This study evaluated and compared the mechanical properties of provisional 3D-printed polymers fabricated using three commonly used 3D printing technologies: stereolithography (SLA), digital light processing (DLP), and liquid crystal display (LCD). Ninety specimens, both bar-shaped and disc-shaped, were printed using standardized resin color and print settings for each technology. Flexural strength was measured using a universal testing machine, while surface hardness and roughness were evaluated using a micro-Vickers hardness tester and atomic force microscopy, respectively. Statistical analyses were performed using one-way ANOVA and Tukey’s post-hoc tests at a significance level of p < 0.05. SLA demonstrated the highest flexural strength (93.39 ± 5.57 MPa), significantly higher than DLP (69.97 ± 8.48 MPa) and LCD (64.69 ± 8.98 MPa). Surface hardness was comparable across SLA (18.80 ± 0.57 kgf/mm²), DLP (17.80 ± 1.85 kgf/mm²), and LCD (18.27 ± 0.93 kgf/mm²). In terms of surface roughness, SLA showed the lowest mean value (14.79 ± 7.96 nm), followed by DLP (24.59 ± 9.76 nm), and LCD exhibited the highest roughness (89.87 ± 28.26 nm). The findings indicate that SLA produces polymers with superior flexural strength and the smoothest surface finish, making it preferable for applications requiring strong, high-quality surfaces, while DLP and LCD provide alternative benefits in specific use cases.

Objectives: To determine the patient-oriented outcomes after complete denture (CD) treatment using neutral zone (NZ) techniques compared with those of conventional dentures. Materials and methods: Electronic and hand searches were conducted up to December 2023 based on PICOS criteria. Population (P) was patients with complete edentulism on maxillary and mandibular arches and were either or not wearing CDs. Intervention (I) focused on the fabrication of mandibular and/or maxillary CD using NZ techniques. Comparators (C) included other CD fabrication approaches, such as conventional and simplified techniques, and the use of old or existing CDs. Outcomes (O) were patient-oriented treatment outcomes. Study design (S) included human studies. Results: Eleven human experimental studies were included. NZ dentures demonstrated better patient-reported outcomes, by providing greater comfort, enhancing denture stability and retention, reducing food traps underneath the denture, as well as improving appearance, chewing efficiency and speech. Objective findings varied, with most studies showing equivalent outcomes for NZ and conventional dentures. However, one study indicated superior, and another demonstrated worse outcomes for NZ dentures. Conclusions: NZ dentures generally improve patient-reported outcomes more than conventional dentures. However, their impact on objective outcomes compared with a conventional denture remains uncertain.

This study aimed to comparatively characterize the chemical composition of four commercial 3D-printed resin composites and quantify residual monomer elution profiles relevant to provisional and permanent fixed restorations. Two provisional resins (Temporary CB, Formlabs and NextDent C&B MFH) and two permanent 3D-printed resins (Saremco print CrownTec and VarseoSmile Crown plus) were analyzed. Unpolymerized resins underwent untargeted liquid chromatography-mass spectrometry (LC-MS) for compositional screening. Polymerized specimens were immersed in artificial saliva (37 °C, 72 h), followed by targeted quantitative LC-MS to quantify eluted residual monomers using certified standards calibration curves for HEMA, TEGDMA, UDMA, and Bis-EMA. Untargeted analysis detected 4125 chemical features, refined to 39 high-confidence resin-derived compounds across four 3D-printed resin composites. These were mainly monomers and derivatives, with some photoinitiators and additives. Compound diversity varied by material, with permanent Saremco and VarseoSmile showing the greatest variety. Bis-EMA predominated in Temporary CB, Saremco, and VarseoSmile, while UDMA was most abundant in NextDent, Saremco, and VarseoSmile. Quantitative analysis of monomer elution revealed that Temporary CB and VarseoSmile released the highest levels of Bis-EMA, NextDent showed the greatest elution of HEMA and UDMA, and VarseoSmile had the highest TEGDMA release. Saremco generally exhibited the lowest concentrations of all monitored monomers. These results demonstrate substantial variability in both composition and monomer elution profiles among commercial 3D-printed dental resins. Chemical composition and monomer elution in 3D-printed dental resins are highly material-specific. The marked variability, especially among permanent crown resins, underscores the need for material-specific biocompatibility testing to ensure long-term clinical safety. Material-specific differences in monomer elutions from 3D-printed dental resins may affect patient safety and restoration durability, underscoring the need for careful material selection and targeted biocompatibility testing in clinical practice.

Increased bond strength between aged CAD/CAM (Computer-Aided Design and Computer-Aided Manufacturing) provisional restorative materials is essential for reparability. This study investigated the impact of three different solvents and airborne-particle abrasion on the shear bond strength (SBS) of aged CAD/CAM provisional restorative materials, which are milled PMMA and 3D-printed resin with flowable resin composite. 3D-printed resin and milled PMMA (N = 160 per type) were fabricated into cylindrical shapes (5 mm in diameter, 5 mm in height), aged by 5,000 thermocycling cycles, and randomize divided at random into five groups (N = 32) based on surface modification protocols: control; non-surface modification, MEK; application with methyl ethyl ketone, THF; application with tetrahydrofuran, Alc; application with isopropyl alcohol, and APA; airborne-particle abrasion with 50-µm alumina oxide particle. The shear bond strength was tested by a universal testing machine with a notch-edged blade placed parallel to the bonded interphase and a crosshead speed of 1 mm/min until failure occurs. Failure modes analyzed under a ×40 stereomicroscopy. Scanning electron microscopy (SEM) at ×1000 magnification was used to evaluate the qualitative surface morphology (N = 2). The surface roughness was measured using a noncontact surface roughness analyzer at ×50 magnification (N = 10). A high-performance adsorption analyzer was used to determine the specific surface area (N = 10), and the data were analyzed two-way ANOVA with Bonferroni post-hoc test. SBS results (mean (95% confidence interval) in MPa) revealed that for both the 3D-printed resin and milled PMMA, the samples in the MEK (3D-printed, 23.2 (21.1-25.2); milled, 16.9 (15.3-18.5)), THF (3D-printed, 27.2 (26.0-28.5); milled,18.4 (16.8-20.0)), and APA groups (3D-printed, 27.9 (26.1-29.8); milled, 19.0 (17.2-20.7)) had significantly greater SBSs than did the samples in the Alc (3D-printed, 16.1 (14.4-17.7); milled, 12.2 (10.5-13.9)) and control groups (3D-printed, 11.7 (10.3-12.9); milled, 11.6 (10.8-12.4)). Compared with milled PMMA, 3D-printed resin presented a greater SBS across all surface modifications, except in the control group, where milled PMMA performed better. Failure mode analysis revealed total adhesive failure in the control and Alc groups, whereas APA resulted in 50% cohesive failure, mixed failure was shown more in 3D-printed resin THF and MEK groups (30%) compared to milled PMMA, THF and MEK group groups (10%). SEM analysis indicated that surface modifications produced rougher surfaces, The surface roughness (µm) was highest in the APA groups for both materials (3D-printed, 1834.2 (1803.8-1864); milled, 1052.8 (1027.0-1078.5)). The specific surface area (m²/g) was highest in the THF (5.22 (5.18-5.26)), MEK (5.18 (5.11-5.25)) and APA groups (5.17 (5.07-5.26)) of milled PMMA, but in the 3D-printed resin, the THF (4.95 (4.84-5.07)) and MEK groups (4.83 (4.77-4.89)) exhibited highest specific surface area. The application of APA techniques and surface modification using THF and MEK solvents can enhance the shear bond strength of aged milled PMMA and 3D-printed resin provisional restorative materials to flowable resin composites, as compared to the Alc and control groups. Additionally, the effectiveness of the surface modification of APA, THF, and MEK is indicated by dominant cohesive and mixed failure. SEM, surface roughness, and specific surface area indicated that surface morphology change in both CAD/CAM provisional restorative materials.

The integration of digital dentistry in the fabrication of complete dentures (CDs) has been facilitated through the use of intraoral scanners and computer‐aided design and manufacturing (CAD/CAM). However, the financial implications associated with the fabrication of digital CDs have been rarely explored. This study is aimed at presenting two different approaches to CD fabrication, combining conventional with digital techniques, and comparing the total cost of fabrication. The first case involved a 70‐year‐old woman without existing denture, while the second case involved a 97‐year‐old woman with inadequate retention and stability of CDs in both jaws. In the first patient, who lacked information about her old denture, the first approach was employed, utilizing milling technology for denture processing. The second patient, who already had an existing denture, underwent the second approach, which employed printing technology for denture processing. CAD/CAM replicas of the existing dentures were used for the final impression, bite registration, and as a guide for tooth arrangement. Two digital protocols and laboratory cost in CD fabrication have been proposed. The relatively high cost of CAD/CAM CDs restricts the widespread of digital technology in CD fabrication.

At present, provisional restorative materials are widely used for both short- and long-term treatment purposes. In esthetic dentistry, for the simulation of natural teeth, fluorescence plays a crucial role in enhancing the elegant, vibrant, and life-like appearance of restorative teeth, making them more closely resemble natural teeth. To achieve ideal esthetic outcomes, restorative materials must replicate the characteristics of natural teeth to provide the most realistic appearance possible. Thus, this study aims to compare the color difference in fluorescence (∆E₀₀) between a normal bovine tooth and eight provisional restorative materials under ultraviolet radiation. Eight provisional restorative materials were fabricated, for a total of 80 specimens (size 13.0 mm × 8.0 mm × 1.0 mm). A sound bovine tooth incisor was collected and used as a control for both enamel and dentine conditions. The color difference in fluorescence (∆E₀₀) was assessed using a spectrophotometer. A one-way ANOVA and Tukey’s test (p < 0.05) were used to analyze the resulting data. The results revealed that the color difference in fluorescence (∆E₀₀) between the normal bovine tooth and eight provisional restorative materials used in this study was higher than the 50% acceptability threshold, indicating a clear mismatch between the fluorescence of the materials and that of the normal bovine tooth. Unifast Trad had the lowest ∆E₀₀ among the provisional restorative materials, while Luxatemp Fluorescence had the highest color difference in fluorescence (∆E₀₀). The color difference in fluorescence (∆E₀₀) between Unifast Trad and Luxatemp Fluorescence is statistically significant. However, no significant difference was observed between Temporary CB, Vipi Block Trilux, and Protemp 4, or between Luxatemp Star and Luxatemp Fluorescence. It can thus be concluded that the ∆E₀₀ mostly differs among the different materials. Luxatemp Star and Luxatemp Fluorescence exhibited the highest ∆E₀₀ by a significant margin compared to the other groups.