The Efficancy Evaluation of Zirconia Crown on Primary Molars with Carious Defects

Abstract

Objectives To estimate the therapeutic effects of preformed metal crown (PMC) and prefabricated Nusmile ZR crowns (ZC) on decayed primary morals in children and to analyze the possible influencing factors. Methods A retrospective cohort study was used in this study. A total of 192 patients aged 3 to 8 were recruited in the Stomatological Department of Shenzhen Children's Hospital ranged from October 2021 to October 2023. The decayed mandibular first molars were selected and restored with vital pulp therapy followed by PMC and ZC , including 96 cases (96 caries) in the PMC group and 96 cases (96 caries) in the ZC group. Oral clinical examination was respectively performed at 3 months, 1 year and 2 years after treatment, overwiewing the clinical therapeutic effects and periodontal status of PMC group and ZC group as well as recording the crown integrity, gingival index (GI), probing bleeding index (BI), plaque index (PLI) and various prosthetic indices. Results There were no significance in periodontal status of PMC group and ZC group at 3 months, 1 year and 2 years after treatment (P > 0.05). However, GI, BI and PLI in PMC group were higher than those in ZC group at 3 months, 1 year and 2 years after treatment , and the difference was dramatically significant (P< 0.05). There had no close bearing on various prosthetic indices(P>0.05). There were no significant differences in GI, BI and PLI between the two groups (P > 0.05). There were also no significant differences in various prosthetic indices between genders after PMC restorations (P > 0.05). The scores of girls in various prosthetic indices after ZC restoration were higher than those of boys (P < 0.05). Pearson correlation analysis indicate that there was an inverse correlation between age in PMC group and the GI, BI, PLI and FDI indices (P < 0.01), rather than in NuSmile ZC groups(P> 0.05). Conclusions PMC and ZC can be applied to restore deciduous molar caries . The periodontal status of deciduous teeth in ZC group was superior to that in PMC group. The periodontal status of deciduous teeth in PMC group may be stable as age increased.