[In vivo degradation of PDLLA membrane made in China:a study on rats]
OBJECTIVE:The possibility of absorbable membrane materials poly PDLLA using in guided tissue regeneration(GTR)was evaluated through degradation in vivo. METHODS: membranes were implanted in the drosal subcutis of rats for periods of 1,2,4,8,12weeks.The surface morphology was observed,the mass loss was measured and molecular weight was determined with gel permeation chromatography(GPC). RESULTS: The mass loss were similar to those in virto,and molecular weight changes were the same to those in vitro,but the number average molecular weight did not fit the Pitt's model. CONCLUSION: The surface morphology of PDLLA membrane remained relatively unaltered,its integrity kept more than 12 weeks,which could meet the requirements of GTR.
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Department of Oral and Maxillofacial Surgery, School of Stomatology, hanghai Second Medical University.Shanghai 200011, China.