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Pontics / orthodontic continuing education


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Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.

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Pontics / orthodontic continuing education

  1. 1. PONTICS INDIAN DENTAL ACADEMY Leader in continuing dental education
  2. 2. Contents • Introduction • History • Classification • Pontic-ridge relationship • Pontic fabrication • Review of literature • Conclusion •
  3. 3. •The restorations of partially edentulous areas with fixed partial dentures present a particular challenge for the clinician. • Because of their ease of use and favorable long term results, conventional FPDs represent the most popular treatment measure today. INTRODUCTION
  4. 4.
  5. 5. • The pontic must fulfill the complex roles of replacing the function of the lost tooth, achieving an esthetic appearance, enabling adequate oral hygiene, and preventing tissue irritation. • In addition the pontic must meet certain structural requirements to ensure the mechanical stability of the restorations.
  6. 6. The Histories of fixed and removable partial prosthesis go more or less in hand and it is difficult at times to tell just where to draw the line between these two types from the available data. HISTORY
  7. 7. • Replaced tooth was sewed in place by using ligatures made from gold or silver. • Egyptians and Phoeniceans were the pioneers in the field of pontics and were the first to construct dental bridge work.
  8. 8. • These were mostly made of calf bone or ivory. • Kerr and Roger (1877) It is suggested that teeth of ivory and bone secured by copper wire or catgut string were used in China for ages before they were introduced in Europe.
  9. 9. • It was Mancy in 1928 who laid the foundation to present day FPD design, • However Pierre Fauchard (1923) has often been referred to as the ‘Father of Modern Dental Prosthesis’.
  10. 10. • In his work in the field of FPD he used what he called ‘Tenons’ which were in reality dowels or pivots screwed into the roots to retain some of the bridges and it is possible that he may have been the first to attach dental bridges to tooth roots by this method.
  11. 11. • Selberg (1936) pointed out that basic materials had changed but little in the past few years. • These materials were gold or porcelain or a combination of the two.
  12. 12. He summed up by saying that the restoration must meet the following requirements • Protection • Comfort • Esthetics • Durability • Utility
  13. 13. The Glossary of prosthodontic terms defines Pontics as “An artificial teeth on a fixed partial denture that replaces missing natural teeth, restores its function and usually fills the space previously filled by the natural teeth.” DEFINITION
  14. 14. Tylman defines Pontics as “The suspended member of a fixed partial denture which replaces the lost natural tooth, restores function and occupies the space of the missing tooth.”
  15. 15. • The pontic or artificial tooth is derived from the Latin word Pons,meaning Bridge • It is not a simple replacement,because placing an exact anatomic replica of the tooth in the space would be hygienically unmanageable
  16. 16. Design of the Prosthetic tooth will be dictated by • Esthetics • Function • Ease of cleaning • Maintenance of healthy tissue on edentulous ridge • Patient comfort
  17. 17. Requirements • Adequate strength • Esthetics • Color stability • Hygiene • Should not overload the abutment teeth
  18. 18. Function • Restore mastication and speech • To maintain tooth relationships • Patients esthetics • Psychological
  19. 19.
  20. 20. Pretreatment Assessment • Pontic space • Residual ridge contour
  21. 21. Pontic space • When orthodontic repositioning is not possible, increasing the proximal contours of adjacent teeth may be better than making an FPD with undersized Pontics
  22. 22.
  23. 23. Residual Ridge Contour • An ideally shaped ridge has a smooth,regular surface of attached gingiva,which facilitates maintenance of a plaque-free environment. • Its height and width should allow placement of a pontic that resembles the neighbouring teeth.
  24. 24. • Ideal ridge contours vary depending on the type of pontic to be used • The ideal ridge form allows for pontic forms to be at same level as a gingival margin of the adjacent teeth
  25. 25. • Bulky ridge contour • Deficient ridge contour
  26. 26. • Loss of residual ridge contour may lead to unesthetic open gingival embrasures(‘black triangles’),food impaction and percolation of saliva during speech
  27. 27. • Seibert has classified residual ridge deformities in to three categories • Class I defects-faciolingual loss of tissue width with normal ridge height
  28. 28. • Class II defects –loss of ridge height with normal ridge width
  29. 29. • Class III defects –a combination of loss in both dimensions
  30. 30. • Allen et al., modified this classification and included Quantification of the Severity of the Defect • Mild-less than 3mm • Moderate –3-6mm • Severe –greater than 6mm
  31. 31. Surgical procedures for ridge augmentation
  32. 32. Roll Technique
  33. 33. Pouch Technique
  34. 34. Interpositional Graft
  35. 35. Onlay Graft
  36. 36.
  37. 37.
  38. 38.
  39. 39.
  40. 40.
  41. 41. Alveolar architecture preservation technique
  42. 42. According to Shillingburg et al Pontics are classified : 1. Depending on the shape of the pontic contacting the tissues 2. Depending on the materials. 3. Depending upon the manufacturer’s design CLASSIFICATION
  43. 43. On Shape i. Saddle/Ridge Lap pontic ii. Modified ridge Lap iii.Hygienic iv.Conical v. Ovate pontic
  44. 44. Pontics may be also classified depending on Material used • Metal ceramic • Cast metal • Resin processed to metal
  46. 46. TRUPONTIC
  51. 51.
  52. 52.
  53. 53. PIN FACING
  54. 54. According to Rosenstiel et al Pontic designs are classified into two general groups: 1) THOSE THAT CONTACT THE ORAL MUCOSA 2) THOSE THAT DO NOT THE ORAL MUCOSA .
  55. 55. A. Mucosal contact B. No mucosal contact 1. Ridge lap 1.Sanitary (hygienic) 2. Modified ridge lap 2. Modified sanitary (hygienic) 3. Ovate 4. Conical
  56. 56. . The design of pontic for a specific FPD is determined by 1.Retainers 2.Esthetics 3.Occluso-gingival Height and Mesio-distal Width of Edentulous Area 4.Ridge Resorption and Contour PONTIC SELECTION
  58. 58.
  60. 60.
  61. 61.
  62. 62. Stein RS: Pontic- residual ridge relationship: A research report. J Prosthet Dent 1966; 16: 251 Shaldon Stein in 1966 did a study on the pontic residual ridge relationship. The purpose of his study was: To determine the frequency and the nature of tissue reaction of underlying residual ridge mucosa to specific pontic designs. To compare the frequency and the nature of tissue reactions of the residual ridge mucosa to various materials used in pontic constructions.
  63. 63. This 1966 Stein classic article on pontic design was largely responsible for a change in philosophy from a “sanitary” shape design to what is now commonly called a “modified ridge lap” design. The modified ridge lap design in the anterior region & in the posterior region offer minimal tissue contact, gives acceptable cosmetic value, proper cheek support, and accessibility for adequate oral hygiene.
  64. 64. He postulated certain specifications for pontic design Posterior pontic design – a correctly designed pontic should have 1. All surfaces should be convex, smooth and properly finished. 2. Contact with the buccal contiguous slopes should be minimal (pin point) and pressure free (modified ridge lap).
  65. 65. 3. Occlusal table must be in functional harmony with the occlusion of all of the teeth. 4. Buccal and lingual shunting mechanism should conform to those of the adjacent teeth. 5. The overall length of buccal surface should be equal to that of the adjacent abutments or Pontics.
  66. 66. Anterior pontic design – a correctly placed anterior pontic should have 1. All surfaces should be convex, smooth and properly finished. 2. Contact with the labial mucosa should be minimal (pin point) and pressure free (lap facing). 3. The lingual contour should be in harmony with adjacent teeth or Pontics.
  68. 68.
  69. 69. Morton L Perel in 1972 described a modified sanitary pontic which has a free archway design and is concave mesiodistally. Proximally the solder joints of the pontic are elongated. This addition increases the strength of what is considered to be the weakest part of any posterior fixed prosthesis. Perel M L : A modified sanitary pontic. J Prosthet Dent 1972; 28: 587
  70. 70. Antony H L in 1983 described a technique of pontic design for extreme resorption of alveolar ridge. In this the undersurface of the pontic was shaped slightly convex or flat bucco-lingually to aid in complete disruption of dental plaque with dental floss or interproximal toothbrushes. The flat undersurface allowed easy cleaning from either the lingual or buccal aspect. Antony H L: A sanitary “ Arc- fixed partial denture” : Concept and technique of pontic design. J Prosthet Dent 1983; 50: 338
  71. 71. Conical
  72. 72.
  73. 73. OVATE PONTIC
  74. 74. Techniques available for this Immediate Pontic Technique (or) Socket Preservation Technique
  75. 75.
  76. 76.
  77. 77.
  78. 78.
  79. 79.
  80. 80.
  81. 81.
  82. 82. Advantages
  83. 83. L.B. Jacques et al in his article describes a technique for the improvement of esthetics with conditioning of tissue beneath the pontics by displacing tissue with a treatment restoration. Lateral displacement of tissues under gradual, controlled pressure enhances the interdental papilla which improves esthetics. Jacques L B et al: Tissue sculpturing: An alternative method for improving esthetics of anterior fixed prosthodontics. J Prosthet Dent 1999; 81: 630
  84. 84. In 2002 Daniel Edelhoff et al did a review of the different clinical and technical options that are available for designing esthetic and functional pontics for anterior region. He mentions the use of Gingiva coloured ceramics, all-ceramic gingival masks and gingival prosthesis to achieve maximum esthetics in the anterior region. Daniel E , H Spiekermann: A review of esthetic pontic design options. Quintessence Int 2002;33:736-746
  85. 85. If augmentative measures are contraindicated or undesirable, small alveolar deficiencies and missing papillae can be reconstructed by restorative measures. First, the exact shade of the gingiva has to be established. This can be accomplished with special gingival shade guides that are supplied with the different commercially available pink veneering materials. GINGIVA-COLORED CERAMICS
  86. 86. The basal surface must demonstrate a convex shape similar to the ovate pontic
  87. 87. Separately fabricated ceramic gingival masks can be used to make subsequent adjustments in permanently placed restorations. This method is particularly suitable for patients with a local alveolar ridge defect that has not been corrected by augmentation of the soft tissue. ALL-CERAMIC GINGIVAL MASKS
  88. 88. For this purpose, an impression is taken of the labial surface of the restoration using a customized tray and a medium viscosity polyether material. The color of the gingiva is determined with an individually fabricated shade guide.
  89. 89.
  90. 90. Donald in 1981 did a study for designing multiple pontics. He said that in multiple pontics, placement of a V-shaped notch between the pontics on their tissue aspect (an inter-pontic embrasure) serves no useful purpose. It acts as a niche to collect plaque and interrupts the smooth passage of dental floss along the tissue surface of the pontics. Donald A B : The design of multiple pontics. J Prosthet Dent 1981; 46: 634
  91. 91. The principle of “fusing” multiple Pontics on their tissue aspect to give a smooth, unbroken surface can be applied to fixed partial dentures in maxillary posterior,and mandibular anterior and posterior region.
  92. 92. His design principle should also be used routinely for the maxillary anterior segment, using pink porcelain to fill inter-pontic embrasures which also enhances esthetics.
  93. 93. The biologic principles of pontic design pertain to the maintenance and preservation of the residual ridge, abutment and opposing teeth, and supporting tissue. BIOLOGIC CONSIDERATIONS
  94. 94. Pressure free contact between the pontic and the underlying tissue is indicated to prevent ulceration and inflammation of the soft tissues. If any blanching of the soft tissues is observed in try-in, the pressure area should be identified with a disclosing medium (i.e pressure indicating paste) and the pontic recontoured until tissue contact is entirely passive. RIDGE CONTACT
  95. 95. This passive contact should occur exclusively on keratinized attached tissue. When a pontic rests on mucosa, some ulcerations may appear as a result of the normal movement of the mucosa in contact with the pontic.
  96. 96. Positive ridge pressure may be due to excessive scraping the ridge area on the working cast. This was once promoted as a way to improve the appearance of the pontic ridge relationship. However, because of the ulceration that inevitably results when flossing is not meticulously performed, the concept is not recommended, unless done as previously described as an ovate pontic.
  97. 97. Cavozos E : Tissue response to fixed partial denture pontics. J Prosthet Dent 1968; 20: 143 Cavazos in 1968 did a study to demonstrate that the adaptations of pontic to the ridge or the amount of “relief” (scraping of the cast provided) on the cast is highly significant and directly proportional to the amount of unfavourable tissue change. 1)Absolute minimal (0.0 to 0.25mm of cast scraping) produced no tissue changes.
  98. 98. 2)When the cast scraping was increased to 1mm, tissue changes were produced varying from mild inflammation to acute ulceration
  99. 99. Any material chosen to fabricate the pontic should provide: 1) Good Esthetic Results Where Needed 2) Biocompatibility 3) Rigidity 4) Strength to Withstand Occlusal Forces 5) Longevity. PONTIC MATERIAL
  100. 100. Occlusal contacts should not fall on the junction between metal and porcelain during centric or eccentric tooth contacts, nor should a metal ceramic junction occur in contact with the residual ridge on the gingival surface of the pontic.
  101. 101. Investigations into the BIOCOMPATIBILITY of materials used to fabricate pontics have centered on two factors : 1. The effect of the materials and 2. The effects of surface adherence.
  102. 102. Glazed porcelain is generally considered the most biocompatible of the available pontic materials Although the critical factor seems to be the material’s ability to resist plaque accumulation (rather than the material itself).
  103. 103. Also its remarkable tissue tolerance, when contacting the gingival has played an important part in advanced fixed bridge work. High fusing porcelain when correctly glazed will display surface traits remarkably close to those of a natural tooth.
  104. 104. Well polished gold is smoother, less prone to corrosion, and less retentive of plaque than an unpolished or porous casting. However, even highly polished surfaces will accumulate plaque if oral hygiene measures are ignored.
  105. 105. Although glazed porcelain looks very smooth, when viewed under a microscope, its surface shows many voids and is rougher than either polished gold or acrylic resin.
  106. 106.
  107. 107. Can be reduced by : Reducing the buccolingual width of the pontic by as much as 30% Analysis reveals that forces are lessened only when chewing food of uniform consistency and that a mere 12% increase in chewing efficiency can be expected from a one-third reduction of pontic width. OCCLUSAL FORCES
  108. 108. The accidental biting on a hard object or by parafunctional activities like bruxism create potentially harmful forces on the FPD These forces are not reduced by narrowing the occlusal table.
  109. 109. Narrowing the Occlusal Table may • Impede or even preclude development of a harmonious and stable occlusal relationship. • It may cause difficulties in plaque control • May not provide proper cheek support.
  110. 110. • One exception is if the residual alveolar ridge has collapsed buccolingually. • Reducing pontic width may then be desired, thereby lessening the lingual contour and facilitating plaque control measures.
  111. 111. Mechanical problems may be caused by • Improper Choice of Materials • Poor Frame Work Design • Poor Tooth Preparation • Poor Occlusion. MECHANICAL CONSIDERATIONS
  112. 112. • When metal ceramic pontic are chosen, extending porcelain onto the occlusal surfaces to achieve better esthetics should also be carefully evaluated. • In addition to its potential for fracture, porcelain may abrade the opposing dentition if the occlusal contacts are on enamel.
  113. 113. OCCLUSAL SURFACE The occlusal surface of the pontic should roughly correspond with that of the tooth it replaces. In posterior region it is important that it be confined within the margins of the abutment teeth.
  114. 114. However width of the pontic required will be governed by factors • Esthetics • Length of Span • The Strength of the Abutment Teeth • The Ridge Form • Occlusion.
  115. 115. It has also been advised that the occlusal surface should not be narrowed Arbitarily since this may create • Food impaction • Plaque retention situation (similar to that of malposed teeth)
  116. 116. The cusp tip-to-cusp tip width of a posterior pontic should be the same width as the original missing tooth.
  117. 117. Some fixed partial dentures are fabricated entirely • Metal • Porcelain • Acrylic Resin • A Combination of Metal and Porcelain. AVAILABLE PONTIC MATERIALS
  118. 118. Acrylic resin veneered Pontics have had limited acceptance because of their reduced durability (wear and discoloration). The newer indirect composites, based on high inorganic filled resins and the fiber reinforced materials have revived interest in composite resin and resin-veneered Pontics.
  119. 119. METAL CERAMIC PONTICS • The framework must provide a uniform veneer of porcelain • Excessive thickness of porcelain contributes to inadequate support and predispose to eventual fracture
  120. 120. This is often true in the cervical portion of an anterior pontic. A reliable technique for ensuring uniform thickness of porcelain is to wax the fixed prosthesis to complete anatomic contour and then accurately cut back the wax to a predetermined depth.
  121. 121. The metal surfaces to be veneered must be smooth and free of pits. Surface irregularities will cause incomplete wetting by the porcelain slurry, leading to voids at the porcelain metal interface that reduce bond strength and increase the possibility of mechanical failure
  122. 122. Sharp angles on the veneering area should be rounded. Any deformation of the metal frame work at the junction can lead to chipping of the porcelain. Therefore , occlusal centric contacts must be placed at least 1.5mm away from the junction.
  123. 123. • Historically, acrylic resin-veneered restorations had deficiencies that made them acceptable only as longer term provisionals. • Dimensional change from water absorption and thermal fluctuations (thermo cycling)occurs because of the relatively high surface area/volume ratio of the thin resin veneer RESIN-VENEERED PONTICS
  124. 124. • The resin was retained by mechanical means (e.g.undercuts). • Continuous dimensional change of the veneers often caused leakage at the metal-resin interface, with subsequent discoloration of the restoration.
  125. 125. • Composite resins can be used in fixed partial dentures without a metal substructure. • A substructure matrix of impregnated glass or polymer fiber provides structural strength. FIBER-REINFORCED COMPOSITE RESIN PONTICS
  126. 126. The physical properties of this system, combined with its excellent marginal adaptation and esthetics, make it a possible metal free alternative for FPD
  127. 127. Mahesh chauhan .,natural tooth pontic fixed partial denture using resin composite-reinforced glass fibers (quintessence int 2004;35:549-553) • Glass fibers reinforced with resin composite can be used as a bonded external framework to support a patient’s own natural anterior tooth that is due for extraction.The extracted tooth,after root sectioning,serves as a “natural tooth pontic”,while glass-fiber bonding simultaneously splints periodontically weak abutment teeth.
  128. 128.
  129. 129.
  130. 130.
  131. 131.
  132. 132.
  133. 133.
  134. 134. • The Gingival Interface • Incisogingival Length • Mesiodistal Width ESTHETIC CONSIDERATIONS
  135. 135. Therefore merely duplicating the facial contour of the missing tooth is not enough If the original tooth contour were followed, the pontic would look unnaturally long incisogingivally. THE GINGIVAL INTERFACE
  136. 136.
  137. 137. • The modified ridge-lap pontic is recommended for most anterior situations • A properly designed, modified ridge lap provides the required convexity on the tissue side, with smooth and open embrasures on the lingual side for ease of cleaning.
  138. 138. If a pontic is poorly adapted to the residual ridge, there will be an unnatural shadow in the cervical area that looks odd and spoils the illusion of a natural tooth. In addition, recesses occurring at the gingival interface will collect food debris, further betraying the illusion of a natural tooth.
  139. 139.
  140. 140. INCISOGINGIVAL LENGTH The height of a tooth is immediately obvious when the patient smiles and shows the gingival margins. An abnormal labiolingual position or cervical contour, however, is not immediately obvious.
  141. 141.
  142. 142.
  143. 143. . MESIODISTAL WIDTH The features of the contra lateral tooth should be duplicated as precisely as possible in the pontic, and the space discrepancy can be compensated by altering the shape of the proximal areas. The retainers and the pontic can be proportioned to minimize the discrepancy.
  144. 144.
  145. 145.
  147. 147.
  148. 148.
  149. 149.
  150. 150.
  151. 151.
  152. 152.
  153. 153.
  154. 154.
  155. 155.
  156. 156.
  157. 157.
  158. 158.
  159. 159.
  160. 160.
  161. 161. Cone placement
  162. 162. Cuspal ridges superimposed
  163. 163. Cones ,Cuspal,Triangular ridges
  164. 164. Cones ,Cuspal,Triangular ridges&marginal ridges
  165. 165. Occlusal morphology
  166. 166. CUT BACK
  167. 167. CONCLUSION
  168. 168. The pontic design is said to determine the success or failure of a bridge. Designs that allow easy plaque control are especially important to a pontic’s long term success.
  169. 169. Minimizing tissue contact by maximizing the convexity of the pontic’s gingival surface is essential. Consideration is needed to create a design that combines easy maintenance with natural appearance and adequate mechanical strength.
  170. 170. 1. Rosenstiel S F et al : Contemporary Fixed Prosthodontics, ed 3, Missouri, Mosby Inc, pg 513 2. Shillingburg H T et al : Fundamentals of fixed prosthodontics, ed 3, Chicago , Quintessence Publishing, pg 485 3. Shillingburg H T et al : Fundamentals of fixed prosthodontics, ed 2, Chicago , Quintessence Publishing, pg 387 4. The Glossary of Prosthodontic terms : J Prosthet Dent 1999; 81 5. Antony H L: A sanitary “ Arc- fixed partial denture” : Concept and technique of pontic design. J Prosthet Dent 1983; 50: 338 REFERENCES
  171. 171. 6. Cavozos E : Tissue response to fixed partial denture pontics. J Prosthet Dent 1968; 20: 143 7.Curtis M B: Current theories of crown contour, margin placement and pontic design. J Prosthet Dent 1981; 45: 268 8.Daniel Edelhoff, H Spiekermann: A review of esthetic pontic design options. Quintessence Int 2002;33:736-746 9.Donald A B : The design of multiple pontics. J Prosthet Dent 1981; 46: 634 10. Jacques L B et al: Tissue sculpturing: An alternative method for improving esthetics of anterior fixed prosthodontics. J Prosthet Dent 1999; 81: 630
  172. 172. 11.Parkinson C.F: Pontic design of posterior fixed partial prosthesis; is it a microbial misadventure? J Prosthet Dent 1984; 51; 51-54. 12. Perel M L : A modified sanitary pontic. J Prosthet Dent 1972; 28: 587 13. Porter CB: Anterior pontic design; a logical progression. J Prosthet Dent 1984; 51; 774-776. 14. Stein RS: Pontic- residual ridge relationship: A research report. J Prosthet Dent 1966; 16: 251
  173. 173.