Bone grafts in dentistry

Dept of Periodontics

1. BONE GRAFTS Kirti Ranka FINAL YEAR b.D.S .

2. CONTENTS DEFINITION INDICATIONS REQUIREMENTS CLASSIFICATION BONE GRAFTING TECHNIQUE EVALUATION CONCLUSION REFERENCES

3. What is a graft? A graft is a viable tissue/organ that after removal from the donor site is implanted/transplanted within the host tissue, which is then repaired, restored and remodeled.

4. When should you consider this option? Ridge augmentation and implants Furcation defects

5. Deep intrabony defects(2-3 walled defects) Advanced bone loss Aggressive periodontitis Aesthetics Sinus lift procedures

6. What to expect after this procedure? Attachment gain Reduction in pocket depth Bone fill Regeneration of other surrounding tissues

7. Ideal requirements Biological acceptibility Predictability Facilitate vascularisation Clinical feasibility Minimum operative hazards Minimum post-op. sequelae Acceptance by the patient Not too expensive

8. CLASSIFICATION According to the type of graft According to their mode of action

9. BONE GRAFTS AUTOGRAFTS ISOGRAFTS ALLOGRAFTS XENOGRAFTS ALLOPLASTS COMPOSITE GRAFTS According to the type of graft

10. According to their mode of action OSTEOGENIC/ OSTEOPROLIFERATIVE OSTEOINDUCTIVE OSTEOCONDUCTIVE OSTEOPROMOTIVE

11. autografts Within same individual GOLD STANDARD Osteogenic , Osteoinductive & Oteoconductive potencies INTRA-ORAL SITES EXTRA-ORAL SITES Tori,Exostosis Ramus, Chin Tuberosity Edentulous spaces, Symphysis Extraction sites Tibia Fibula Ribs Iliac crest

12. Mixture of bone dust obtained by grounding cortical bone and blood. Round carbide bur-25,000-30,000 rpm Donor bone Small particles Patient’s blood coating Coagulum Sources : -Lingual ridge on the mandible - Exostosis -Edentulous ridges -Bone distal to the terminal tooth -Bone removed from osteoplasty OSSEOUS COAGULUM

13. ADVANTAGES Relatively rapid technique Complements osseous resective procedures that may be required at the surgical site. Particle size provides additional surface area for the interaction between cellular and vascular elements DISADVANTAGES Cannot be used in larger defects because of inability to procure adequate material Poor surgical visibility Relatively low predictability Inability to use aspiration during accumulation of coagulum Fluidity of the material makes it difficult to handle

14. Removal of bone from accessible intra oral donor sites by chisels. Placing them in a sterile plastic amalgam capsule Triturating it with a pestle. BONE BLEND

15. BONE SWAGING Edentulous area near the defect required • Bone is pushed into the root surface without fracturing the bone at the base • Technically difficult

16. isografts Monozygotic twins A.k.a. “ Syngenous grafts”

17. Bone graft harvesting 1. Cortico-cancellous block grafts harvested with a 6-mm trephine and ground to particulated bone chips in a bone mill 2 . Bone chips harvested with a sharp bone scraper 3 . Bone particles collected from the aspirator with a bone trap filter during the preparation of the osteotomy 4 . B one particles harvested with a piezo -surgery device. It is for harvesting particulate autogenous bone

18. Precautions while harvesting bone grafts Carefully evaluate the donor sites for any risks- Radiographically Use extreme care in making incisions laterally towards the mental nerve and dissect the area with blunt instruments to locate the foramen Do not elevate or reflect the muscle attachments beyond the inferior border of the mandible. Suture the wound in layers (muscles and overlying mucosa separately) to prevent post-op wound separation. While using trephines, drills or saws to cut the bone it must always be done with profuse irrigation to keep the instruments and bone cool. Exceeding 47ºC can cause bone necrosis

19. Do not elevate or reflect the muscle attachments beyond the inferior border of the mandible . Limit bone cuts to at least 5mm away from the tooth apices, inferior border of mandible and mental foramen . Do not extend cuts beyond 6mm deep Do not include both the lingual and the labial cortical plates

20. HEALING : • Granulation Stage : When hematoma develops , an inflammatory response occurs and the formation of granulation tissue takes place • Callus Stage : Mesenchymal cell differentiates mainly into osteoblasts • Remodelling Stage : Hard callus tissue is replaced by lamella bone • Modelling Stage : Bone adapts to the structural demands due to functional stimuli

21. 7 days: Initiation of new bone formation 21 days: Cementogenesis 3 months: New PDL 8 months: Graft fully incorporated into the host with functionally oriented fibers between the bone and the cementum Maturation may take as long as 2 years

22. allografts Genetically dissimilar members of the same species. Eg . :-Demineralized Freeze Dried Bone Allografts(DFDBA) Freeze Dried Bone Allografts(FDBA) DFDBA FDBA Demineralised Not Demineralized More radiolucent More radiopaque Rapid resorption Breakdown by way of foreign body reaction Primary indication-Periodontal disease asso . with natural tooth Primary indication-Bone augmentation asso . with implant treatment Osteoinductive Osteoconductive More BMP Less BMP

23. To supress their antigenic potential

24. xenografts Donor is of another species. They are usually referred to as “ anorganic bone” A vailable source: – Bovine bone -Natural coral -Calf bone -Kiel bone

25. alloplasts A.k.a. Inert biologic fillers Eg . : Tricalcium phosphate(TCP) Hydroxyapatite(HA) Bioactive glass

26. Biocompatibility composite polymers( Bioplant HTR ) Polymethyl methacrylate + Polyhydroxyethyl methacrylate beads Coated with Calcium Hydroxide Calcium Hydroxide forms Calcium Carbonate when introduced into the body Surface for osteoblast cell attachment and bone deposition 1-3 years later- complete bone formation

27. COMPOSITE GRAFTS Made of- Na 2 O– CaO –SiO 2 –P 2 O 5 Reffered to as 45S5 bioactive glass. The material exists in particulate form(90-710µm diameter)- PerioGlas and (300-350 µm diameter)- BioGran Facilitates bone formation

28. Bone grafting procedure INCISION Sulcular incisison made on the lingual and facial aspects

29. FLAP DESIGN Prevent flap perforation, Removal of granulation tissue from the lesion that usually attaches to the inner aspect of the flap. Excess thinning of the flap hampers blood supply

30. ROOT DEBRIDEMENT Remove hard and soft accretions on the root surface Root biomodification -Saturated solution of Citric Acid (pH=1)

31. DEFECT DEBRIDEMENT Debride defects of soft tissues using hand, ultrasonic, rotating instruments

32. PREPARATION OF GRAFT MATERIALS Bone grafts should be wetted with patient’s blood rather than saline or water

33. PROMOTION OF BLEEDING SURFACE In case of a chronic bone lesion the bone is perforated, forms a bleeding environment .

34. PRESUTURING Loose sutures placed prior to filling the defect to reduce displacement of bone graft during suturing

35. PLACEMENT OF GRAFT INTO OSSEOUS DEFECT The bone graft is transferred with bone graft scoop. Graft is packed firmly but not too tight and should not be overfilled

36. FINAL SUTURING Monofilament sutures placed as interrupted or vertical mattress suture technique

37. evaluation CLINICAL METHODS Probing depth measurement Clinical gingival indices Determine the attachment level RADIOGRAPHIC METHODS -Careful standardized techniques for reproducing the position of the film and tube are required. -Linear-CADIA method offers the highest level of accuracy.

38. SURGICAL RE-ENTRY -The state of the bony crest, after healing can be compared with the state of the bone before surgery. Models can also be used. - Disadvantages - Requires frequent and unnecessary 2 nd operation. -Does not show the type of attachment that exists. HISTOLOGIC METHODS -The type of attachment can be determined by this method only. -The tooth needs to be removed along with its periodontium after successful treatment to assess the attachment. -Limited to volunteers who undergo extraction for prosthetic or other reasons and agree to the procedure.

39. CONCLUSION A graft is a viable tissue/organ that after removal from the donor site is implanted/transplanted within the host tissue, which is then repaired, restored and remodeled. Classification- Based on type, mode of action Autografts-GOLD STANDARD Technique- Incision, Flap design Root debridement Defect debridement Preparation of Graft material Promotion of bleeding surface Presuturing Placement of graft Final suturing Evaluation- Clinically, Radiographically , Surgical re-entry, Histologically.

40. REFERENCES DENTAL BULLETIN (V OL.15 NO.3 MARCH 2010) Intra-oral Autogenous Bone Grafting for Dental Implant Site Preparation by Dr. Gregory TAYLOR ARTICLE BY NCBI-Bone Grafts in dentistry CLINICAL PERIODONTOLOGY- Caranzza 10 th Edition TEXTBOOK OF PERIODONTICS- Shalu Bathla

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