Finish-line designs for ceramic crowns: A systematic review and meta-analysis

Different finish-line designs have been advocated for tooth preparations of ceramic crowns. However, scientific evidence is lacking to help clinicians make a proper selection.

The purpose of this systematic review and meta-analysis was to evaluate the effects of finish-line designs on the marginal and internal adaptations of ceramic crowns.

This report follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The literature search was conducted in MEDLINE via the PubMed, Embase, and Web of Science databases with no publication year or language limits. In vitro studies comparing the marginal and internal adaptations of ceramic crowns with rounded shoulder and chamfer finish lines were included in the meta-analysis.

Sixteen studies were included in the qualitative synthesis and meta-analyses. Statistical analyses were conducted using the Review Manager Software. Meta-analyses were performed with random-effects models (α=.05). Ceramic crowns with rounded shoulders exhibited significantly better marginal adaptation than those with chamfers (P<.001; mean difference=-7.8; 95% confidence interval=-11.6 to -4.1). Moreover, ceramic crowns with chamfers exhibited significantly better internal adaptation than those with rounded shoulders (P=.020; mean difference=35.0; 95% confidence interval=6.5 to 63.5).

The difference in marginal adaptation of ceramic crowns using 2 finish-line designs was small, and the clinical significance was low, whereas the results of internal adaptation favored the chamfer finish line.