Comparison of Dimensional Changes Between CAD‐CAM Milled Complete Denture Bases and 3D Printed Complete Denture Bases: An In Vitro Study

Abstract

This study compared the dimensional changes between computer-aided design and computer-aided manufacturing (CAD-CAM) milled complete denture bases (CDBs) and three-dimensional (3D) printed CDBs. Materials and methods: One maxillary completely edentulous stone model was fabricated with three reference points at the incisive papilla, right molar, and left molar areas marked as X, Y, and Z, respectively. It was scanned to produce a standard tessellation language (STL) file, which was imported to a metal milling machine software to produce the metal model. This metal model was used to fabricate 30 CDBs for analysis. The CDBs were divided into three groups (n = 10 each) according to the fabrication method used as follows: Group 1, CAD-CAM milled CDBs; Group 2, 3D printed CDBs; and Group 3, conventional compression molded CDBs. The CDBs of all groups were scanned after fabrication, and the dimensional changes in each were evaluated by two methods. The first was the two-dimensional evaluation method that involved linear measurement of the distances between the reference points (X-Y, X-Z, and Y-Z) of the scanned reference cast and dentures. The second method was the 3D evaluation method that involved the superimposition of the STL files of the dentures on the STL file of the reference cast. Data were calculated and were statistically analyzed using one-way analysis of variance and Tukey's pairwise post hoc tests. Results: There was a significant difference in the dimensional accuracy between the CAD-CAM milled, 3D printed, and conventional compression molded CDBs (p < 0.05). Conclusion:The dimensional accuracy of the CAD-CAM milling system in complete denture fabrication is superior to that of the compression molding and 3D printing systems.

Digital duplication of maxillary complete denture: A dental technique

“…The CAM methods in complete denture construction are either additive manufacturing through 3D printing or subtractive using milling processes 15 . The 3D printed dentures are cheaper but they are used to be temporary dentures due to the low mechanical properties of either 3D printed teeth resin or denture base 13,16 . With the development of 3D printing resin materials by the addition of ceramic fillers,3D printed dentures are now used as permanent dentures.…”

“…With the development of 3D printing resin materials by the addition of ceramic fillers,3D printed dentures are now used as permanent dentures. The two techniques have comparable results in patient satisfaction, although milled dentures have shown slightly better intaglio surface adaptation and dimensional accuracy results in in vitro studies 16–18 . The better mechanical properties of the milled dentures are due to the fact that they are fabricated from pre‐polymerized resin blocks, removing the possibility of dimensional changes 15 …”

“…15 The 3D printed dentures are cheaper but they are used to be temporary dentures due to the low mechanical properties of either 3D printed teeth resin or denture base. 13,16 With the development of 3D printing resin materials by the addition of ceramic fillers,3D printed dentures are now used as permanent dentures. The two techniques have comparable results in patient satisfaction, although milled dentures have shown slightly better intaglio surface adaptation and dimensional accuracy results in in vitro studies.…”

“…The two techniques have comparable results in patient satisfaction, although milled dentures have shown slightly better intaglio surface adaptation and dimensional accuracy results in in vitro studies. [16][17][18] The better mechanical properties of the milled dentures are due to the fact that they are fabricated from prepolymerized resin blocks, removing the possibility of dimensional changes. 15 Takeda et al 6 reported using 3D printing technology for denture duplication.…”

Evaluation of the machinability and machining accuracy of polymer-based CAD/CAM blocks using merlon fracture test model

“…Thus, the obtained fitting accuracies are affected by the friction between the dental prosthesis and abutment, application load, and position of the dental prosthesis 38,39) . On the contrary, a superimposing method between the CAD reference and specimen data has been widely used to perform three-dimensional (3D) shape analysis of the fabricated samples via CAD/CAM systems [40][41][42] . Particularly, this method facilitates a structural analysis of the location of the polymer blanks subjected to machining damage to ascertain the degree of the local position of deformation that is generated while the composite resin blank is being machined.…”