Marginal adaptation of CAD-CAM and heat-pressed lithium disilicate crowns: A systematic review and meta-analysis

Abstract

Statement of problem: Lithium disilicate crowns can be manufactured by computer-aided design and computer-aided manufacturing (CAD-CAM) or with the heat-pressed technique. The outcome of studies comparing the effect of the manufacturing method on the marginal adaptation of these crowns is not clear.

Purpose: The purpose of this systematic review and meta-analysis was to investigate the effect of the CAD-CAM system and pressing technique on the marginal adaptation of lithium disilicate crowns.

Material and methods: This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A literature research was conducted in MEDLINE via PubMed and Scopus databases, relevant journal sites, and the authors' collected references, from January 2009 to April 2019.

Results: The electronic and manual searches that could be read in full totaled 24 studies; of which, 9 were included in the systematic review and meta-analysis, 7 of which were in vitro and 2 in vivo. Statistical analyses were conducted by using Review Manager software program. Meta-analyses were performed with the random effects model (α=.05). In vitro studies showed no difference in the manufacturing (P>.001; 95% confidence interval -0.687 to 0.632), and no significant difference was found for in vivo studies (P=.7, 95% confidence interval 0.00 to 54.77). In the joint analysis of the in vivo and in vitro articles, there was a significant difference between the manufacturing methods (P<.001).

Conclusions: Differences were detected between the marginal adaptation of lithium disilicate crowns fabricated with the CAD-CAM system and the pressing technique, but the accuracy values were clinically acceptable.