Evaluation of trueness in a denture base fabricated by using CAD-CAM systems and adaptation to the socketed surface of denture base: An in vitro study

Abstract

Statement of problem. Computer-aided design and computer-aided manufacturing (CAD-CAM) systems are increasingly used to fabricate removable complete dentures. However, comparisons and analyses of the trueness and adaptation of the socketed surface of denture bases produced by milling (MIL) and digital light processing (DLP) are lacking. Purpose. The purpose of this in vitro study was to evaluate and compare the trueness and socketed surface adaptation of denture bases fabricated by using additive and subtractive manufacturing. Material and methods. Based on a denture base standard tessellation language (STL) file, a total of 15 denture bases were produced by using DLP (horizontal and vertical direction) and MIL. The intaglio and cameo surfaces of the fabricated denture bases were scanned with a dental scanner. The scanned intaglio and cameo surfaces were overlapped with the corresponding reference denture base STL file for trueness evaluation. In addition, the ridge lap STL file of the diagnostic tooth arrangement, in which reverse normal was performed, was superimposed on the socketed surface of the denture base of all groups to evaluate adaptation. Results. The root mean square (RMS) values of trueness and adaptation showed statistically significant differences (P<.05). For the trueness RMS value of the intaglio surface of the denture base, the MIL-denture base (MDB) group had the lowest value of 150 +/- 6 mu m whereas the vertical denture base (VDB) of the DLP group was the largest with 328 +/- 4 mu m For the trueness RMS value of the cameo surface, the MDB group was the lowest with 50 +/- 1 mu m whereas the VDB group was the largest with 334 +/- 24 mu m For the adaptation RMS value of the socketed surface of the denture base, the MDB group was the lowest with 44 mu m whereas the VDB group was the largest with 117 +/- 2 mu m. Conclusion. Within the limits of this in vitro study, the MDB group showed better trueness and socketed surface adaptation than the DLP groups (HDB and VDB).