Comparative evaluation of hybrid resin polymer crowns versus preformed metal crowns in primary molars of children aged 3-7 years: a prospective parallel-group clinical study.

PURPOSE: Early childhood caries (ECC) is a prevalent condition affecting preschool children worldwide. Although preformed metal crowns (PMCs) are considered the gold standard for restoring primary teeth, their poor aesthetics remain a concern. Hybrid resin polymer crowns (HRPCs; BioFlx, Kids-e-Dental LLP), have been developed to address this limitation. The present study aimed to compare the clinical effectiveness of HRPCs and PMCs in children aged 3-7 years. METHODS: This prospective parallel-group clinical study included 60 children divided into two parallel groups receiving either PMCs or HRPCs. Clinical parameters assessed were retention, marginal integrity, gingival inflammation, plaque accumulation, occlusal wear, proximal contact, resistance to displacement, and parental satisfaction. Evaluations were conducted at 3, 6, and 9 months, and data were analysed using the chi-square test (p < 0.05). RESULTS: No statistically significant differences were observed between groups in retention, marginal integrity, secondary caries, resistance to displacement, or proximal contact (p > 0.05). However, gingival inflammation and plaque accumulation were significantly higher in the HRPC group at 6 and 9 months. Additionally, crown wear and anatomical form were better preserved in the PMC group. Parental satisfaction was slightly higher for HRPCs, though not statistically significant. CONCLUSION: Both crown types showed acceptable clinical performance. While PMCs demonstrated superior durability and periodontal outcomes, HRPCs offered better aesthetics and greater parental preference. HRPCs may serve as a suitable alternative when aesthetics are prioritized. Further long-term studies with larger sample sizes are recommended.