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Clinical and histologic evaluation of extraction socket grafting and implant site developement. Extraction socket. After extraction More buccal bone resorption than lingual/palatal portion Schropp et al.2003
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Clinical and histologic evaluation of extraction socket grafting and implant site developement
After extraction More buccal bone resorption than lingual/palatal portion Schropp et al.2003 • Dog study ( after extraction ) • 4 weeks : woven bone • 8 weeks : lamellar bone and marrow Cardaropoli et al. 2003 • more 2.5mm bone resorption in buccal than lingual Araujo & Lindhe 2005
+ 48天apical旁邊會開始往上往內側長bone 60天開始會有bone marrow的生長
Bundle bone : histologic term for portion of alveolar bone surrounding tooth and embedded with PDL
Bundle bone resorption • Tooth anchored to jaws via bundle bone and PDL • Extraction of tooth bundle bone resorption • Buccal hard tissue most of bundle bone, resorption in first 4 weeks, little in 4 to 8 weeks • Lingual hard tissue bundle bone and lamella bone Buccal side bone 的resorption量是lingual side的兩倍 (Buccal side全為bundle bone) (Lingual side為bundle bone加上lamella bone)
以狗為研究的study , 放入implant來保留bone high的實驗 Buccal side 比 lingual side低
Human study: • Blood clot granulation tissue (1 week) osteoid formation, bone remodeling (6 week) Amler,1969 • Problems of human study: • Tissue samples : diseased ? Cadavers ? • Experiment protocol ? • Small sample size • Short time interval observation
Material and methods • 24 cases( 27 sockets ), single rooted-teeth , fused root of molar or premolar • Impression for stent to measure depth • Flap reflection extraction ( no graft or membrane ) primary closure with flap • 2-24 weeks healing • Biopsy for histologic and immunohistochemical analysis • Exclusion : • periapical lesion • socket depth < 5mm
Histologic analysis • Early phase • Blood clot • Granulation tissue • Intermediate healing phase • Provisional matrix ( mesenchymal cells, collagen fiber, vessels, no or limited inflammation cells • Woven bone • Late phase • Lamellar bone and marrow 和狗的實驗數據差不多 4~6個星期
Early phase3 weeks 有血塊以及紅血球聚集
Intermediate healing phase4 weeks 四個星期,有產生provisional matrix
Intermediate healing phase6 weeks 6 weeks,有fiber產生以及圍繞 , ,
Late healing phase12 weeks 3~4 months , lamina bone形成 ,
Schropp et al.2003 • Bone remodeling of extraction sites in man is a slow process • Dimensions change after extraction • 3 months >30%, 12 months≈ 50% (buccal-ingual/palatal width) • Molar > premolar • First 6 months : large amount mineralized tissue filled in socket • 6 to 12 months : lamellar bone replaced woven bone
Human study– immediate implant • 18 subjects, 24 immediate implants • 4 months healing • Horizontal resorption : • Buccal :3.4mm 1.5mm, difference : 1.9mm, 56% • Lingual : 3.0 2.2mm, difference : 0.8mm, 30% Botticelli, Berglundh, Lindhe, 2004 Buccal side 為 lingual side的兩倍量
Bone graft Auto grafts Allografts : FDBA,DFDBA Xenografts Alloplastic grafts
Barrier materials for regenerative surgery Biocompatible Act as barrier to exclude undesirable cell types and allows passage of nutrients and gases Tissue integration : prevent rapid epithelial down growth on the membrane Space making Easy trim
會產生CO2 , H2O2 • Non-bioabsorbable material : e-PTFE • Bioabsorbable materials : • Collagen • Polylactic acid • Polyglycolic acid • Calcium sulfate
e- PTFE ( expanded polytetrafluorethylene ) Biocompatible Act as barrier to exclude undesirable cell types and allows passage of nutrients and gases Tissue integration : prevent rapid epithelial down growth on the membrane ? Space making Easy trim
Calcium sulfate Calcium sulfate ( CS )in orthopedics for 100 years or more CS implantation may facilitate healing of bone defect Peltier, 1959 CS enhanced bone growth in fractured mandible of dog Calhoun, 1963 CS resorbed within 33 days, replaced by new bone Bell, 1964 When primary closure is challenging, CS may offer a potential For GTR Payne, 1996 • 最大優點為Biocompatibility • 最大缺點為resorption太快(33天),也因此不會單獨使用
Sottosanti 1993~1997 • CS may prevent epi. Migration – as membrane for GTR • 20% + 80% DBM for composite grafting • Osteoinduction from DBM • Enhance ossification by Ca++ from CS • Enhance retention of DBM from CS
不 J Periodontol 1996;67:236-244
Study purpose • Determine migration ability of gingival fibroblast over 3 different membranes • Polytetrafluoroethylene ( e-PTFE ) • Polylactic acid • Calcium sulfate • In vitro
Materials and Methods • Fibroblast cultures • In vitro cell migration assay • 4 groups • Polytetrafluoroethylene ( e-PTFE ) • Polylactic acid • Calcium sulfate • Control ( polystyrene ) • Directed migration Hanks balanced salt solution(HBSS) • Random migration PDGF-BB homodimer
Result Fibroblast Migration Light microscopic Study Scanning electron Microscopy Examination
Fibroblast Migration 會有酸性物質產生
Scanning electron Microscopy Examination ( Calcium sulfate group )
Discussion • All three barrier membranes significantly less than control • Pore size 50-200 um greatest strength for fibroblast attachment Bobyn et al, 1982 • Calcium sulfate greatest migration and least effect on cellular morphology biocompatible (+) • Only in vitro
Study purpose 用在GTR , 3walls的defect
4 mongrel dogs • 4 conditions • CS+DBM • DBM • CS • GFS ( gingival flap surgery )
DBM+CS DBM CS GFS 以DBM+CS 以及單獨用DBM的效果最好