Sp.imp.procedures. /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

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Sp.imp.procedures. /certified fixed orthodontic courses by Indian dental academy

  1. 1. SPECIAL IMPRESSION PROCEDURES FOR COMPRISED CLINICAL CONDITIONS INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  2. 2. AIMS To customize the denture bases to the supporting tissues To develop the functional border of the denture To enhance retention & stability To obtain optimal esthetics To maintainwww.indiandentalacademy.com health of the oral tissues
  3. 3. PRINCIPLES Denture base should cover maximum possible supporting area. Impression surface should achieve closest possible contact with underlying tissues. Border form of the prosthesis should establish a peripheral seal ; support lips and cheeks functionally and esthetically. www.indiandentalacademy.com
  4. 4. SPECIAL IMPRESSION PROCEDURES 1. Controlled techniques, - Minimally displacive impression E.g. displaceable (flabby) upper ridge. 2. Controlled – Pressure impression techniques, E.g. Fibrous / Knife edge / Unemployed lower ridge 3. Functional impressions, E.g. Indeterminate peripheral extensions 4. Denture space impressions, (External impressions), E.g. When the denture is subjected to excessive displacing forces from surrounding musculature www.indiandentalacademy.com
  5. 5. Controlled - Minimally displacive impression techniques Patients wearing upper complete denture opposed by lower natural teeth. Chronic complete denture wearers Maxillary anterior ridge replaced by fibrous tissue; reduced support for dentures. Patient complains of loose dentures Impression techniques to avoid undue tissue displacement. www.indiandentalacademy.com
  6. 6. Controlled - Minimally displacive impression techniques (Contd…) Method A Special tray with a window cut in the region of the displaceable tissue. www.indiandentalacademy.com
  7. 7. Controlled - Minimally displacive impression techniques (Contd…) Border molding with low fusing compound. Wash impression with ZOE paste. www.indiandentalacademy.com
  8. 8. Controlled - Minimally displacive impression techniques (Contd…) Tray re-inserted, impression syringed over displaceable tissue. www.indiandentalacademy.com plaster
  9. 9. Controlled - Minimally displacive impression techniques (Contd…) Completed impression. www.indiandentalacademy.com
  10. 10. Controlled - Minimally displacive impression techniques (Contd…) • Method B – Special tray with a window cut in the region of the displaceable tissue. – Border molding with low fusing compound. www.indiandentalacademy.com
  11. 11. Controlled - Minimally displacive impression techniques (Contd…) Impression made with medium – bodied / monophase elastomer. www.indiandentalacademy.com
  12. 12. Controlled - Minimally displacive impression techniques (Contd…) Light - bodied elastomer syringed over window area. Dental plaster syringed over set, light - bodied elastomer. www.indiandentalacademy.com
  13. 13. Controlled - Minimally displacive impression techniques (Contd…) Completed Impression www.indiandentalacademy.com
  14. 14. Controlled - Minimally displacive impression techniques (Contd…) Method C Special tray fabricated with no window. Border molding with low fusing compound. www.indiandentalacademy.com
  15. 15. Controlled - Minimally displacive impression techniques (Contd…) Impression made using ZOE paste / monophase elastomer. When set, impression material corresponding to displaceable tissue removed and tray perforated. www.indiandentalacademy.com
  16. 16. Controlled - Minimally displacive impression techniques (Contd…) Impression plaster / light bodied elastomer syringed over displaceable tissue. Tray reseated and impression completed. www.indiandentalacademy.com
  17. 17. Controlled – Pressure impression techniques Indicated Unemployed lower alveolar ridge unable to provide acceptable support against vertical loads and positive stability against lateral forces. www.indiandentalacademy.com
  18. 18. Controlled – Pressure impression techniques (Contd…) Method Primary impression made with alginate or putty elastomer. Impression relieved over ridge crest area and wash impression obtained with low viscosity material. www.indiandentalacademy.com
  19. 19. Controlled – Pressure impression techniques (Contd…) Customized special tray with 2mm spacer constructed. Spacer removed ; tray perforated in crestal region . www.indiandentalacademy.com
  20. 20. Controlled – Pressure impression techniques (Contd…) Low fusing compound used to obtain impression of primary cast with special tray. www.indiandentalacademy.com
  21. 21. Controlled – Pressure impression techniques (Contd…) Impression reduced in the region of buccal & lingual sulci ; border molding refined in patient’s mouth. Painful areas relieved. Tray re-insertion not result in pain. should Impression completed with light – bodied elastomer. www.indiandentalacademy.com
  22. 22. Functional impressions Indications Reduced retentive forces ( Atrophic ridges ) High displacing forces ( Uncontrolled muscle activity) Peripheral form molded by peri–denture musculature. Existing denture utilized for the procedure. www.indiandentalacademy.com
  23. 23. Functional impressions (Contd…) Method Tissue conditioning materials employed for the procedures. www.indiandentalacademy.com usually
  24. 24. Functional impressions (Contd…) Impression surface & periphery of existing denture reduced by 1.5-2mm to create space. Fitting surface of denture cleaned & dried. Material mixed & spread over fitting surface. www.indiandentalacademy.com
  25. 25. Functional impressions (Contd…) Denture seated in patients mouth; patient instructed to close in centric occlusion. Patient encourage to perform functional movements such as talking, swallowing, smiling, to obtain a functionally generated impression. www.indiandentalacademy.com
  26. 26. Functional impressions (Contd…) Denture removed after 5 – 6 minutes ; inspected and surplus material trimmed. www.indiandentalacademy.com
  27. 27. Functional impressions (Contd…) Patient returns after few / 24 hours; impression inspected & cast poured. www.indiandentalacademy.com
  28. 28. Denture space determination (External Impressions) Aims To determine the space within which the denture can be sited without being subjected to excessive displacing forces from the surrounding musculature. www.indiandentalacademy.com
  29. 29. Denture space The portion of the oral cavity that is or may be occupied by the maxillary and / or mandibular denture (s). www.indiandentalacademy.com
  30. 30. Neutral Zone That area in the mouth, where, during functions the forces of the tongue pressing outward are neutralized by the forces of the cheeks and lips pressing inward. Hence a possible zone of equilibrium www.indiandentalacademy.com
  31. 31. Denture space determination (Contd…) Indications Past denture looseness due to powerful lower lip activity. Non-replacement of missing teeth leading to tongue / cheeks / lips partially occupying the usual denture space. Enlarged tongue, E.g. Down’s Syndrome. Abnormal anatomy, E.g. Hemimandiblectomy. Inability to wear a lower denture www.indiandentalacademy.com
  32. 32. Denture space determination (Contd…) How to record neutral zone? Generally done for lower Done at any stage of CD fabrication Materials used-Waxes,ZnOE,rubber base putty, self-cure acrylic, impression compound,tissue conditioners. www.indiandentalacademy.com
  33. 33. Denture space determination (Contd…) On accurate master casts, stabilized denture bases are constructed. Wire loops embedded over ridge crest for retention. www.indiandentalacademy.com
  34. 34. Denture space determination (Contd…) Low fusing compound rims attached to bases. Patient trained to perform a range of functional movements such as smiling, swallowing, speaking, etc. Compound rims softened and denture bases inserted ; functional movements carried out. www.indiandentalacademy.com
  35. 35. Denture space determination (Contd…) Recommended movements Smile Swallow ‘ooh’ ‘ah’ www.indiandentalacademy.com
  36. 36. Denture space determination(Contd…) www.indiandentalacademy.com
  37. 37. Denture space determination (Contd…) Wash impression obtained with light – bodied elastomer brushed on compound rims. Functional movements repeated. www.indiandentalacademy.com
  38. 38. Denture space determination (Contd…) Plaster matrices constructed around records. Matrices guide in arranging & waxing teeth & polished surfaces in optimum denture space. www.indiandentalacademy.com
  39. 39. Denture space determination (Contd…) www.indiandentalacademy.com
  40. 40. Denture space determination (Contd…) After wax trial is completed, external impressions are obtained using ZOE paste / light – bodied elastomer. www.indiandentalacademy.com
  41. 41. Denture space determination (Contd…) Precautions Stable record bases not interfering with muscle activity. Patient to be trained in molding procedure prior to insertion of loaded tray. Excessive volume of molded material to be avoided – causes distortion of potential denture space. External impression may be totally unlike the shape of a “normal” denture, hence laboratory staff must be instructed about reproduction of the recorded contours. www.indiandentalacademy.com
  42. 42. Denture space determination Modifications of basic technique Determination of the optimal space for a segment of a denture. ( E.g. The lower anterior region) Determination of the fit of the completed denture to the potential space. www.indiandentalacademy.com
  43. 43. Determination of the optimal space for a segment of a denture Teeth & majority of the base trimmed from appropriate segment. Patient trained in molding routine. Insert loaded tray in mouth, mold while setting and inspect after set. Re-insert in mouth and check for stability. Matrices help to contour teeth & base appropriately. www.indiandentalacademy.com
  44. 44. Determination of the fit of the completed denture to the potential space To detect interference to normal muscle activity by an existing denture. Coat low viscosity elastomer on borders & polished surfaces of denture. Denture inserted & molding routine performed. Exposed denture base indicative of interference & corrected accordingly. www.indiandentalacademy.com
  45. 45. In a Nut Shell… CLINICAL FINDING PRIMARY IMPRESSIONS SECONDARY IMPRESSIONS TECHNIQUE Upper ridge displaceable Alginate Two - step technique Controlled minimally displacive technique Resorbed, fibrous, lower ridge – pain on palpation Alginate / putty elastomer ZOE / light – bodied elastomer wash on low fusing compound impression Controlled pressure impression technique Atrophic ridges with indeterminate peripheral extensions - Functional molding with tissue conditioners Existing denture modified & material molded by functional movements Resorbed ridges with hyper active musculature Impression compound / alginate / putty 1.ZOE / monophase for master impression. 2.Low fusing compound / tissue conditioner / light bodied elastomer / resin for external impression. www.indiandentalacademy.com Denture Space determination done by external impressions for contour of polished surfaces
  46. 46. www.indiandentalacademy.com