Alveolar ridge preservation using a non-resorbable membrane: randomized clinical trial with biomolecular analysis

The aim of this randomized clinical trial was to evaluate the newly formed tissues in post-extraction sockets and to compare ridge dimensional changes with and without the use of a dense polytetrafluoroethylene membrane (d-PTFE). Twenty human extraction sockets (lower molars and premolars) received either an intentionally exposed d-PTFE membrane (test group) or no biomaterial (control group). After 4 months, during preparation for implant placement, bone and gingival tissues were collected for histological and biomolecular analysis. Clinically, the test and control groups showed mean gains of keratinized gingiva of 4.30±1.20mm and 2.50±2.20mm, respectively. A reduction in ridge width was observed in the control (2.90±2.70mm) and test (3.30±2.00mm) groups. The bone height alteration ranged from a reduction of 0.12±1.60mm to a gain of 0.60±3.60mm on average for both groups. Analysis of gene expression (OPG/RANKL) in gingival fibroblasts and osteoblasts revealed no difference between the two groups. Ridge preservation using the d-PTFE membrane increased the formation of keratinized tissue. A reduction in width and mild reduction/gain in height of the alveolar ridge was observed in both groups. The membrane had no influence on the healing process.