Treatment of Osseous Defects
What is the risk of disease transfer with bone allografts?
- 1 in 8 million - Donors are very healthy - No blood borne pathogens - Grafts taken within 24 hrs of death - Tissue banks highly regulated - Overall, very safe!
What are overall conclusions about bone grafts?
- 3 mm plus or 60-80% bone fill - Total regeneration not generally possible - Allografts are safe - Crestal bone fill not consistently possible - Regeneration: DFDBA/autogenous bone - Growth factors - promising
What are characteristics of osseous coagulum?
- Autogenous - Bone Dust & Blood - Sources: Exotoses, edentulous ridge - Use carbide (slow speed) bar (#6 or 8) (5,000-30,000 rpms) - Pack coagulum into defect
What are different types of osseous grafts?
- Autograft - new bone comes from self - Allograft - new bone comes from another human (cadaver) - Non-bone grafts or alloplast
What are the types of bone morphic proteins?
- BMP-1 - BMP-2 (formerly BMP-2A) - BMP-3 (osteogenin) - BMP-4 (formerly BMP-2B) - BMP-5 - BMP-7 (OP-1) - BMP-8 (OP-2) - BMP-9
What are regeneration procedures that can be done in periodontal therapy?
- Bone grafts - Guided tissue regeneration
What is positive bony architecture?
See interdental space
What is negative bony architecture?
See interdental space (flat bony architecture is flat)
What is an ostectomy?
Shaping to ideal form which may sacrifice some supportive bone
What is an infrabony defect?
The base of the pocket is apical to the crest of the alveolar bone
Is it possible to have combinations of classifications for infrabony defects?
Yes - for example, you can have two full osseous walls and 1/2 of the third wall
What are bone morphogenic proteins?
Protein with osteogenic potential
What are the intraoral sources of autogenous bone grafts?
- Maxillary tuberosity - Mandibular ramus - Chin - Extraction socket - Tori - Edentulous ridges
What are the advantages of allograft bone?
- No second site morbidity - Preservation of patient's tissue - Reduced surgical time - Availability - Utility
What are the levels of bone fill?
- Overfill - avoid because it can disrupt blood supply - Standard fill - Underfill - avoid
What are clinical applications of bone grafts?
- Periodontal defects - Alveolar ridge augmentation - Extraction site bone fill - Sinus augmentation
What is regeneration?
- Reproduction of a lost part (periodontium). - Result in new bone, cementum and periodontal ligament
What are non-bone graft materials that can be used?
- Sclera - Cartilage - Plaster of Paris (CaSO4) - Plastic Materials (HTR Polymers) - Calcium Phosphate: Hydroxyapatite (HA, 1.67) Tricalcium phosphate (TCP, 1.5) - Coral-derived materials - Glass granules - Others
What size should bone particles be?
- Small particles active in inducing regeneration of periodontium - Small particles more predictably resorbed (250-300 microns)
Where does demineralized freeze-dried bone come from and what are its advantages?
- Source: cadaver - Advantage: Quantity, predictability, lack of adverse reactions
What are characteristics of allograft bone (regeneration)?
- Used to use iliac cancellous bone but that is not used anymore - Freeze-dried (50% fill) - Decalcified freeze-dried - releases growth factors like bone morphogenic protein (Cortical better than cancellous)
What are indications for osseous resection?
- Wide 3-wall defects - Interproximal craters - Hemiseptums - Furcations - Thick alveolar bone
What are the classifications of infrabony defects?
1. One osseous wall 2. Two osseous walls 3. Three osseous walls
What are three ways to treat osseous defects?
1. Osseous resection 2. Debridement 3. Grafting
What is repair?
Healing of a wound by tissue that does not fully restore the architecture or function
What is dihiscence?
Loss of alveolar bone on the facial aspect of a tooth
What is an osteoplasty?
Reshaping without sacrificing supporting bone