1 / 79

POSTERIOR TEETH SELECTION IN COMPLETE DENTURES

POSTERIOR TEETH SELECTION IN COMPLETE DENTURES. BY, Dr.BHUMA JAYARAM. CONTENTS. INTRODUCTION DEFINITIONS DIFFERENCES BETWEEN NATURAL AND ARTIFICIAL OCCLUSION AXIOMS FOR ARTIFICIAL OCCLUSION SELECTION OF TEETH ■ SIZE : BUCCOLINGUAL WIDTH MESIODISTAL LENGTH

avedis
Download Presentation

POSTERIOR TEETH SELECTION IN COMPLETE DENTURES

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. POSTERIOR TEETH SELECTION IN COMPLETE DENTURES BY, Dr.BHUMA JAYARAM

  2. CONTENTS • INTRODUCTION • DEFINITIONS • DIFFERENCES BETWEEN NATURAL AND ARTIFICIAL OCCLUSION • AXIOMS FOR ARTIFICIAL OCCLUSION • SELECTION OF TEETH ■ SIZE : BUCCOLINGUAL WIDTH MESIODISTAL LENGTH OCCLUSOGINGIVAL HEIGHT ■ SHADE ■ MOLD NUMBERING SYSTEMS

  3. FORM OF THE TEETH - SPECIFICATIONS FOR ARTIFICIAL POSTERIOR TEETH - HISTORY - EVALUATION OF OCCLUSAL FORMS - ANATOMIC TEETH - NON ANATOMIC TEETH - FACTORS AFFECTING SELECTION OF FORM OF TEETH MATERIALS - REQUIREMENTS OF PROSTHETIC DENTURE TEETH - ACRYLIC TEETH - PORCELAIN TEETH - COMPARISON OF ACRYLIC VS PORCELAIN TEETH - COMBINATION OF ACRYLIC AND PORCELAIN TEETH

  4. - COMPOSITE TEETH - METAL INSERT TEETH - TEETH WITH METAL OCCLUSALS • SUMMARY • CONCLUSION • REFERENCES

  5. INTRODUCTION

  6. DEFINITIONS • Anatomic teeth • Non anatomic teeth • Zero degree teeth • Occlusion GPT - 8

  7. DIFFERENCES BETWEEN NATURAL AND ARTIFICIAL OCCLUSION Essentials of complete denture prosthodontics – Winkler, 2nd Ed

  8. AXIOMS FOR ARTIFICIAL OCCLUSION(By Sears) • The smaller the area of occlusal surface acting on food, the smaller will be the crushing force on food transmitted to the supporting structures • Vertical force applied to an Inclined occlusal surface causes nonvertical force on the denture base. • Vertical force applied outside (lateral) to the ridge crest creates tipping forces on the base. • Vertical force applied to a denture base supported by yielding tissue causes the base to teeter when the force is not centeredon the base. Essentials of complete denture prosthodontics – Winkler, 2nd Ed

  9. SELECTION OF TEETHSIZE : • BUCCOLINGUAL WIDTH Must be reduced to - aid in the stability of the denture - reduce stress during function to supporting structures - reduce buccolingual leverage. Wehner P.J, Hickey J. C, Boucher C. O Selection of Denture Teeth for Esthetics and Function, J. PROSTHET. DENT.1967;18(3): 222-232 McCord J.F,GrantA.A.Registration:StageIII — selection of teeth, British Dental Journal.2000; 188: 660–666

  10. Complete denture Prosthodontics – John. J. Sharry, 3rd Ed

  11. Relationship between the width of the occlusal table and pressures under dentures during function - J. PROSTHET. DENT.1976;36(1): 24-34 - William H. Roedema, D.D.S.,TheUniversity of Michigan, School of Dentistry Purpose of the study : To determine the effect of reducing the occlusal table of a complete denture on masticatory pressures developed between supporting mucosal tissues and the base of the prosthesis. Conclusions of the study are as follows : • The mean pressure at the crest of the residual ridge varied directly with the width of the occlusal table. • The mean total pressure developed at the crest of the residual ridge varied directly with the width of the occlusal table. • The number of masticatory strokes required before swallowing generally varied inversely with the width of the occlusal table.

  12. The width of the occlusal table had little effect on the frequency of the masticatory stroke. • The duration of the masticatory sequence generally varied inversely with the width of the occlusal table.

  13. MESIODISTAL LENGTH • from the approximate position of the canines to the beginning of the upward turn of the residual ridge toward the retromolarpad • When space is less – eliminate premolar of a larger mould • posterior teeth arranged over steep inclines - displaces the dentures from their supporting structures • posterior teeth donot extend far enough posteriorly - heavier load on anterior part of residual ridges. Wehner P.J, Hickey J. C, Boucher C. O Selection of Denture Teeth for Esthetics and Function, J. PROSTHET. DENT.1967;18(3): 222-232 Sears V.H. The Selection And Management Of Posterior Teeth,J. PROSTHET. DENT.1957;7(6): 723-737

  14. Boucher’s Prosthodontic Treatment for Edentulous Patients – 9th Ed

  15. CERVICO OCCLUSAL HEIGHT • selected based on - interarchspace - the length of the anterior teeth Boucher’s Prosthodontic Treatment for Edentulous Patients – 9th Ed

  16. The superoinferior position of the lower teeth - determined by the character of the residual ridges. • If both ridges are equally well formed - the occlusal plane is placed halfway between them. • If lower ridge is considerably flatter - the lower posterior teeth should be placed closer to that ridge inorder to lessen the torque on that ridge Complete denture Prosthodontics – John. J. Sharry, 3rd Ed

  17. SHADE • must harmonise with the shade of the anterior teeth • For maxillary bicuspids -select a shade slightly lighter than other posterior teeth but not lighter than the anterior teeth. Syllabus of Complete Dentures – Charles.M.Heartwell, Arthur.O.Rahn,4thEd.

  18. MOLD NUMBERING SYSTEMS • Artificial teeth are available in numerous molds and shapes • Mold numbering system differs for each manufacturer • IMPERIAL MOLD CHART Imperial mold chart

  19. Portrait IPN 20 degree posterior or bioform IPN 20 degree posterior Portrait IPN 10 degree posterior or bioform IPN Anatoline posterior Portrait IPN 0 degree posterior Portrait IPN 22 degree Biostabil Posterior Portrait/Bioform IPN 33 degree posterior Bioform IPN 30 degree posterior Portrait IPN 40 degree Euroline Posterior Dentsply Teeth Mold Chart

  20. AcryRock mold Chart

  21. FORM OF THE TEETH • SPECIFICATIONS FOR ARTIFICIAL POSTERIOR TEETH • SPECIFICATIONS FOR WORKING OCCLUSAL SURFACES • The working occlusal surfaces should be void of cusps or inclined planes that might hinder the free horizontal gliding of opposing surfaces as the mandible carries the teeth into protrusive occlusion • The working occlusal surfaces should have no inclined planes (or only low ones) that might hinder the free horizontal gliding of opposing surfaces as the mandible carries the teeth laterally Sears V.H.SPECIFICATIONS FOR ARTIFICIAL POSTERIOR TEETH, J. PROSTHET. DENT.1952;2(3): 353 – 361.

  22. The working occlusal surfaces should be so incorporated that more than 50 per cent of such surfaces can be placed lingual to the ridge center • The working occlusal surfaces should be so incorporated that the greatest load can be applied at a desired mesiodistal point. This provides against front-to-back teetering • The working occlusal surfaces should be so incorporated that they can be placed parallel with the underlying alveolar ridge as seen from the side Sears V.H.SPECIFICATIONS FOR ARTIFICIAL POSTERIOR TEETH, J. PROSTHET. DENT.1952;2(3): 353 – 361.

  23. The area of the combined working occlusal surfaces should be in proportion to the supporting value of the weaker of the two denture foundations. Weaker foundations require smaller occlusal surfaces. • The teeth should be so designed that they can be altered by grinding without losing their mechanical or esthetic advantages. This has special reference to the possibility of reducing, either buccolingually or mesiodistally, teeth that may be slightly too large. • There should be no wells, traps, boxlike cavities, or hollows into which food can pack. All major depressions should be provided with adequate escapeways • Sears V.H.SPECIFICATIONS FOR ARTIFICIAL POSTERIOR TEETH, • J. PROSTHET. DENT.1952;2(3): 353 – 361.

  24. The working occlusal surfaces should be so formed that there will be no necessity to leave spaces distal to the upper cuspids • Those parts of the occlusal surfaces on which it is desired to maintain the principal load (usually the first molars) should be composed of a more wear resistant material than the other parts. Sears V.H.SPECIFICATIONS FOR ARTIFICIAL POSTERIOR TEETH, J. PROSTHET. DENT.1952;2(3): 353 – 361.

  25. SPECIFICATIONS FOR BALANCING SURFACES • Balancing occlusal surfaces should be so incorporated that they can be made to maintain contact on the right and left sides as the mandible carries the teeth into left and right lateral occlusions. Such lateral balancing occlusal surfaces can be placed on the upper first molars or the lower second molars • The balancing occlusal surfaces should be used only for balancing. This means that these surfaces should not be used also for working occlusal surfaces as is the case with so-called anatomic teeth.

  26. Right and left balancing occlusal surfaces should be so incorporated that they can be made to maintain contact simultaneously on the right and left sides as the mandible carries the teeth into protrusive occlusion Sears V.H.SPECIFICATIONS FOR ARTIFICIAL POSTERIOR TEETH, J. PROSTHET. DENT.1952;2(3): 353 – 361.

  27. All balancing occlusal surfaces should be adjustable independently of the buccal, lingual, working, and subocclusal surfaces. This is in contrast to the so-called anatomic scheme in which balance is obtained by tilting the entire tooth and thus disturbing the angles of the other surfaces Sears V.H.SPECIFICATIONS FOR ARTIFICIAL POSTERIOR TEETH, J. PROSTHET. DENT.1952;2(3): 353 – 361.

  28. SPECIFICATIONS FOR BUCCAL AND LINGUAL SURFACES • The buccal surfaces should be so incorporated that they make satisfactory contact with the cheeks without contributing to cheek biting. • The visible buccal surfaces should simulate the forms of natural teeth. • The lingual surfaces should be so incorporated that they make satisfactory contact with the tongue in eating and speaking without contributing to tongue biting. Sears V.H.SPECIFICATIONS FOR ARTIFICIAL POSTERIOR TEETH, J. PROSTHET. DENT.1952;2(3): 353 – 361.

  29. SPECIFICATIONS FOR SUBOCCLUSAL SURFACES • Subocclusalsurfaces should be so incorporated that they make no contact either as working or balancing occlusal units. • Subocclusal surfaces should, for esthetic reasons, carry carvings to make the teeth appear similar to natural forms. Sears V.H.SPECIFICATIONS FOR ARTIFICIAL POSTERIOR TEETH, J. PROSTHET. DENT.1952;2(3): 353 – 361.

  30. HISTORY Teeth were carved from stone, wood, ivory and metal. Human teeth were also used in early dentures. Gysi’s Trubyte or normal bite 330 anatomical teeth Pilkington and Turner 300 teeth Essentials of complete denture prosthodontics – Winkler, 2nd Ed

  31. GysiCrossbite teeth Sear’s Channel tooth Hardy, I. R,: Developments in Occlusal Patterns of Artificial Teeth, J. PROSTHET. DENT. 1: 14-28, 1951

  32. Hall’s inverted cusp teeth Hardy, I. R,: Developments in Occlusal Patterns of Artificial Teeth, J. PROSTHET. DENT. 1: 14-28, 1951

  33. French’s teeth Hardy, I. R,: Developments in Occlusal Patterns of Artificial Teeth, J. PROSTHET. DENT. 1: 14-28, 1951

  34. Swenson’s nonlock teeth Avery’s teeth Hardy, I. R,: Developments in Occlusal Patterns of Artificial Teeth, J. PROSTHET. DENT. 1: 14-28, 1951

  35. McGrane’s curved cusp posterior teeth John Vincent’s metal insert posteriors Hardy, I. R,: Developments in Occlusal Patterns of Artificial Teeth, J. PROSTHET. DENT. 1: 14-28, 1951

  36. Hardy’s metal insert teeth Hardy, I. R,: Developments in Occlusal Patterns of Artificial Teeth, J. PROSTHET. DENT. 1: 14-28, 1951

  37. Coe Masticators Bader’s cutter bar Essentials of complete denture prosthodontics – Winkler, 2nd Ed

  38. Sosincrossbladed teeth Levin B: A review of artificial posterior tooth forms including a preliminary report on a new posterior tooth , J. PROSTHET. DENT. 1977,38(1): 3-15.

  39. Lingual bladed teeth Levin B: A review of artificial posterior tooth forms including a preliminary report on a new posterior tooth , J. PROSTHET. DENT. 1977,38(1): 3-15

  40. EVALUATION OF OCCLUSAL FORMS : COMPARISON OF DIFFERENT TYPES OF TEETH IN THE SAME DENTURE WEARER (Based on masticatory efficiency) • Thompson : 330 anatomic= 200 anatomic = inverted cusp tooth >Sear’s channel tooth • Sobolick : Inverted cusp > True cusp> French> Trubyte 330>Trubyte 200 • Payne : Anatomic teeth > Non anatomic teeth ( True Kusp, French’s, Hardy’s) • Trapozzano and lazzari : Anatomic teeth (Trubyte200) > Non anatomic teeth (Inverted cusp, De Van’s non anatomic) • Schultz : Chewing efficiency was reduced by 16 – 32% when maxillary palatal cusps were reduced to a flatter cusp form. Essentials of complete denture prosthodontics – Winkler, 2nd Ed

  41. Commonly used cuspal inclinations are 33,20 and 0 degrees • Measuring cuspal inclination : angle formed by the incline of mesiobuccal cusp of lower first molar with the horizontal plane Boucher’s Prosthodontic Treatment for Edentulous Patients – 9thEd Krishna Prasad D, RajendraPrasdB,Bardia A, Anupama Prasad D,ENHANCING STABILITY : A REVIEW OF VARIOUS OCCLUSAL SCHEMES IN COMPLETE DENTURE PROSTHESIS – NUJHS 2013, 3(2) 105 – 112.

  42. ANATOMIC TEETH Artificial teeth that duplicate the anatomic forms of natural teeth INDICATIONS: • To achieve a more esthetic and natural appearance • To achieve stability, comfort and function by having teeth contact during all ranges of functional and non functional movements • To accommodate patients with good neuromuscular control • To provide balanced occlusion Savitha K.C,Srinivas L S Occlusal Schemes for Complete Dentures - A Review Article. BUJOD, 2013,3(1):67 – 72 Mastering the art of Complete dentures – Halperin, Graser, Rogoff

  43. ADVANTAGES: • requires less chewing force thereby reduces vertical force on the ridge. • greater denture stability during parafunctionalmovements. • Achieve better esthetics and natural appearance. • Acts as a guide for proper jaw closure Savitha K.C,Srinivas L S Occlusal Schemes for Complete Dentures - A Review Article. BUJOD, 2013,3(1):67 - 72

  44. DISADVANTAGES: • Precise reproducible records are required - time consuming. • slight ridge resorption changes occlusal position of denture • Presence of cusps generate greater horizontal and lateral forces during function - result in ridge resorption • Use of anatomic occlusion with tight interdigitationof cusp makes it difficult for use in class II and class III jaw relation • Mesiodistalinterlocking will not permit settling of the base without horizontal forces developing • Balanced occlusion is lost when settling occurs Savitha K.C,Srinivas L S Occlusal Schemes for Complete Dentures - A Review Article. BUJOD, 2013,3(1):67 – 72 Essentials of complete denture prosthodontics – Winkler, 2nd Ed

  45. MODIFICATIONS OF ANATOMIC FORMS • The mesiodistal unlocking - by grinding the transverse ridge of the occlusal surface • The modification of the buccolingualinclines to control lateral thrust during functional and nonfunctionalmandibular movements can be based on the shape and prominence of the ridge and its ability to withstand lateral forces Essentials of complete denture prosthodontics – Winkler, 2nd Ed

  46. NON ANATOMIC (MONOPLANE,ZERO DEGREE) OCCLUSION: INDICATIONS • For patients with class II and class III jaw relation • For patients with cross bite • For patients with parafunctionalmovements • Resorbed ridges • Patients with neuromuscular disturbances Savitha K.C,Srinivas L S Occlusal Schemes for Complete Dentures - A Review Article. BUJOD, 2013,3(1):67 - 72

  47. ADVANTAGES • It is simple and less time consuming than other occlusal scheme • Donot lock the dentures together in one position of tooth contact • Elimination of inclined plane forces which creates horizontal displacement of bases during function • Enhanced denture stability • Lack of interference when the dentures settle. Essentials of complete denture prosthodontics – Winkler, 2nd Ed

  48. DISADVANTAGES • Nonanatomic (flat) teeth occlude in only two dimensions (length and width), but the mandible has an accurate three-dimensional movement due to its condylar behavior. • Decreased masticatory efficiency. • Difficult to achieve balanced occlusion • The flat teeth do not function efficiently unless the occlusion surface provides cutting ridges and generous spillways (sluiceways) • Compromised esthetics Essentials of complete denture prosthodontics – Winkler, 2ndEd Becker C.M, Swoope C.C, Guckes A.D, Lingualized occlusion for removable prosthodontics - J. Prosthet. Dent.1977,38(6): 601-608.

  49. Essentials of complete denture prosthodontics – Winkler, 2nd Ed

More Related