Saori Muta1, Masaomi Ikeda2, Toru Nikaido3, Mahmoud Sayed1, Alireza Sadr4, Tetsuya Suzuki5, Junji Tagami1. 1. Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bukyo-ku, Tokyo 113-8549, Japan. 2. Oral Prosthetic Engineering, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan. Electronic address: ikeda.csoe@tmd.ac.jp. 3. Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bukyo-ku, Tokyo 113-8549, Japan; Department of Operative Dentistry, Division of Oral Functional Science and Rehabilitation, School of Dentistry, Asahi University, 1851 Hozumi, Mizuho-city, Gifu 501-0296, Japan. 4. Department of Restorative Dentistry, University of Washington School of Dentistry, 1959 NE Pacific St. Box 357456, Seattle, WA 98195-7456, USA. 5. Oral Prosthetic Engineering, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
Abstract
PURPOSE: The purpose of this study was to evaluate the dimensional accuracy of crowns fabricated using a polyvinyl alcohol (PVA) dental model. METHODS: An intraoral scanner (LAVA TDS) was used to scan a prepared molar abutment as a master model. The STL file obtained from the scanning process was transferred into the FDM 3D printer (Value 3D Magix MF-1000) and then models were fabricated with PVA filament. In order to compare with the conventional method, an impression of the master model was taken using silicone impression material to fabricate the conventional stone cast model (Conv). An indirect resin composite (Gradia) and self-cured acrylic resin (Curergrace) were used to fabricate crowns (n = 20) according to the manufacturer's instructions. Surface accuracy of the Conv and PVA models and internal accuracy of the crowns set on the models were measured using two methods; 3D digital analysis and silicon-fitting evaluation. Statistical analysis of the results was done using t-test and Willcoxon signed rank test with Bonferroni correction at 5% significance. RESULTS: Digital analysis showed the Root Mean Square (RMS) value of PVA model surface was higher than that of Conv, while there was no significant difference between the two crown materials. However, the silicon-fitting analysis showed marginal discrepancy of crowns fabricated on PVA model were within 100 µm. CONCLUSION: 3D printed PVA model can be used for chairside crown fabrication with an acceptable accuracy.
PURPOSE: The purpose of this study was to evaluate the dimensional accuracy of crowns fabricated using a polyvinyl alcohol (PVA) dental model. METHODS: An intraoral scanner (LAVA TDS) was used to scan a prepared molar abutment as a master model. The STL file obtained from the scanning process was transferred into the FDM 3D printer (Value 3D Magix MF-1000) and then models were fabricated with PVA filament. In order to compare with the conventional method, an impression of the master model was taken using silicone impression material to fabricate the conventional stone cast model (Conv). An indirect resin composite (Gradia) and self-cured acrylic resin (Curergrace) were used to fabricate crowns (n = 20) according to the manufacturer's instructions. Surface accuracy of the Conv and PVA models and internal accuracy of the crowns set on the models were measured using two methods; 3D digital analysis and silicon-fitting evaluation. Statistical analysis of the results was done using t-test and Willcoxon signed rank test with Bonferroni correction at 5% significance. RESULTS: Digital analysis showed the Root Mean Square (RMS) value of PVA model surface was higher than that of Conv, while there was no significant difference between the two crown materials. However, the silicon-fitting analysis showed marginal discrepancy of crowns fabricated on PVA model were within 100 µm. CONCLUSION: 3D printed PVA model can be used for chairside crown fabrication with an acceptable accuracy.