Comparison of Coronal Tooth Reductions Resulting from Different Crown Preparations

Purpose: The aim of this study was to quantify the coronal tooth structure reductions (CTSRs) resulting from a variety of different types of crown preparations performed by undergraduate dental students in a simulation clinic teaching program. Materials and Methods: A total of 76 students each submitted 21 different crown preparations completed on typodont teeth, which were individually weighed and analyzed in relation to whole and sectioned reference teeth to calculate the CTSR resulting from each preparation. Results: The largest CTSR resulted from preparations for porcelain bonded to zirconia crowns (50.6%), followed by those for porcelain bonded to metal (PBM) crowns (44.3%), PBM fixed partial dentures (32.8%), shell crowns (32.5%), and full gold crowns (24.6%). Conclusion: A wide range of CTSRs resulted from the different types of crown preparations investigated in this study. The crown preparations performed by the undergraduate students produced more conservative coronal reductions than comparable crown preparations generated under controlled in vitro conditions.