Evaluation of the marginal fit of lithium disilicate single crowns fabricated with the conventional (Emax press) and the CAD/CAM (Emax CAD) method: A systematic review and meta-analysis.

The purpose of this systematic review and meta-analysis is to evaluate the marginal adaptation of single unit full coverage lithium disilicate fixed dental restorations fabricated with the conventional heat pressed technique and the digital CAD/CAM workflow.This study is according to the Preferred Reporting Items for Systematic Reviews and Meta- Analyses (PRISMA) statement. study research was conducted in MEDLINE via PubMed and Cochrane Library databases together with a hand search of studies published until June 2022. The search terms were combining suitable Medical Subject Headings (MeSH terms) together with free text words in single or multiple conjunctions. A modified methodological index was used to assess the risk of bias of the included studies. A random effect model was applied to pool the effect estimates, and further assessment of the heterogeneity across studies using the Q test and the I2 metric was conducted. All statistical analyses were performed using Rstudio software, version 4.1.2, using the "meta" package.The electronic search and hand search identified 51 articles. Eighteen met the inclusion criteria and were included in the systematic review, 17 of which were in vitro and only one was an in vivo study. However, 17 of the initial 18 could be included in the meta-analysis, due to lack of statistical data in one of the in vitro studies. Statistical analyses were conducted by using the Rstudio software program. Meta-analysis was performed with the random effects model (α=.05). No statistical difference was found between the two fabrication methods (p-value=0.49).Although the mean marginal adaptation of lithium disilicate single crowns was found to be better with the heat-pressed technique, there was no statistical significance with the CAD/CAM fabricated restorations and both resulted in a clinically acceptable result. Nonetheless, more clinical studies are needed for safer conclusions.