Block allograft technique versus standard guided bone regeneration: a randomized clinical trial

Abstract

Purpose: The aim of this randomized clinical trial was to compare the potential of deproteinized bovine bone added to autologous bone or corticocancellous allograft block with or without the addition of recombinant human platelet-derived growth factor-BB (rhPDGF-BB) to regenerate mandibular atrophic ridges.

Trial design: parallel, allocation ratio of 1:1 using a split-mouth model. Eligibility criteria for patients: adult patients; bilateral atrophic edentulous areas in the posterior area of the mandible; a preoperatory cone beam computed tomography scan; and absence of systemic diseases affecting the bone metabolism. Bone graft intervention for control group consisted of bone chips collected with a scraper mixed with deproteinized bovine bone covered with a resorbable membrane. Bone graft intervention for test group consisted of a corticocancellous allograft block, shaped before surgery, and protected with a collagen membrane. In addition, both groups received rhPDGF-BB or a saline solution as control. As primary outcome quantity, bone variation after a 1-year healing period was considered. A p-value of.05 was considered statistically significant.

Results: Sixteen patients were enrolled in this trial. A total of 50 implants and 32 bone grafts were placed. All patients concluded the study (no dropouts). Change at 1 year in bone volume was not significantly different between the two groups (p-value = .25). Effect of treatment in terms of change in bone volume at 1 year was not significant (p-value = .89) when saline solution was used while was at limit of significance when rhPDGF-BB was used (p-value = .052). After 1 year, all the implants were successfully integrated.

Conclusions: The block allograft and the standard regenerative procedure showed similar results in terms of regenerated bone volume after 1 year of functional loading. The rhPDGF-BB positively influenced soft-tissue healing.

Keywords: allograft; augmentation; bone graft; dental implant; guided surgery; resorption.