Histological and dimensional changes of the alveolar ridge following tooth extraction when using collagen matrix and collagen‐embedded xenogenic bone substitute: A randomized clinical trial

AIM: To assess the horizontal and vertical dimensional changes of the alveolar ridge when using a collagen matrix in combination with collagen embedded xenogenic bone substitute, in comparison with natural healing after tooth extraction. METHODS: Patients that required extraction in non‐molars areas were included. Test group‐15 sockets were treated with deproteinized bovine bone mineral containing 10% collagen (DBBM‐C), covered by a procaine collagen membrane (CMXs). Control group‐15 sockets left for spontaneous healing. We used a custom‐made acrylic stent as a reference for alveolar ridge measurements. Six‐month postoperative, a single implant was placed in the experimental site. A core biopsy was taken from the site, using a trephine bur. Histomorphometric analysis assessed bone area, connective tissue, bone marrow, and residual bone graft. RESULTS: Six months later, horizontal ridge width at −3 mm showed a significant (p < 0.05) reduction in both groups albeit smaller in the test group 1.19 ± 1.55 mm, compared with the control 2.27 ± 1.52 (p = 0.087). At −5 mm sub‐crestally, statistically non‐significant reduction was noted in both groups, 1.61 ± 1.53 and 1.96 ± 1.52 mm for the test and control groups, respectively (p = 0.542). Vertical changes were smaller in the test group (0.14 ± 1.84 mm) compared with control (0.98 ± 1.49 mm). Keratinized tissue (KT) width was 7.3 ± 2.13 and 7.5 ± 3.49 mm in the test and control groups, respectively. Newly formed bone occupied 33.79 ± 17.37% and 51.14 ± 23.04% in the test and control groups, respectively, (p = 0.11). Connective tissue volume was 33.74 ± 13.81% and 30.12 ± 18.32% in the test and control groups, respectively (p = 0.65). Bone marrow occupied 19.57 ± 10.26% and 18.74 ± 17.15% in the test and control groups, respectively (p = 0.91). Residual graft occupied 12.9 ± 9.88% in the test group. CONCLUSION: Alveolar ridge preservation using DBBM‐C resulted in reductions of the vertical and horizontal dimensions albeit not reaching statistical significance. The larger than anticipated standard deviation and smaller inter‐group differences might account for this phenomenon.