Xenogeneic blocks match autogenous bone at 4 years — except in the esthetic zone

Can a ready-to-use xenogeneic block spare the patient a bone harvest? This four-year follow-up of a randomized controlled trial re-evaluated 20 patients who had undergone lateral ridge augmentation with collagenated xenogeneic bone blocks (CXBB, n=11) or autogenous bone blocks (ABB, n=9), with implants placed after 30 weeks of healing. Outcomes were implant survival and success, peri-implant clinical parameters, Pink Esthetic Score (PES) and patient-reported outcomes (OHIP-14).

Both grafting strategies performed well at four years. Implant survival was high in both groups, with a single late failure in the autogenous group and no statistically significant difference in survival or success between CXBB and ABB. Peri-implant tissues were healthy in both, again without significant between-group differences. Esthetics told a more nuanced story: overall PES was similar, but the autogenous group scored significantly higher for soft-tissue level and contour, a reminder that autogenous bone retains an edge where tissue architecture is more demanding. Patient-reported satisfaction (OHIP-14) was comparable.

The conclusion is pragmatic. For staged lateral ridge augmentation, the collagenated xenogeneic block delivers clinical and patient-reported results on par with autogenous bone while avoiding a second surgical site and its morbidity. Autogenous bone may remain preferable in the esthetic zone, where soft-tissue level and contour matter. The main limitation is sample size, 20 patients split across two arms, so these results should be read as an encouraging signal rather than definitive proof, pending confirmation in larger cohorts.