Polylactic Acid Membrane as a Sole Treatment for Ridge Preservation

Methods: Patients undergoing extraction with subsequent implant placement were recruited. Teeth in the esthetic zone, molar teeth and extraction sockets without intact bony walls were excluded. Stents were fabricated prior to extraction and measurements of relative alveolar bone crest height and gingival tissue margin position were taken immediately after extraction. Participants were randomly assigned to either experimental (extraction, socket decortication, PLA membrane and soft tissue suturing) or control group (same as experimental without membrane), and scheduled for implant placement after 4-month healing. A core biopsy (2mm diameter x 6mm length) was harvested from the healed socket (central portion) at time of implant placement. Micro-computed tomography (CT), cone beam-CT and histomorphometric analysis will be performed to determine newly formed bone quality when all cores are collected. Measurements of relative alveolar bone crest height and gingival tissue margin position were repeated prior to implant placement. Differences in alveolar crest height (DCH) and gingival margin position (DGM) were calculated. Descriptive statistics are reported.

Results: Preliminary data based on 7 completed subjects (control=3; experimental=4; additional subjects being recruited) show a tendency of more bone preservation in the experimental group. Mean (±sd) DCH was -1.06±0.51mm for the control and 0.29±1.79mm for the experimental group, while mean DGM was 0.94±1.21mm and 0.10±1.39mm, respectively.

Conclusion: Within the limitations of this study, the results indicate that PLA membrane alone may have the ability to preserve alveolar ridge height after tooth extraction.