Efficacy of Xenogeneic Collagen Matrices in Augmenting Peri-Implant Soft Tissue: A Systematic Review and Meta-Analysis

Abstract

Background: Xenogenic collagen matrices (XCMs) are gaining popularity for soft tissue augmentation in dental implants; yet, gaps exist in our understanding of their comparative effectiveness. Objective: This systematic review and meta-analysis focuses on studies that utilize soft tissue augmentation techniques for dental implants to improve keratinized mucosa width (KMW), soft tissue thickness (STT), and soft tissue volume (STV). We compared porcine collagen matrices with autogenous grafts when no bone grafts were utilized. Materials and Methods: We searched databases such as PubMed, Scopus, and the Cochrane Central Register of Controlled Trials for randomized controlled trials and controlled clinical trials published between January 2013 and July 2023 that assessed the efficacy of XCM in peri-implant soft tissue augmentation. The primary outcome included KMW changes while the secondary outcome was STT/STV changes. Statistical analyses were conducted using a random- or fixed-effects model, and heterogeneity was assessed using I2 statistics. Results: Nine studies were included in the qualitative analysis, and six were included in the meta-analysis. No significant intergroup differences were observed (p > 0.05), but a significant difference was observed in favor of KMW ≥ 2 mm. Heterogeneity among the studies varied at the 6- and 12-month follow-ups, with I2 values of 78% and 0%, respectively. The pooled mean difference between the XCM and autograft groups was −0.96 (−1.71 to −0.21), which shows that there was a larger increase in KMW in the autograft group compared with the XCM group (p < 0.05). Conclusions: Collagen matrices are less effective than autogenous grafts at increasing keratinized tissue and STT/STV, but the two techniques yield comparable aesthetic outcomes. Additional studies are necessary to better guide clinical practice and improve patient outcomes.