The topical literature lacks any comparison between stereolithography (SLA) and direct light processing (DLP) printing methods with regard to the accuracy of complete denture base fabrication, thereby utilizing materials certified for this purpose. In order to investigate this aspect, 15 denture bases were printed with SLA and DLP methods using three build angles: 0°, 45° and 90°. The dentures were digitalized using a laboratory scanner (D2000, 3Shape) and analyzed in analyzing software (Geomagic Control X, 3D systems). Differences between 3D datasets were measured using the root mean square (RMS) value for trueness and precision and mean and maximum deviations were obtained for each denture base. The data were statistically analyzed using two-way ANOVA and Tukey’s multiple comparison test. A heat map was generated to display the locations of the deviations within the intaglio surface. The overall tendency indicated that SLA denture bases had significantly higher trueness for most build angles compared to DLP (p < 0.001). The 90° build angle may provide the best trueness for both SLA and DLP. With regard to precision, statistically significant differences were found in the build angles only. Higher precision was revealed in the DLP angle of 0° in comparison to the 45° and 90° angles.

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(1) Background: To date, no information on the polishability of milled and 3D-printed complete denture bases has been provided, which is relevant in terms of plaque accumulation. (2) Methods: three groups (n = 30) were manufactured using the cold-polymerization polymethilmethacrilate, milling (SM) and 3D printing (AM). 10 specimens of each group were left untreated (reference). 10 more specimens were pre-polished (intermediate polishing) and 10 final specimens were highgloss polished. An additional 20 specimens were 3D printed and coated with the liquid resin (coated), 10 of which were additionally polished (coated + polished). For each group Ra and Rz values, gloss value and REM images were obtained. (3). The “highgloss-polished” specimens showed statistically lower Ra and Rz values in the SM, followed by AM and conventional groups. In the AM group statistically lower surfaces roughness was revealed for highgloss-polished, “coated + polished”, and “coated” specimens, respectively. (4) Conclusions: The milled specimens demonstrated superiors surface characteristics than 3D printed and conventionally produced after polishing. The polished specimens demonstrated superior surface characteristics over coated specimens. However, the surface roughness by both polished and coated specimens was within the clinically relevant threshold of 0.2 µm.

Additive manufacturing is a breakthrough technology used in digital dentistry that offers an efficient, accurate, and customized approach to the fabrication of denture bases [1,2]. Among the various additive manufacturing technologies, vat photopolymerization is a widely used process, in which a liquid photopolymer is selectively cured by radiation/light in a controlled manner[3]. Digital light processing (DLP) is one of the most promising technologies for denture base fabrication owing to its advantages, which include rapid processing and high resolution[4]. Previous studies have demonstrated that DLP-printed denture bases possess sufficient physical proper-ties[5], favorable reparability[6], superior denture base adaption[7], and high patient satisfaction[1,2]. Nevertheless, considering their clinical applications, the material properties and related microbial adhesion of DLP-printed dentures are mainly determined by the printing parameters, supporting structures, and post-processing procedures[8].Denture stomatitis presents mucosal inflammation mainly caused by a yeast infection, affecting up to half of the diagnosed patients [9]. Among the microorganisms, Candida albicans (C. albicans) is regarded as a critical opportunistic pathogen that is frequently observed in the biofilms of stomatitis patients [9,10]. More importantly, the surface characteristics of denture bases determine the initial microbial adhesion and biofilm formation, leading to the development of stomatitis [10,11]. Notably, the impression (intaglio) surface of 3Dprinted dentures is not recommended for any mechanical grinding and polishing, lest they adversely affect the trueness and adaptation to denture-bearing tissue [12]. Therefore, the intaglio surface of 3Dprinted dentures retains the original printed surface with a layer-wise J Prosthodont Res. 2023; **(**):

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