Osseous Regeneration Flashcards
Procedures allowing the repop of a perio defect by cells capable of forming new CT attachment and alveolar bone
Guided Tissue Regeneration
Desirable/Undesirable: Bone Cells
Desirable
Desirable/Undesirable: Gingival Epithelial Cells
Undesirable
Desirable/Undesirable: Gingival CT
Undesirable
Desirable/Undesirable: PDL
Extremely Desirable
Criteria (4) for GTR Success
- Primary soft tissue closure
- Secluded space maintenance
- Membrane stabilization
- Adequate healing period
Qualities of an Ideal Membrane
Absorbable Bio Compatible Cell Occlusive Space Maintenance Tissue Integration Clinically Manageable
Non-Resorbable GTR Materials
ePTFE
Resorbable GTR Materials
Cross-linked collagen membranes
Calcium Sulfate
PLA/PGA
Doxycycline 4%
About ePTFE
2nd stage surgery required to remove (4-6 weeks) - use small incision, do not disturb tissue, cover new tissue with flap
PLA/PGA
Degrades 4-6 weeks, one stage surgery
Collagen, and what do you add to it
Cross-linked, adding zinc prevents breakdown, bovine of porcine source
Functionally Graded Membranes
Stem cells
3 layers- core layer: protein
SL to epithelium= metornidazole
SL to bone= hydroxyapatite
Space Maintenance Guidelines (2)
- Reinforce the membrane
- Create a scaffold - using tenting screws and fillers
Bio Mechs of Graft Integration
Osteogenesis - viable cells
Osteoinduction - uncommitted CT cells induced
Osteoconduction- non viable scaffold
Osteogenesis
Osteoblasts from the graft material contribute to bone growth
Osteoinduction
Graft induces osteoprogenitor cells in the bone to form into osteoblasts and start producing bone
Osteoconduction
Graft serves as a scaffold for new growth that is perpetuated by the native bone
Conductive/Inductive/Genic? Autograft
Yes, Yes, Yes
Conductive/Inductive/Genic? Allograft
Conductive and Usually Inductive, but NOT Genic
Conductive/Inductive/Genic? Alloplast/xenograft
Conductive, but NOT Inductive or Genic
Autogenous Grafts - Advantages
- Gold Standard- predictable
- Osteogenic
Autogenous Grafts- Disadvantages
- second surgical site in same human
- insufficient material
- membranous bone vascularizes faster than endochondral bone
- membranous bone resorbs slower that endochondral bone
Allografts - Advantages
- Availability
- No Donor Site
- Reduced surgical time
- Fewer complications
Allografts - Disadvantages
- antigenicity
- longer healing
- less volume
Alloplasts and Xenografts
- hydroxyapatite
- bovine derived
- tricalcium phosphate
- synthetic bone material
- coralline
- hard tissue replacement polymer
- bioactive glass
Biological Mediators (2)
- Enamel matrix proteins
- rhBMP
Human BMP-2 (INFUSE)
Stimulates bone formation
mix w/ water and applied to collagen sponges
Enamel Matrix Derivative (Emdogain)
Forms layer of extracellular matrix on the root surface that promotes selective cell colonization - enhances mesenchymal adhesion and inhibits epithelial adhesion
Use PrefGel to wipe smear layer off root
Benefits of Emdogain (EMD)
Improved AL, pocket reduction
formation of new bone, PDL, and cementum in primates
PDGF in Tri-Calcium Phosphate (GEM21S)
PDGF stimulates migration of proliferation of osteoblasts, fibroblasts, and cementolblasts–> form new bone, PDL, cementum
Effects of GEM21S
- greater radiographical bone fill
- But, no AL gain
- Good for furcations
Furcation Defects Regeneration
- predictable GTR with Class 2 furcas on mand molars
- Consider GTR in areas with isolated Class 2 furcas
Predictability of Furca Regeneration
- Most- Mand or Buccal Max class 2’s
- Mes or Dist Max class 2’s
- Least - Class 3’s
