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Bone graft


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Bone Grafts In Periodontics

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Bone graft

  1. 1. Bone Grafts In Periodontics Dr. Anuj Singh Parihar Senior Lecturer Department of Periodontics
  2. 2. WHAT IS GRAFT ?  A viable tissue that after removal from a donor site is implanted with in a recipient tissue is then restored repaired & regenerated.
  3. 3. WHAT IS GRAFTING ? Procedure used to replace / restore missing bone or gum tissue.
  4. 4. WHAT ARE BONE GRAFTS?  Bone grafts are the materials used for replacement or augmentation of the bone. Food and Drug Administration (FDA) regulates bone grafting materials
  7. 7.  Ellgaard et al & Nielson et al ----- graft material may be  osteoproliferative (osteogenic)  Osteoconductive  osteoinductive
  8. 8. OSTEOINDUCTION  A chemical process by which molecules contained in the graft(bmp)convert the neighbouring cells into osteoblasts which in turn form bone.  Process by which graft material is capable of promoting - osteogenesis - cementogenesis - new PDL (Urist & McLean)
  9. 9.  A graft, a biomaterial or a substance is osteo inductive when implanted in a non osseous environment called as an ectopic site, bone formation occurs.
  10. 10. OSTEOGENESIS  represents all the steps & processes leading to bone formation. This term has been used by some authors to define bone grafts capable of forming bone through osteoblastic cells contained in the transplanted graft OR  the process of bone formation, which begins with either osteoblasts in the patient's natural bone or from surviving cells in the bone graft that is placed.
  11. 11. OSTEOCONDUCTION  A physical effect by which the matrix of the graft forms a scafold that favours outside cells to penetrate the graft and form new bone.  The Graft material acts as a passive matrix like a trellis or scaffolding for new bone to cover over itself. ( Urist & colleagues )
  12. 12.  Process also known as Trell's effect  occurs with the ingrowth of capillaries in the new connective tissue.  A material is osteo conductive when its structure & its chemical composition facilitate new bone formation from existing bone.
  13. 13.  OSTEOSTIMULATION - “The stimulation of osteoblast proliferation and differentiation as evidenced during in vitro osteoblast cell culture studies by increased DNA content and elevated osteocalcin and alkalinephosphatase levels” FDA 2005
  14. 14. CONTACT INHIBITION  The process by which the graft material prevents apical proliferation of epithelium (Ellegaard & colleagues 1972)
  15. 15. INDICATIONS FOR GRAFTS  Deep Intraosseous Defects  Tooth Retention  Support for Critical Teeth  Bone Defects Associated With Aggressive Periodontitis  Esthetics (Shallow Intraosseous Defects)  Furcation Defects
  16. 16. OBJECTIVES OF BONE GRAFTING  probing depth reduction  clinical attachment gain  bone fill of the osseous defect  regeneration of new bone, cementum, and periodontal ligament
  17. 17. ADVANTAGE  Potential regeneration of non correctable periodontal defect.  By reconstructing the periodontium, it is possible to reverse the disease process.  Increased tooth support, improved function, and enhanced esthetics are concomitant results of successful bone graft therapy
  18. 18. DISADVANTAGE  Increased t/t time  Longer postop t/t  Autograft requires 2 site  Inc. postop care  Variability in repair & predictability  Greater expense  Availability ( Mellonig 1992)
  20. 20. Human bone  Autogenous grafts (autografts)  Extraoral  Intraoral  Allogenic grafts (allografts)  Fresh frozen bone  Freeze-dried bone allografts  Demineralized freeze-dried bone allografts
  21. 21. Bone substitutes  Xenogeneic grafts (xenografts)  Bovine-derived hydroxyapatite  Coralline calcium carbonate  Alloplastic grafts (alloplasts)  Polymers  Bioceramics  - Tricalcium phosphate  - Hydroxyapatite  Bioactive glasses
  22. 22. SELECTION OF GRAFT MATERIAL  Osteoinductive potential  Predictability  Accessability  Availability  Safety  Rapid vascularization ( Bell 1964, Schallhorn 1976)
  23. 23. IDEAL CHARACTERISTIC OF BONE GRAFT  Nontoxic  Nonantigenic  Resistant to infection  No root resorption or ankylosis  Strong and resilient  Easily adaptable  Readily and sufficiently available  Minimal surgical procedure  Stimulates new attachment
  24. 24. AUTOGRAFTS  first bone replacement grafts reported for periodontal applications  ‘‘Gold Standard’’ for bone grafting procedures  Rich source of bone & marrow cells  osteogenic potential
  25. 25. SITES
  26. 26. BASED ON INDUCTIVE POTENTIAL  Extraoral—hip marrow  Fresh  Frozen  Intraoral  Osseous coagulum—bone blend  Tuberosity  Extraction sites  Osseous coagulum  Continguous autograft
  27. 27. EXTRAORAL SITES  Schallorn (1967/ 1968) introduced use of autogenous” HIP MARROW “Grafts (illiac crest marrow) in t/t of periodontal defects.  highest inductive potential  Obtained using a Turkell bone trephine
  29. 29. INTRAORAL SITES  overall mean bone fill of 3.0 to 3.5 mm  significant gains in probing attachment level in treating one-, two-, or three-wall (or combination) defects (Nabers & O’Leary, 1965; Hiatt & Schallhorn, 1973; Froum, 1976;)
  31. 31. CORTICAL BONE CHIPS  Impetuss for modern-day use of periodontal bone grafts can be traced to the work of Nabers & O'Leary (1965)  Shavings of cortical bone removed by hand chisels during osteoplasty & ostectomy  Successfully to effect a coronal increase in bone height
  32. 32.  Zayer and Yukna, 1983 Relatively large particle size — 1,559.6 ×183µm potential for sequestration Were replaced
  33. 33. OSSEOUS COAGULUM (ROBINSON, 1969)  Technique uses mixture of bone shaving & blood from surgical field  Concept based on fact that mineralized substances can induce osteogenesis  Smaller the particle size of the donor bone, the more certain its resorption and replacement with host bone  extension of the technique developed by Nabers and O’Leary (1965)
  34. 34. SITES  Exostoses  Tori  Heavy marginal ridges &  Adjacent sites undergoing osseous correction.
  35. 35.  obtained with high- or low-speed round burs during osteoplasty  Collected on a large retractor or mirror  Mixed with Pt’s blood in a sterile dappen dish
  36. 36. DISADVANTAGE  inability to aspirate during the collection process  unknown quantity & quality of collected bone fragments  Fluidity of the material
  37. 37. OSSEOUS COAGULUM- BONE BLEND  Diem and colleagues (1972) modified Robinson’s original technique  Permit easier access & collection of donor material  Sites  Extraction sites  Exostoses  Tori  Edentulous ridges
  39. 39.  Same regenerative potential as iliac marrow  Significantly greater regenerative potential than that of open débridement Froum and colleagues ( 1 9 7 5, 1 976)  particle size 2 1 0 x 10 5 µm
  40. 40. ADVANTAGES  Ease of procurement  Same surgical field  Benefits of both cancellous and cortical techniques.
  41. 41. DISADVANTAGES  More extensive armamentarium  Extensive defects may require more material than can be procured with this approach.
  42. 42. TUBEROSITY SITE  Hiatt and Schallhorn (1973)  Alternative source to iliac crest  Tuberosity potential source for residual red marrow  Cancellous bone potential source of osteoblast
  43. 43.  Bone obtained after careful removal of cortical plate by rongeurs & curets  Regeneration α Adequacy of soft tissue coverage & with surface area of vascularized bony wall  α 1/ root surface area.
  44. 44. EXTRACTION SITE  Halliday (1969)  Artificial defect created using bone trephine.  Extraction required were timed to coincide with treatment of intraosseous defect
  45. 45. BONE SWAGGING  Ewen (1965) --- treating bony defects  Bone from an edentulous area was moved next to the tooth to get rid of the defect.  This required that the bone be fractured, without completely severing it to maintain the blood supply, & at the same time be moved next to the tooth (Nabers and O’Leary, 1 9 67)
  46. 46. LIMITATION  difficult, impractical technique, the results of which have not been borne out by research.  It is further limited by the need for an adjacent edentulous ridge and bone quality that permits bending without fracturing.
  47. 47. INTRAORAL CANCELLOUS BONE AND MARROW  Hiatt & Schallhorn, 1973  Healing bony wounds, healing extraction sockets, edentulous ridges, mandibular retromolar areas, & maxillary tuberosity have all been used as sources  Edentulous ridges can be approached with a flap, and cancellous bone and marrow are removed with curettes.  Healing sockets are allowed to heal for 8 to 12 weeks, and is used as donor material. The particles are reduced to small pieces
  48. 48.  Bone fill in all types of intraosseous & furcation defects has been demonstrated with this material.  A mean bone fill of 3.65 mm, with bone fill of up to 12 mm in some defects & more than 50% fill on a predictable basis has been reported.
  49. 49.  Ellegaard & Loe ( 1971) reported that grafts of intraoral cancellous bone & marrow did not appear to influence the clinical outcome when compared with surgical curettage.  Renvert e t al. ( 1985) found limited differences between grafted & nongrafted sites.
  50. 50. Advantages  Relative ease of procurement  Relatively high induction potential for osteogenesis Disadvantages  Additional Surgical exposure may be necessary to procure donor material  Extensive defects may require more material than can be obtained.
  51. 51. EXTRAORAL CANCELLOUS BONE & MARROW  Cushing (1969 )--- extraoral cancellous bone & marrow offer the greatest potential new bone growth.  In 1968 Schallhorn obtained this material either from anterior or posterior iliac crest.
  52. 52.  Iliac Autografts - Data from human & animal studies support its use, & the technique has proved successful in bony defects with various numbers of walls, in furcations.  It is generally agreed that extraoral cancellous bone and marrow from the iliac crest offer the greatest osteogenic potential.
  53. 53. Advantages:  Greatest induction potential for osseous regeneration  Sufficient quantities for extensive defects.  May be stored for future use.
  54. 54. Disadvantages:  Additional surgical insult to the patient.  additional expense i.e. orthopedic surgeon or hematologist.  Potential for root resorption with fresh material.
  55. 55. COMPLICATION Schallhorn R.G (1972) described the post operative problems associated with iliac bone grafts  postoperative infection  exfoliation  sequestration  varying rates of healing  root resorption  rapid recurrence of the defect
  56. 56. ALLOGRAFT  Bone grafts harvested from one person for transplantation in another.  Used in periodontal therapy since last 3 decades.  most frequently used alternative to autogenous bone for bone grafting procedures in the US.
  57. 57. NEED …………….?????????????????  Problems associated with autogenous bone procurement - morbidity accompanying a second surgical site - need for a sufficient quantity of material to fill multiple defects (Mellonig, 1980 & 1991)
  58. 58. Classification  fresh frozen bone  Demineralized freeze-dried bone allografts  Freeze-dried bone allografts (FDBAs)/ autogenuous bone grafts (ABGs)
  59. 59. FRESH FROZ EN BONE  Possibility of disease transfer  Antigenicity 4 C ASES OF HIV HAVE BEEN REPORTED  need for extensive cross-matching DISALLOWED the use of fresh frozen bone in modern periodontics.
  60. 60.  Evidence suggest that freeze-drying markedly reduces antigenicity & other health risks associated with fresh frozen bone Freeze-dried bone allografts
  61. 61. WHICH BONE TO USE….? ? ? ? ? ?  Cortical bone is recommended rather than cancellous bone -------- American Academy of Periodontology  cancellous bone is more antigenic  cortical bone contains more bone matrix and consequently more osteoinductive components
  62. 62.  Bone allografts are procured usually within 12 hours of death of a suitable donor.
  64. 64.  Freeze-drying removes more than 95% of the water content from the bone.  It preserves three major specimen characteristics; size, solubility, and chemical integrity.  freeze-drying destroys all cells & graft is rendered non-viable
  65. 65. ADVANTAGES  Material is available in large quantities  No donor site within the patient  Reduces antigenicity  Facilitates long-term storage  Vacuum sealing in glass containers protects against contamination and degradation of the graft material while permitting storage at room temperature for an indefinite period of time
  66. 66. DISADVANTAGE  Process of preparing the graft material’s integrity & osteogenic potential, & immunological response to it may diminish its incorporation into the recipient bone  A major concern is potential for disease transfer, particularly viral transmission more particularly HIV
  67. 67. AMERICAN ASSOCIATION OF TISSUE BANKS (AATB) Excludes collection of bone under following circumstances:  Donors from high-risk groups, as determined by medical testing and/or behavioral risk assessments.  Donors test positive for HIV antibody by ELISA.  Autopsy of donor reveals occult disease.  Donor bone tests positive bacterial contamination.  Donor & bone test positive for HBsAG or HCV.  Donor tests positive for syphilis.
  68. 68. FDBA  Introduced to periodontal therapy in 1976  osteoconductive.  Although FDBA contains inductive proteins, the polypeptides are sequestered by calcium.  This material is resorbed and replaced by host bone very slowly.  only graft material that has undergone extensive field testing for the treatment of adult periodontitis.
  69. 69.  Mellonig, Bowers, and co-workers - reported bone fill exceeding 50% in 67% of the defects grafted with FDBA and in 78% of the defects grafted with FDBA plus autogenous bone.  FDBA-------- osteoconductive material  DFDBA-------osteoinductive graft.
  70. 70. FREEZE DRIED GRAFTS +ANTIBIOTICS  Terranova V et al. ----Addition of tetracycline theoretically enhance its osteogenic potential.  The addition of the antibiotic appears to enhance fibroblast chemotaxis, be anticollagenolytic, & produce a zone of antibacterial activity during the critical stages of wound healing.  Yukna R 1982 FDBA + tetracycline in a 4:1 volume ratio has shown promise in t/t of osseous defects associated with localized juvenile periodontitis.
  71. 71.  Significantly greater bone fill and defect resolution have been shown with the FDBA and tetracycline composite than with the allograft alone or the nongrafted control.
  72. 72.  Sanders et al 1 9 83 found that more than 50% bone fill was achieved in 80% of test cases grafted with FDBA + autogenous bone but in only 63% of controls grafted with FDBA alone.  Mellonig 1990 DFDBA has a higher osteogenic potential & provides more bone fill than FDBA.  FDBA is still used today, but a large-scale research review showed that FDBA mixed with autogenous bone is more effective at increasing bone fill than FDBA alone by Mellonig 1991.
  73. 73. DFDBA  synonymous - allogeneic, autolyzed, antigen-extracted (AAA) bone, demineralized bone powder, demineralized bone matrix, and demineralized bone matrix gelatin with decalcified freeze-dried bone.
  74. 74.  Demineralization of allografts was performed because the bone mineral blocked the effect of the factors stimulating bone growth sequestered in bone matrix including BMP.
  75. 75.  Experiments by Urist and co-workers have established the osteogenic potential of DFDBA. Demineralization in cold, diluted hydrochloric acid exposes the components of bone matrix, closely associated with collagen fibrils, that have been termed bone morphogenetic protein.
  76. 76.  BMP are a group of acidic polypeptides belonging to the transforming growth factor-β gene super- family. They stimulate bone formation through osteoinduction by inducing pleuripotential stem cells to differentiate into osteoblasts
  77. 77.  Experimental animal studies have shown that demineralized freeze-dried bone allograft has osteogenic potential  The bioactivity appears to be age dependent.  Younger animals ≥ older animals
  78. 78.  Bowers & associates, in a histologic study in humans, showed new attachment and periodontal regeneration in defects grafted with DFDBA.  Mellonig & associates tested DFDBA against autogenous materials in the calvaria of guinea pigs and showed it to have similar osteogenic potential.  These studies provided strong evidence that DFDBA in periodontal defects results in significant probing depth reduction, attachment level gain, and osseous regeneration
  79. 79. FACTORS AFFECTING  Delaying the procurement of donor bone after death, improper storage conditions, or other processing factors may play a significant role in the bioactivity of the final DFDBA preparation that makes its way to the clinician's office  age, gender, and medical status of deceased donors may also affect osteogenic activity in the grafts taken from them.
  80. 80.  The inductive activity gradually decreases& eventually is reduced to 0 within a period of 1 5 days when decalcification with 0.6 N HCI is performed at 2 5 °C, whereas in the cold ( 2 °C) the inductive activity is fairly maintained even at 30 days (Urist & Dowell, 1 9 68).  Ethyl or isopropyl alcohols in 0.6 N HCI produce total inactivation of inductive substrate.  Heating above 60 °C inhibits bone formation
  81. 81. FUTURE DIRECTIONS WITH DFDBA  The enhanced osteogenic potential of DFDBA is the result of a variety of bone-inductive proteins located within the bone matrix.  At the very least, nine BMPs (BMP-1 through BMP-9) have been cloned and characterized, and some are available in human recombinant form.  Animal experiments have demonstrated that the BMPs have the ability to induce bone and repair bone defects at a variety of anatomic sites as reported by Wang EA et al 199 0.
  82. 82.  Osteogenin (BMP-3) isolated from long bones of humans in association with a bone-derived collagenous matrix will rapidly initiate the cascade of bone development.
  83. 83. CONCERN  Potential for disease transfer, particularly viral transmission,& particularly HIV.  More freezing of bone allografts reduces the risk of disease transfer to 1 in 8 million  Russo et al The probability of HIV transfer following appropriate DFDBA preparation has been calculated to be 1 in 2.8 billion
  84. 84. X ENOGRAFT  Graft taken from a donor of another species.  naturally derived deproteinized cancellous bone from another species (such as bovine or porcine bone).  prepared by chemical or low-heat extraction of the organic component from the bovine bone  C/d anorganic bone  osteoconductive
  85. 85.  Boplant (Calf bone) : treated by detergent extraction, sterilized, &freeze dried  Ospurum : Fosberg described the use of ospurum for treatment of periodontal defects. This is Ox bone which is soaked in warm potassium hydroxide to remove connective tissue , in acetone to remove lipids, and in a soft solution to remove proteins.  Anorganic bone is ox bone from which the organic material has been extracted by means of ethylenediamine, it is then sterilized by autoclaving.
  86. 86. BOVINE DERIVED BONE REPLACEMENT GRAFTS  Bovine bone is processed to yield natural bone mineral - organic component.  act as an osteoconductive scaffold due to their porosity  Provide structural components similar to that of human bone.  Historically, bovine xenografts have failed due to rejection in past, as materials used chemical detergent extraction, which left residual protein & therefore produced adverse reactions
  87. 87.  Currently available graft are deproteinated  Eg- Osteograf/N and Bio-Oss  Both have been reported to have good tissue acceptance with natural osteotrophic properties
  88. 88. CORALLINE CALCIUM CARBONATE  Biocoral C a CO 3 is obtained from a natural coral, genus Porites, & is composed primarily of aragonite (> 9 8% Ca CO3)  pore size of 100 to 200 pm is similar to the porosity of spongy bone  It is resorbable, & highly osteoconductive  does not require a surface transformation into a carbonate phase as do other bone replacement grafts to initiate bone formation
  89. 89. Advantages  they are osteoconductive  readily available Disadvantage  bovine-derived grafts can cause disease transmission, which was evident in the case of bovine spongiform encephalopathy reported in Great Britain
  90. 90. Bone graft substitute ---------Gross 1997
  91. 91. ALLOPLASTS  The 1 9 9 6 World Workshop in Periodontics concluded “synthetic graft materials function primarily as defect fillers”  AAP 2003 / Position paper 2005 Synthetic graft materials function predominantly as biologic space fillers & that other materials should be considered if regeneration is desired
  92. 92. ADVANTAGES  Absence of antigenicity  NO potential for disease transmission  Unlimited supply
  93. 93.  Alloplasts marketed for periodontal regeneration fall into 2 broad classes:  Ceramics &  Polymers
  94. 94. CERAMIC-BASED BONE GRAFTS  Widely used  Function primarily through osteoconduction  Have also been considered osteointegrative, because of the tenacious, intimate bond formed between the new mineralized tissue & graft material
  95. 95. CALCIUM SULFATE  Calcium sulfate or plaster of Paris was first documented as being used for fracture treatment by the Arabs in the 10th century, who would surround the affected limb in a tub of plaster.  In 1852 a Dutch army surgeon named Mathysen incorporated plaster into the bandageable form which we are familiar with today
  96. 96.  Osteoconductive matrix for the in- growth of blood vessels and associated fibrogenic and osteogenic cells.  For this to occur, it is critically important that the implanted calcium sulfate is adjacent to viable periosteum or endosteum  Reabsorbed by a process of dissolution Over a period of 5–7 weeks,
  97. 97.  Medical grade calcium sulfate impregnated with tobramycin is commercially available (Osteoset)  Calcium sulfate in its set form has a compressive strength greater than cancellous bone and a tensile strength slightly less than cancellous bone.  Requires a dry environment to set and if it is re- exposed to moisture it tends to soften & fragment.  No reliable mechanical properties in vivo and its application is limited
  98. 98. TRICALCIUM PHOSPHATE  Porous form of calcium phosphate  most commonly used form β -tricalcium phosphate  Biological filler which is partially resorbable & allows bone replacement
  99. 99.  α & β TCP produced similarly  Display different resorption properties.
  100. 100.  Structurally porous beta TCP has a compressive strength & tensile strength similar to that of cancellous bone.  It undergoes resorption over a 6–18 month period.  The replacement of beta TCP by bone does not occur in an equitable way  There is always less bone volume produced than the volume of the graft material resorbed.
  101. 101.  TCP as a bone substitute has gained clinical acceptance, but results are not always predictable.  In direct comparison with allogeneic cancellous grafts, allogeneic grafts appear to outperform TCP  Amler MH TCP particles generally become encapsulated by fibrous connective tissue & do not stimulate bone growth
  102. 102. HYDROXYAPATITE  The primary mineral component of bone  Became available in the 1 970’s.  Available in resorbable & non-resorbable  Depends on the temperature at which it is prepared
  103. 103. DENSE HYDROXYAPATITE GRAFTS  Osteophillic , osteoconductive  Act primarily as inert biocompatible fillers  They have produced clinical defect fill greater than flap debridement alone in the treatment of intrabony defects  Histologically, new attachment is not achieved  They yield similar defect fill as other bone replacement grafts & the clinical improvement  is more stable than with debridement alone
  104. 104. POROUS HYDRO X YAPATITE  Obtained by the hydrothermal conversion of CaCO3 exoskeleton of the natural coral genus Porites into the calcium phosphate hydroxyapatite  pore size of 1 9 0 to 200 µm  Which allows bone ingrowth into the pores & ultimately within the lesion itself  Clinical defect fill, probing depth reduction, and attachment gain have been reported
  105. 105.  Kenney et al. provided histological evidence suggesting that porous hydroxyapatite supports bone formation.  But since no evidence of a new CT attachment or cementum was noted, it should be considered a biocompatible filling material
  106. 106. RESORBABLE PARTICULATE GRAFT  non-sintered (nonceramic) precipitate  Particles size 300 to 400 µm.  It has been proposed that non-sintered hydroxyapatite resorbs acting as a mineral reservoir inducing bone formation via osteoconductive mechanisms  Its reported advantage is the slow resorption rate, allowing it to act as a mineral reservoir at the same time acting as a scaffold for bone replacement
  107. 107. BIPHASIC CALCIUM PHOSPHATE Combination of the two primary forms of calcium phosphate  A histological study---------Hashimoto-Uoshima et al. biphasic calcium phosphate supported active bone replacement from surrounding bone which may have been triggered by macrophages.  However, further studies are needed before clinical acceptance
  108. 108. BIOACTIVE GLASSES  Composed of CaO, Na 2O, SiO,, P 205  Bond to bone through the development of a surface layer of carbonated hydroxyapatite  When exposed to tissue fluids in vivo, the bioactive glass is covered by a double layer composed of silica gel and a calcium phosphorus- rich (apatite) layer.
  109. 109. calcium phosphate-rich layer Promotes adsorption and concentration of proteins Used by osteoblasts to form a mineralize extracellular matrix.
  110. 110.  It is theorized that these bioactive properties guide and promote osteogenesis,allowing rapid & quick formation of new bone  There are two forms of bioactive glass currently available.  PerioGlas (BioGlass synthetic bone graft particulate)  Biogran (resorbable synthetic bone graft).
  111. 111. PerioGlas – osteoconductive  Particle size ranging from 90 to 710 μm,  Fetner AE 1 9 9 4 -------In surgically created defects in nonhuman primate, 68% defect repair was achieved when measuring new attachment  He also compared T C P, HA, &unimplanted controls, & showed PerioGlas to produce significantly greater osseous and cementum repair.  It also appeared to retard epithelial downgrowth, which the authors contend may be responsible for its enhanced cementum and bone repair.
  112. 112. Biogran  Particle size - 300 to 355 μm  Formation of hollow calcium phosphate growth chambers occurs with this particle size because phagocytosing cells can penetrate the outer silica gel layer by means of small cracks in the calcium phosphorus layer and partially resorb the gel.  leads to formation of protective pouches where osteoprogenitor cells can adhere, differentiate, & proliferate.
  113. 113.  According to the manufacturers, larger particles do not resorb in the same manner, which slows the healing process theoretically because bone healing must progress from the bony walls of the defect and smaller particles cause a transient inflammatory response, which retards the stimulation of osteoprogenitor cells.  Optimal particle size 100-300 micron
  114. 114. POLYMER S
  115. 115.  Polymers are more widely used as barrier materials in GTR procedures for t/t of periodontal defects.  At present, several polymer systems are being used for bone & periodontal regeneration  Polylactic acid (PLA)-based polymers  Copolymers These polymers have proved to be effective in periodontal applications as barrier materials
  116. 116.  Biocompatible microporous polymer containing PMMA, PHEMA, & calciumhydroxide is available  hydrophilic and osteophilic  Histologic evaluations revealed that the polymer was associated with minimal inflammation & infrequent foreign body giant cells, with evidence of both bone apposition & soft tissue encapsulation, at 1 to 30 months following implantation
  117. 117. HTR (BIOPLANT)  Nonresorbable biocompatible microporous composite of PMMA,PHEMA& calcium hydroxide.  Favorable clinical results have been achieved with HTR for T/t of infrabony & furcation defects.  Improved clinical results with this synthetic substitute have not always been achieved.  Shahmiri et al 1 9 9 2 -----no clinical improvement in probing depth, most reports have supported the use of HTR as a bone substitute.
  118. 118. NANOCYSTALLINE HYDROXY APPATITITE  65% water  35% nanstructured appatitite  Introduced for augmentation procedure in osseous defect  Advantage - Close contact with surrounding tissue - Quick resorption - Large no. of molecule on the surface
  119. 119. HYDROXYAPATITE PASTE IN THE TREATMENT OF HUMAN PERIODONTAL BONY DEFECTS – A RANDOMIZED CONTROLLED CLINICAL TRIAL: 6-MONTH RESULTS JOURNAL OF PERIODONTOLOGYMARCH 2008, VOL. 79, NO. 3, PAGES 394-400  Twenty-eight subjects, each displaying one intrabony defect with probing depth (PD) ≥6 mm & radiographic evidence of an intraosseous component ≥3 mm participated in the study.  significant improvement in PD and CAL was observed at 6 months after surgery compared to baseline in both treatment groups (P <0.001).  T/t of intrabony periodontal defects with NHA paste significantly improved clinical outcomes compared to open flap debridement
  120. 120. INJECTABLE CALCIUM PHOSPHATE CEMENT Comparison of Injectable Calcium Phosphate Bone Cement Grafting and Open Flap Debridement in Periodontal Intrabony Defects: A Randomized Clinical Trial Journal of PeriodontologyJanuary 2008, Vol. 79, No. 1, Pages 25-32  Injectable, moldable fast setting bioabsorbable  Has high compressive strength  Orthopeadic & material study  In vivo  Osteoconductive carbonated appatite  Chemical & physical characteristic similar to mineral stage of bone  Gradually replaced by natural bone
  121. 121.  Thirty subjects (mean age, 53.4 ± 9.1 years) with periodontitis and narrow intrabony defects were enrolled in the study.  This study failed to demonstrate any superior clinical outcomes for the CPC group compared to the OFD group
  122. 122. SUPERPOROUS HYDROXYAPATITE (HA) BLOCK  A superporous (85%) hydroxyapatite (HA) block was recently developed to improve osteoconductivity, but it was often not clinically successful when used to treat periodontal osseous defects. 
  123. 123. BONE GRAFT AVAILABLE Bone graft property type ORTOGRAF-LD/PB osteoinductive and osteogenic properties. 90% hydroxyapatite (HA) & 10% tri calcium phosphate (TCP). Ossifi - Bone Graft osteoconductive Hydroxyapatite and ß- tricalcium phosphate in 70/30 ratio Osseograft osteo-inductive demineralised bone graft material Osseomold osteo-inductive demineralised bone graft material DFDBA-TATA MEMORIAL TISSUE BANK osteo-inductive
  124. 124. Bone graft Property Type BioGraft Bone Substitute osteoconductive 100% Synthetic Hydroxyaptite  100% Beta Tri Calcium Phosphate  Biphasic 60% Synthetic Hydroxyaptite and 40% Beta Tri Calcium Phosphate  Biphasic 70% Synthetic Hydroxyapatite and 30% Beta Tri
  125. 125. Bone graft Property Type FISIOGRAFT type SPONGE - POWDER - GEL l-d-polylactic acid and polyglycolic acid. G-Bone porous hydroxyapatite  Perioglass Osteoconductive & osteostimulation calcium phospho silicate  Dental putty Osteoconductive & osteostimulation Calcium phosphosilicate
  126. 126. Bone graft Property Type Bone medik Osteo-conductive Coralline hydroxyapatite Ostofom Osteo-conductive & osteo-inductive Hydroxyapatite & collagen Sybograft Osteo-conductive Nano cyrstalline hydroxyappetite RTR Osteo-conductive ß-tricalcium phosphate Bio-oss granule Porcine collagen
  128. 128. REMOVE ALL ETIOLOGIC FACTORS  Local and systemic factors must be under control for grafts to be successful.
  129. 129. STABILIZE TEETH IF NECESSARY  Generally temporary, provisional or permanent stabilization of teeth undergoing grafting is not necessary.  Teeth with slight to moderate mobility appear to heal well whether splinted or not.  However, extremely mobile teeth that are going to be treated may benefit from provisional stabilization for at least 6 months postsurgically is of therapeutic measures such as root planning.
  130. 130. FLAP DESIGN  Internally beveled scalloped incisions with full gingival preservation are necessary to be able to completely close the site at the completion of surgery.  Full thickness flaps, reflected beyond the mucogingival junction, are recommended.Vertical releasing incisions should be used as necessary for proper access to the defect
  131. 131. DEGRANULATION OF DEFECT AND FLAP  All granulomatous soft tissues should be removed from the bony walls of the defect and the associated tooth surfaces.  The inner aspect of the flap should be checked for tissue tags & epithelial remnants, which should also be removed
  132. 132. ROOT PREPARATION  It is essential that all calculus, bacterial plaque, other soft debris & altered cementum be removed from the involved root surfaces.  Ultrasonic and hand instruments as well as finishing burs are useful for this purpose.  This aspect of therapy is the most tedious, difficult & time-consuming but the most essential aspect.
  133. 133.  There is some suggestion that the use of chemicals such as citric acid or tetracycline paste may be an aid in root detoxification & in making the root surface more biologically acceptable for healing.
  134. 134. ROOT SURFACE BIOMODIFICATION  Earliest reported clinical approaches to prepare root surfaces for optimal attachment of periodontal tissues and regeneration.  Agents  Citric acid  Tetracycline  EDTA  Result detoxification, demineralization & collagen fiber exposure.
  135. 135.  Ann Periodontol 2003  Chemical root modifiers do not enhance reductions in probing depth or gains in clinical attachment level following periodontal surgery
  136. 136. ENCOURAGE A BLEEDING BONY SURFACE  Generally already accomplished by proper defect debridement.  However, if the defect walls are relatively dry and/or glistening, healing may be enhanced by intramarrow penetration to encourage bleeding and allow the ingress of reparative cells, vessels and other tissues.  Such penetrations can be accomplished with a small round bur or hand instruments.
  137. 137. PRESUTURING  Loose placement of sutures, left untied, prior to the filling of the defect reduces the possibility of displacing the graft material during the suturing process.  It also simplifies the last steps of the procedure, in that once defect fill has been completed, the already placed sutures need only to be tied to complete the surgical procedure
  138. 138. CONDENSE GRAFT MATERIAL WELL  The graft material should be placed in small increments  sterile plastic or Teflon-lined amalgam carriers place the material and sterile amalgam squeeze  cloths to use over the suction tip to dry the defect without removing any of the graft material  process is repeated until the defect is filled
  139. 139. FILL TO A REALISTIC LEVEL  defects should be filled with the synthetic graft materials only to the level of the defect walls, There is little suggestion that overfilling with these materials results in supracrestal bone formation.  Overfilling may actually be counterproductive in that it may preclude proper flap closure, thereby retarding healing
  140. 140. GOOD TISSUE COVERAGE  If flap design has been good, primary closure with replaced flaps and contact of the interproximal papillae can usually be obtained .  If tissue coverage of the alloplastic graft material is not satisfactory, additional releasing incisions or reflection may be necessary.
  141. 141. PERIODONTAL DRESSING  The use of a firm, protective periodontal dressing for 10 days following bone replacement graft surgery is suggested.  It has become popular not to use dressing for many periodontal surgical procedures, but prudence would seem to suggest that the possible impingement of foreign materials into the graft site, flap displacement and loss of graft material that would jeopardize the success of treatment make the use of protective dressings preferable.
  142. 142. ANTIBIOTIC COVERAGE  Tetracycline-type drugs are the antibiotics of choice for immediate postsurgical plaque suppression due to their broad spectrum of activity, attraction to healing wound sites and concentration in GCF.  They are administered in therapeutic doses for the first 10 days following surgery or until the patient can practice proper plaque control in the area
  143. 143. POSTSURGICAL CARE  If the dressing and sutures are removed prior to 10 days, another dressing is often indicated. When the first postoperative treatment is at 10 or more days following surgery,additional dressings are rarely indicated  The patient is started immediately on gentle but thorough plaque-control methods, including the use of antibacterial rinses
  144. 144.  Schedule for professional plaque control in the office as follows:  every 10 days for 3 visits;  every month for 2 visits; and  every 3 months
  145. 145.  The grafted areas should not be probed prior to 3 months postsurgically  Radiographs taken prior to 6 months provide uncertain information.
  146. 146. HEALING  First wound-healing phase is revascularization.  initiated within the first few days following the grafting procedure. Blood vessels originating from the host bone invade the graft.  A pore size of 100 to 200 µm is very conducive to vascular invasion.
  147. 147.  incorporation of the grafted bone particles by new bone emanating from the host.  If the graft material contains vital osteogenic precursor cells that survive the transplantation process, these cells may contribute to new bone formation.
  148. 148.  The graft may possess inductive proteins that actively stimulate the host to form new bone, or the graft may simply act passively as a lattice network over which the new host bone forms
  149. 149.  Creeping substitution - As the graft is being incorporated, it is gradually resorbed and replaced by new host bone.  The final phase of healing is bone remodeling.  Resorption, replacement , and remodeling take many years.
  150. 150. FATE OF BONE GRAFT  Once the material is placed in the bony defect it may act in a number of ways which may decide the fate of the graft material. The various possibilities include:  Bone graft material may have no effect at all.  The bone graft material may act as a scaffolding material for the host site to lay new bone.  The bone graft material may itself deposit new bone because of its own viability.
  151. 151. CONCLUSION  Future bone grafting materials will likely build on innovative polymeric &ceramic platforms with controlled biophysical properties that enable the targeted delivery of drugs, biologics,& cells, thereby improving the degree & predictability of periodontal regeneration
  152. 152. REFERENCES Carranza F.A and Newman M.G : Clinical Periodontology 9th edition.  Periodontal therapy. Clinical approaches and evidence of success. Myron Nevins, Iames T, Mellonig. Vol-I 1998.  Periodontal Surgery: A Clinical Atlas. – Naoshi Sato  Atlas of Cosmetic and Reconstructive Periodontal Surgery, 3rd Ed by Edward Cohen
  153. 153.  Periodontics Medicine, Surgery, And Implants  by Louis F. Rose, Brian L. Mealey,Robert J. Genco,Walter Cohen  January 2010 (Vol 54, Issue 1 Treatment of periodontal disease  Tissue Banking of Bone Allografts Used in Periodontal Regeneration JOP 2001  Periodontal regeneration JOP 2005
  154. 154.  Bone replacement grafts, Bone substitutes. Aichelmann Reidy : DCNA 2005:491-504.  Bone and Bone substitutes. Nasr H.Fet al. Perio 2000, 1999 :74-86.  Synthetic Bone grafts in periodontics. Yukna R.A Periodontology 2000;1993:1:92-99  Development and regeneration of th periodontium parallel &contrasts. Periodontology 2000, Vol. 19, 1999, 8-20