Accuracy and Reproducibility of 3D Printed Dies versus Stone Dies

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) mm 3 as a (mean±SD) and 3D printed model (0.176±0.211) mm 3 as a mean±SD. Conclusion:Digital work flow can eventually replace the conventional techniques with minimal volumetric discrepancies in 3D printed dies.

Effect of printing layer thickness on the trueness and fit of additively manufactured removable dies

“…9 However, physical casts with removable dies are still required, particularly when managing complex treatment plans or to improve esthetics. [8][9][10][11] A digital dental cast can be converted into a physical cast by using either subtractive or additive manufacturing. 12,13 Additive manufacturing has the advantage of fabricating complex structures with less waste material.…”

“…16 Regardless of the manufacturing technique, accurate dental casts are essential to ensure precise prostheses. 1,12 Even though studies have shown that additively manufactured dental casts have an accuracy similar to that of gypsum casts, 4,5,10,[17][18][19][20] conflicting results have been reported. 4 Therefore, knowledge of the factors that affect the accuracy of additively manufactured casts, 21 including layer thickness, is essential.…”

“…However, the authors are unaware of a study that investigated the effect of combining different layer thicknesses in a single fabrication process on the accuracy of removable dies. In addition, among the limited number of studies on the accuracy of additively manufactured removable dies, 7,9,10,14,24,25 only 1 focused on the effect of layer thickness on their properties. 25 Therefore, the present study aimed to evaluate the effect of layer thickness on the trueness of removable dies and their fit into an additively manufactured dentate cast.…”

Análise comparativa da exatidão de modelos para próteses fixas obtidos por fluxo analógico e digital

“…e outro não encontrou diferença com modelos DLP(MAHROUS;ABOULMAGD, 2018). Ainda, outro estudo não encontrou diferença na exatidão de modelos Hoffman; Cho e Bansal 2017 compararam as distâncias interproximais de modelos de gesso e SLA não seccionados e troquelizados obtidos a partir de manequim odontológico contendo preparo para PPF de três elementos e coroa unitária.…”