Evaluation of Tooth Reduction for Prefabricated Zirconia Crowns in Primary First Molars Using 3D Scanner

The aim of this study was to quantitatively evaluate the amount of tooth reduction required for prefabricated zirconia crowns (PZCs) of maxillary and mandibular primary first molars by evaluating different areas of the tooth. A total of 271 intact primary first molars were scanned using a 3D scanner, and PZCs were virtually superimposed to analyze the amount of tooth reduction. The results indicated that in the maxillary primary first molars, more reduction was required on the buccal occlusal surface compared to the lingual occlusal surface, whereas in the mandibular primary first molars, a similar amount of reduction was required on both buccal and lingual occlusal surfaces. For the axial surfaces, the maxillary primary first molars required the most reduction on the lingual surface than buccal and proximal surfaces, whereas the mandibular primary molars required significantly less reduction on the lingual surface. Additionally, a trend was observed where larger crowns required less reduction on the buccal and lingual surfaces. This study provides detailed guidelines on the required amount of reduction for PZC restorations, contributing to more efficient preparation in clinical practice.