Osseointegration / academy of fixed orthodontics


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Osseointegration / academy of fixed orthodontics

  1. 1. INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.comwww.indiandentalacademy.com
  2. 2. Endosseous osseointegrated dental implant www.indiandentalacademy.comwww.indiandentalacademy.com
  3. 3. www.indiandentalacademy.comwww.indiandentalacademy.com
  4. 4. www.indiandentalacademy.comwww.indiandentalacademy.com
  5. 5. Contents : Historical reviewHistorical review Development of concept of osseointegrationDevelopment of concept of osseointegration DefinitionsDefinitions Scope of osseointegrationScope of osseointegration Fibrointegration Vs OsseointegrationFibrointegration Vs Osseointegration Ultra structure of osseointegrationUltra structure of osseointegration Biology of OsseointegrationBiology of Osseointegration www.indiandentalacademy.comwww.indiandentalacademy.com
  6. 6. Mechanism of osseointegration  Contact osteogenesis vs distant osteogenesis Anchorage mechanism or Bonding mechanism  Biomechanical bonding  Biochemical bonding www.indiandentalacademy.comwww.indiandentalacademy.com
  7. 7. Key factors responsible for successful osseointegration Success criteria of implants Clinical evaluation of osseointegration  Invasive methods  Non invasive methods Failure and loss of osseointegration Conclusion References www.indiandentalacademy.comwww.indiandentalacademy.com
  8. 8. HISTORICAL REVIEWHISTORICAL REVIEW www.indiandentalacademy.comwww.indiandentalacademy.com
  9. 9. 500 BC – Etruscan population www.indiandentalacademy.comwww.indiandentalacademy.com
  10. 10. 600 AD – Mayan population “First evidence of use of implants” www.indiandentalacademy.comwww.indiandentalacademy.com
  11. 11. 1700 – John hunter → “Transplantation” Transmission of various diseases www.indiandentalacademy.comwww.indiandentalacademy.com
  12. 12. 1809-Maggiolo Gold roots 1939-Strock Vitallium screw www.indiandentalacademy.comwww.indiandentalacademy.com
  13. 13. 1943 - Dahl 1948 - Goldberg and Gershkoff Subperiosteal implant www.indiandentalacademy.comwww.indiandentalacademy.com
  14. 14. Consistent failures : 1960 – Linkow Blade vent implant www.indiandentalacademy.comwww.indiandentalacademy.com
  15. 15.  Inflammatory reaction  Gradual bone loss  Fibrous encapsulation www.indiandentalacademy.comwww.indiandentalacademy.com
  16. 16. www.indiandentalacademy.comwww.indiandentalacademy.com
  17. 17. “CONCEPT OF OSSEOINTEGRATION” Dr. Per-Ingvar Branemark Orthopaedic surgeon Professor University of Goteburg, Sweden. Threaded implant design made up of pure titanium. www.indiandentalacademy.comwww.indiandentalacademy.com
  18. 18. www.indiandentalacademy.comwww.indiandentalacademy.com
  19. 19. www.indiandentalacademy.comwww.indiandentalacademy.com
  20. 20. Integrated titanium fixture 1952 vital microscopic studies (Bone marrow of rabbit fibula) “Osseointegration” Optical chamber (Bone marrow of rabbit fibula) www.indiandentalacademy.comwww.indiandentalacademy.com
  21. 21. Integrated titanium fixture Repair of major mandibular and tibial defects. Clinical Study Development of procedures for rehabilitation of edentulism : www.indiandentalacademy.comwww.indiandentalacademy.com
  22. 22. Experimental study in dogs www.indiandentalacademy.comwww.indiandentalacademy.com
  23. 23. Subperiosteal and Soft tissue reaction Use of titanium fixtures Transosseous First experimental study www.indiandentalacademy.comwww.indiandentalacademy.com
  24. 24. Two stage procedure www.indiandentalacademy.comwww.indiandentalacademy.com
  25. 25. Evidence for osseointegration Macroscopic level Histological level Radiological level www.indiandentalacademy.comwww.indiandentalacademy.com
  26. 26. Intact bone to implant surface Intact bone to implant surface www.indiandentalacademy.comwww.indiandentalacademy.com
  27. 27. Basic research 1952 to 1965 → 13-15 year extensive research 1965 → First clinical evidence of implant insertion “Edentulous human patient for resorbed edentulous ridge” www.indiandentalacademy.comwww.indiandentalacademy.com
  28. 28. DefinitionsDefinitions “The apparent direct attachment or connection of osseous tissue to an inert, alloplastic material without intervening connective tissue”. - GPT 8 Structurally oriented definition : “Direct structural and functional connection between the ordered, living bone and the surface of a load carrying implants”. - Branemark and associates (1977) www.indiandentalacademy.comwww.indiandentalacademy.com
  29. 29. Histologically : Direct anchorage of an implant by the formation of bone directly on the surface of an implant without any intervening layer of fibrous tissue. - Albrektson and Johnson (2001) www.indiandentalacademy.comwww.indiandentalacademy.com
  30. 30. Clinically : Ankylosis of the implant bone interface. -Schroeder and colleagues 1976 “functional ankylosis” “It is a process where by clinically asymptomatic rigid fixation of alloplastic material is achieved and maintained in bone during functional loading” - Zarb and T Albrektson 1991 www.indiandentalacademy.comwww.indiandentalacademy.com
  31. 31. Biomechanically oriented definition : “Attachment resistant to shear as well as tensile forces” - Steinmann et al (1986). www.indiandentalacademy.comwww.indiandentalacademy.com
  32. 32. Scope of osseointegration in dentistry 1) Prosthetic rehabilitation of missing teeth Complete edentulous maxilla and mandible rehabilitation. Removable prosthesisFixed prosthesis www.indiandentalacademy.comwww.indiandentalacademy.com
  33. 33. Single tooth replacementPartial dental loss replacement www.indiandentalacademy.comwww.indiandentalacademy.com
  34. 34. 2) Anchorage for the maxillofacial prosthesis Auricular Prosthesis www.indiandentalacademy.comwww.indiandentalacademy.com
  35. 35. Ocular Prosthesis www.indiandentalacademy.comwww.indiandentalacademy.com
  36. 36. Nasal prosthesis www.indiandentalacademy.comwww.indiandentalacademy.com
  37. 37. 3) For rehabilitation of congenital and developmental defects - Cleft palate - Ectodermal dysplasia www.indiandentalacademy.comwww.indiandentalacademy.com
  38. 38. 4) Complex maxillofacial defect rehabilitation 5) Orthodontic anchorage. www.indiandentalacademy.comwww.indiandentalacademy.com
  39. 39.  “ Fibrous integration as tissue to implant contact with interposition of healthy dense collagenous tissue between the implant and bone”.  “Direct bone to implant interface without any intervening layer of fibrous tissue”. FIBROINTEGRATION Vs Concept of Bony Anchorage Branemark (1969) Concept of soft tissue anchorage Linkow (1970), James (1975), Weiss (1986). OSSEOINTEGRATION www.indiandentalacademy.comwww.indiandentalacademy.com
  40. 40. Fibro-Osseousintegration : “Pseudoligament”, “Periimplant ligament”, “Periimplant membrane”. Hypothesis – Collagen fibers function similar to the sharpeys fibers in the natural dentition. Fact : The histological difference between the sharpeys fibers and collagen fibers around the implant. www.indiandentalacademy.comwww.indiandentalacademy.com
  41. 41. Natural teethNatural teeth ImplantImplant Oblique and horizontalOblique and horizontal group of fibersgroup of fibers Parallel, irregular,Parallel, irregular, completecomplete encapsulationencapsulation Uniform distribution ofUniform distribution of load (load (Shock absorberShock absorber)) Difficult to transmitDifficult to transmit the loadthe load Failure : Inability to carry adequate loads - Infection www.indiandentalacademy.comwww.indiandentalacademy.com
  42. 42. Parallel fiber arrangement Complete fiber encapsulation www.indiandentalacademy.comwww.indiandentalacademy.com
  43. 43. Fibrosseousintegration Osseointegration www.indiandentalacademy.comwww.indiandentalacademy.com
  44. 44. ULTRASTRUCTURE OF OSSEOINTEGRATION Soft tissue interface Cortical bone Spongy bone www.indiandentalacademy.comwww.indiandentalacademy.com
  45. 45. Biology of Osseointegration (Branemark) www.indiandentalacademy.comwww.indiandentalacademy.com
  46. 46. Mechanism of osseointegration PhasePhase TimingTiming Specific occurrenceSpecific occurrence 11.. InflammatoryInflammatory phasephase Day 1-10Day 1-10 Adsorption of plasma proteinsAdsorption of plasma proteins Platelet aggregation and activationPlatelet aggregation and activation Clotting cascade activationClotting cascade activation Cytokine releaseCytokine release Nonspecific cellular inflammatoryNonspecific cellular inflammatory responseresponse Specific cellular inflammatorySpecific cellular inflammatory responseresponse Macrophage mediated inflammation.Macrophage mediated inflammation. www.indiandentalacademy.comwww.indiandentalacademy.com
  47. 47. PhasePhase TimingTiming Specific occurrenceSpecific occurrence 2.2. Proliferative phaseProliferative phase Day 3 - 42Day 3 - 42 NeovascularizationNeovascularization Differentiation, ProliferationDifferentiation, Proliferation and activation of cells.and activation of cells. Production of immatureProduction of immature connective tissue matrix.connective tissue matrix. www.indiandentalacademy.comwww.indiandentalacademy.com
  48. 48. PhasePhase TimingTiming Specific occurrenceSpecific occurrence 3.Maturation3.Maturation phasephase AfterAfter day 28day 28 Remodeling of the immature bone matrixRemodeling of the immature bone matrix with coupled resorption and deposition ofwith coupled resorption and deposition of bone.bone. Bone remodeling in response to implantBone remodeling in response to implant loadingloading Physiological bone recession.Physiological bone recession. www.indiandentalacademy.comwww.indiandentalacademy.com
  49. 49. Contact osteogenesis vs distant osteogenesis Osborn and Newesley (1980) : Proposed 2 different phenomena Distant osteogenesis www.indiandentalacademy.comwww.indiandentalacademy.com
  50. 50. Contact osteogenesis www.indiandentalacademy.comwww.indiandentalacademy.com
  51. 51. Contact Osteogenesis Relies on Migration of Differentiating Osteogenic cell to Implant surface Undifferentiated Perivascular connective cells Differentiating Osteogenic cells www.indiandentalacademy.comwww.indiandentalacademy.com
  52. 52. Key factors responsible for successful osseointegration Implant material biocompatibility Loading conditions Implant design characteristic Implant surface characteristic State of the implantation or host bed Surgical considerations www.indiandentalacademy.comwww.indiandentalacademy.com
  53. 53. IMPLANT MATERIAL BIOCOMPATIBILITY www.indiandentalacademy.comwww.indiandentalacademy.com
  54. 54. Implant materials Metals Ceramics Polymers Chemical composition Biological compatibility Bio inertBio tolerant Bio active www.indiandentalacademy.comwww.indiandentalacademy.com
  55. 55. BiologicalBiological biocompatibilitybiocompatibility Chemical compositionChemical composition MetalsMetals CeramicsCeramics PolymersPolymers BiotolerantBiotolerant GoldGold PolyethylenePolyethylene Cobalt-chromiumCobalt-chromium alloysalloys PolyamidePolyamide Stainless steelStainless steel PolymethylmethacrylatePolymethylmethacrylate ZirconiumZirconium PolytetrafluoroethylenePolytetrafluoroethylene NiobiumNiobium PolyurethanePolyurethane TantalumTantalum BioinertBioinert Commercially pureCommercially pure titaniumtitanium Aluminum oxideAluminum oxide Titanium alloy (Ti-Titanium alloy (Ti- 6Al-4V)6Al-4V) Zirconium oxideZirconium oxide BioactiveBioactive HydroxyapatiteHydroxyapatite TricalciumTricalcium phosphatephosphate CalciumCalcium pyrophosphatepyrophosphate FluorapatiteFluorapatite Carbon:vitreous,Carbon:vitreous, pyrolyticpyrolytic BioglassBioglass www.indiandentalacademy.comwww.indiandentalacademy.com
  56. 56. Metals Commercially pure titanium (CPTi) : 99.75% Most biocompatible material → excellent long term clinical function Adherent, self repairable titanium dioxide (TiO2/ TiO) passivated layer. (10A0 within seconds, 100A0 within a minute.) www.indiandentalacademy.comwww.indiandentalacademy.com
  57. 57. Steinman (1988) referred this layer as Biologically inert On Histological investigation → intimate contact between the titanium surface and the periimplant bone. (Branemark 1977, Alberktsson et al 1984) Chemical purity, surface cleanliness - Osseointegration www.indiandentalacademy.comwww.indiandentalacademy.com
  58. 58. Titanium alloys : Ti6Al4V(90%Ti, 6% Al, 4% V) Johanson (1992) - Cp titanium higher torque removal values than Ti6Al4V screw 23 vs 16 N/cm. - Higher bony contacts 59 vs 50% after 3 months implant insertion Experimental investigation at 3, 6 and 12th months Significantly stronger bone reaction to Cp Ti Retarded bone formation around the Ti6Al4V→ leaked out Al ion competing with calcium during early stage of calcification causing osteomalacia www.indiandentalacademy.comwww.indiandentalacademy.com
  59. 59. Tantalum and Niobium : High degree of osseointegration  There was evidence of exaggerated macrophage reaction compared to Cp titanium. www.indiandentalacademy.comwww.indiandentalacademy.com
  60. 60. CERAMICS (Calciumphosphate hydroxyapatite, Al2O3, Tricalcium phosphate) • Makeup the entire implant • Applied in the form of coating • Hydroxyapatite coated implant • Gottlander 1994 – short term and longterm reaction Short term reaction – Positive, enhanced interfacial bone formation Long term reaction – Cp titanium 50-70% more interfacial bone compared to HA coated. • Hahn J (1997) HA coated implant – 97.8%(6 yrs) clinical success. www.indiandentalacademy.comwww.indiandentalacademy.com
  61. 61. Matter of concernMatter of concern HA coating loosening – macrophage activation and bone resorption Beisbrock & Edgertson – Microbial adhesion, Osseousbreakdown, coating failure. www.indiandentalacademy.comwww.indiandentalacademy.com
  62. 62. POLYMERS Not used Inferior mechanical properties Lack of adhesion to living tissues Adverse immunological reaction Limited to  Shock absorbing components – supra structure component www.indiandentalacademy.comwww.indiandentalacademy.com
  63. 63. IMPLANT DESIGN CHARACTERISTIC www.indiandentalacademy.comwww.indiandentalacademy.com
  64. 64. Implant Design characteristics : Implant design refers to the three dimensional structure of the implant. Form, shape, configuration, geometry, surface macrostructure, macro irregularities. Cylindrical Screw shaped implants. www.indiandentalacademy.comwww.indiandentalacademy.com
  65. 65. Threaded Non threaded. www.indiandentalacademy.comwww.indiandentalacademy.com
  66. 66. “Precision fit in the vital bone” → Osseointegration Cylindrical implants / press fit implants : Severe bone resorption Lack of bone steady state – micro movements Alberktsson 1993 – continuing bone saucerization of 1mm -first year, 0.5mm anually and thereafter increasing rate of resorption upto 5 year follow up. www.indiandentalacademy.comwww.indiandentalacademy.com
  67. 67. Threaded implants Documentation for long term clinical function. Alteration in the design, size and pitch of the threads can influence the long term osseointegration. www.indiandentalacademy.comwww.indiandentalacademy.com
  68. 68. Advantages of threaded implants More functional area for stress load distribution than the cylindrical implants. Threads improves the primary implant stability avoids micro movement of the implants till osseointegration is achieved. www.indiandentalacademy.comwww.indiandentalacademy.com
  69. 69. Non threaded Tendency for slippage Bonding is required  No slippage tendency  No bonding is required Threaded www.indiandentalacademy.comwww.indiandentalacademy.com
  70. 70. IMPLANT SURFACE CHARACTERISTIC www.indiandentalacademy.comwww.indiandentalacademy.com
  71. 71. Implant surface characteristics Topographic properties Implant surface texture & roughness Physical properties Surface energy and charge Physiochemical properties Implant surface chemistry www.indiandentalacademy.comwww.indiandentalacademy.com
  72. 72. Orientation of irregularities on the surface Degree of roughness of the surface Orientation of irregularities may give : -Isotopic surface and anisotropic surface Wennerberg (1996) Ivanoff (2001) : Better bone fixation (osseointegration) will be achieved with implants with an enlarged isotropic surface as compared to implant with turned anisotropic surface structure. Surface topography www.indiandentalacademy.comwww.indiandentalacademy.com
  73. 73. 1) Turned surface/ machined surface 2) Acid etch surface - HCl and H2SO4 3) Blasted surface – TiO2 / Al2O3 particles 4) Blasted + Acid etch surface (SLA surface) - Al2O3 particles & HCl and H2SO4 - Tricalcium phosphate & HF Different machining process results in different surface topographies www.indiandentalacademy.comwww.indiandentalacademy.com
  74. 74. 5) Hydroxyapatite coated surface (HA) 6) Titanium plasma sprayed surface (TPS) 7) Oxidized surface 8) Doped surface 9) Nanosized hydroxyapatite coated surfaces www.indiandentalacademy.comwww.indiandentalacademy.com
  75. 75. Additive surface treatment : Titanium plasma spraying (TPS) hydroxyapatite (HA) coating Substractive surface treatment : Blasting with titanium oxide / aluminum oxide and acid etching Modified surface treatment : Oxidized surface treatment Laser treatment Ion implantation www.indiandentalacademy.comwww.indiandentalacademy.com
  76. 76. Machined / turned surfaces : gold standard. Moderately rough implant surfaces • Roughness parameter (Sa) 0.04 –0.4 µm - smooth 0.5 – 1.0 µm – minimally rough 1.0 –2.0 µm – moderately rough > 2.0 µm – rough : For faster & firmer bone integration 0 www.indiandentalacademy.comwww.indiandentalacademy.com
  77. 77.  Wennerberg (1996) – moderately rough implants developed the best bone fixation as described by peak removal torque and bone to implant contact.  In vivo studies  Smooth surface < 0.2 µm will – soft tissue →no bone cell adhesion → clinical failure.  Moderately rough surface more bone in contact with implant → better osseointegration. www.indiandentalacademy.comwww.indiandentalacademy.com
  78. 78. • Wennerberg (1996) – moderately rough implants developed the best bone fixation as described by peak removal torque and bone to implant contact. • In vivo studies Smooth surface < 0.2 µm will – soft tissue →no bone cell adhesion → clinical failure. Moderately rough surface more bone in contact with implant → better osseointegration. www.indiandentalacademy.comwww.indiandentalacademy.com
  79. 79. Carlsson et al 1988, Gotfredsen (2000) – positive correlation between increasing surface roughness and degree of implant incorporation (osseointegration). Advantages of moderately rough surface : Faster osseointegration, retention of the fibrin clot, osteoconductive scaffold, osteoprogenator cell migration. Increase rate and extent of bone accumulation → contact osteogenesis www.indiandentalacademy.comwww.indiandentalacademy.com
  80. 80.  Increased surface area renders greater osteoblastic proliferation, differentiation of surface adherent cells.  Increased cell attachment growth and differentiation. Increased rough surfaces :  Increased risk of periimplantitis  Increased risk of ionic leakage / corrosion www.indiandentalacademy.comwww.indiandentalacademy.com
  81. 81. Machined / turned surface SEM x 1000 SEM x 4700 Cp Titanium Surface roughness profile 5 µm www.indiandentalacademy.comwww.indiandentalacademy.com
  82. 82. Titanium plasma sprayed coating (TPS) The first rough titanium surface introduced Coated with titanium powder particles in the form of titanium hydridePlasma flame spraying technique www.indiandentalacademy.comwww.indiandentalacademy.com
  83. 83.  6-10 times increase surface area. (Steinmann 1988, Tetsch 1991) Roughness Depth profile of about 15µm www.indiandentalacademy.comwww.indiandentalacademy.com
  84. 84. Hydroxyapatite coatings HA coated implant bioactive surface structure – more rapid osseous healing comparison with smooth surface implant. ↓ Increased initial stability Can be Indicated - Greater bone to implant contact area - Type IV bone - Fresh extraction sites - Newly grafted sites SEM 100X www.indiandentalacademy.comwww.indiandentalacademy.com
  85. 85. Sand blasting Acid etch The objective Sand blasting – surface roughness (Substractive method) Acid etching – cleaning SEM 1000X SEM 7000X Lima YG et al (2000), Orsini Z et al (2000). - Acid etching with NaOH, Aq. Nitric acid, hydrofluoric acid. Decrease in contact angle by 100 – better cell attachment. Acid etching with 1% HF and 30% NO3 after sand blasting - increase in osseointegration by removal of aluminium particles (cleaning). Wennerberg et al 1996. superior bone fixation and bone adaptation www.indiandentalacademy.comwww.indiandentalacademy.com
  86. 86. Laser induced surface roughening Eximer laser – “Used to create roughness” Regularly oriented surface roughness configuration compared to TPS coating and sandblasting SEM x 300 SEM x 300SEM x 70 www.indiandentalacademy.comwww.indiandentalacademy.com
  87. 87. Physical characteristic : •Physical characteristic refers to the factors such as surface energy and charge. Hypothesis : A surface with high energy →high affinity for adsorption → show stronger osseointegration. www.indiandentalacademy.comwww.indiandentalacademy.com
  88. 88. Baier RE (1986) – Glow discharge (plasma cleaning) results in high surface energy as well as the implant sterilization, being conductive to tissue integration. Charge affects the hydrophilic and hydrophobic characteristic of the surface. A hydrophilic / easily wettable implant surface : Increases a initial phase of wound healing. Fact : Increase surface energy would disappear immediately after implant placement www.indiandentalacademy.comwww.indiandentalacademy.com
  89. 89. Implant surface chemistry Chemical alteration → increases bioactivity → increase implant bone anchorage. www.indiandentalacademy.comwww.indiandentalacademy.com
  90. 90. Chemical surfaces : • Ceramic coated – hydroxyapatite (HA), Calcium phosphate • Oxidized/anodized surfaces with electrolytes containing phosphorous, sulfur, calcium, magnesium and flouride. • Alkali + Heat treatment. • Ionization, implantation of calcium ion, floride ions • Doped surfaces with the BONE stimulating factors / growth factors. www.indiandentalacademy.comwww.indiandentalacademy.com
  91. 91. Anchorage Mechanism or Bonding Mechanism in Osseointegrated implants : Biomechanical bonding In growth of bone into small surface irregularities of implant surface → three dimensional stabilization Seen in : • Machined / turned screw implant • Blasted /Acid etch surface → moderately rough implant surface. Based on : • Design characteristic → Macrostructure (Threads, vent, slots) • Surface characteristic → Microstructure. (Chemical surface treatmentwww.indiandentalacademy.comwww.indiandentalacademy.com
  92. 92. Surface roughness at the micrometer level / nanometer level Requirement : Minimum size of •50-100µm cavities or pores → complete bone tissue (ground substance + cellular components + Haversian system) • 1-10µm for calcified bone ground substance. ? At nanometer level - no experimental evidence Some investigators – nanometer size rough surface can carry proper load. www.indiandentalacademy.comwww.indiandentalacademy.com
  93. 93. Biochemical bonding Seen with certain bioactive implant surfaces like : • Calcium phosphate coated implant surfaces • HA coated implant surfaces • Oxidized/ anodized surfaces Bone bonding / Bonding osteogenesis Biointegration : •“Strong chemical bond may develop between the host bone and bioactive implant surfaces and such implants are said to be biointegrated”. www.indiandentalacademy.comwww.indiandentalacademy.com
  94. 94. Doped surfaces that contain various types of bone growth factors or other bone-stimulating agents may prove advantageous in compromised bone beds. However, at present clinical documentation of the efficacy of such surfaces is lacking : BMP = Bone morphogenetic protein. Doped surfaces www.indiandentalacademy.comwww.indiandentalacademy.com
  95. 95. BONE FACTOR • Bone quality → bone with well formed cortex and densely trabaculated medullary spaces • Bone quantity → Refers to the dimension of available bone in reference to length, width and depth. Initial implant stability www.indiandentalacademy.comwww.indiandentalacademy.com
  96. 96. Branemark system (5 year documentation) Mandible – 95% success Maxilla – 85-90% success Aden et al (1981) – 10% greater success rate in anterior mandible compared to anterior maxilla. Difference in bone composition www.indiandentalacademy.comwww.indiandentalacademy.com
  97. 97. •Factors compromising the bone quality Infection ,Irradiation & Heavy smoking Schnitman et al (1988) – lower success rate in posterior mandible compared to anterior mandible - posterior maxilla higher failure rates. www.indiandentalacademy.comwww.indiandentalacademy.com
  98. 98. LEKHOLM AND ZARB CLASSIFICATION 1985 Class I : Jaw consist almost exclusively of homogeneous compact bone Class II : Thick compact bone surrounds highly trabecular core Class III : Thin cortical bone surrounds highly trabecular core Class IV : Thin cortical bone surrounds loose, spongy core www.indiandentalacademy.comwww.indiandentalacademy.com
  99. 99. D1 D2 D3 D4 MISCH CLASSIFICATION 1988 www.indiandentalacademy.comwww.indiandentalacademy.com
  100. 100. According to Branemark and Misch D1 and D2 bone → initial stability / better osseointegration D3 and D4 → poor prognosis D1 bone – least risk D4 bone - most at risk www.indiandentalacademy.comwww.indiandentalacademy.com
  101. 101. Jaffin and Berman (1991) – 44% failure in type IV bone Selection of implant D1 and D2 – conventional threaded implants D3 and D4 – HA coated or Titanium plasma coated implants www.indiandentalacademy.comwww.indiandentalacademy.com
  102. 102. Osteopromotion : Procedure to enhance the formation of bone approximating the implant surface : • Bone regeneration techniques (using PTFE membrane) • Bone growth factors like PDGF, IGF, PRP, TGF-B1 → stimulates osteoprogenator cells, enhance the bone growth. www.indiandentalacademy.comwww.indiandentalacademy.com
  103. 103.  Stefini CM et al (2000) recommend to apply PDGF and IGF on the implant surfaces before placing into cervical bed. This method showed better wound healing and rapid osseointegration. www.indiandentalacademy.comwww.indiandentalacademy.com
  104. 104. Indications : 1) Localized ridge augmentation prior to implant placement 2) Treatment of periimplant bone defect. Exposed implant surface PTFE membrane Regeneration of bone Increased bone to implant contactwww.indiandentalacademy.comwww.indiandentalacademy.com
  105. 105. Implantation bed / host bed Objective → Healthy implant host site Nature of the host site - vascularity - cellularity (osteogenic potential) www.indiandentalacademy.comwww.indiandentalacademy.com
  106. 106. Two Factors •Patient Considerations - Age •History of proposed host bed -Previous irradiation - Infection - History of smoking - Advanced ridge resorption - Osteoporosis or osteoporotic like bone lesion www.indiandentalacademy.comwww.indiandentalacademy.com
  107. 107. Age : Old age – no poorer result. Extreme young age - Relative contraindication to insertion of implants. Infrapositioning of implant because of alveolar growth Wait till the completion of growth. www.indiandentalacademy.comwww.indiandentalacademy.com
  108. 108.  Bone anchored hearing aids Maxillofacial deformities : implant placement is delayed until the child is at puberty. Only in selected cases ex: Ectodermal dysplasia Anterior part of the jaw + over denture therapy. 2-3 year old child.www.indiandentalacademy.comwww.indiandentalacademy.com
  109. 109. Smoking and osseointegration : • History of smoking affect the healing response in osseointegration. • Lower success rates with oral implants • Mechanism behind Vasoconstriction Reduced bone density Impaired cellular function • Mean failure rates in smoker is about twice than in non smoker. www.indiandentalacademy.comwww.indiandentalacademy.com
  110. 110. Radiation therapy and osseointegration : • Jacobson (1985) previous irradiation – relative contraindication for implant placement. • Expected success rate 10-15% lower than the non irradiated patients. Number of factors to be considered : • Dose and fraction of irradiation • Timing from radiotherapy to implant surgery • Anatomic region in which the implant to be inserted • Loading factors and handling of the soft tissue. • Johnson (1987) Surgical risk → 1m before and 6m after, Low risk → 6m to 1.5 yr Increased risk → there after. www.indiandentalacademy.comwww.indiandentalacademy.com
  111. 111. Hyperbaric oxygen therapy (HBO) : • HBO → Elevates the partial pressure of oxygen in the tissues. • Granstrom G (1998) → HBO can counteract some of the negative effect from irradiation and act as a stimulator for osseointegration. • Role of HBO in osseointegration – Bone cell metabolism - Bone turnover - Implant interface and the capillary network in the implant bed (angiogenesis) www.indiandentalacademy.comwww.indiandentalacademy.com
  112. 112. SURGICAL CONSIDERATIONS www.indiandentalacademy.comwww.indiandentalacademy.com
  113. 113.  Violent surgical techniques Objective: Minimum tissue violence – osseointegration Controlled surgical technique Surgical skill / technical excellence www.indiandentalacademy.comwww.indiandentalacademy.com
  114. 114. Use of well sharpened drills and use of graded series of drills • Profuse irrigation for continuous / Adequate cooling Parameters : www.indiandentalacademy.comwww.indiandentalacademy.com
  115. 115. Slow drill speeds Proper drill geometry Intermittent drilling Eriksson R.A : Drill speed < 2000 rpm, tapping at 15 rpm. Cooling during tapping and insertion of screw Others Cooling the irrigants Using internally irrigated drills Violent surgical technique Frictional heat / overheating → increased temperature rise in bone → wide zone of necrosis → fibrous tissue, primary failure of osseointegration. www.indiandentalacademy.comwww.indiandentalacademy.com
  116. 116. www.indiandentalacademy.comwww.indiandentalacademy.com
  117. 117. Critical temperature for bone necrosis • Previously 560 to 700 for 1 min. • 560 C critical temperature for bone necrosis → Irreversible bone damage. • Recently 47 0 C for 1 min. Denaturation of alkaline phosphate enzyme → inhibition of Alkaline Ca synthesis → Loss osseointegration (Erickson 1986, Albrektsson 1984) www.indiandentalacademy.comwww.indiandentalacademy.com
  118. 118. Insertion torque  Insertion torque is high – removal torque is low. Poor osseointegration  High torque if used → stress / compression in bone  Holding power of implant will fall. 45 N/cm Moderate torque should be used www.indiandentalacademy.comwww.indiandentalacademy.com
  119. 119. I M P L A N T L O A D I N Gwww.indiandentalacademy.comwww.indiandentalacademy.com
  120. 120. Loading condition Objective : “No loading while healing” → successful osseointegration. Movement of the implant within the bone – fibrous tissue encapsulation rather than osseointegration. Premature loading leads to implant movement The end result “Soft tissue interface” “Bony interface” www.indiandentalacademy.comwww.indiandentalacademy.com
  121. 121. Branemark, Albrektson – two stage implant insertion. First stage – Installation of fixture into bone Second stage – Connection of abutment to the fixtures Maxilla 6 months Mandible 3 months Misch – Progressive / Gradual loading Different Philosophies regarding Loading conditions Suggested in Softer bone less number of implants to be used www.indiandentalacademy.comwww.indiandentalacademy.com
  122. 122. Immediate functional loading protocol Clinical trials successful osseointegration (95-100% success rate- Completely edentulous patients)  Bone quality is good Functional forces are controlled More favourable in mandible compared to maxilla Over loading – Stress concentration, undermining bone resorption without apposition (Branemark 1984) www.indiandentalacademy.comwww.indiandentalacademy.com
  123. 123. To decrease the bio-mechanical load Prosthetic design considerations Cantilever length may be shortened or eliminated Narrow occlusal table Minimizing the offset load Increasing the implant number Use of wider implant with D4 bone compared to D1 & D2 www.indiandentalacademy.comwww.indiandentalacademy.com
  124. 124. Success criteria of implants Schuitman and Schulman criteria (1979) 1) The mobility of the implant must be less than 1mm when tested clinically. 2) There must be no evidence of radiolucency 3) Bone loss should be less than 1/3rd of the height of the implant 4) There should be an absence of infection, damage to structure or violation of body cavity, inflammation present must be amneable to treatment. 5) The success rate must be 75% or more after 5 years of functional service. www.indiandentalacademy.comwww.indiandentalacademy.com
  125. 125. Albrektson and Zarb G (1980) 1) The individual unattached implant should be immobile when tested clinically 2) The radiographic evaluation should not show any peri - implant radiolucency 3) Vertical bone loss around the fixtures should be less than 0.2mm annually after first year of implant loading. 4) The implant should not show any sign and symptom of pain, infection, neuropathies, parastehsia, violation of mandibular canal and sinus drainage. 5) Success rate of 85% at the end of 5 year observation period and 80% at the end of 10 year service. 6) Implant design allow the restoration satisfactory to patient and dentist. - Smith and Zarb (1989) www.indiandentalacademy.comwww.indiandentalacademy.com
  126. 126. METHODS OF EVALUATION OF OSSEOINTEGRATION Invasive method • Histological section • By using torque gauges •Pullout test • Histomorphometric www.indiandentalacademy.comwww.indiandentalacademy.com
  127. 127. Non-invasive methods : •Radiographs •Periotest •Reverse torque www.indiandentalacademy.comwww.indiandentalacademy.com
  128. 128. •Resonance frequency analysis •Impulse testing www.indiandentalacademy.comwww.indiandentalacademy.com
  129. 129. www.indiandentalacademy.comwww.indiandentalacademy.com
  130. 130. References : 1.Osseointegration in clinical dentistry – Branemark, Zarb, Albrektsson 2.Osseointegration and occlusal rehabilitation – Sumiya Hobo 3.Contemporary Implant Dentistry – Carl E.Misch 4.Endosseous implants for Maxillofacial reconstruction – Block and Kent 5.Implants in Dentistry –Block and Kent 6.Dental and Maxillofacial Implantology – John. A. Hobkrik, Roger Watson www.indiandentalacademy.comwww.indiandentalacademy.com
  131. 131. 6.Endosseous Implant : Scientific and Clinical Aspects – George Watzak 7.Optimal Implant Positioning and Soft Tissue management – Patrik Pallaci 8.Osseointegration in craniofacial reconstruction- T. Albrektssson. 9.Osseointegration in desntistry : an introduction : Philip Worthington, Brein. R. Lang, W.E. Lavelle. www.indiandentalacademy.comwww.indiandentalacademy.com
  132. 132. Schroeder et alSchroeder et al.,(1981).The reactions of bone, connective.,(1981).The reactions of bone, connective tissue, and epithelium to endosteal implants with titanium-tissue, and epithelium to endosteal implants with titanium- sprayed surfaces.sprayed surfaces. Journal of Maxillofacial Surgery 9,15-Journal of Maxillofacial Surgery 9,15- 25.25. Adell et alAdell et al.,(1981). A 15 year study of osseointegrated.,(1981). A 15 year study of osseointegrated implants in the treatment of edentulous jaw.implants in the treatment of edentulous jaw. InternationalInternational journal of Oral Surgery 6,387-399.journal of Oral Surgery 6,387-399. Zarb & SymingtonZarb & Symington (1983).Osseointegrated dental implants:(1983).Osseointegrated dental implants: preliminary report on a replication study.preliminary report on a replication study. Journal ofJournal of prosthetic dentistry 50,271-279.prosthetic dentistry 50,271-279. Albrektsson et alAlbrektsson et al.,(1986).The long-term efficacy of currently.,(1986).The long-term efficacy of currently used dental implants: a review and proposed criteria forused dental implants: a review and proposed criteria for success.success. International journal of Oral and MaxillofacialInternational journal of Oral and Maxillofacial ImplantsImplants 1,11-25.1,11-25. www.indiandentalacademy.comwww.indiandentalacademy.com
  133. 133. Johansson & AlbrektssonJohansson & Albrektsson. (1987) Integration of screw implants. (1987) Integration of screw implants in the rabbit. A 1- year follow-up of removal of titaniumin the rabbit. A 1- year follow-up of removal of titanium implants.implants. International journal of 0ral and MaxillofacialInternational journal of 0ral and Maxillofacial ImplantsImplants 2,69-75.2,69-75. Zarb & AlbrektssonZarb & Albrektsson.(1991).Osseointegration –A-requiem for.(1991).Osseointegration –A-requiem for the periodontal ligament ? Editorial.the periodontal ligament ? Editorial. International Journal ofInternational Journal of Periodontology and Restorative DentistryPeriodontology and Restorative Dentistry 11,88-91.11,88-91. Albrektsson & SennerbyAlbrektsson & Sennerby.(1991) State of the art in Oral.(1991) State of the art in Oral implants.implants. Journal of clinical periodontologyJournal of clinical periodontology 18,474-481.18,474-481. Wennerberg & AlbrektssonWennerberg & Albrektsson.(1993) Design and Surface.(1993) Design and Surface Characteristics of 13 commercially available oral implantCharacteristics of 13 commercially available oral implant systems.systems. International Journal of Oral and MaxillofacialInternational Journal of Oral and Maxillofacial ImplantsImplants 8,622-238,622-23 www.indiandentalacademy.comwww.indiandentalacademy.com
  134. 134. For more details please visit www.indiandentalacademy.com www.indiandentalacademy.comwww.indiandentalacademy.com