Soft tissue management /General orthodontics

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Soft tissue management /General orthodontics

  1. 1. 1 INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  2. 2.  Cast gold inlays/ onlays  Partial veneer crowns  Complete metal crowns  Metal ceramic crowns  All ceramic crowns  Dental caries, cervical abrasions, restorations extending subgingivally  Crown lengthening not indicated  Additional retention  Proximal contacts too gingival  Esthetics  Root sensitivity 2 INTRODUCTION:- www.indiandentalacademy.com
  3. 3. 3 IMPRESSION DIES RESTORATION www.indiandentalacademy.com
  4. 4.  METHODS FOR MOISTURE CONTROL  DEFINITION  CLASSIFICATION OF GINGIVAL RETRACTION METHODS  CRITERIA FOR SELECTION  MECHANICAL METHOD  Rubber dam  Cotton twills with ZnOE cement  Copper band impression  Temporary acrylic resin copings www.indiandentalacademy.com
  5. 5. Chemico-mechanical methods • Various chemicals used • Advantages and Disadvantages • Classification of retraction cords • Technique for Gingival cord retraction Rotary Gingival curettage • Criteria • Technique 5www.indiandentalacademy.com
  6. 6.  Electro surgery • History • Mechanism of Action • Types of current • Tissue considerations • Advantages and disadvantages • Contraindications • Basic principles  Recent Advances in Gingival Retraction material  Summary  References 6www.indiandentalacademy.com
  7. 7. CRITERIAS FOR ACCEPTING AN IMPRESSION Be an exact record of all aspects of the prepared tooth. Should include sufficient unprepared tooth structure immediately adjacent to the margins of the preparation. All teeth and soft tissues surrounding the tooth preparation must be reproduced. The impression must be free of air bubbles ,tears ,thin spots and other imperfections that might produce inaccuracies. Rosenstiel, Land, Fujimoto. Contemporary fixed prosthodontics-2nd edition. 7www.indiandentalacademy.com
  8. 8. IMPORTANT ASPECTS OF MAKING A FPD IMPRESSION ADEQUTE MOISTURE CONTROL • Includes the exclusion of sulcular fluid ,saliva and gingival bleeding • Saliva flow either should be controlled or diverted GOOD SOFT TISSUE HANDLING • To allow access • To provide adequate thickness of impression material 8www.indiandentalacademy.com
  9. 9. OBJECTIVES OF MOISTURE CONTROL Shillinburg et al. Fundamentals of FIXED prosthodontics. 3rd edition To obtain a dry, clean ,operating field For easy access and visibility To improve properties of dental materials To protect the patient and operator To improve the operating efficiency 9www.indiandentalacademy.com
  10. 10. METHOD OF FLUID CONTROL MECHANICAL CHEMICAL OTHERS 1. Rubber dam 2. High volume vacuum 3. Saliva ejector 4. Svedopter 1. Anti-sialogogues 2. Local anesthetics 1. Cotton rolls 2. Cellulose wafers 3. Throat shields 10www.indiandentalacademy.com
  11. 11. Introduced by S.C BARNUM in 1864 . In fixed prosthodontics , its use is restricted to only during impression making and cementation. Most appropriate of all isolation devices in presence of Supragingival margins Heavy and extra heavy rubber dams are used Retraction is done by rubber dam or clamps (No. 212 cervical retainer). It should not be used while making a polyvinyl siloxane impression, as it will inhibit its polymerization . 11www.indiandentalacademy.com
  12. 12. CONDITIONS THAT PRECLUDE USE OF RUBBER DAM Teeth that have not erupted sufficiently to receive a retainer Some third molars Extremely malpositioned teeth Patient suffering from asthma 12www.indiandentalacademy.com
  13. 13. A high –volume suction tip is extremely useful during the preparation phase and is most effectively utilized with an assistant It makes an excellent lip retractor while the operator uses a mirror to retract and protect the tongue .  However, it’s use is not practical during impression or cementation phases. 13www.indiandentalacademy.com
  14. 14.  Most useful as an adjunct to high volume evacuation .  Can be used for evacuation when the maxillary arch is being treated .  Effective on the maxillary arch during impression and cementation .  Placed at the corner of the mouth, opposite to the quadrant being operated and the patient ‘s head is turned toward it 14www.indiandentalacademy.com
  15. 15. It is used for isolating the mandibular teeth . It is the metal saliva ejector attached with a tongue deflector. Disadvantages Access to the lingual surface of mandibular teeth is limited Since it is a metallic device , care must be taken to avoid any injury to the floor of the mouth . Presence of mandibular tori precludes its use . 15www.indiandentalacademy.com
  16. 16. Most effective when patient is in a nearly upright position . PRECAUTIONS:-  Selection of an oversized reflector should be avoided..  For better positioning ,the anterior part of the svedopter should be placed in the incisor region with the tubing under the patient ,arm . 16www.indiandentalacademy.com
  17. 17. Helpful for short period of Isolation .Especially in conjunction with profound anesthesia  Cotton roll holder are used for holding cotton roll in position .But this is inconvenient and time-consuming .  Cotton roll holders retract the cheeks and tongue are slightly 17www.indiandentalacademy.com
  18. 18. ANTI-SIALOGOGUES  Gastrointestinal anti-cholinergics , producing a dry mouth as a side effect . Commonly used anti-sialogogues Methantheline bromide (Banthine) :50 mg Propantheline bromide (Pro-banthine) : 7.5-15 mg Glycopyrrolate (Robinul) : 1-2 mg Atropine sulphate (Sal-Tropine) : 0.4mg Dicyclomine HCl (Antipas) : 10-20 mg 18www.indiandentalacademy.com
  19. 19. Contraindication Hypersensitivity Glaucoma Asthma Obstructive conditions of the gastrointestinal or urinary tracts Congestive cardiac failure Lactating females Patients on antihistaminics, tranquilizers, narcotic analgesics or corticosteroids Side effect  Drowsiness  Blurred vision  Bitter taste 19www.indiandentalacademy.com
  20. 20.  A 0.2-mg dose of this drug is as effective as 50 mg of Banthine in diminishing salivary flow.  CONTRAINDICATIONS:  To be used cautiously in patients receiving other antihypertensives.  Has a sedative effect, so not indicated in patients who use machinery or heavy duty tools. 20www.indiandentalacademy.com
  21. 21.  Obtaining a complete impression is complicated when some or all of the preparation finish line lies at or apical to the crest of the free gingiva .  Marginal fit of a restoration essential in preventing recurrent caries and gingival irritation,  The finish line must be temporarily exposed to insure reproduction of the entire preparation . 21www.indiandentalacademy.com
  22. 22. • “Gingival Retraction is deflection of the marginal gingiva away from a tooth.” OR • “Gingival retraction is a process of exposing margins when making impression of prepared teeth.” 22www.indiandentalacademy.com
  23. 23. 23 To widen the gingival sulcus Recording the contour beyond the finish line While cementing a restoration Prevents injury to crest of the gingiva. www.indiandentalacademy.com
  24. 24. 1.Surgical Retraction Gingivectomy and Gingivoplasty Periodontal flap procedures Electrosurgery Rotary Gingival Curettage 24 JADA 1978; 96: 1002- 1007www.indiandentalacademy.com
  25. 25. 2.Non-Surgical Retraction Rubber dam and clamps Retraction cords Impregnated and non-impregnated Retraction rings Copper bands 25www.indiandentalacademy.com
  26. 26. • B. 1.Conventional 2.Radical • C. 1.Mechanical method 2.mechanico-chemical method 3.Rotary gingival curettage 4.Electrosurgical methods. 26 JPD 1986;55 :171 www.indiandentalacademy.com
  27. 27. 27JADA 2008; 139: 1354- 1363www.indiandentalacademy.com
  28. 28. • Milford B.Reiman (1976)  A trough must be created  The trough should be wide enough  Must be free of blood and fluid  There must be minimal tissue damage  The tissue must recover within a reasonable period of time.  General systemic effects must be minimal  Should be non-toxic, non- poisonous  Should take minimum chairside time  Should be economical 28 JPD 1976; 36: 649- 654www.indiandentalacademy.com
  29. 29. • A. RUBBER DAM • B.COPPER BAND /TUBE IMPRESSION • 1st described by John j .Lucca (1959) • Used to carry the impression materials as well as to displace the gingiva to expose the finish line . • Impression compound or elastomeric impression materials can be used along with this band . 29www.indiandentalacademy.com
  30. 30. TECHNIQUE:- After positioning, it is filled with modelling compound, is seated carefully in place along the path of insertion of the tooth preparation and the impression is made . One end of the tube is festooned ,or trimmed to follow the profile of the finish line. Copper band is welded to form a tube corresponding to the size of the prepared tooth DISADVANTAGE:- It can cause injury to the gingival tissues. 30www.indiandentalacademy.com
  31. 31. C.COTTON TWILLS WITH ZnOE CEMENT  Employs gentle pressure over a period of time.  Min.48 hrs but not >7 days. Pack held in place with fast setting ZnOE cement. Should reflect the tissue laterally. Prevents sticking of pack to the instruments and gives ease in handling. Cotton twills rolled into this mass and then on a towel to gain compactness. ZnOE mixed into creamy consistency, 31www.indiandentalacademy.com
  32. 32. D. ACRYLIC RESIN COPING • By Anthony La Forgia (1967) A complete arch impression is subsequently made over the coping and the coping becomes an integral part of the complete arch impression. The temporary restoration is then filled with an elastomeric impression material. The inside is relived by approximately 1mm and adhesive is applied. 32 JPD 1967; 17: 379-386 www.indiandentalacademy.com
  33. 33. • E. Lawrence Wiland (1964) • Described a technique of combination of mechanical and chemical retraction using • Modified acrylic resin crown with a retraction collar + chemically treated retraction cord. • F. Korn field • Aluminium shell:- 33www.indiandentalacademy.com
  34. 34. TECHNIQUE Shell placed on tooth and cemented temporarily for 12 hrs. Shell removed and excess material trimmed Under occlusal pressure excess material will displace the gingiva Fill it with impression compound or gutta percha and place it on the prepared tooth Select Al shell of correct size , trim it to conform to the gingival contour and occlusion 34www.indiandentalacademy.com
  35. 35. 35www.indiandentalacademy.com
  36. 36. • “A gingival retraction cord is the one which is having a tapered diameter throughout its length and having a length sufficient to enable the cord to be wrapped several times about a tooth.” 36 H. GINGIVAL RETRACTION CORD www.indiandentalacademy.com
  37. 37.  Plain cotton cord was used for sulcus enlargement physically pushing away the gingiva from the finish line .  Its effectiveness is limited because the use of pressure alone often will not control sulcular hemorrhage  Available in various sizes and colors  Appropriate size selected by evaluating the tissue bulk and its adaptation to the tooth. 37 H. RETRACTION CORD---- NON- IMPREGNATED www.indiandentalacademy.com
  38. 38.  Flexible  Nondisintegrating  circular in cross section  including a starter end and a remote opposite end  length at least approximately 50 mm  starter end having a first diameter of approximately 0.8 mm,  opposite end having a second diameter of approximately 1.3 mm  When spirally packed about a tooth creates a V-shaped gingival retraction crevice between the tooth and surrounding gum. 38www.indiandentalacademy.com
  39. 39. • Twisted • Knitted • Plain • Braided CONFIGURATION • Waxed • Unwaxed SURFACE FINISH • Plain • Impregnated CHEMICAL TREATMENT • Single • Double NO. OF STRANDS 39www.indiandentalacademy.com
  40. 40. 40 BLACK #OOO YELLOW #OO PURPLE #O BLUE #1 GREEN #2 RED #3 DEPENDING UPON THE THICHNESS & COLOR www.indiandentalacademy.com
  41. 41. Anterior teeth Double packing Substitute for black silk suture as lower cord in the "two- cord" technique 41 INDICATIONS OF #000 www.indiandentalacademy.com
  42. 42. Preparing and cementing veneers Restorative procedures dealing with thin, friable tissues 42 INDICATIONS OF #00 www.indiandentalacademy.com
  43. 43. Lower anteriors When luting near gingival and subgingival veneers Class III, IV and V restorations Second cord for "two-cord" technique 43 INDICATIONS OF #0 www.indiandentalacademy.com
  44. 44. Tissue displacement when soaked in coagulative / haemostatic solution prior to crown preparations as protective "pre- preparation" cord on anteriors and after preparation 44 INDICATIONS OF #1 www.indiandentalacademy.com
  45. 45. Upper cord for "two-cord" technique Tissue control and/or displacement when soaked in coagulative haemostatic solution prior to and/or after crown preparations Protective "pre- preparation" cord on anteriors 45 INDICATIONS OF #2 www.indiandentalacademy.com
  46. 46. Areas that have fairly thick gingival tissues where a significant amount of force is required Upper cord for those desiring the "two-cord" technique 46 INDICATIONS OF #3 www.indiandentalacademy.com
  47. 47. • “CORD PLACEMENT IS A FINESSE MOVE , NOT A POWER PLAY ”  The operating area should be dry. Fluid control should be done with an evacuating device and the quadrant containing the prepared tooth is isolated with cotton rolls.  Hemorrhage can be controlled by using haemostatic agent like hemodent liquid. 47www.indiandentalacademy.com
  48. 48. 1. Single cord technique. 2. Double cord technique. 3. Infusion technique of gingival displacement. 4. Every other tooth technique. 48 DCNA 2004; 48: 433-444 www.indiandentalacademy.com
  49. 49. 49www.indiandentalacademy.com
  50. 50. 50www.indiandentalacademy.com
  51. 51. 51www.indiandentalacademy.com
  52. 52. 52  After 10 minutes , the cord should be removed slowly in order to avoid bleeding .  If active bleeding persists , a cord soaked in ferric sulphate should be placed in the sulcus and removed after 3 minutes  The impression should be made only after cessation of bleeding .  The retraction cord must be slightly moist before removal . Removing dry cord from the crevice can injure the delicate epithelial lining of the gingiva . www.indiandentalacademy.com
  53. 53. 53 Indication: When making impression of multiple prepared teeth  When making impression when tissue health is compromised. Procedure: Small diameter cord is placed in sulcus. This cord is left in the sulcus during impression making. Second cord is soaked haemostatic agent of choice is placed in the sulcus above small diameter cord. After waiting 8-10 minutes, the larger cord is removed.www.indiandentalacademy.com
  54. 54.  Indicated to control the haemorrhage. Infuser with ferric sulphate medicament is used is used with a burnishing motion in the sulcus and carried circumferentially 360° around the sulcus. Haemostasis is verified, a knitted retraction cord is soaked in ferric sulphate and packed into the sulcus. The cord is removed after 1-3 minutes. 54www.indiandentalacademy.com
  55. 55. 55 • Placing retraction cord around all prepared teeth simultaneously may result in strangulation of gingival papilla. • Loss of papilla • Unaesthetic black triangles • Can be used with single or double cord technique • Starting from most distal prepared tooth cord placed around every alternate tooth. • Impression made . www.indiandentalacademy.com
  56. 56. 56 • Gingival displacement accomplished on remaining prepared teeth • A second impression is made • A pick-up impression allows fabrication of a master cast www.indiandentalacademy.com
  57. 57. 57  The cord can be packed with special instrument like Fischer packing instrument . It is a double ended, serrated or smooth edges stainless steel instrument facilitates placing of retraction cord around the tooth.  Both ends of the retraction cord packers are shaped at an angle which allows the cord to be packed swiftly right around the tooth. www.indiandentalacademy.com
  58. 58. • Gingival retraction using chemically impregnated retraction cord Mechanical aspect involves physical displacement of gingiva by placement of the cord into the gingival sulcus. Chemical aspect involves effect of the chemicals/medicaments in the cord on the gingival sulcus. 58 ChemicO - MECHANICAL methodS www.indiandentalacademy.com
  59. 59. Ideal requirement for chemical used with gingival retraction cords 59 It should produce effective gingival displacement and haemostasis. It should not produce any irreversible damage to the gingiva . it should not have any systemic side effect . www.indiandentalacademy.com
  60. 60. 1. 0.1% and 8% Epinephrine 2. 100% Alum solution (potassium aluminium sulfate) 3. 5% and 25% aluminium chloride solution 4. 13.3% ferric sulfate solution 5. 8% and 40% zinc chloride solution 6. 20% and 100% tannic acid solution 7. 45% Negatol solution(45% condensation product of meta cresol sulfonic acid and formaldehyde) 8. Caustic acid –sulfonic acid ,trichloracetic acid. 60www.indiandentalacademy.com
  61. 61. • NEWER GINGIVAL RETRACTION AGENTS (Nasal and ophthalmic decongestants) Phenylephrine hydrochloride 0.25 %  Oxymetazoline hydrochloride 0.05 %  Tetrahydrozoline hydrochloride 0.05 % • COMBINATIONS OF CHEMICALS  Cocaine 10% with 0.1% epinephrine  8% Zinc chloride with 8% epinephrine 61www.indiandentalacademy.com
  62. 62. MECHANISM OF ACTION A. Vasoconstrictors – Physiologically restrict the blood supply to the area by decreasing the size of the blood capillaries, tissue fluid seepage and consequently size of the free gingiva.  Ex: epinephrine and norepinephrine 62www.indiandentalacademy.com
  63. 63. MECHANISM OF ACTION B. Biologic fluid coagulants: Coagulate blood and tissue fluids locally, creating surface layer that is efficient sealant against blood and crevicular fluid seepage. Ex: 100% alum, 15-25% aluminium-chloride, 10% aluminium potassium sulphate and 15-25% tannic acid. 63www.indiandentalacademy.com
  64. 64. MECHANISM OF ACTION C) Surface layer tissue coagulants – coagulates surface layer and free gingival epithelium as well as seeped fluids, thus creating temporarily impermeable film for underlying fluids. Disadvantage: – Ulceration – local necrosis – change in the dimension and location of the free gingiva. Ex: 8% zinc chloride and silver nitrate 64www.indiandentalacademy.com
  65. 65. MECHANISM OF ACTION 3 BASIC CATEGORIES:- 1. styptics:- zinc chloride (8%), ferric subsulphate, tannic acid(20%), alum(14%) 2. Chemical cautery:- zinc chloride (40% ), potassium hydroxide. 3. Vasoconstrictors:- epinephrine ; ephedrine sulphate(3%). 65 JADA 1982; 104: 482-484www.indiandentalacademy.com
  66. 66. 66 Some silent point about epinephrine The amount of epinephrine absorbed is highly variable ,depending on the degree of exposure of the vascular bed as well as the time of contact and the amount of medication in the cord . The amount of epinephrine absorbed from 2.5 cm of typical retraction cord during 5 to 15 minutes in the gingival sulcus is 71 µg .It is approximately 1/3 rd the maximum dose of 0.2 mg (200 µg ) for a healthy adult and nearly twice the recommended amount of 0.04 mg (40 µg ) for a cardiac patient . J.A.D.A. 1982,vol.104,pg.482 www.indiandentalacademy.com
  67. 67. 67 Some silent point about epinephrine If cord is placed around more than one tooth ,if more than one impression is made of a single tooth , and /or if the epinephrine-containing anesthetic is used , a patient could easily exceed the recommended maximum dose of epinephrine . WEIR and WILLIAMS (1984) ,in an in vivo study of 120 human teeth ,found no significant difference between the hemorrhage control offered by cords impregnated with aluminum sulphate ,and those impregnated with epinephrine www.indiandentalacademy.com
  68. 68.  Patients with cardiovascular disease, hypertension, diabetes, hyperthyroidism, or a known hypersensitivity to epinephrine,  Patients taking Rauwolfia compounds, ganglionic blockers, or epinephrine-potentiating drugs.  Patients taking monoamine oxidase inhibitors for depression. • “ EPINEPHRINE SYNDROME” 68www.indiandentalacademy.com
  69. 69. 69 Ferenc C. Sempesz et al in 2003 conducted a study to determine the optimum soaking time for 3 retraction cords of different thickness to ensure adequate uptake of the hemostatic solution and concluded that 20 mins of soaking time was necessary for saturation of the cords before use. In addition to soaking time, the saturation of the cord with solution largely depends on wetting of the cords. JPD 2003; 89: 45-9. www.indiandentalacademy.com
  70. 70. 70 ROTARY CURETTAGE (GINGETTAGE /DENTTAGE) • The concept described by Amsterdam in 1954 . The technique described by Hansing & Ingraham • Troughing technique • Purpose is limited removal of epithelial tissue while a chamfer finish line is being created. • The following criteria should be fulfilled for gingettage  Absence of bleeding on probing from the gingiva  The depth of the sulcus should be less than 3 mm  Presence of adequate keratinized gingiva .www.indiandentalacademy.com
  71. 71. 71 ROTARY CURETTAGE (GINGETTAGE /DENTTAGE)  It has been compared with periodontal curettage.  Kamansky et al (1984 ) reported that less change in gingival height with rotary curettage than with lateral gingival displacement using retraction cord . With curettage there was an apparent disruption of the apical sulcular and attachment epithelium ,resulting in apical repositioning and an increase in sulcus depth . www.indiandentalacademy.com
  72. 72. Prior to rotary curettage ,a shoulder finish line is formed at the level of the gingival crest . A torpedo diamond point simultaneously forms a chamfer finish line and removes the epithelial lining of the sulcus. 72 Disadvantages • Technique sensitive as the instrument offers poor tactile sensation. • It can potentially damage the peridontium if used incorrectly. www.indiandentalacademy.com
  73. 73. 73 History Experiments of D’Arsonvol (1891) demonstrated that electricity at high frequency will pass through a body without producing a shock or 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. www.indiandentalacademy.com
  74. 74. Electrosurgery unit is a high frequency oscillator or radio transmitter that uses either a vacuum tube or a transistor to deliver a high frequency electrical current of at least 1.0 MHZ (one million cycles per second ) . The procedure is also called as surgical diathermy 74www.indiandentalacademy.com
  75. 75. 75 ELECTROCAUTERY • Refers to direct current • Current does not enter the patient’s body • Cutting electrode remains cold ELECTROSURGERY • Uses alternating current • The patient is included in the circuit and current enters the patient’s body • A hot electrode is applied JPD 1968; 20(5): 417- 425 www.indiandentalacademy.com
  76. 76. SURGICALELECTRODE OR CUTTING ELECTRODE PARTS OF ELECTRODE Handle Shank Cutting edge Handle designed to fit on to the hand piece of the electrosurgical unit Numerous cutting edge designs are available but the most commonly used ones are:- 76www.indiandentalacademy.com
  77. 77. GROUND ELECTRODE  Also known as Ground plate, Indifferent plate, Indifferent electrode, Neutral electrode, Dispersive electrode, Passive electrode or Patient return.  The single most important safety factor when electrosurgery is used . 77  ORINGER recommends that the ground be placed under the thigh rather than behind the back , as is often done . www.indiandentalacademy.com
  78. 78. 78 Current flows through a small cutting electrode. Producing high current density and rapid temperature rise . Cells directly adjacent to the electrode are destroyed due to this temperature increase. www.indiandentalacademy.com
  79. 79. 79 1) Patient with cardiac pacemakers, TENS, Insulin pump etc.. 2) The use of topical anesthetics such as ethyl chloride and other inflammable aerosols should be avoided when electrosurgery is to be used . www.indiandentalacademy.com
  80. 80. 80 Disadvantage  Very technique sensitive  Application of excessive pressure may produce severe tissue damage  Difficult to control lateral dissipation of heat  Slight loss of crestal bone (Kamansky F.W. et al)  Burn mark on the root surface.  Not suitable for thin gingiva.  Unpleasant odor and taste. Advantages  Can be used in case with gingival inflammation  Produce little to no bleeding .  Incision site free of bacteria (Self sterilizing)  Healing by primary intension.  Lack of pressure to incise tissue  Reduces chairside time of operator www.indiandentalacademy.com
  81. 81. Characterized by recurring peaks of power that rapidly diminishes. Produces intense lack of moisture (dehydration) ,necrosis and coagulation of the cells .It produces slow and painful healing , hence it is avoided . 81 Unrectified, dampedcurrent (oudinor telsa current) www.indiandentalacademy.com
  82. 82. PARTIALLY RECTIFIED , DAMPEDCURRENT(HALF WAVE MODULATED) Here the current during the second half of each cycle is damped so that only the peak waves act on the electrode . It produces good coagulation and haemostasis . but it also produces slow and painful healing with considerable tissue destruction because the electrical flow is intermittent . 82www.indiandentalacademy.com
  83. 83. FULLY RECTIFIED CURRENT (FULLWAVE MODULATED)  Here the frequency is similar to a partially rectified current but it is continuous .It produces adequate sulcus enlargement with good cutting characteristics along with good haemostasis 83www.indiandentalacademy.com
  84. 84. FULLY RECTIFIED ,FILTERED CURRENT Here the peak waves are repeated so that there is continuous flow without any dip . Lower frequency waves are filtered in this current . it produces excellent cutting . Hence it is most preferred. 84www.indiandentalacademy.com
  85. 85.  Local anesthesia should be given.  Aromatic oils such as peppermint oil can be applied at the vermilion border of lip.  Grounding should be done before the usage of the electrode in order to protect the patient from electrical accidents. 85DCNA 1980; 24: 247- 269www.indiandentalacademy.com
  86. 86. 86 Electrodes must be completely seated in the hand piece . i. During its use, the electrode should be applied with very light pressure and swift strokes. Tactile control for the operator is vital for this procedures. www.indiandentalacademy.com
  87. 87. 87  The electrode should never be placed stagnant at any one point as it may lead to lateral dissipation of heat producing gingival injury.  In order to prevent lateral heat dissipation, the probe should be moved at a minimal speed of 7 mm per second.  Moist tissues can be cut best. If it is necessary to redo the cutting in a particular region, a rest period of 5 seconds should be allowed to elapse before beginning the second stroke.  The electrode should pass through the tissue in a very smooth motion without dragging or charring the tissue. A wooden tongue depressor , plastic handle mirror and a plastic vaccum tip should be kept close to the surgical site . Electrode must not touch any metallic restorations. The operator should stop frequently to clean any fragments of tissue from the electrode . The electrode can be cleaned by wiping it with an alcohol –soaked sponge. www.indiandentalacademy.com
  88. 88. 88  Before any tissue is removed , it is important to assess the width of the band of attached gingiva .  To enlarge the gingival sulcus for impression making , a small (straight or J shaped ) electrode is selected .  With the electrosurgery unit off , the electrode is held over the tooth to be operated and the cutting strokes are traced over the tissue .  A whole tooth can be covered in four separate motion namely :facial ,mesial ,lingual and distal . For surgical crown lengthening For removal of edentulous cuff For recontouring of edentulous ridges For removal of opercula www.indiandentalacademy.com
  89. 89. 89 Healing after electrosurgery Kalkwarf et al reported…….. Wounds by fully rectified filtered current in a healthy gingiva of adult males showed epithelial bridging at 48 hours and complete clinical healing at 72hrs Study by Ruel j and j.Peter showed that it takes 16 to 24 days for complete healing JPD 1980;44(5) DCNA 1982;26(4);851 www.indiandentalacademy.com
  90. 90.  Lasers helps in exposure of subgingival finish lines, controls the hemorrhage, and removes just enough epithelial attachment to facilitate the placement of retraction cord.  Minimum gingival recession.  Laser tips 400-600 micron in diameter.  A feather light stroke should be used.  The laser handpiece should be kept moving.  Along with the attached gingiva, approximately 1mm of epithelial attachment should be removed and coagulated to achieve haemostasis and to expose the crown margins.  980-nm Diode and 1064-nm Nd:YAG Laser are used for Gingival Retraction in Fixed Prostheses 90www.indiandentalacademy.com
  91. 91. 91www.indiandentalacademy.com
  92. 92. 92  The first expanding VPS material.  Easy and fast retraction of the sulcus without potentially traumatic packing or pressure.  Stops bleeding without invasive materials or techniques More efficient – when doing multiple preparations www.indiandentalacademy.com
  93. 93. 93 Syringe Foam Cord around the preparation Place pre- fitted Comprecap over tooth and ask patient to bite down Wait 5 min. to allow Foam Cord material to fully set and sulcus to expand Preparation ready for final impression www.indiandentalacademy.com
  94. 94. Supplied in a syringe, it is designed to be injected into the unretracted sulcus. Once in the sulcus, it expands and provides displacement and hemostasis. 94JADA 2003; 134: 1485www.indiandentalacademy.com
  95. 95.  They are strips of a synthetic material that is specifically chemically extracted from a biocompatible polymer (hydroxylate polyvinyl acetate).  It creates a netlike strip without debris or free fragments. 95JPD 1996; 75: 242- 247www.indiandentalacademy.com
  96. 96. • By Jeffrey O. Earle • The retraction cord (or tape) includes a thermoplastic material such as polytetrafluoroethylene (i.e. PTFE or Teflon) so that the cord is resistant to shredding, tearing, and sticking to dental restorative and impression taking materials. • Additionally, chemical treatment of the cord may be avoided so as to reduce the risk of harmful side effects in chemically sensitive patients. 96www.indiandentalacademy.com
  97. 97. • By Steven D. Jensen et al • Retraction cords incorporating propylhexedrine do not cause increased blood pressure or accelerated heart rate as seen with conventional epinephrine cords. • In addition, such retraction cords may include astringents, such as iron (III) salts without causing discoloration of the retraction cord, the patient's teeth or gums, or the fingers of the dental practitioner, 97www.indiandentalacademy.com
  98. 98. By Uni-Braid+, DUX Dental. • Unit dose dispensing of retraction cords has been introduced where the chemically treated braided cord is pre-cut and individually packaged in 2-inch lengths 98 ALL-IN-ONE DELIVERY SYSTEM Short-Cut dispenses the braided gingival retraction cord (GingiBRAID+) by merely turning the click-stop dial of the ShortCut device.  The number of clicks specific to the length of cord needed.  3-4 clicks ---- Anterior tooth  4-5 clicks ---- premolar tooth  5-6 clicks ---- molar toothwww.indiandentalacademy.com
  99. 99. • Braided cord wrapped around an ultrathin copper wire • Described as being more stable in the sulcus once placed. 99 ) www.indiandentalacademy.com
  100. 100. 100  Blunt-tipped retraction cord scissors with less risk to tissue. . Uniband spring handle provides for smooth control. www.indiandentalacademy.com
  101. 101. Four clinical challenges frequently hinder the replication of subgingival margins 101 Low- or medium-viscosity materials typically have a durometer hardness (40 to 50) that is insufficient to displace soft tissue, blood, or saliva Necessity to maintain a dry field Bleeding from the gingiva Potential for damage to the peridontium if electrosurgery or lasers are used www.indiandentalacademy.com
  102. 102. • Dual-arch impression technique • Make accurate final impressions of subgingival margins without use of retraction cord, gingival excision, or application of haemostatic agents • Relies on specific physical properties of the chosen materials, sequential use of high- and low-viscosity impression materials, and the application of hydraulic force using a standardized method of material application 102www.indiandentalacademy.com
  103. 103.  Technique involves two steps,  Hence, the materials are referred to as first-step and second-step materials.  The first-step material must have a high durometer hardness (no less than 85);  Exhibit a whipped consistency with a high viscosity; and  Maintain placement without running or slumping after the material is extruded and before it is set . 103www.indiandentalacademy.com
  104. 104.  The second-step material must have a durometer hardness of 40-50;  Exhibit a low viscosity; yet maintain placement without running or slumping after the material is extruded and before it is set. 104www.indiandentalacademy.com
  105. 105. 105www.indiandentalacademy.com
  106. 106. • Gus J. Livaditis (1998) • A matrix of polyether occlusal registration elastomeric material is made over the tooth preparation. 106www.indiandentalacademy.com
  107. 107. 107www.indiandentalacademy.com
  108. 108. 108www.indiandentalacademy.com
  109. 109. Introduced by Bob Margeas  The instrument does not need to be twirled to get the end orientation needed Design maintains the instrument in the field of view 109www.indiandentalacademy.com
  110. 110. 1. Peri-implant mucosa lacks keratinized epithelium at the base of the sulcus & 2. Peri-implant mucosa does not have the same capacity for regeneration as peridental mucosa.  Mechanical retraction of gingival tissues by using cords around implant restorations can lead to ulceration of the junctional epithelium as forces used in cord placement are likely to exceed peri-implant tissues’ capacity to resist them.  Addition of chemical adjuncts to retraction cords further complicates the situation and may lead to increased inflammation of the subsulcular tissues. 110www.indiandentalacademy.com
  111. 111.  Electrosurgery is not recommended around implants . The concentrated electrical current at the tip of electrodes can generate heat, which may cause osseous or mucosal necrosis.  Rotary curettage is inappropriate for use around implant restorations because of poor tactile control when cutting soft tissue, which could lead to bur contact damage to the implant surface and overinstrumentation. 111www.indiandentalacademy.com
  112. 112.  Use of Nd:YAG lasers is contraindicated near implant surfaces, because they tend to absorb energy, which causes them to heat up and transmit the heat to bone, owing to the effects of this laser’s wavelength on metal.  There is also a tendency for Nd:YAG lasers to damage the fragile subjunctional epithelium at the sulcus base around implants.  Erbium:yttrium-aluminum-garnet (Er:YAG) lasers(2,940) nm are reflected by metal implant surfaces and minimally penetrate the soft tissues, are relatively safe to use. The hemostasis achieved not as effective as that achieved with the carbon dioxide (CO2)laser (10,600nm) 112www.indiandentalacademy.com
  113. 113.  Use of 15 percent aluminum chloride in an injectable kaolin matrix is effective.  Delivery of chemicals via an injectable matrix shows promise for peri-implant tissue retraction, because it preserves the gingival tissues with no risk of lacerating or inflaming the junctional epithelium.  Another inert matrix of polyvinyl siloxane material for gingival retraction was introduced in 2005. It works by generating hydrogen, causing expansion of the material against the sulcus walls during setting. 113 JADA 2008; 139: 1354- 1363www.indiandentalacademy.com
  114. 114. • Gingival displacement is an important procedure while fabricating indirect restorations. • Relatively simple and effective when dealing with healthy gingival tissues and when margins are properly placed a short distance into sulcus. • Most common technique is use of retraction cord with a haemostatic medicament but epinephrine containing cords should be avoided. • Several techniques have proven to be relatively predictable, safe and efficacious. No scientific evidence has established the superiority of one technique over other , so choice of technique depends on the clinical situation and operator preference. 114www.indiandentalacademy.com
  115. 115. • Fundamentals of fixed prosthodontics, Shillinburg, 3rd edition • Contemporary fixed prosthodontics, Rosenstiel, 2nd edition • Tylman’sTheory and practice of fixed prosthodontics- Malone , Roth, 8th ed. • JPD 1986; 55: 175-81 • JPD 1980; 44: 508-15 • JPD 1974; 31: 647-50 • JPD 1978; 39: 287-292 • JPD 1985; 53: 525-31 • JPD 1984; 51: 647-51 • DCNA 1976; 20: 273-83 115www.indiandentalacademy.com
  116. 116. • JPD 1984; 51: 326-29 • JPD 1993:70:114-117 • JPD 1981; 46: 509-15 • JPD 1968; 20: 417-25 • DCNA 1980; 24 :247-69 • JPD 1986: 56: 145-47 • JADA 1993; 124: 37-47 • JPD 1996; 75: 245-247 • JPD; 50; 565-569; 1983 • JPD1964;14: 1107-1114 • DCNA 2004;48: 433-444. 116www.indiandentalacademy.com
  117. 117. • JPD 1987;44:234-245 • JPD 1997; 67: 25-265 • JPD 1987; 44: 567-570 • IJP 1997;10: 3 • J.P.D.1976 ;20:649-654. • JADA 2003; 134(11):1485 • www.ultradent.com • www.valleylab.com 117www.indiandentalacademy.com
  118. 118. Thank you For more details please visit www.indiandentalacademy.com 118www.indiandentalacademy.com

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