Survival Rates of Full Coronal Restorations in Primary Maxillary Incisors

Abstract

Purpose: The purpose of this study was to compare the survival rates of zirconia crowns (ZC) with that of resin strip crowns (RSC) on primary maxillary incisors of children diagnosed with ECC with a minimum follow-up period of 12 months in a university pediatric dental clinic. Methods: Inclusion/exclusion criteria included primary maxillary incisors that received a RSC or ZC in children (24 to 60 months of age) under general anesthesia (N=587). For this longitudinal study, data collection included demographics, baseline dmft, date of crown placement, age of patient at crown placement, tooth number(s) treated, tooth type, and restoration type. Variables collected at follow-up appointments included appointment dates, survival of crown or category of failure, and secondary treatments completed for restoration failures. Descriptive statistics were calculated for all variables while Kaplan-Meier survival curves were used to summarize success of each crown type. Unadjusted and adjusted hazard ratios (HR) from Cox Proportional Hazard Regression with robust standard errors were used to compare survival rates for variables of interest (P<0.05). Results: The overall survival rates for RSCs at 12-, 24-, and 36-months were 98 percent, 89 percent, and 81 percent, respectively. The overall survival rates for ZCs at 12-, 24-, and 36-months were 93 percent, 81 percent, and 72 percent, respectively. Both RSCs and ZCs placed on teeth in patients between 49 and 60 months of age were associated with higher survival probabilities than when placed in children of younger age groups. Conclusion: Both RSCs and ZCs exhibited clinically acceptable survival rates at 12-, 24-, and 36-months post-treatment. Acceptable patient behavior and adequate isolation are important for long-term success of RSCs.