Hang-Nga Mai1, Kyu-Bok Lee2, Du-Hyeong Lee3. 1. Graduate student, Department of Prosthodontics, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea. 2. Professor, Department of Prosthodontics, School of Dentistry, A3DI, Kyungpook National University, Daegu, Republic of Korea. 3. Assistant Professor, Department of Prosthodontics, School of Dentistry, A3DI, Kyungpook National University, Daegu, Republic of Korea. Electronic address: deweylee@knu.ac.kr.
Abstract
STATEMENT OF PROBLEM: The fit of interim crowns fabricated using 3-dimensional (3D) printing is unknown. PURPOSE: The purpose of this in vitro study was to evaluate the fit of interim crowns fabricated using photopolymer-jetting 3D printing and to compare it with that of milling and compression molding methods. MATERIAL AND METHODS: Twelve study models were fabricated by making an impression of a metal master model of the mandibular first molar. On each study model, interim crowns (N=36) were fabricated using compression molding (molding group, n=12), milling (milling group, n=12), and 3D polymer-jetting methods. The crowns were prepared as follows: molding group, overimpression technique; milling group, a 5-axis dental milling machine; and polymer-jetting group using a 3D printer. The fit of interim crowns was evaluated in the proximal, marginal, internal axial, and internal occlusal regions by using the image-superimposition and silicone-replica techniques. The Mann-Whitney U test and Kruskal-Wallis tests were used to compare the results among groups (α=.05). RESULTS: Compared with the molding group, the milling and polymer-jetting groups showed more accurate results in the proximal and marginal regions (P<.001). In the axial regions, even though the mean discrepancy was smallest in the molding group, the data showed large deviations. In the occlusal region, the polymer-jetting group was the most accurate, and compared with the other groups, the milling group showed larger internal discrepancies (P<.001). CONCLUSIONS: Polymer-jet 3D printing significantly enhanced the fit of interim crowns, particularly in the occlusal region.
STATEMENT OF PROBLEM: The fit of interim crowns fabricated using 3-dimensional (3D) printing is unknown. PURPOSE: The purpose of this in vitro study was to evaluate the fit of interim crowns fabricated using photopolymer-jetting 3D printing and to compare it with that of milling and compression molding methods. MATERIAL AND METHODS: Twelve study models were fabricated by making an impression of a metal master model of the mandibular first molar. On each study model, interim crowns (N=36) were fabricated using compression molding (molding group, n=12), milling (milling group, n=12), and 3D polymer-jetting methods. The crowns were prepared as follows: molding group, overimpression technique; milling group, a 5-axis dental milling machine; and polymer-jetting group using a 3D printer. The fit of interim crowns was evaluated in the proximal, marginal, internal axial, and internal occlusal regions by using the image-superimposition and silicone-replica techniques. The Mann-Whitney U test and Kruskal-Wallis tests were used to compare the results among groups (α=.05). RESULTS: Compared with the molding group, the milling and polymer-jetting groups showed more accurate results in the proximal and marginal regions (P<.001). In the axial regions, even though the mean discrepancy was smallest in the molding group, the data showed large deviations. In the occlusal region, the polymer-jetting group was the most accurate, and compared with the other groups, the milling group showed larger internal discrepancies (P<.001). CONCLUSIONS:Polymer-jet 3D printing significantly enhanced the fit of interim crowns, particularly in the occlusal region.
Authors: Duygu Karasan; Juan Legaz; Philippe Boitelle; Philippe Mojon; Vincent Fehmer; Irena Sailer Journal: J Prosthodont Date: 2022-03 Impact factor: 3.485