RESORPTION RATES OF 2 COMMERCIALLY AVAILABLE BIORESORBABLE MEMBRANES - A HISTOMORPHOMETRIC STUDY IN A RABBIT MODEL

The respective resorption rates of recently commercialized collagen ve rsus polylactic acid-citric acid ester membranes were compared. 16 rab bits were implanted with 2 mmx4 mm pieces of membrane of both types in the alveolar mucosa just apically to the incisors on either side of t he mouth. 1 animal was sacrificed on day 0, just after the operation. The others were sacrificed at 1, 2, 3, 5, 7, 9 and 12 weeks. The speci mens were prepared fbr histologic examination. Observations showed tha t the cross-linked collagen membranes induced severe inflammation and were resorbed within 2 weeks. the polylactic acid-citric acid ester po lymer barriers produced a much more moderate infiltrate and were still not totally resorbed at 12 weeks. Although resorption rates in the ra bbit may not be similar to those observed in humans, it seems that the durability of the polymer barrier is more adequate for guided tissue regeneration than the cross-linked collagen.