ABSTRACT Background: The incorporation of digital techniques has gained popularity in the fabrication of fixed dental prostheses (FDPs) over the last decade; however, limited evidence exists regarding the marginal and internal fit when using conventional versus digital impression techniques. This systematic review and meta-analysis aimed to compare the marginal and internal fit of tooth-supported multi-unit FDPs produced from conventional and digital impressions. Materials and Methods: A comprehensive search was conducted in electronic databases, including Cochrane Library, PubMed, and Scopus. A meta-analysis was conducted using the standardized mean differences (SMDs) to quantify the effect sizes. Results: Fourteen studies, three randomized controlled trials (RCTs) and 11 in vitro were included in the review, all complying with the inclusion criteria. The meta-analysis revealed that multi-unit FDPs fabricated using digital impressions generally exhibited improved marginal and internal fit compared with those produced using conventional impressions. In the RCT subgroup, digital impressions showed a trend toward improved marginal fit (SMD: −0.25; 95% confidence interval CI: −0.64–0.14) and statistically significant improvement for internal fit (SMD: −0.15; 95% CI: −0.55 to −0.24). In contrast, in vitro studies demonstrated statistically significant superiority of digital impressions for both marginal fit (SMD: −0.81; 95% CI: −1.06, −0.56) and internal fit (SMD: −0.52; 95% CI: −0.79 to −0.24). Conclusion: Although digitalized impressions demonstrated statistically superior marginal and internal fit compared with conventional impressions, the observed differences should be interpreted with caution. Most outcomes remained within clinically acceptable limits. Among the intraoral scanners, the Trios system showed a trend toward improved marginal fit.
Sinha et al. (Wed,) studied this question.