Search Results (150)

The dimensional accuracy of the intaglio surface of complete dentures fabricated using liquid crystal display (LCD) three-dimensional (3D) printing might be influenced by the build angle and post-processing storage conditions. This study evaluated the effect of build angle and natural light exposure duration on the intaglio surface trueness of maxillary complete denture bases. Standardized denture base designs (2 mm uniform thickness) were fabricated using an LCD 3D printer (Lilivis Print; Huvitz, Seoul, Republic of Korea) at build angles of 0°, 45°, and 90° (n = 7 per group). All specimens were printed using the same photopolymer resin (Tera Harz Denture; Graphy, Seoul, Republic of Korea) and identical printing parameters, followed by ultrasonic cleaning and ultraviolet post-curing. Specimens were stored under controlled light-emitting diode lighting and exposed to natural light (400–800 lux) for 0, 14, or 30 days. The intaglio surfaces were scanned and superimposed on the original design data, following the International Organization for Standardization 12836. Quantitative assessment included root mean square deviation, mean deviation, and tolerance percentage. Statistical analyses were performed using one-way analysis of variance and paired t-tests (α = 0.05). Build angle and light exposure duration significantly affected surface trueness (p < 0.05). The 90° build angle group exhibited the highest accuracy and dimensional stability, while the 0° group showed the greatest deviations (p < 0.05). These findings underscore the importance of optimizing build orientation and storage conditions in denture 3D printing. Full article

Background/Objectives: Digital prosthodontics increasingly utilize both additive (3D printing) and subtractive Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM), yet comprehensive comparisons remain limited. This scoping review evaluates their relative performance across prosthodontic applications. Methods: Systematic searches (PubMed, Scopus, Web of Science, Embase, 2015–2025) identified 28 studies (27 in vitro, 1 retrospective). Data were extracted on accuracy, efficiency, materials, and outcomes. Results: CAD/CAM milling demonstrated superior accuracy for fixed prostheses, with marginal gaps for milled zirconia (123.89 ± 56.89 µm), comparable to optimized 3D-printed interim crowns (123.87 ± 67.42 µm, p = 0.760). For removable prostheses, milled denture bases achieved a trueness of 65 ± 6 µm, while SLA-printed dentures post-processed at 40 °C for 30 min showed the lowest root mean square error (RMSE) (30 min/40 °C group). Three-dimensional printing excelled in material efficiency (<5% waste vs. milling > 30–40%) and complex geometries, such as hollow-pontic fixed dental prostheses (FDPs) (2.0 mm wall thickness reduced gaps by 33%). Build orientation (45° for crowns, 30–45° for veneers) and post-processing protocols significantly influenced accuracy. Milled resins exhibited superior color stability (ΔE00: 1.2 ± 0.3 vs. 3D-printed: 4.5 ± 1.1, p < 0.05), while 3D-printed Co-Cr frameworks (SLM) showed marginal fits of 8.4 ± 3.2 µm, surpassing milling (130.3 ± 13.8 µm). Digital workflows reduced chairside time by 29% (154.31 ± 13.19 min vs. 218.00 ± 20.75 min). All methods met clinical thresholds (<120 µm gaps). Conclusions: Milling remains preferred for high-precision fixed prostheses, while 3D printing offers advantages in material efficiency, complex designs, and removable applications. Critical gaps include long-term clinical data and standardized protocols. Future research should prioritize hybrid workflows, advanced materials, and AI-driven optimization to bridge technical and clinical gaps. Full article

Background: Candida albicans adhesion to denture base materials is a primary contributor to denture stomatitis. To address this issue, numerous studies have explored the incorporation of various additives into denture base resins to enhance their antifungal properties. Titanium tetrafluoride (TiF₄) is an inorganic fluoride compound that has proven antimicrobial properties but has not yet been tested with denture materials. This study aimed to evaluate the effect of TiF₄ addition into different denture base materials on antifungal activity, surface roughness, hardness, and color properties. Methodology: A total of 200 disc-shaped specimens were prepared—100 heat-polymerized acrylic resins and 100 3D-printed NextDent resins. Four different concentrations of TiF₄ were incorporated: 1 wt%, 2 wt%, 3 wt%, and 4 wt% for both resins, while one group of each resin remained unmodified as a control. All specimens were subjected to thermal cycling for 5000 cycles, and four tests were conducted: Candida albicans adherence, surface roughness, hardness, and color change. A scanning electron microscope (SEM) was used to prove Candida albicans colonies’ adhesion on the specimens’ surfaces, and Fourier-transformed infrared (FTIR) analysis was performed to show the presence of TiF₄ in the resin material; data were analyzed using one-way ANOVA followed by a post hoc test (α = 0.05). Results: TiF₄ significantly reduced the Candida albicans adhesion to heat-polymerized specimens (p < 0.001). Compared to the control group, the incorporation of TiF₄ resulted in a substantial reduction in C. albicans colony counts, with reductions of approximately 97.6% in 1HP, 97.2% in 2HP, 97.4% in 3HP, and complete inhibition (100%) in 4HP. However, there was no significant difference between the 3D-printed ones (p = 0.913). Surface roughness, hardness, and color change of heat-polymerized groups were not significantly affected by TiF₄ (p > 0.05) except the color of the group treated with 4% (p < 0.05). For the 3D-printed groups, no significant differences were detected between the groups regarding candida count, hardness was significantly increased at 2% TiF₄ compared to the control (p = 0.002), and roughness was least with 4% TiF₄, while the color varied significantly between the groups (p < 0.001). Conclusions: TiF₄ addition decreased Candida albicans adhesion to heat-polymerized denture base materials but showed no antifungal effect on the 3D-printed resin. While roughness remained low in 3D-printed groups at higher concentrations. Hardness was not significantly altered in the heat-polymerized resin, whereas it increased significantly in the modified 3D-printed resin. Color stability was compromised at higher TiF₄ concentrations, particularly in the 3D-printed groups. The type of denture base material and TiF₄ concentration both influenced antifungal activity and denture surface properties. Full article

Objectives: This study evaluated the dental and alveolar bone stress distribution of a mandibular Kennedy Class I restored with a bilateral implant-assisted removable partial denture (IARPD) compared with a conventional removable partial denture (CRPD) through the application of finite element analysis (FEA). Methods: Kennedy Class I plaster models were made, including teeth from the lower left first premolar and lower right canine. The models were scanned, resin-based replicated and digitized. Using Solidworks software, internal hexagonal implants (10 mm × 4 mm) were virtually placed at the level of the first molars. Each model was grouped into a unit, and a load of 200 N was applied, simulating masticatory forces. Von Mises stress distributions were calculated via FEA for the vertical, diagonal and combined forces. Results: In the IARPD, the stress generated in the alveolar bone by the vertical (4.2 Mpa), diagonal (12.2 MPa) and combined forces (12.3 MPa) was lower than that of the CRPD (7 MPa, 26.3 MPa and 32 MPa, respectively). Similarly, at the lower central incisor, the IARPD generated less stress than the CRPD due to the action of the vertical, diagonal and combined forces. Conclusions: Our preliminary data suggest that bilateral implant placement may result in less stress on bone and teeth during rehabilitation with a Kennedy Class I IARPD, with different orientations of the forces applied. Full article

Objectives: The disinfection of fabricated prostheses is crucial to prevent cross-infection between dental laboratories and clinics. However, there is a lack of information about the effects of chemical disinfection on 3D-printed denture base resins. This study aimed to evaluate the impact of different disinfectants on the flexural strength, elastic modulus, micro-hardness, surface roughness (Ra), and change in color of 3D-printed and conventional heat-polymerized (HP) denture base resins (DBRs). Methods: A total of 240 specimens (80 bar-shaped (64 × 10 × 3.3 mm) and 160 disk-shaped (10 × 2 mm)) were made from HP and 3D-printed DBRs. For each resin, the specimens were divided into four groups (n = 10) according to the disinfectant solution. One remained in water without disinfection as a control group, while the other three groups were disinfected using 1% sodium hypochlorite, 2% glutaraldehyde, or 10% Micro 10+ for 30 min. The flexural strength, elastic modulus, micro-hardness, Ra, and color change were measured. The collected data were statistically analyzed using a two-way ANOVA and Tukey’s post hoc test (α = 0.05). Results: A significant decrease in flexural strength, elastic modulus, and hardness was found with sodium hypochlorite (p < 0.05). When comparing the resins per solution, the 3D-printed resin showed a significant decrease in flexural strength, elastic modulus, and hardness compared with PMMA (p < 0.001), while no change was found in the Ra of both resins with all disinfectants (p > 0.05). Disinfecting with sodium hypochlorite resulted in a significant increase in color change for both resins (p < 0.05); however, all the changes were within clinically acceptable limits. Sodium hypochlorite showed the highest color change, while 2% glutaraldehyde and 10% Micro 10+ showed no significant changes in the tested properties (p > 0.05). Conclusions: Neither resin showed a change in surface roughness with immersion in disinfectants. Sodium hypochlorite had an adverse effect on the flexural properties, hardness, and change in color of the PMMA and 3D-printed DBRs, while the other disinfectants had no effect on the tested properties. Full article

A variety of printable resins for denture bases are available, without detailed instructions on print parameters. This study aimed to evaluate the effect of the printing build angle and the layer thickness of 3D-printed denture base resins before and after thermocyclic aging on flexural strength values and surface properties. The flexural strength, surface roughness (Ra, Rz) and hardness (HM, HV2) of two 3D-printed denture base resins (Formlabs (FL) and V-print dentbase, VOCO, (VC)) were therefore compared to a conventionally pressed cold-curing control material (PalaXpress (PP)). The specimens were printed at a 0°, 45° or 90° build angle and the layer thickness was varied for FL at 50 and 100 µm and evaluated before and after thermocyclic aging (N = 200; n = 10). Differences in flexural strength values were analyzed using multifactorial ANOVAs (α = 0.05). The build angle and aging significantly affected the flexural strength of the 3D-printed denture base resins (p < 0.05), while the layer thickness showed no effect for FL (p = 0.461). The required threshold value of 65 MPa defined by ISO 20795-1 was exceeded by PP (70.5 MPa ± 5.5 MPa), by FL when printed at 90° (69.3 MPa ± 7.7 MPa) and by VC at 0° (69.0 MPa ± 4.6 MPa). The choice of an appropriate build angle for each material and printing technology is crucial for the flexural strength and consequently the clinical longevity of a printed denture base. Full article

Color stability of acrylic resins is essential for preserving the aesthetic appearance of denture bases over time. This study explores how food pigments and thermal changes affect the color stability of commonly used denture base resins. Four acrylic resins were tested: three heat-cured acrylic resins with different characteristics (Zhermack^® Villacryl H Plus V2, H Plus V4, and H Rapid FN V4) and one self-cured acrylic resin (Zhermack^® Villacryl S V4). To simulate the oral environment, the resins underwent 1000 thermal cycles between 5 °C and 55 °C, followed by a 7-day immersion period in beverages such as coffee, red wine, a caramel-colored soft drink (cola), and distilled water (control), forming sixteen group of specimens (n = 5). Color changes (∆E) were measured using the VITA Easyshade V^® spectrophotometer, following the CIEDE2000 standard. The findings revealed that thermal aging caused noticeable color changes in all resins (p < 0.001). Red wine led to the most intense discoloration, followed by coffee. The caramel-colored soft drink caused moderate staining, while distilled water had a negligible effect. The type of polymerization did not affect the degree of discoloration, as no significant differences were found between the resins after exposure to beverages (p > 0.05). Overall, this study highlights how both internal and external factors impact the appearance of acrylic resins. Thermal aging can accelerate polymer degradation, while pigments in beverages cause visible staining. Among the tested beverages, red wine proved to be the most aggressive due to its high pigment concentration and low pH. These findings emphasize the need for improved material formulations to enhance the longevity and aesthetic performance of dentures. Full article

This study evaluated the strength, hardness, and color stability of 3D-printed denture base resins and compared the outcome with conventional heat-cured denture base resins after aging by thermocycling. A total of 72 specimens from conventional and 3D-printed materials were fabricated in different shapes and dimensions based on the mechanical and color tests performed. The specimens were divided into five groups: flexural, tensile, and compressive strengths (n = 20), hardness, and color stability (n = 6). In all these groups, half of the specimens were stored in a distilled water bath at 37 °C for 24 h, and the remaining half of the specimens were subjected to aging by thermocycling. The 3D-printed specimens demonstrated the highest means of tensile strength (32.20 ± 3.8 MPa), compressive strength (106.31 ± 4.07 MPa), and Vickers hardness number (24.51 ± 0.36), and the lowest means of flexural strength (54.29 ± 13.17 MPa) and color difference (ΔE = 2.18 ± 1.09). Conventional heat-cured specimens demonstrated the highest means of flexural strength (59.96 ± 8.39 MPa) and color difference (ΔE = 4.74 ± 2.37) and the lowest means of tensile strength (32.17 ± 9.06 MPa), compressive strength (46.05 ± 4.98 MPa), and Vickers hardness number (10.42 ± 1.05). Aging significantly reduced the flexural strength (−27%), tensile strength (−44%), and hardness (−7%) of 3D-printed resins in contrast to the conventional resin’s compressive strength (−15%) and color stability (p < 0.05). The 3D-printed resin had comparable flexural and tensile strength and significantly superior compressive strength, hardness, and color stability compared with conventional resins. Aging significantly and negatively affected the flexural strength, tensile strength, and hardness of 3D-printed resin. Full article

Background: Polymethyl methacrylate (PMMA) is ideal for denture bases but is prone to biofilm accumulation, leading to denture stomatitis (DS), often involving Candida albicans. Dimethylaminohexadecyl methacrylate (DMAHDM) and 2-methacryloyloxyethyl phosphorylcholine (MPC) are introduced into dental materials for their antimicrobial and protein-repellent properties. This study investigates the effects of incorporating dimethylaminohexadecyl methacrylate (DMAHDM) and 2-methacryloyloxyethyl phosphorylcholine (MPC) into heat-polymerized (HP) and 3D-printed (3DP) denture base resins on microbial adhesion and cytotoxicity. Methods: HP and 3DP denture base specimens were prepared using varying concentrations of DMAHDM and MPC. Microbial adhesion was quantified using CFU counts of C. albicans, and cytotoxicity was assessed via an MTT assay using fibroblast cells after 24 h, 3 days, and 7 days. Results: Both DMAHDM and MPC significantly reduced the CFU counts in both HP and 3DP materials; the combination of 1.5% DMAHDM and 3% MPC exhibited the most substantial antimicrobial effects. Cytotoxicity results varied between materials and time points; however, all treated groups maintained cell viability above the 70% threshold, indicating no significant cytotoxic effects. Conclusion: Incorporating DMAHDM and MPC into denture base resins can effectively reduce microbial adhesion while maintaining acceptable cytotoxicity levels. Full article

Surface roughness is primarily determined by the inherent characteristics of a material, the specific polishing protocol and the manual operator’s dexterity. This research intends to conduct a comparative analysis between a conventional and mechanized polishing protocol concerning surface roughness and its impact on surface topography. Thirty samples were included in this in vitro study: six samples for each type of acrylic resin. All specimens underwent a polishing protocol by a conventional method and a mechanized approach with a controlled polishing tool (CPT). Profilometric measures were extracted: arithmetic mean height (Pa), skewness (Psk) and kurtosis (Pku). The Pa values acquired through both the mechanized and conventional polishing techniques are significantly lower compared to the control group. The mechanized polishing notably yielded higher roughness compared to the control group. Relatively consistent skewness and lower-to-moderate values of kurtosis were found across resin types. Differences in the dispersion and pattern for Pa were not detected between the polishing protocols. The CPT protocol reliably maintains consistent skewness and kurtosis values. The conventional protocol remains significant due to the variations observed in the Pa values obtained. Full article

Newly developed 3D-printed polymer materials are used for denture base fabrication. The aim of the present study was to evaluate the color stability of two new 3D-printed resins, a hard PPMA-based and a soft Urethane-based resin, in relation to a traditional heat-polymerized PMMA resin, which was used for comparison purposes. Specimens of the materials were immersed in five solutions (distilled water, red wine, black tea, coffee, and Coke^®) for definite periods of time (one day, one week, and one month). The color measurements were carried out utilizing a spectrometer supported by a microscope and using special software. Color changes between immersion periods were calculated and statistically compared. The results showed that all types of resins were influenced during immersion periods. The heat-polymerized resin was influenced less than the others but with no significant difference to the 3D-printed hard PMMA resin. In respect to the materials compared, the discoloration effect for the 1 month immersion time was significantly more intense for the soft 3D-printed resin. In respect to the solutions’ staining effects, black tea and red wine significantly discolored all materials regardless of immersion periods. The new 3D-printed materials need further improvements for dental use. Full article

The integration of three-dimensional (3D) printed resin denture teeth represents a significant advancement in digital dentistry. This study aims to assess the ability of 3D-printed denture teeth to withstand chipping and indirect tensile fractures, comparing them with conventionally manufactured resin denture teeth. Four groups, each comprising 30 specimens, were examined: Group 1 featured 3D-printed denture teeth (NextDent, 3D Systems, Soesterberg, The Netherlands), while the others included commercially obtained Ivostar Shade, SpofaDent Plus, and Major Super Lux teeth. Stereolithography 3D printing was utilized to produce methacrylate-based photopolymerized resin teeth models for Group 1, while the remaining groups were commercially sourced. Chipping and indirect tensile fracture tests were performed at a rate of 0.8 mm/min until material failure, offering valuable insights into the mechanical properties of the tested denture teeth. Statistical analysis was carried out using one-way analysis of variance (ANOVA), coupled with Tukey’s honestly significant difference test to compare multiple groups, with a significance threshold of p < 0.05. The findings showed that 3D-printed resin denture teeth exhibited greater indirect tensile fracture resistance than Major Super Lux and Ivostar Shade, though they were surpassed by SpofaDent Plus. In the chipping test, the 3D-printed teeth experienced buccal chipping without distortion, indicating their structural stability under localized force. Fractures during the indirect tensile test originated near the loading point and extended cervically along the inner slopes of both cusps, displaying consistent fracture patterns. These results demonstrate that 3D-printed denture teeth made from resin materials provide adequate fracture resistance for clinical use, although further refinement of materials could enhance their performance relative to conventional alternatives. Full article

Background: Grapefruit seed skin particles (GSSPs) have antifungal properties due to the presence of flavonoids. Therefore, it has the potential to display antifungal characteristics when added to acrylic resin, but it could affect the mechanical properties of the resin. This study investigated the effects of adding GSSPs on the mechanical characteristics of 3D-printed denture base resins. Purpose: The aim of the present study was to determine the effects of the addition of GSSPs to 3D-printed acrylic at different concentrations on the degree of conversion (DC), surface hardness, flexural strength, and tensile strength. Methods: In this study, 90 samples were printed with acrylic resin via a Digital Light Processing (DLP) printer. Thirty square samples were used for the surface hardness test. Thirty rectangular samples were used for the flexural strength test, and thirty dumbbell-shaped samples were used for the tensile strength test. These materials were prepared by adding different concentrations of GSSPs (0.0 wt.%, 5.0 wt.%, and 7.0 wt.%), which were determined by a pilot study to be the most effective in 3D denture base resins. The Durometer Shore Hardness Scale (DSHS) was used to measure the surface hardness, and a universal testing machine was employed to gauge the flexural strength and tensile strength. Field emission scanning electron microscopy (FE-SEM) was employed for particle size analysis and fracture behavior determination. Results: Compared with those of the control group, the degree of conversion (DC), surface hardness, flexural strength, and tensile strength of the treated groups significantly improved after the addition of 5.0 wt.% and 7.0 wt.% GSSPs. The FE‒SEM images revealed a decrease in porosity as the concentration of GSSPs increased with a brittle fracture behavior. Conclusions: The addition of GSSPs to 3D-printed acrylic is recommended because of their significant positive impacts on the mechanical properties of 3D-printed denture base resin. Full article

Background: Denture stomatitis is an inflammatory condition involving swelling and redness of the oral mucosa beneath a denture. Among various available treatments, zinc oxide nanoparticles (ZnONPs) and nano-wire nanostructures have been suggested as potential future therapies. However, there is a lack of information in the literature about the effectiveness of ZnONPs regarding microbial adhesion to different denture base resins. Here, we review studies on the effect of ZnONP use on microbial adhesion to denture base resins to answer the following study question: “Does incorporating ZnONPs into denture base resins reduce microbial adhesion?” Methods: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, an electronic and manual search ranging from Jan 2000 to May 2024 was performed using PubMed, Web of Science, and Scopus databases to answer the study question. All full-length English-language articles investigating the effects of ZnO nanostructures on Candida albicans adhesion to polymethyl methacrylate (PMMA) denture base resins were included. The extracted data were tabulated for qualitative and quantitative analysis of the included studies. Results: Of the 479 studies reviewed, 7 studies successfully met the eligibility criteria. All included studies utilized PMMA as the denture base material with different polymerization methods. C. albicans was the most extensively studied microbial species, with various count methods used. Six studies concluded a statistically significant impact of ZnONPs on decreasing C. albicans adhesion to the denture base. However, one study reported the opposite. Conclusions: Incorporating ZnONPs into PMMA denture base resin has a positive impact on reducing C. albicans adherence and could be recommended for denture stomatitis treatment. However, further studies are needed to cover the notable gap in data regarding the safety and effectiveness of ZnO nanostructures. Full article

Candida albicans (C. albicans) adhering to denture-based resins (DBRs) is a known cause of denture stomatitis. A new approach to prevent denture stomatitis is to include antimicrobial substances within DBRs. Here, we examined the mechanical performance and antifungal properties of DBRs containing benzyldimethyldodecyl ammonium chloride (C₁₂BDMA-Cl) as an antimicrobial compound. C₁₂BDMA-Cl is a quaternary ammonium compound, and its antifungal properties have never been investigated when combined with dental acrylic resin. Therefore, we modified a commercially available heat-polymerized acrylic DBR to contain 3 and 5 wt.% of C₁₂BDMA-Cl. Unmodified DBR was used as a control group. Specimens were prepared using the conventional heat processing method. The specimen’s flexural strength, elastic modulus, microhardness, and surface roughness were evaluated. C. albicans biofilm was grown on the specimens and assessed via colony-forming units (CFUs) and scanning electron microscopy (SEM). In silico molecular docking was applied to predict the potential C₁₂BDMA-Cl inhibition activity as an antifungal drug. The 3% C₁₂BDMA-Cl DBR demonstrated antifungal activities without a deterioration effect on the mechanical performance. SEM images indicated fewer colonies in DBR containing C₁₂BDMA-Cl, which can be a potential approach to managing denture stomatitis. In conclusion, C₁₂BDMA-Cl is a promising antifungal agent for preventing and treating denture stomatitis. Full article