A Comparative Study of Marginal Adaptation between Monolithic and Layered Zirconia Crowns: A Literature Review

Marginal adaptation highly affects the long-term success of crowns. This study intends to investigate the marginal adaptation of monolithic zirconia and veneered zirconia crowns.

Based on our searches in PubMed and Google Scholar from 2011 to 2020, 22 articles were obtained, and after studying their full-texts. Five articles that were most related to our subject were selected. 

In almost all articles, the greatest mean marginal gap value was recorded for monolithic zirconia, whereas layered zirconia crowns demonstrated the lowest mean marginal gap values. 

  Based on finding of the current study, monolithic zirconia restorations had a superior marginal adaptation than layered zirconia restorations. However, clinically both restorations have an acceptable marginal fit