(11) Comparative Histological Assessment Following Ridge Preservation Using a Composite Bovine Derived Xenograft Versus an Alloplast Hydroxyapatite-Sugar Cross-Linked Collagen Matrix

Introduction: This randomized controlled trial was designed to evaluate the histological wound healing and alveolar ridge dimensional changes following ridge preservation using two different xenograft/collagen matrices.

Methods: Fifty-four patients each with a non-molar tooth requiring extraction and replacement with a dental implant were enrolled. Teeth extractions were completed with minimal flap reflection and were randomized to receive ridge preservation with either 90% bovine-derived xenograft granules in a 10% porcine collagen matrix (Group A) or a sponge-like matrix of 80% microparticulate hydroxyapatite alloplast graft with 20% sugar cross-linked porcine type 1 collagen (Group B). After 16 weeks of healing and at the time of implant placement, a bone core biopsy was harvested for histological analysis, followed by dental implant placement. Ridge width 4mm apical from the bony crest and buccal and lingual ridge height were measured at both surgeries utilizing a customized acrylic stent for repeated clinical measurements of the alveolar ridge.
To the authors’ knowledge, this is the first human study that evaluated the test product, Group B, for ridge preservation. The product is unique due to its proprietary Glymatrix(TM) technology for collagen cross-linking. This technology includes non-enzymatic glycation of the collagen with non-toxic natural reducing sugars that cross-link the collagen forming the graft matrix.
The primary histological outcomes evaluated were percent (%) vital bone formation and connective tissue (CT)/other (fibrous tissue and marrow space). Secondary outcomes included the change in alveolar ridge width and the buccal and lingual ridge height. Statistical analysis was completed with two-sample t-test and Fisher’s exact test.

Results: Forty-four patients completed the study, 23 in group A and 21 in group B. Group B presented with statistically significantly (p = 0.02) more % vital bone (39.3 ± 17.8) than group A (26.8 ± 15.8). No statistically significant difference was observed for changes in alveolar ridge dimensions.

Conclusions: Group B, when used for ridge preservation, yields statistically significantly more vital bone over a 4-month healing period. Ridge dimension changes were similar between the two groups and were adequate for implant placement.

Lead Author’s Contributions to the Research Project: The lead author contributed to design, data acquisition and interpretation, and composition of the abstract.