Biocompatibility and resorbability of a polylactic acid membrane for periodontal guided tissue regeneration.

The biocompatibility and degradation processes of biomembranes made of a mixture of a high molecular weight racemic polylactic acid (PLA50P) with 0, 10, 20 and 30% w/w racemic polylactic acid oligomers (PLA50p) were assessed for morphological changes in subcutaneous abdominal membrane implantations after 15, 21, 30 and 60 d in 45 Wistar rats. These membranes, prepared for periodontal guided tissue regeneration, showed excellent tissue tolerance without an inflammatory reaction. The higher the content in low molecular weight polylactic acid, the higher the degradation rate. At 60 d, the resorption process was almost complete. This process was initiated by outgrowths of short vascular septa, which developed into lobular networks infiltrating the membranes, which were progressively replaced by normal fibrous connective tissue.