Clinical Outcomes for Prefabricated Zirconia Crowns in Primary Dentition: A Systematic Review and Meta-Analysis

Purpose: This systematic review and meta-analysis evaluated the clinical outcomes of prefabricated zirconia crowns (PZC) in primary teeth compared to stainless steel crowns (SSCs) and resin-based alternatives over six to 36 months. Methods: PubMed??, Google Scholar™, Web of Science®, Scopus, Embase®, and Cochrane Library® were searched for randomized clinical trials and observational studies. Cochrane risk of bias tool (RoB 2) and ROBINS-I were used for quality assessment. The pooled results were analyzed using either a fixed-effect model or a random-effects model, with the latter applied when heterogeneity was significant (I² >50%). Results: A total of 40 studies were included in the systematic review. Meta-analyses revealed comparable retention between PZCs and controls at six months (relative risk [RR] equals 1.04, 95 percent confidence interval [95% CI] equals 0.99 to 1.09, P=0.233) and 12 months (RR equals 1.03, 95% CI equals 0.98 to 1.08, P=0.11). Zirconia crowns showed non-significant improvement in gingival health (Cohen's d equals 1.85, 95% confidence interval equals -0.25 to 3.95, P=0.081) but significantly reduced plaque retention (RR equals 1.17, 95% confidence interval equals 1.02 to 1.34, P=0.025) at 12 months. Recurrent caries were equivalent (RR equals 1.02, 95% CI equals 0.98 to 1.05, P=0.26) and opposing tooth wear was insignificant (RR equals 0.96, 95% CI equals 0.91 to 1.00, P=0.091) at 12 months. Conclusion: While prefabricated zirconia crowns matched stainless steel crowns and resin-based alternatives in retention, gingival health, opposing tooth wear, and caries prevention, they provided superior outcomes in plaque resistance with moderate-certainty evidence.