubing under the patients arm www.indiandentalacademy.com
  9. 9. Antisialagogues  1)Drugs used to create a dry zone in the oral cavity, Methantheline bromide (Banthine) Propanthaline bromide (Probanthine) (These are anticholinergics that act on the smooth muscles of the GIT,Urinary and biliary tracts,producing dry mouth as a side effect) Dosage (50mg of Banthine or 15mg of Probanthine – 1 hr before the appt) www.indiandentalacademy.com
  10. 10.  Side Effects  1)Drowsiness,blurred vision,bitter taste  Contraindications  1)Hypersensitivity,  2)Eye problems , GIT problems , UTI problems  3)Upper Respiratory tract problems  4)Cardiac problems  5)Lactating mothers www.indiandentalacademy.com
  11. 11.  Drug interactions  1)Potentiated by antihistamines ,tranquilizers, and narcotic analgesics  Alternatives  1)Propantheline- 2 to 6 mg injected intraorally  2)Clonidine hydrochloride – 0.2mg (an hour before appt www.indiandentalacademy.com
  12. 12. FINISH LINE EXPOSURE  1.Tooth preparations in the presence of untreated gingivitis makes task more difficult and compromises chances for success.  2.Marginal fit of a restoration is essential in preventing recurrent caries and gingival irritation  Hence finish line of the preparation must be reproduced in the impression www.indiandentalacademy.com
  13. 13. Techniques for exposure of finish line  1)Complete impression is complicated when some or all of the finish line lies at or apical to the crest of the free gingiva  2)In such cases finish line of a prep must be temporarily exposed to insure reproduction of the entire preparation  3)Methods employed are : a)mechanical b)Chemicomechanical c)surgical – 1)rotary curettage 2)electro surgery www.indiandentalacademy.com
  14. 14. Mechanical Methods  1)Physically displacing the gingiva was one of the method for finish line exposure  2)Copper band or tube can serve as a means of carrying the impression material as well as a mechanism for displacing the gingiva to insure the capture of the finish line  3)Copper bands are especially useful when several teeth are have been prepared  4)rubber dam can also be used to expose finish line,generally when limited number of teeth are being restored and in which preparations do not have to be extended too far subgingivally www.indiandentalacademy.com
  15. 15. MEDICAMENTS FOR CORD IMPREGNATION  Epinephrine (8%)  Alum (Aluminium Potassium Sulphate) www.indiandentalacademy.com
  16. 16.  Epinephrine  1)causes local vasoconstriction ,which results in transitory gingival shrinkage.  2)should not be used on patients taking Rauwolfia compounds,ganglionic blockers or epinephrine potentiating drugs www.indiandentalacademy.com
  17. 17.  Alum Used in patients with cardiovascular diseases or hyperthyroidism or a known hypersensitivity to adrenaline. www.indiandentalacademy.com
  18. 18. Gingival Retraction -Procedure  1)2 inch piece of retraction cord is cut off  2)Cord is twisted to make it as ight and as small as possible www.indiandentalacademy.com
  19. 19. 3)Loop of retraction cord is formed around the tooth and and held taut with the thumb and the forefinger 4)Placement is started by pushing the cord into the sulcus on the mesial surface.It is also slightly tacked into the distal crevice to hold the cord in position while www.indiandentalacademy.com it is being placed
  20. 20.  5)As the cord is placed subgingivally the instrument must be pushed slightly toward the area already tucked into place.If the force of the instrument is directed away from the area previously packed,the already packed cord will be pulled out www.indiandentalacademy.com
  21. 21.   6)Occasionally it is necessary to hold the cord with one instrument while packing with the second 7)Instrument is slightly angled towards the root to facilitate the sublingual placement of the cord www.indiandentalacademy.com
  22. 22.  8)If the instrument is held parallel to the long axis of the tooth,the cord will be pushed against the wall of the gingival crevice and it will rebound  9)The excess cord is cut off from the mesial interproximal area www.indiandentalacademy.com
  23. 23.  10)The placement of the distal end is finished until it overlaps the mesial . It is made sure that the force of the instrument is directed toward the cord previously packed (To the distal in this case) www.indiandentalacademy.com
  24. 24.  Placement of the cord in the sulcus  A)Correct  B)Incorrect www.indiandentalacademy.com
  25. 25. Usage of ferric Sulphate Solution  Cord removal is done after made damp  If bleeding persists,Electro coagulation and ferric sulphate are sometimes effective in stopping persistent bleeding  If ferric sulfate is used as a chemical,soak a plain knitted cord in it and place the cord in the gingival sulcus  After 3 minutes, remove the cord  Then 1 cc special syringe is loaded with the stringent chemical and a special fibrous tip is used to rub or burnish cut sulcular tissue until all bleeding stops. www.indiandentalacademy.com
  26. 26. Rotary Curettage  1)It is a troughing technique  2)Purpose is to produce limited removal of epithelial tissue in the sulcus while a chamfer finish line is being created in the tooth structure  3)Must be done only on healthy,inflammation free tissue to avoid tissue shrinkage that occurs when diseased tissue heals www.indiandentalacademy.com
  27. 27.  1)A shoulder is formed at the level of the gingival crest prior to rotary curettage  2)A Torpedo tipped diamond bur simultaneously forms a chamfer finish line and removes the epithelial lining of the gingival sulcus  3)A cord is placed in the troughed sulcus for hemostasis www.indiandentalacademy.com
  28. 28. Electrosurgery  1)Employed in situations where gingiva cannot be handled with retraction cord alone.  (Ex – Areas of inflammatiion and granulation tissue around a tooth,as a result of overhangs or previous restoration or caries itself  2)Generally recommended for enlargement of gingival sulcus and control of heamorrhage  3)Employs a high frequency electrical current of 1.0 MHz (Million Cycles per second) or more to www.indiandentalacademy.com produce controlled tissue destruction
  29. 29.   1)Typical electrosurgery unit with active electrode (A) and ground electrode (B) 2)Five commonly used electrodes – a)coagulating b)diamond loop c)round loop d)small straight e)small loop www.indiandentalacademy.com
  30. 30. Electro surgery – Mode of Action  1)Unit generates heat in a way similar to microwave heating oven or a diathermy machine  2)Current flows from a small cutting electrode which produces a high current density and rapid temperature rise at its point of contact  3)Cells directly adjacent to to the electrode are volatilizedwww.indiandentalacademy.com at this temperature
  31. 31. Types of current  1)unrectified damped  2)partially rectified,damped(Half wave modulated)  3)fully rectified(Full wave modulated) www.indiandentalacademy.com  4)fully rectified,filtered(filtered)
  32. 32. Electrosurgery - Contraindications  1)Patients with Cardiac Pacemakers  2)Should not be used in the presence of inflammable agents(Since generates sparks)  – Hence use of topical anesthetic such as ethyl chloride and other flammable aerosols should be strictly avoided when electro surgery is used www.indiandentalacademy.com
  33. 33. Electro surgery Technique  1)Anesthesia is verified in the site of surgery  2)Aromatic oil (Peppermint) is placed on the vermillion of the upper lip to (For masking unpleasant smell arising during tissue cutting  3)Connections of the unit are checked  4)Cutting electrode should be applied with light pressure only  5)Strokes should be quick and deft  6)Electrode should be kept moving and no stroke should be repeated immediately,smoothly without tissue charring www.indiandentalacademy.com
  34. 34. Contd……  7)Moist tissue will cut best  8)High volume vacuum tip(Plastic tip used – to avoid burns when contact is made with electrode) is used to draw off unpleasant odors generated  9)Wooden tongue depressor is used rather than normal mouth mirror  10)Frequently fragments are cleaned from tip with an alcohol soaked sponge www.indiandentalacademy.com
  35. 35. Gingival Sulcus Enlargement  1.Small ,straight or j shaped electrode is selected for this purpose. www.indiandentalacademy.com
  36. 36. Cuts for gingival crevice enlargement are made with a small straight electrode , Facial,mesial , lingual and distal www.indiandentalacademy.com
  37. 37.  Debris are cleaned from the enlarged sulcus with hydrogen peroxide on a cotton pellet www.indiandentalacademy.com
  38. 38. Removal of Edentulous Cuff   1.Remnants of interdental papilla adjacent to an edentulous space will form a hypertrophic roll or cuff – hence fabricating a pontic with cleanable embrasures and strong connectors 2.A Large Loop electrode is used for removing large roll www.indiandentalacademy.com of hypertrophied tissue
  39. 39. Crown Lengthening procedure  1)If there is a sufficiently wide band of attached gingiva surrounding a tooth,its removal can be accomplished with a gingivectomy using a diamond electrode  2)Periodontal dressing is placed after surgery  3)Lengthened tooth offers better retention for any crown placed on it ,with the margin placement in an area of the tooth more accessible for cleaning www.indiandentalacademy.com
  40. 40. Impressions  Impression – Definition  A negative likeness or copy in reverse of the surface of an object;an imprint of the teeth and adjacent structures for use in dentistry www.indiandentalacademy.com
  41. 41. www.indiandentalacademy.com
  42. 42. Requirements of a good impression  1.Exact duplication of the prepared tooth(all of the preparation and enough undercut tooth surface beyond the preparation –For being certain about the location and configuration of the finish line www.indiandentalacademy.com
  43. 43. Requirements……..  2.Teeth and tissue adjacent to the prepared tooth must be accurately reproduced to permit accurate articulation of the cast and to allow proper contouring of the restoration  3.Impression of the preparation must be bubble free especially in the area of the finish line www.indiandentalacademy.com
  44. 44. Impressions procedures www.indiandentalacademy.com
  45. 45. Reversible hydrocolloid      1)Packaged as a semisolid gel in polyethylene tubes 2)Liquefied in a hydrocolloid conditioner by placing it in boiling water. 3)Liquid Sol is too hot for intraoral usage – Hence cooled in two stages , storage and tempering. 4)Tray filled with tempered sol is place in the mouth,cool tap water is circulated through double walled jacket of the tray to complete the gelation process. 5)when completely gelled,tray is removed from the mouth www.indiandentalacademy.com
  46. 46. 6)Distortion problem is inherent – since can lose or absorb water (Syneresis or imbibition),Hence have to be poured immd.  7)Conditioning Unit – Parts 1)Liquefying bath – loaded syringes are boiled for 10 mins here 2)Storage bath – Stored at 150 F for 10 mins 3)Tempering bath – Tempered at 110 F for 5 to 10 mins  www.indiandentalacademy.com
  47. 47. 8)Two impressions are usually made – Sectional (Quadrant) impression for making a die and a full arch impression for the working cast.  9)Procedure ( Refer to OHP sheet ).  www.indiandentalacademy.com
  48. 48. Custom Resin trays  1.These trays are used in elastomeric impression techniques because these materials are more accurate in thin layers of 2 to 3 mm.  2)Tray preparation a)Baseplate wax is softened in flame b)Fold it in half and place on diagnostic cast c)Adapt to cast and trim excess more than 2 to 3mm beyond necks of teeth d)3*3 mm hole is cut through wax over posterior teeth on both sides of arch and in incisor area – (Stops of the tray) www.indiandentalacademy.com
  49. 49.  4)Aluminum foil piece is adapted over the wax and stone cast to provide separation(Prevents wax from impregnating the surface of tray when exothermic reaction occurs during setting of acrylic  5)acrylic resin is mixed, adapted over foil covered wax,molded  6)Handle is also made and a a wing on either side to facilitate its removal.  7)Resin is allowed to polymerize,and after it is hard smoothening and polishing are done www.indiandentalacademy.com
  50. 50. Polysulphide impression  1)Also known as as Mercaptan,Thiokol .  2)The material is packaged into 2 tubes – a base and an accelerator  3)Base – A liquid polysulphide polymer mixed with inert fillers  4)Accelerator – Lead dioxide mixed with small amounts of sulphur and oil,acts as an oxidation initiator on terminal thiol groups on the polymer When the two are mixed – polymer chains are lengthened and cross linked through oxidized thiol groups www.indiandentalacademy.com
  51. 51.  5)Dimensionally more stable than hydrocolloid . But contract as curing occurs(Hence have to be poured within 1 hour  6)Large undercut areas in interproximal region should be blocked out in the mouth with soft wax (Or else impression may get locked within mouth – attempt to force it out- it distorts  7)Hydrophobic- therefore no moisture on the prep should be there while making the impression  8)Unique quality –it is radiopaque & any entrapped fragment can be easily seen on a xray www.indiandentalacademy.com
  52. 52.  1)Anesthesia is checked.  2)Custom tray tried,Retraction cord placed  3)On disposable pad squeeze out – 1.5 inches each of light (Syringe) base and accelerator  4)On second pad – 5 inch strips of regular tray base and accelerator are placed.  5)Mixing is done ( Tray material mixing is started 30 seconds before syringe material mixing)  6)Mixed syringe material is loaded into the syringe – Using a cone 0r by scraping the back end across the mixing pad to scoop up the material www.indiandentalacademy.com
  53. 53.  7)Cord is removed after damping.  8)Syringe material is injected into the sulcus,around the entire circumference of the tooth ,until entire tooth is covered  9)Air is directed over the injected material to spread it evenly.  10)Tray is seated slowly until the stops hold the tray solidly in one position and held with light pressure for 8 to 10 mins.  11)After it is set – the impression is removed as fast and as straight as possible  12)Impression is rinsed,blown dry and soaked in disinfectant www.indiandentalacademy.com pouring it solution before
  54. 54. Polyvinyl Siloxane  1)Also known as addition silicones  2)Dimensional stability of this group is much better than that of condensation silicones  3)Usually packaged as two pastes 1)One contains silicone with terminal silane hydrogen groups and an inert filler 2)The other is made up of a silicone with terminal vinyl groups,chloroplatinic acid catalyst and a filler 4)On mixing – addition of silane hydrogen groups across vinyl double bonds with the formation of nowww.indiandentalacademy.com by products
  55. 55. 5)Least affected by pouring delays – accurate even when poured after one week after removal from the mouth.  6)Earlier formulations released hydrogen – voids occurred in the setting cast – hence pouring had to be delayed for 1 day .Now palladium has been incorporated to counter the problem (Absorbs hydrogen gas)  7)Hydrophobic material – Surfactants are incorporated to make it less hydrophobic and easy to pour  www.indiandentalacademy.com
  56. 56.  8)Two pastes can be packaged in separate tubes(Mixed on a pad) or placed in twin barelled cartridge(dispenser or gun is used for mixing)  9)Putty and light body consistencies are made for his type of silicone also.  10)While mixing putty – gloves should not be worn as polymerization retardation results from sulfur derivatives in latex www.indiandentalacademy.com
  57. 57.  1.Paint the custom tray with adhesive at least 15 minutes before the impression is to be made  2)Using a tube dispensed material. The assistant and operator start mixing at about same time,until all streaks are eliminated Then the tray and syringe are loaded  3)Using a cartridge system. A cartridge of light bodied material is loaded into one dispenser and cartridge of medium or heavy bodied material into another 4)DEMO www.indiandentalacademy.com
  58. 58. 5)After mixing the ,cord is removed and Impression material is injected starting in one interproximal area 6)Operator applies the light body material with the syringe and the tray is loaded with medium/heavy body by the assistant. 7)Then loaded tray is seated firmly in the mouth and held in place for 7 to 8 minutes 8)Impression is removed as quickly and straight as possible to avoid distortion. 9)Blown dry and poured with extreme care www.indiandentalacademy.com
  59. 59. Polyether  1)1)It is a copolymer of 1,2 epoxyetane and tetrahydofuran that is reacted with an alpha,beta unsaturated acid,to produce esterification of the terminal hydroxyl groups  2)double bonds are reacted with ethylene amine to produce the final polymer.Aromatic sulfonate produces cross linking by cationic polymerization.  3)It is packaged in two tubes using a larger volume of base than accelerator www.indiandentalacademy.com
  60. 60.  4)Highly accurate  5)Improved dimensional stability(Can be poured even after 1 week)  6)hydrophilic material and hence should not be stored in moist environment.  7)Stiff material and hence undercuts have to be blocked out www.indiandentalacademy.com
  61. 61.  1)7.5 inches each of base and accelerator are dispensed onto a mixing pad.  2)Mixed for 1 minute  3)Syringe and tray are loaded  4)Impression making is carried out similar to that employed in other types  5)Tray is held in mouth only for 4 mins. www.indiandentalacademy.com
  62. 62. Conventional Silicone Rubber Base  1.Also known as condensation silicones.  2.Base paste a)Is a liquid silicone polymer with terminal hydroxy groups mixed with inert fillers 3.Reactor a)Is a viscous liquid ,consists of a cross linking agent ,ethyl silicate,with an organo tin activator,tin octoate. www.indiandentalacademy.com
  63. 63.  4.Two are mixed –materials are mixed by a cross reaction between terminal hydroxyl groups and ethyl orthosilicate  5.Condensation occurs by elimination of ethyl or methyl alcohol(Evaporation of this causes shrinkage and hence poor dimensional instability.-Hence have to be poured immediately. www.indiandentalacademy.com
  64. 64.  Technique  1)2 inches of base are mixed with two drops of accelerator to provide the material used in the syringe.  2)8 inches of base and eight drops of accelerator are used to for tray filling material.  3)Other variant employs a putty material relined with a thin wash  4)Putty has a silica filler content of 75% (More than double than that in wash).  5)Hence has a very low dimensional change in the putty impression. www.indiandentalacademy.com
  65. 65.  Preliminary impression is made with a heavily filled stock tray with putty material.  Preliminary impression serves as a custom tray for wash impression with less heavily filled conventional silicone www.indiandentalacademy.com
  66. 66.  Tray preparation (Done before tooth preparation is begun) and impression making  1)Stock tray is selected  2)Tray adhesive is applied  3)2 scoops putty (Base)+ six drops of accelerator for each scoop is taken on a pad.  4)Mixed on pad for sometime and then then transferred to palm on hand and kneaded for 30 seconds,until streak free.  5)Rolled and placed on a stock tray  6)Covered with a polyethylene spacer and placed in the mouth www.indiandentalacademy.com
  67. 67.  7)Tray is removed from mouth,excess removed with sharp knife,set aside.  8)After tooth prep,Gingival retraction procedure is done  9)8 inches of the thin wash silicone base+1 drop of accelerator per inch of base is added onto mixing pad  10)Mixed for 30 seconds,free of streaks  11)Simultaneous loading is done into the syringe (operator) and remainder into the tray(assistant) www.indiandentalacademy.com
  68. 68.  12)Gingival retraction cord is removed after made damp,and tooth is dried.  13)Syringe material is injected into the sulcus , and thoroughly around the entire prepared tooth till it is completely covered  14)Syringe is exchanged for loaded now  15)Tray is seated firmly and held in place for 6 minutes without any pressure application(Pressure application will incorporate stresses which will later get relieved when removed from the mouth leading to dimensional in accuracy  16)Tray is removed and poured immediately www.indiandentalacademy.com
  69. 69. Thank you For more details please visit www.indiandentalacademy.com www.indiandentalacademy.com

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