Evaluation of surface roughness of differently manufactured denture base materials

The popularity of computer-aided design and computer-aided manufacturing (CAD-CAM) dentures has led to the introduction of new denture materials and resins. However, studies on the surface characteristics of these materials and how they compare to dentures fabricated by more traditional methods are lacking.

The purpose of this cross-sectional study was to determine whether the surface roughness (Ra) of denture base materials differed based on manufacturing technique.

Disks of Ø10×2-mm (n=10) were fabricated using 6 different manufacturing techniques, including compression molding (Lucitone 199), injection molding (Ivocap High Impact), Computer Numerical Control (CNC) milling (Ivotion Base), and additive manufacturing on the Carbon M2 (Lucitone Digital Print), the SprintRay Pro55 S (Dentca Denture Base II), and the Envision One (Flexcera Base) systems. An automatic, noncontact laser confocal microscope (VK-X1000 Series; KEYENCE) was used to analyze the Ra surface roughness of each specimen at ×5 magnification. The images were imported into a multifile analyzer, horizontal and vertical roughness profiles were inserted into each scan, and Ra values were calculated and averaged by following the International Organization for Standardization (ISO) 4287 standard. A 1-way analysis of variance (ANOVA) was performed to compare the effect of manufacturing technique on surface roughness, followed by the Tukey multiple comparisons test (α=.05).

The additively manufactured Dentca Denture Base II (AM-DB) exhibited a statistically significantly higher Ra when compared with the other test groups (P<.001). The additively manufactured Flexcera Base (AM-FB) showed a higher Ra mean value when compared with injection molding (IM) (P=.036). No statistically significant difference in surface roughness was found among the other tested materials representing the different processing methods (P>.05).

The manufacturing method influences the Ra of denture base materials with varying results. The injection molding method resulted in the smoothest surface compared with additively manufactured and CNC-milled denture base materials.