Accuracy and Reproducibility of 3D Printed Dies versus Stone Dies

Document Type : Original Article

Authors

1 Lecturer Fixed Prosthodontics Department, Faculty of Dentistry, Fayoum University, Egypt.

2 Lecturer oral Radiology Department, faculty of Dentistry, Fayoum University, Egypt.

Abstract

Statement of the problem: researches studying the accuracy of the 3D printed dies were very rare.
Aim: The aim of the current study was to assess the difference in accuracy and reproducibility of the three dimensionally printed dies versus the stone dies.
Materials& Methods: A maxillary typodont (D13PP-TR.1; Nissan, Kyoto, Japan) model with missing upper 1st molar was prepared as master model. Two types of dies were obtained from the master model (n=6). Group 1 was the conventional stone dies using type IV stone (GC FujiRock EP; GC) while group 2 representing the 3D printed dies (Dent2 Mogassam LLC Co. Egypt, Cairo) using resin (industrial blended resin, Funtodo Co. Netherlands). All working models were scanned (Open Technologies 3D scanner, Brescia, Italy) and STL file was superimposed on the STL file of the master model with the best-fit alignment method to analyze the volumetric changes and color maps were provided using 3Shape 3D software software. The mean average distance between the master dies and the working dies in all groups was recorded. Data were fed to the computer and analyzed using IBM SPSS software package version 20.0. Quantitative data were explored for normality using Kolmogorov-Smirnov and Shapiro-Wilk tests.
Results: There were no statistically significant differences in volumetric discrepancies between stone model (0.186±0.231) mm3 as a (mean±SD) and 3D printed model (0.176±0.211) mm3 as a mean±SD.
Conclusion: Digital work flow can eventually replace the conventional techniques with minimal volumetric discrepancies in 3D printed dies.

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