Comparative Evaluation of Augmentation Stability of L-Shaped Collagenated Soft Block Bone with Physically Crosslinked and Non-Crosslinked Collagen Membranes: A Retrospective Observational Cohort Study

Background/Objectives: The aim of this study was to compare the augmentation stability and clinical outcomes of L-shaped collagenated soft block bone substitutes (BBS) used in combination with either a self-assembly technology (SAT)-based physically crosslinked resorbable collagen membrane (RCM) or a conventional non-crosslinked RCM for peri-implant dehiscence defects. Methods: This retrospective cohort study included 30 patients who underwent guided bone regeneration (GBR) with simultaneous implant placement. The patients were treated with either a physically crosslinked membrane (PCM group, n = 15) or a non-crosslinked membrane (NCM group, n = 15). Clinical, radiographic, and profilometric parameters were evaluated at baseline, immediately post-GBR, and at re-entry surgery. Early wound healing complications and patient-reported outcomes were also assessed. Results: Both groups achieved significant defect resolution without severe adverse events. The mean reductions in defect width and height were 4.47 ± 1.82 mm (92.9%) and 4.07 ± 2.19 mm (89.4%) in the PCM group and 3.80 ± 1.59 mm (89.5%) and 4.13 ± 1.64 mm (86.9%) in the NCM group, respectively. Both groups showed comparable dimensional changes in hard and soft tissues, with no statistically significant differences in radiographic or profilometric outcomes. The incidence of wound healing complications, as well as patient-reported postoperative pain and swelling, were similar between the groups. Conclusions: Within the limitations of this retrospective pilot cohort study, SAT-based physically crosslinked RCMs used in combination with L-shaped soft BBS demonstrated clinical, radiographic, profilometric, and patient-reported outcomes similar to those observed with conventional non-crosslinked RCMs, without major short-term postoperative complications. These preliminary findings suggest that SAT-based RCMs may represent a feasible membrane option for GBR; however, these findings should be interpreted as preliminary and hypothesis-generating and should be confirmed in larger, adequately powered prospective clinical studies.