Evaluation of healing at molar extraction sites with ridge preservation using a non-resorbable dense polytetrafluoroethylene membrane: A four-arm cohort prospective study.

OBJECTIVES: To examine ridge dimensional changes and histologic parameters of healing when ridge preservation (RP) was performed at molar sites using dense polytetrafluoroethylene (dPTFE) membrane alone, without a bone graft. MATERIAL AND METHODS: Eighteen patients had molar extraction and RP using dPTFE membrane alone. Ridge dimensions were measured using two standardized cone beam computerized tomography (CBCT) scans taken within 72 h and 3 months following extraction. Following a 3-month healing period, an implant osteotomy was prepared using a trephine drill and bone cores were collected for histological analysis. Four-arm analyses were performed using data from three previously published study arms of the same research group. RESULTS: There was a significant change in the buccal ridge height between the four groups at all aspects of the socket. Alveolar ridge width reduction at 3 mm from crest for all aspects (mesial, midpoint, distal) of the socket showed statistically significant difference for dPTFE alone group compared to the other three groups. Percentage of vital bone formation (62.10%) was significantly greater in dPTFE alone group compared to the other groups. CONCLUSIONS: RP using dPTFE membrane alone in molar sites with intact socket walls showed successful outcomes in maintaining ridge dimensions and in histologic wound healing.

Evaluation of healing at molar extraction sites with and without ridge preservation: A three-arm histologic analysis.

BACKGROUND: Little evidence is available regarding the benefit of ridge preservation (RP) at molar sites. The primary objective of this three-arm cohort study was to histologically compare the healing outcome between natural healing after molar tooth extraction and two different techniques of RP using freeze-dried bone allograft (FDBA) and a nonresorbable dense polytetrafluoroethylene (dPTFE) membrane, or an absorbable collagen sponge as a barrier. METHODS: Seventy-nine patients requiring extraction and delayed implant placement were placed into three groups: extraction alone (control); ridge preserved using FDBA; and either dPTFE (Test1) or collagen sponge (Test2). Bone cores were harvested from implant osteotomies at ≈3 months after extraction for histomorphometric analysis to determine the percentage of vital bone, residual graft, and connective or other tissue. Ridge dimension changes were also evaluated radiographically (cone-beam computed tomography). RESULTS: The percentage of vital bone was significantly greater in control group compared with Test1 but was not statistically different among other groups. Test2 showed significantly less connective or other tissue than control and Test1. The percentage of residual graft was significantly lower in Test1 compared with Test2. There was no significant correlation between the percentage of vital bone or residual graft and the following parameters: healing time, patient age, gender, buccal plate thickness, or radiographic changes in ridge dimensions. CONCLUSION: RP at molar sites using FDBA and an absorbable collagen sponge may be a sufficient and economic way to preserve the ridge dimension without interfering with the amount of new bone formation.