Effect of zinc-modified dental implants on osseointegration outcomes: a systematic review and meta-analysis of preclinical animal studies

Surface modification for dental implants has been generally studied to enhance osseointegration. Though, the beneficial effects of zinc-modified implants remain debatable depending on preclinical studies that present very different results. Consequently, the purpose of this systematic review and meta-analysis was to assess the effects of zinc-modified titanium implants on osseointegration. According to the PRISMA 2020 guidelines, an electronic search was conducted using PubMed, Scopus, and Web of Science to identify animal studies that evaluated the effect of zinc modified titanium implants on osseointegration. The included studies were evaluated based on the ratio of bone-to-implant contact (BIC), bone area (BA), and bone volume/total volume (BV/TV). Reporting quality was evaluated using ARRIVE 2.0 and the SYRCLE Risk of Bias tool, respectively. A total of 16 studies were identified and included in the review. Compared with zinc-free Ti implants, zinc-modified implants showed significantly greater BIC (Z = 3.89, P < 0.001), BA (Z = 8.40, P < 0.001), and BV/TV (Z = 5.43, P < 0.001). Although there was considerable heterogeneity, the overall effect consistently favored zinc-modified surfaces. Within the limitations of the available data from preclinical studies, implant surfaces modified with zinc were associated with improved histomorphometric indicators of osseointegration. However, there were significant methodological variations among the studies and lack of evidence of clinical relevance and hence a need for well-designed clinical studies.