Healing following ridge preservation using demineralized allograft particles or fibers alone, and combined with xenograft.

backgroundAllografts and xenografts are viable options for alveolar ridge preservation. This study evaluated histologic wound healing when using demineralized freeze-dried bone allograft (DFDBA) alone, in fiber or particulate form, and in combination with xenograft. Alveolar dimensional changes were also evaluated.

methodsThis four-arm, parallel, randomized controlled trial included 120 patients with a nonmolar tooth receiving extraction and ridge preservation who were blindly randomized into one of four groups: DFDBA particulate alone (DCP), DFDBA fibers alone (DCF), xenograft combined with DCP (DPX), and xenograft combined with DCF (DFX). After 18-20 weeks of healing, bone cores were collected for histologic analysis of vital bone, residual allograft, residual xenograft, and connective tissue. Ridge dimensional changes were evaluated with standardized measuring stents.

resultsThere was no difference in mean vital bone formation between DCP (37.33%) and DCF (40.76%) or between DPX (24.46%) or DFX (23.85%), but more vital bone was present when DFDBA in either form was used alone (DCF, DCP) compared to combining with xenograft (DFX, DPX). Significantly less residual allograft was found in DCF (3.57%) compared to DCP (16.5%). Similarly, when combined with xenograft, there was less residual allograft with DFDBA fibers (DFX = 2.19%) than with particles (DPX = 9.88%). No significant differences in alveolar ridge dimensional change were noted between the groups.

conclusionDFDBA fibers resulted in less residual allograft compared to DFDBA particulate. Allograft-alone groups had more vital bone than groups with xenograft, but there was no difference between fiber allograft and particulate allograft alone. CLINICAL TRIAL NUMBER: Clinicaltrials.gov NCT05400213 PLAIN LANGUAGE SUMMARY: Placing a bone graft in the socket after tooth extraction can decrease bone loss during healing in preparation for a dental implant. This study collected histologic wound healing data on human bone graft materials in a fiber and particle form alone and in combination with a cow-derived (bovine) bone graft material. One hundred twenty patients who needed a tooth extracted enrolled in the study, and one of the four bone graft materials was placed in the site. After 18-20 weeks of healing, patients returned for placement of a dental implant. At this time, a bone sample was collected for microscopic examination. Measurements of the bone dimensions at the site were also done. The fiber bone graft material resorbed more rapidly relative to the particulate form, but there was no difference in new bone formed between the fibers and particles. The human bone grafts in either fiber or particle form used alone also formed more new bone than when they were mixed with the bovine bone graft. Clinically, the bone dimensions did not show significant differences between the four groups.