Statistical analysis
The sample size for the study was calculated using G Power V3.1.8 software based on the results of a previous study [Data were analyzed with SPSS 23.0 software (SPSS Inc., Chicago, IL, USA). Shapiro-Wilk test was used to determine the normality of distribution. Differences between numerical measurements and time points were analysed with one-way analysis of variance for repeated measurements when the assumption of normality was satisfied, otherwise, analysed with the Friedman test. Differences in numerical measurements between crown types were analysed with Student’s t test when the assumption of normality was provided, otherwise, the Mann-Whitney U test was used. Chi-square test, Fisher’s Exact test, or Fisher Freeman-Halton test were used to determine the differences between the categorical variables (e.g., retention, marginal adaptation) of the test groups. Kaplan–Meier analysis was used to evaluate the cumulative survival rates of the crowns.All clinical assessments were performed by two calibrated pediatric residents. Cohen’s kappa test was used to assess intra- and inter-examiner reliability. In case of disagreement, a consensus scoring was made. For all statistical tests, p < 0.05 was considered statistically significant.