OHTSUKA Hideyuki Iwate Medical University School of dentistry, removable prosthodontics Assistant, 歯学部, 助手 (20285638)
MUSHIMOTO Eiko Iwate Medical University School of dentistry, removable prosthodontics Assistant, 歯学部, 助教授 (50131397)
吉田 光宏 岩手医科大学, 歯学部, 助手 (10265168)
佐藤 博 岩手医科大学, 歯学部, 助手 (90235383)
|Budget Amount *help
¥5,500,000 (Direct Cost: ¥5,500,000)
Fiscal Year 1998: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1997: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1996: ¥3,000,000 (Direct Cost: ¥3,000,000)
A guided bone regeneration method using a barrier membrane (usually e-PTFE membrane (GTAM^<<encircledR>>)) is currently in use to generate bone tissue around implants. However, there is no clear consensus of research supporting the effectiveness of GTAM^<<encircledR>> in acceleraling bone regeneration. Therefore, we have tried to apply electric stirnulalion to facilitate bone regeneration around dental implants. Results showed that the electrical VDF,TrFB film had a significant effect in accelerating bone regeneration as well as increasing maturity of new bone tissue in early stages, while GTAM^<<encircledR>> had no effect. Yet both membranes are non-resorhable and must be removed in a second surgical procedure. Recently, Poly lactic acid film (PLA) has been shown to have excellent properties as a barrier membrane : it is biocomnpatible, hioresorbahle, and easily shaped to fit bone surface to maintain desired spa6e near the bone defects around implants. Furiherniore, Poly-L-lactic acid
film (PLLA) has electrical potential when placed under stress. Therefore, we have investigated the use of this film to facilitate bone regeneration around implants.
The aim of this study was to investigate the effectiveness of bioresorbable electrified PLLA as a guided bone regeneration method, to evaluate the electrical potential changes of PLLA due to material hydrolysis, and to determine whether PLLA hydrolysis will alTect bone regeneration.
1) The PLLA groups showed more accelerated bone growth and bone maturity than with the GTAM^<58R> groups in the early stages, especially in the 30*1O^4 Mw group, where a greater amount of bone tissue and Increase of maturity(quantitative and qualitative) was observed.
2) Results of the GTAM^<58R> groups were almost the same as the control group, and inferior to the PLLA groups through all experimental periods.
3) PLLA is easily shaped to fit bone surface to maintain desired space for bone formation above the cortical bone. From these results, PLLA might therefore be used in clinical applications in guided bone regeneration for immediate implant and periodontal intrabony defect, as well as for increasing the width arid height of the alveolar ridge, with no influence on peripheral tissue.
4) Although the amount of electrical potential of PLLA decreased due to absorption according to period, it had no effect on bone regeneration.
5) PLLA underwent hydrolysis, but still remained at 12 and 16 weeks later ; although it was surrounded by fibrous connective tissue, neither acute nor chronic inflammatory signs were observed. Less