Mesiodistal Marginal Bone Loss around Implants with Porcine Xenografts: A Preliminary Retrospective Comparison of Collagenous Block and Powder Forms

This study aimed to compare marginal bone level changes around implants placed using two forms of porcine-derived xenografts—particulate and collagen-containing block—and to assess their clinical performance relative to native bone healing. This retrospective study included 267 patients (444 implants) who underwent ridge augmentation or sinus floor elevation using either particulate or collagenous block-type porcine bone grafts. Patients were classified into three groups: collagenous block-type graft for ridge augmentation, powder-type graft for ridge augmentation, and sinus graft without marginal ridge augmentation as the control group. The third group served as a control to assess natural bone healing. Marginal bone loss was measured using standardized periapical radiographs, and implant stability was assessed using ISQ values. Both graft groups demonstrated comparable early and late marginal bone loss without any complications. The collagenous block-type showed lower secondary ISQ values (79.4 ± 8.8 and 82.2 ± 4.9, p=0.006). The control group exhibited the least initial marginal bone loss, despite the absence of marginal grafting, highlighting the natural healing potential of native bone. Porcine-derived grafts, whether in collagenous block or powder form, showed stable peri-implant bone outcomes comparable to sites with no marginal grafting. These findings support their clinical reliability in implant therapy.