Comparison of bioabsorbable and non-resorbable membranes in the treatment of dehiscence-type defects. A histomorphometric study in dogs.

BACKGROUND

The goal of this investigation was to compare, histologically and histometrically, the healing process of dehiscence-type defects treated by guided tissue regeneration (GTR) with bioabsorbable polylactic acid (PLA) membranes and non-resorbable expanded polytetrafluoroethylene (ePTF) membranes.

METHODS

Six mongrel dogs were used. Buccal osseous dehiscences were surgically created on the distal roots of the mandibular third and fourth premolars. The defects were exposed to plaque accumulation for 3 months. After this period, the defects were randomly assigned to one of the treatments: GTR with bioabsorbable membrane (PLA), GTR with non-resorbable membrane (ePTFE), open flap debridement (OFD), and non-treated control (NTC). After 3 months of healing, the dogs were sacrificed and the blocks were processed. The histometric parameters evaluated included: gingival recession, epithelial length, connective tissue adaptation, new cementum, and new bone area.

RESULTS

A superior length of new cementum was observed in the sites treated by GTR, regardless of the type of barrier used, in comparison with OFD (P <0.05). No statistically significant differences were found between PLA and ePTFE in any of the parameters with the exception of bone area. PLA presented a greater bone area when compared to ePTFE, OFD, and NTC (P <0.05).

CONCLUSIONS

Within the limits of this study, it can be concluded that both barriers are equally effective for new cementum formation. The bioabsorbable membrane may provide a greater bone area than the non-resorbable membrane.