Bone remodeling around implants placed after socket preservation: a 10-year retrospective radiological study

Background: To evaluate and compare the long-term clinical and radiological outcomes of post-extraction socketsafter ridge preservation either with porcine xenograft or collagen alone. Patients underwent single-tooth extractionin the posterior mandible. Fresh extraction sockets were filled with pre-hydrated cortico-cancellous porcine bone orcollagen sponge. Two or 3 months later, a ridge expansion technique with immediate implant positioningplacement was performed. Primary (alveolar width changes) and secondary outcomes (adverse events and longtermmaintenance of buccal plate covering the implant) were evaluated.Results: Thirty-four women and 20 men were selected: 30 implants (group A) placed into healed post-extractionsockets grafted with porcine bone and 24 (group B) into sockets filled with a collagen sponge. There was asignificant loss in width in both groups from the first and second surgery (ranging between 2.7 mm and 4.5 mm).The ridge splitting with bone expansion resulted in significant long-term increases in width for both proceduresand implant sites. Non-significant differences in alveolar width were registered between the groups at 10-yearfollow-up even if the analysis of the implant buccal bone coverage suggested that group A had significantly worstresults.Conclusions: Porcine bone group had significantly better short-term outcomes with lower long-term maintenanceof the buccal plate.Keywords: Alveolar ridge preservation, Split crest procedure, Xenogeneic bone substitute, Collagen sponge, Dentalimplants