BONE GRAFTS

1. BONE GRAFTS

2. Project overview • What is Graft? • What is Grafting? • What are Bone Grafts? • Historical Review • Objectives & Rationale of Bone Grafts • Biologic concept of using Bone Grafts • Bone Grafts used in correction of periodontal defects • Technique

3. 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. What is grafting ? Grafting is a procedure used to replace / restore missing bone or gum tissue.

4. What are bone grafts? Bone grafts are the materials used for replacement or augmentation of the bone.

5. Historical Review: The use of bone grafts for reconstructing osseous defects produced by periodontal disease dates back to Hegedus in (1923 ) • Revived by Nabers & O’Leary in (1965)

6. Objectives & Rationale of Bone Grafts : • Increase in clinical bone defect fill. • To preserve & augment bone for future implant placement & / or esthetics. • Formation of functional P D L

7. Biologic concept of using Bone grafts • Contains bone forming cells (osteogenesis) • Serve as scaffold for bone formation (osteoconduction) • Matrix of bone grafting material contains bone inductive substances (osteoinduction)

8. Biologic concept of using BoneGrafts: • Osteoconduction: • Formation of bone by osteoblasts from the margins of defect on the bone graft material. • Osteoconductive material facilitate bone formation by bridging the gap between the existing bone & a distant location that otherwise would not be occupied by bone

9. Osteoinduction: Cell mediators at the defect (BMP) Stimulation of osteoprogenitor cells Osteoblasts New bone formation

10. Osteogenesis : Osteoblasts in the transplanted bone having adequate blood supply & cellular viablity. Forms new centers of ossification within the graft

11. Bone Grafts used in correction of Periodontal Defects: • Autografts • Allografts / Homografts • Xenografts / Hetrografts • Alloplasts

12. Autografts:A tissue transferred from one position toanother within the same individual . Allografts / Homografts: Obtained from genetically dissimilar individual of same species . Xenografts / Hetrografts:Tissue transferred from one species to another species. Alloplasts:A synthetic graft or inert foreign body implanted into tissue.

13. Autografts : Widely used in periodontics for treatment of intrabony defects. Promotes bone healing through osteogenesis & / or Osteoconduction. Can be harvested from either intraoral or extraoral donor sites.

14. Autografts from intraoral site -Hegedus (1922) • Sources include: • Maxillary tuberosity • Exostoses • Healing wounds • Extraction sites • Edentulous ridges. • Mandibular symphysis • Mandibular body • Osteoplasty Osteotomy sites

15. Bone Grafts harvested from intraoral sites are: • Osseous coagulum • Bone Blend • Intraoral Cancellous Bone Marrow Transplants • Bone swaging

16. Osseous Coagulum: - (Robinson) • Technique uses mixture of bone dust & blood • Small particles ground from cortical bone used • ADVANTAGES: • * Additional surface area for interaction of cellular & vascular elements. • * Ease of obtaining bone from already exposed surgical site. • DISADVANTAGES: • * Inadequate materials for large defects.

17. Bone Blend: • Uses an autoclaved capsule & pestle. • Bone removed from perdetermined site , triturated in capsule to a workable , plastic like mass, & packed into bony defects • Intraoral Cancellous Bone Marrow: • Cancellous bone obtained from Maxillary tuberosity, Edentulous area & healing socket

18. Bone Swaging: Technique requires existance of an edentulous area adjacent to the defect from which bone is pushed into contact with the root surface without fracturing the bone at its base.

19. Autografts from extraoral site • Schallorn (1967/ 1968)introduced the use ofautogenous” HIP MARROW“Grafts(illiaccrest marrow)in treatment of intrabonydefects.

20. Not recommended now a days due to: • - Morbidity of donor site. • - Ankylosis & Root resorption. • - Post op’ impaction, exfoliation, & sequestration. • - Rapid reoccurence of defect. • - Patients expense & difficulty.

21. Allografts: Allografts used in the treatment of intrabony defects could be: • Frozen cancellous iliac bone and marrow • Cryopreserved bone from the head of a femur • Freeze-dried bone allograft (FDBA) • Demineralized freeze-dried bone allograft. (DFDBA)

22. Freeze dried bone allografts (FDBA) • Osteoconductive • Cortical bone is deflated, cut into pieces, washed in absolute alcohol , deep frozen, freeze dried & vaccume sealed. • Ground particle size : 250 – 750 micron. • 50 – 60% bone fill.

23. Decalcified Freeze dried bone allografts (DFDBA) -Urist(1965) • Decalcified with 0.6N Hcl , washed in sodium phosphate buffer & vaccume sealed to expose the bone inducing agent c/a bone morphogenic proteins(BMP). • These proteins are osteoinductive. • More osteogenic potential than FDBA • DISADVANTAGE: Potential of disease transfer from cadaver.

24. Frozen iliac crest marrow Need for cross – matching to decrease the likelihood of graft rejection as well as disease transmission eliminate the use of frozen iliac crest marrow.

25. Xenografts: Anorganic bovine bone (ABB) : Bovine bone that has been chemically treated with ehylenediamine to remove its organic components, leaving a trabecular & porous architecture similar to human bone.It is osteoconductive. Boplant: Calf bone treated by detergent extraction, sterlized in propriolactone & freeze dried.

26. Kiel bone : Calf / ox bone denaturated with H2O2 (20%) dried with acetone & sterlized with etylene oxide. Ospurane: Cow bone soaked in KOH , acetone & salt solution. Boiled bone: Cow bone boiled or autoclaved.

27. Alloplasts: • Synthetic inorganic inert material • Synthetic graft material function primarily as defect fillers. -World Workshop (1996) • Characterstics: • - Biocompatible &/or Bioactive • - Osteogenic potential • - Resorbable in long run.

28. Classification:on the basis of their ability to be resorbed as: Absorbable materials Nonabsorbable materials • Porous hydroxyapatite • Dense hydroxyapatite • Bioglass • Calcium-coated polymer of hydroxyethylmethacrylate and polymethylmethacrylate. • Ceramics, • Beta tricalcium phosphate • Hydroxyapatite • Calcium sulfate • Calcium carbonate.

29. Bioceramics:Composed of CaPO4 with Ca & Po4 ratio similar to bone Beta tricalcium phosphate:Porous form of CaPo4 Hydroxyapetite: Porous non resorbable Solid non resorbable or solid resorbable.

30. Polymers: 2 types 1) A non-resorbable , calcium hydroxide coated co- polymer of poly - methyl – methacrylate(PMMA). 2) Poly – hydroxylethyl - methacrylate(PHEMA) / (HTR) Hard tissue replacement.

31. Bioactive glass: CaO, Na2O, SiO2,P2O5 • Bonds to bone through development of surface layer of carbonated hydroxyapetite. • Bio glasses exposed to tissue fluids….formation of double layer of silica gel & calcium phosphate on their surfaces….absorption & concentration of proteins through this layer….proteins used by osteoblasts to form extracellular bone matrix. • Commertially available bioglass in particulste form , theoretically resorbable proposed for peridontal treatment.

32. Technique • Patient selection • Should be in good physical health • Should demonstrate an acceptable level of oral hygiene • Could be committed to a long-term maintenance program. • Ideally should be a nonsmoker

33. Defect selection

34. Preoperative preparation • Perform plaque control . • Occlusal therapy consisting of adjustment or splinting of teeth . • A pre-procedural rinse with a substantive antimicrobial agent, such as 0.12% chlorhexidine gluconate for 30 seconds, immediately prior to the surgery can help reduce intraoral bacteria .

35. Anesthesia Regional Anesthesia for patients comfort Local infilteration with epinephrin to facilitate hemostasis

36. Flap design A sulcular incision full thickness flap is reflected. A three wall intrabony defect is visualized at the distal of the first molar.

37. Defect or root debridement Rotary instrumentation using a multifluted surgical length bur on a high-speed handpiece is needed to gain access to the depth of the lesion and to plane the root surface, which is subsequently treated with citric acid (pH 1).

38. Graft management The choice of graft material should be based on clinical considerations, including treatment objectives and potential patient morbidity. If morbidity with graft procurement is a concern, an allograft of demineralized freeze-dried bone may be used. There are no reports of disease transmission, graft rejection or ankylosis after the use of demineralized freeze-dried bone allograft.

39. Placement of demineralized freeze-dried bone allograft is accomplished with light incremental pressure so that the graft overfills the defect. The root surface has been treated with citric acid (pH 1) and the defect has been decorticated.

40. Flap closure A monofilament suture is used to close the flaps by primary closure.

41. Postoperative management/periodontal maintenance • Post operative antibiotics to aid in plaque control • Topical antimicrobial rinse • Postoperative visits include plaque removal • (both mechanically and with topical chlorhexidine) • Periodontal probing or recording of attachment levels should not be done prior to 6–12 months, since probing force may damage the healing site, thereby diminishing the regenerative outcome

42. Pre op Post op

44. Pre op Post op

45. Summary • Bone grafts are the material used for replacement or augmentation of the bone around the teeth.Biologic concept of using Bone grafts :* Osteoconduction * Osteoinduction * Osteogenesis

46. Bone Grafts used in correction of periodontal defects: • Autografts • Allografts / Homografts • Xenografts / Hetrografts • Alloplasts