Comparison of Reproducibility of Milled Acrylic Resin and Zirconia Models for 3-unit bridge Using Three-dimensional Analysis

Copyright © 2018. The Korean Academy of Oral & Maxillofacial Implantology This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons. org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. OPEN ACCESS Purpose: The objective of this study was to investigate the reproducibility of milled acrylic resin and zirconia models using three-dimensional analysis. Material and Methods: Zirconia discs and acrylic resin blocks were milled to make models. Each model was scanned with a model scanner. The zirconia models were superimposed with other zirconia model, and the acrylic resin models were superimposed with other acrylic resin model threedimensionally. Root-mean-square (RMS) values were obtained. Distances between two superimposed models were measured. Statistical significances were tested using the Mann-Whitney U test and t-test. Results: The RMS values of the zirconia model and the acrylic resin model were not significantly different (p≥0.05). At the premolar site, distances between the zirconia models at the upper axial and at the lower axial wall were significantly smaller than for the acrylic resin models (p<0.05). At the molar site, distance between the zirconia models at the lower axial wall was significantly smaller than for the acrylic resin models (p<0.05). Conclusion: Although there is a difference in reproducibility between the milled acrylic resin model and the zirconia model in the localized region, no significant difference was found in the whole model.