A randomized, controlled, multicentre clinical trial of post-extraction alveolar ridge preservation

Aim To compare the effectiveness of two‐ridge preservation treatments. Materials and Methods Forty subjects with extraction sockets exhibiting substantial buccal dehiscences were enrolled and randomized across 10 standardized centres. Treatments were demineralized allograft plus reconstituted and cross‐linked collagen membrane (DFDBA + RECXC) or deproteinized bovine bone mineral with collagen plus native, bilayer collagen membrane (DBBMC + NBCM). Socket dimensions were recorded at baseline and 6 months. Wound closure and soft tissue inflammation were followed post‐operatively, and biopsies were retrieved for histomorphometric analysis at 6 months. Results Primary endpoint: at 6 months, extraction socket horizontal measures were significantly greater for DBBMC + NBCM (average 1.76 mm greater, p = 0.0256). Secondary and Exploratory endpoints: (1) lingual and buccal vertical bone changes were not significantly different between the two treatment modalities, (2) histomorphometric % new bone and % new bone + graft were not significantly different, but significantly more graft remnants remained for DBBMC; (3) at 1 month, incision line gaps were significantly greater and more incision lines remained open for DFDBA + RECXC; (4) higher inflammation at 1 week tended to correlate with lower ridge preservation results; and (5) deeper socket morphologies with thinner bony walls correlated with better ridge preservation. Thirty‐seven of 40 sites had sufficient ridge dimension for implant placement at 6 months; the remainder were DFDBA + RECXC sites. Conclusion DBBMC + NBCM provided better soft tissue healing and ridge preservation for implant placement. Deeper extraction sockets with higher and more intact bony walls responded more favourably to ridge preservation therapy.