Tissue Management & Impression Technique


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Overview of final impression and soft tissue management technique for excellent impressions.

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Tissue Management & Impression Technique

  1. 1. Tissue Management and Impression Techniques and Material <ul><li>Parag R. Kachalia DDS </li></ul><ul><li>Jessie V. Vallee, DDS </li></ul>Preclinical Fixed Prosthodontics Class of 2011
  2. 2. <ul><li>If the restoration is to fit precisely, the cast on which it is made must be as nearly an exact duplicate of the prepared tooth as possible </li></ul>Impression Musts!
  3. 3. <ul><li>High potential for improper use of material </li></ul><ul><li>Much variation from material to material </li></ul><ul><li>Accurate impressions have been destroyed due to incorrect handling </li></ul><ul><li>Have also been destroyed due to delays between removal from the mouth and pouring </li></ul>Impressions
  4. 4. <ul><li>Exact duplicate of the prepared tooth and enough tooth structure below the margin for accurate definition of the finish line </li></ul><ul><li>Other teeth must accurately be reproduced in order to articulate the casts correctly </li></ul><ul><li>It must be free of bubbles and voids (especially in the area of the finish line) </li></ul>Impression Must Meet Following Requirements
  5. 5. <ul><li>Your choice is based on: </li></ul><ul><li>1) personal preference </li></ul><ul><li>2) ease of manipulation </li></ul><ul><li>3) strength and shelf life </li></ul><ul><li>4) predictability </li></ul><ul><li>5) economics </li></ul><ul><li>6) accuracy </li></ul>Comparison of Impression Materials
  6. 6. <ul><li>Final Impressions: </li></ul><ul><li>1) Polysulfides </li></ul><ul><li>2) Reversible Hydrocolloids </li></ul><ul><li>3) Condensation Silicone </li></ul><ul><li>4) Polyvinyl Siloxane* </li></ul><ul><li>5) Polyether* </li></ul><ul><li>* - used at UOP </li></ul>Choice of Materials
  7. 7. <ul><li>Can be described as ease of pouring with gypsum products </li></ul><ul><li>Classified as readily wettable (hydrophilic), resistant to wetting (hydrophobic) </li></ul>Wettability
  8. 8. <ul><li>Hydrophilic Materials: </li></ul><ul><ul><li>Irreversible Hydrocolloid (alginate) </li></ul></ul><ul><ul><li>Reversible Hydrocolloid </li></ul></ul><ul><ul><li>Polyether </li></ul></ul>Love it or leave it <ul><li>Hydrophobic Materials: </li></ul><ul><li>Polysulfide </li></ul><ul><li>Polyvinyl Siloxane </li></ul><ul><li>Condensation-Reaction Silicones </li></ul>
  9. 9. <ul><li>Shear Thinning - a materials viscosity decreases as it is expressed through a syringe, yet maintains its body when left alone. This allows for a “monophasic” material to respond differently under different conditions </li></ul><ul><li>This type of material may also be termed thixotropic </li></ul>Viscosity
  10. 10. <ul><li>Materials on today’s market range from 2.6 pounds of pressure required to express through a syringe to 112 pounds of pressure (polysulfide through a small diameter syringe) </li></ul>Viscosity
  11. 11. <ul><li>Should not be considered as a primary factor in impression material selection </li></ul><ul><li>Least expensive impression found is a polysulfide in custom trays (average of $5.50 in 1998) </li></ul><ul><li>Most expensive impression found is a polyvinyl siloxane in stock metal trays (average of $13.50 in 1998) </li></ul><ul><li>Today’s average cost of a final impression is approximately $15.00 </li></ul>Cost
  12. 12. <ul><li>In use for over 60 years </li></ul><ul><li>Sold in a semi-solid state </li></ul><ul><li>Liquefied by placing in boiling water, then cooled in two stages </li></ul><ul><li>Cool tap water is circulated through the tray </li></ul><ul><li>Material is 85% water </li></ul><ul><li>Inexpensive and can be removed in 3 minutes! </li></ul>Reversible Hydrocolloids
  13. 13. <ul><li>What then are the drawbacks of this material? </li></ul><ul><ul><li>Can only be poured once </li></ul></ul><ul><ul><li>Quite temperature dependent </li></ul></ul><ul><ul><li>Potential injury to the patient </li></ul></ul><ul><ul><li>If left exposed, can begin to distort readly </li></ul></ul>Reversible Hydrocolloids
  14. 14. <ul><li>1) Excellent dimensional stability </li></ul><ul><li>2) Hydrophilic in nature </li></ul><ul><li>3) Will lock into undercuts if not blocked out </li></ul><ul><li>4) 0.5% of individuals have shown some reaction to this material </li></ul><ul><li>5) 8:1 ratio of base-accelerator </li></ul><ul><li>6) Can be somewhat brittle </li></ul>Polyether
  15. 15. <ul><li>Commonly called rubber base </li></ul><ul><li>Comes as two tubes of base and catalyst </li></ul><ul><li>Will begin to shrink after one hour from removal </li></ul><ul><li>Should be poured immediately </li></ul><ul><li>Only radiopaque impression material </li></ul><ul><li>Can become locked into undercuts </li></ul>Polysulfide
  16. 16. <ul><li>Can have pronounced shrinkage due to evaporation of alcohol during reaction [poor dimensional stability] </li></ul><ul><li>Used in a similar fashion to polysulfides </li></ul><ul><li>Must be poured within six hours </li></ul><ul><li>Dies produced from this material are undersized </li></ul><ul><li>The above occurs due to the evaporation of the biproduct of the condensation reaction.( H2O for polysulfides and ethanol for Condensation silicones) </li></ul>Condensation Silicones
  17. 17. <ul><li>Also know as addition silicones </li></ul><ul><li>Dimensional stability is quite high in this group </li></ul><ul><li>Least affected by pouring delay of any material (due to no volatile biproduct formation, carbon double bonds, in the form of vinyl groups open up during polymerization and link the monomer groups together via an addition reaction) </li></ul><ul><li>Comes in many varieties (putty-wash, wash-wash) </li></ul><ul><li>Surfactants have been added to the material to decrease it hydrophobia, but dies are 14-33% softer </li></ul>Our Material - Polyvinyl Siloxanes
  18. 18. <ul><li>Mixing guns are the most popular form of this material </li></ul><ul><li>We utilize a monophase-wash system (one step) </li></ul><ul><li>Latex gloves retard the setting of this type of material </li></ul><ul><li>Must not come into contact with any surface touched by a glove </li></ul>Our Material - Polyvinyl Siloxanes
  19. 19. <ul><li>Type of Impression: </li></ul><ul><ul><li>Heavy body wash (Monophasic material) in a stock tray with medium or light wash around </li></ul></ul><ul><ul><li>Light body wash in a custom tray </li></ul></ul>Polyvinyl Siloxane Impression Technique
  20. 20. <ul><li>One step monophasic-wash technique: </li></ul><ul><ul><li>Stock tray preparation </li></ul></ul><ul><ul><li>Tissue management </li></ul></ul><ul><ul><li>Final wash </li></ul></ul><ul><ul><li>Evaluation </li></ul></ul>Polyvinyl Siloxane Impression Technique
  21. 21. Stock Tray Preparation
  22. 22. Washing Hands Is A Must! Powder from latex gloves can react with impression material. It must be removed to prevent incomplete setting of the impression material.
  23. 23. <ul><li>Armamenterium </li></ul>Phase One: Stock Tray Preparation
  24. 24. <ul><li>Tray adhesive is applied to help retain material within tray [ the adhesive for aquasil and impragum are different ] </li></ul>Phase One: Stock Tray Preparation
  25. 25. <ul><li>Techniques: </li></ul><ul><ul><li>No cord - margins supragingival </li></ul></ul><ul><ul><li>Single cord technique </li></ul></ul><ul><ul><li>Dual cord technique </li></ul></ul><ul><ul><li>Either single or dual cord technique with hemostatic agent </li></ul></ul><ul><ul><li>Either single or dual cord technique with epinephrine </li></ul></ul><ul><ul><li>Electrosurgery/laser </li></ul></ul>Phase Two: Tissue Management
  26. 26. <ul><li>Astringedent contains 20% Ferric Sulfate which stimulates blood clotting </li></ul><ul><li>ViscoStat contains 20% Ferric Sulfate </li></ul>Phase Two: Tissue Management
  27. 27. <ul><li>Different delivery options for hemostatic agent. </li></ul>Phase Two: Tissue Management
  28. 28. <ul><li>Reaction begins immediately upon application to bleeding area </li></ul>Phase Two: Tissue Management
  29. 29. <ul><li>The Ferric Sulfate [ViscoStat] is applied to the bleeding tissue using this tip attached to a syringe </li></ul>Phase Two: Tissue Management
  30. 30. <ul><li>The Ferric Sulfate can be injected onto a cord that has been previously packed into the gingival sulcus </li></ul>Phase Two: Tissue Management
  31. 31. <ul><li>Cord packing (placing) instrument </li></ul>Cord Placement Armamenterium
  32. 32. <ul><li>Clinical presentation after completion of preparation </li></ul>Phase Two: Tissue Management
  33. 33. <ul><li>Ferric sulfate being scrubbed into sulcus via tufted syringe tip </li></ul>Phase Two: Tissue Management
  34. 34. <ul><li>Two types of cord are available for purchase: </li></ul><ul><li>1) Braided and 2) Knitted </li></ul>Phase Two: Tissue Management Braided Knitted
  35. 35. <ul><li>Cord can be purchased in a variety of sizes to be used in varying sulcus widths and depths </li></ul>Phase Two: Tissue Management
  36. 36. <ul><li>Different cord thickness </li></ul>Phase Two: Tissue Management
  37. 37. <ul><li>Cord is positioned above the sulcus and using a length cut to surround the tooth without overlap </li></ul>Phase Two: Tissue Management
  38. 38. <ul><li>Cord is packed into the sulcus to retract tissue and aid in moisture control </li></ul>Phase Two: Tissue Management
  39. 39. <ul><li>Tissue is rinsed after scrubbing with ferric sulfate, hemostasis is confirmed, more ferric sulfate is placed into sulcus prior to introducing the first dry cord. </li></ul>Phase Two: Tissue Management
  40. 40. Phase Two: Tissue Management <ul><li>Tooth with first cord in place. Ferric sulfate is scrubbed into sulcus again and rinsed </li></ul>
  41. 41. <ul><li>Second cord (larger) Placed into sulcus for lateral retraction of soft tissue </li></ul>Phase Two: Tissue Management
  42. 42. <ul><li>Second cord is in place circumferentially </li></ul>Phase Two: Tissue Management
  43. 43. <ul><li>Coronal cord is removed to expose margin and apical cord </li></ul>Phase III: Introduction of wash
  44. 44. <ul><li>View margin and check for any heme. If heme is present rescrub with ferric sulfate </li></ul>Phase III: Introduction of wash Note retraction could be better at ML line angle
  45. 45. <ul><li>Wash is introduced into the sulcus making sure tip stays in contact with material at all times </li></ul>Phase III: Introduction of wash
  46. 46. <ul><li>Once the prepared tooth has had wash placed around it insert stock tray with monophase material into the patients mouth. </li></ul><ul><li>Seat the tray completely and do not allow the tray to move once setting has begun. </li></ul>Phase III: Introduction of wash and tray material
  47. 47. <ul><li>The impression material cervical to the margin is termed “flash”. </li></ul><ul><li>The more flash cervical to the impression, the easier it is to trim the dies during the laboratory phase of any project. </li></ul>Lingual View Of Our Impression Flash
  48. 48. <ul><li>All of the margin has been captured on the facial surface </li></ul><ul><li>Far less flash is present on the facial making that portion of the die far more difficult to trim </li></ul>Lingual View Of Our Impression
  49. 49. <ul><li>Note marginal clarity around each of the four anterior teeth . This was accomplished with Aquasil and good tissue management. </li></ul>Ideal Impression
  50. 50. Apply Tray Adhesive Load cartridges
  51. 51. <ul><ul><ul><ul><ul><li>Bleed Cartridge Attach Mixing tip </li></ul></ul></ul></ul></ul>
  52. 52. <ul><li>Load Tray - Monophase Inject Around Prep </li></ul>
  53. 53. <ul><li>Working time 2 min. 30 sec. (seat tray) </li></ul><ul><li>Setting time 5 min. </li></ul><ul><li>Remove and inspect for accuracy. </li></ul>
  54. 54. <ul><li>Need to measure sulcus with periodontal probe </li></ul><ul><li>And assess need for hemostatic agent </li></ul>Phase Two: Tissue Management
  55. 55. <ul><li>Cord is placed into the sulcus. This will allow for the tissues to be position laterally from the margin. </li></ul>Cord Placement
  56. 56. <ul><li>Make sure tip is not made too large. This will prevent adequate force on the impression material </li></ul>Preparing the Syringe Tip
  57. 57. <ul><li>Wash Materials used an Pacific </li></ul><ul><li>Aquasil light body </li></ul><ul><li>Impragum light body </li></ul>Phase Three: Final Wash
  58. 58. <ul><ul><ul><li>Tip must be kept in contact with the impression tray and impression material to prevent bubble formation </li></ul></ul></ul>Loading The Tray and Syringe
  59. 59. <ul><li>Final wash is applied with force so that impression material is expressed into the sulcus. </li></ul>Final Wash of Preparation
  60. 60. Alternative Soft Tissue Management Techniques
  61. 61. Electrosurgery <ul><li>State of the art high frequency electrical device used for easy and effective soft tissue contouring and coagulation </li></ul>
  62. 62. <ul><li>Gingivectomy –removing excess tissue </li></ul><ul><ul><li>must not violate biologic width </li></ul></ul><ul><ul><li>adequate attached gingiva </li></ul></ul><ul><ul><li>caution in cosmetic areas (adequare sulcus depth, and attatched gingiva), although it can be used for aesthetic contouring of gingival tissue </li></ul></ul>Electrosurgery
  63. 63. <ul><li>Advantages over blade surgery </li></ul><ul><ul><li>Less bleeding </li></ul></ul><ul><ul><li>Less need for sutures </li></ul></ul><ul><ul><li>Less scarring </li></ul></ul><ul><ul><li>Better access </li></ul></ul>Electrosurgery
  64. 64. <ul><li>Gingivectomy –removing excess tissue </li></ul>Electrosurgery Straight tip (scalpel)
  65. 65. Electrosurgery <ul><li>Uses of the electrosurge </li></ul><ul><li>Inflamed tissue </li></ul><ul><li>Hyperplastic tissue </li></ul><ul><li>Frenum removal </li></ul><ul><li>Sulcus expansion </li></ul>
  66. 66. <ul><li>Pacific’s laser: </li></ul><ul><ul><li>diode laser </li></ul></ul>Dental Lasers Laser unit Fiber optic Protective eyewear Handpiece Foot pedal
  67. 67. DioDent Laser <ul><li>Gallium Alluminum Arsenide Solid State laser diode provides the optical energy </li></ul><ul><li>Fiber optic handpiece delivers up to 10 watts of laser energy </li></ul><ul><li>Pulse and power output can be adjusted </li></ul>
  68. 68. DioDent Laser <ul><li>Cosmetic Dentistry </li></ul><ul><li>Endodontics </li></ul><ul><li>Periodontal proceedures </li></ul><ul><li>Oral soft tissue surgery including gingivectomy, gingivoplasty, biopsy,etc. </li></ul><ul><li>Tissue retraction for impressions </li></ul><ul><li>I and D’s </li></ul><ul><li>Implant recovery </li></ul>
  69. 69. Today’s project <ul><li>Refine patient preparation as needed </li></ul><ul><li>Place retraction cord </li></ul><ul><li>Take final impressions utilizing Aquasil </li></ul>