Neo-osteogenesis using an intentionally exposed polypropylene membrane after tooth extraction versus guided bone regeneration technique: a single-blind randomized controlled trial

Introduction: The intentionally exposed polypropylene (PP) membrane has been proposed for guided bone regeneration (GBR) of the alveolar bone after extraction; however, there are biological limitations to this proposal. This study aimed to describe the effects of the PP membrane on neo-osteogenesis after tooth extraction, comparing to intentionally exposed and primary soft tissue coverage techniques. Methodology: This clinical trial followed the TIDieR checklist and guide. Clinical and histological parameters of alveolar repair were compared between groups: 1 (control group), without regenerative procedure; 2, GBR; and 3, intentionally exposed membrane. Results: Group 3 showed slight effect on the quality of new bone, compared to the control group. Although the GBR was underestimated by the early exposure of the membrane, alveolar repair and newly formed bone were superior to the other groups. Polypropylene membrane intentionally exposed compromised the volume density of the immature and mineralized bone matrix, the osteoblast and osteocyte count, and stimulated the granulation tissue formation and local inflammatory infiltrate. Conclusions: Despite the exposure of the PP membrane in GBR, this technique improved the quality of new bone and alveolar repair compared to the surgical technique of intentional exposure and alveolus only sutured.