Effect of Membrane Perforations With and Without Collagen Membrane Coverage in Vertical Ridge Augmentation: An Experimental Pilot In Vivo Study

Abstract

Objectives

Given the proposed bioactive role of collagen membranes, we aimed to evaluate whether the perforation size of titanium-reinforced dPTFE membranes, with or without an additional collagen membrane, influences outcomes of vertical alveolar ridge augmentation (VARA).

Materials and Methods

In 12 beagle dogs (24 sites), standardized bilateral chronic mandibular ridge defects (8 × 30 mm) were created and healed for 12 weeks. Sites were randomized (1:1:1) to VARA using porcine xenograft covered with either: (i) non-perforated titanium-reinforced dPTFE (NON-PERF), (ii) perforated titanium-reinforced dPTFE (PERF), or (iii) perforated titanium-reinforced dPTFE covered by a collagen membrane (PERF+CM). After 16 weeks, specimens underwent micro-CT, histology/histomorphometry, vessel quantification, and immunohistochemistry (OCN, ALP, VEGF, TRAP). Continuous outcomes were summarized as medians and compared using the Kruskal–Wallis test with Dunn's post hoc testing when applicable; inflammatory cell scores were analyzed using ordinal logistic regression (α = 0.05).

Results

Of 24 treated sites, four had complications and were excluded. All remaining sites achieved around 60% new bone area with no significant intergroup differences (new bone p = 0.5047; soft tissue p = 0.2994; residual graft p = 0.9689). Linear vertical gain was comparable (medians 2.33, 2.87, 2.74 mm; p = 0.7119). Micro-CT outcomes did not differ (e.g., BV/TV, p = 0.2739). Ordinal models did not show significant group differences in inflammatory scores; plasma cell scores in PERF+CM versus control were borderline (OR 15.61; p = 0.0587).

Conclusions

Perforated dPTFE membranes yielded comparable bone gain to unperforated dPTFE. Adding a collagen membrane over perforated dPTFE did not improve VARA outcomes.