Comparative Evaluation of the Survival Rates of Zirconia Crown and Stainless Steel Crown for Proximal Caries in Primary Molars: a Retrospective Study

Abstract

Due to increasing demand for aesthetics, zirconia crowns have become a popular choice for treating primary molars. However, there is limited literature available comparing the survival rates of zirconia crowns with those of other restorative materials. The objective of this study was to compare the 36-month survival rates of zirconia crowns and stainless steel crowns for proximal caries, as well as to analyze failure types associated with each crown type. Electronic medical records and radiographs of 1,061 primary molars from 498 patients treated with 2 types of prefabricated crowns at Chosun University Dental Hospital and 2 private dental clinics between 2017 and 2019 were collected and analyzed. The survival rate of zirconia crowns was found to be lower compared to that of stainless steel crowns. Regarding the groups without pulp treatment, the survival rate of stainless steel crowns was significantly higher than that of zirconia crowns. However, in the groups that received pulp therapy, no significant difference in the survival rates was observed between the two preformed crowns. Notably, abnormal root resorption or periapical lesions were identified as the primary cause of restorative failure in stainless steel crowns, whereas loss of restoration was the predominant cause in zirconia crowns. This study holds valuable implications for clinicians when selecting preformed crowns for primary molars.