Search Results (136)

In the continuous development of additive technologies and light-sensitive resins, the biological performance of 3D-printed resins is strongly dependent on photopolymerization efficiency and post-processing conditions. This study evaluated the effect of post-curing duration on the cellular response to two denture base resins using direct contact and indirect eluate-based pathways. Human gingival fibroblasts were assessed through viability, membrane integrity, nitric oxide production, fluorescence live/dead staining, and caspase-3/7 activity. As a result of contact between the cells and the surface interface of the specimen disks, reduced metabolic activity was noticed compared with the control under direct exposure, indicating cellular stress. Extended polymerization has been demonstrated to improve metabolic activity and reduce apoptotic signals for the V-Print dentbase resin, whereas FotoDent Denture presented a less uniform response under the same parameters. Therefore, for evaluating the cytotoxicity of light-sensitive resins, it is not sufficient to assess only the saliva-soluble substances released from the resin, such as residual monomers, but also the 3D printing parameters. Full article

Selective laser melting (SLM) is an additive manufacturing method based on powder bed fusion that has gained prominence in prosthodontics for its capability to create intricate, patient-specific metal restorations with precision and consistency. SLM has become an important part of digital dental workflows, allowing for the direct creation of dental frameworks from computer-aided design (CAD), offering advantages over traditional casting and subtractive milling techniques. This review outlines the fundamentals of SLM, the dental alloys commonly employed, and the microstructural characteristics that affect mechanical properties, corrosion resistance, and biocompatibility. It explores current uses in removable partial denture frameworks, fixed dental prostheses, metal–ceramic restorations, implant-supported prosthetics, and maxillofacial rehabilitation. Alloys based on cobalt–chromium and titanium produced through SLM exhibit strong mechanical properties, fatigue resistance, and biological compatibility when suitable post-processing is conducted. Despite these advantages, issues such as surface roughness, porosity, anisotropy, powder handling, and high costs remain, and there is a lack of extensive long-term clinical data. Ongoing process refinement and clinical validation are crucial for the wider integration of SLM into standard prosthodontic practice. Full article

Background/Objectives: Although digital workflows for complete denture fabrication are increasingly implemented in clinical practice, randomized controlled pilot trials directly comparing their clinical performance and patient satisfaction with conventional complete dentures (CCDs) remain scarce. This study aimed to compare patient satisfaction and clinical effectiveness between conventionally and digitally fabricated complete dentures (DCDs). Methods: In the present exploratory randomized controlled clinical pilot study using a cross-over design, 15 edentulous patients received both a conventionally fabricated and a digitally fabricated complete denture in randomized order. Each denture was worn for a three-month adaptation period. Patients were blinded to the fabrication method. Oral health-related quality of life was assessed using the OHIP-G49 questionnaire, and clinical performance was evaluated using standardized criteria at baseline, after three months with the first denture, and after three months with the second denture. Results: Both fabrication methods yielded satisfactory clinical outcomes in all patients. All 15 patients rated the DCDs as highly satisfactory, while 14 patients rated the CCDs equally favorably; one patient was unable to tolerate the conventional denture. DCDs demonstrated a slight but consistent advantage in oral health-related quality of life (OHRQoL) scores. Conclusions: Both conventional and digital complete dentures are clinically effective and well accepted by edentulous patients. However, DCDs offer a modest improvement in patient satisfaction and OHRQoL. Digitally fabricated complete dentures provide comparable clinical results to conventional methods while offering potential advantages in patient comfort and perceived quality of life. Given the exploratory nature of the study and the limited sample size, the results should be interpreted with caution and primarily serve to inform future, adequately powered randomized clinical trials. Full article

Objectives: This study aimed to compare the retention and fit precision of removable partial denture circumferential clasps fabricated from cast cobalt–chromium, 3D-printed cobalt–chromium, and polyether ether ketone. Methods: A maxillary right first premolar abutment was prepared. Eighty circumferential clasps were allocated into three material groups: cast Co–Cr (n = 20), 3D-printed Co–Cr (n = 20), and PEEK (n = 40). The terminal third of metal retentive clasps was designed to engage 0.25 mm and 0.50 mm undercuts. PEEK clasps were fabricated with two designs: partial (two-thirds) and full-arm undercut engagement. Each group was examined for retentive forces after 1440 cycles (simulating 1 year). Initial and final retentive forces were recorded. Clasp deformation was assessed by measuring inter-arm distance before and after cycling using digital photography and ImageJ software. Results: All clasp groups demonstrated a statistically significant reduction in retention after 1440 cycles (p < 0.05). At both undercut depths, cast and 3D-printed Co–Cr clasps exhibited significantly higher retentive forces than PEEK (p < 0.001). Within the PEEK group, full-arm engagement showed significantly higher retention than partial engagement at the 0.25 mm undercut (p < 0.001), whereas no significant difference was observed between designs at the 0.50 mm undercut (p = 0.406). Fit precision revealed a significant increase in inter-arm distance after cycling (p < 0.05). PEEK clasps exhibited significantly smaller dimensional changes than Co–Cr clasps (p < 0.02). Conclusions: Clasp material, undercut depth, and design significantly influenced retention and fit precision. Co–Cr clasps maintained higher retentive forces, whereas PEEK clasps demonstrated reduced deformation after cycling. Full article

Biofilm formation on denture base materials may contribute to oral diseases such as denture stomatitis and therefore represents an important factor in prosthodontic treatment. This in vitro study investigated biofilm formation on dental prosthetic materials manufactured by additive, subtractive, and conventional techniques. Disc-shaped specimens were fabricated from 3D-printed Denture Base Resin (Formlabs), milled Lucitone Digital Fit (Dentsply Sirona), and conventionally processed cold-polymerized PALAPress (Kulzer). Biofilm formation by Streptococcus mutans and Streptococcus sanguinis was assessed separately over a 21-day incubation period using crystal violet staining and photometric determination of optical density at eight predefined time points. Surface characteristics before and after microbial colonization were qualitatively evaluated by scanning electron microscopy. For S. mutans, significant material-dependent differences were observed only at selected time points, while overall biofilm accumulation remained low. In contrast, S. sanguinis exhibited pronounced and repeated differences, with milled PMMA generally showing lower biofilm accumulation compared with additively manufactured and conventionally processed materials. Overall, S. sanguinis formed significantly more biofilm than S. mutans across all materials and time points. These findings indicate that both manufacturing technique and bacterial species influence biofilm formation on denture base materials. Full article

Purpose: Pure three-dimensional (3D)-printed resin for denture base shows strength in comparison with the conventional heat-cured materials. The purpose of this study was to assess how physical and mechanical properties of 3D-printed denture base resins are affected by the addition of cerium zirconium oxide nanofibers (CeZrO₄ NFs), which have a unique combination of thermophysical and mechanical properties. Materials and Methods: The specimens were digitally created utilizing Microsoft Corporation’s 3D builder software through computer-aided design. To meet the test criteria for transverse strength, impact strength, hardness, radiopacity, and degree of conversion (DC), specimens were designed and printed with specific dimensions according to the relevant standards. The 3D-printed denture base resin was mixed with CeZrO₄ NFs (diameter: 300–800 nm, length: 2–10 µm) at weight percentages of 0.5, 1.0%, 1.5%, 2%, and 2.5%. The data were analyzed using Tukey’s post hoc test (α = 0.05) and ANOVA. Field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDX) were used to evaluate surface morphologies of the composites and nanofibers, and the dispersion of the NFs within the resin matrix respectively. Results: The results demonstrated that compared with those of the control group, the average transverse strength, impact strength, and hardness values of the CeZrO₄ NF reinforcement groups significantly increased up to a nanofiller concentration of 1.5 wt.%., whereas those of the other reinforcement groups significantly decreased. For example, the impact strength significantly increased from 5.84 kJ/m² (0 wt.%) to the maximum value 8.76 kJ/m² at 1.0 wt.% CeZrO₄ NF. On the other hand, the Shore D hardness increased from 80.84 for the control group to the maximum value 83.27 at 1.5 wt.% CeZrO₄ NF. The radiopacity increased as the NF concentration increased. Although Fourier transform infrared (FTIR) spectroscopy analysis did not show any noticeable change in the chemical structure of the resin after incorporating the NFs, there was a notable improvement in the DC of the nanocomposites with NF concentrations of 0.5, 1.0 and 1.5 wt.%. Energy dispersive X-ray spectroscopy (EDX) and field emission scanning electron microscopy (FESEM) showed evidence of uniform distribution of the CeZrO₄ NFs in the 3D-printed specimens. Conclusions: The properties of the denture bases fabricated from 3D-printed resin were enhanced by the addition of 0.5%, 1 wt.% and 1.5 wt.% CeZrO₄-milled NFs, though the latter two concentrations produced the most significant results. Full article

Three-dimensional (3D) printing, also known as additive manufacturing (AM), has become increasingly integrated into dentistry because of its high precision, efficiency, and ability to fabricate patient-specific devices. This review comprehensively discusses the historical development of 3D printing and outlines the fundamental principles of the most widely used technologies in dentistry, including stereolithography (SLA), digital light processing (DLP), and liquid crystal display (LCD). These technologies enable the accurate and efficient fabrication of dental models, crowns, bridges, dentures, surgical guides, orthodontic appliances, and tissue engineering scaffolds. Current clinical applications are systematically summarized across major dental disciplines, including prosthodontics, orthodontics, oral and maxillofacial surgery, endodontics, periodontics, and pediatric dentistry. Despite existing challenges, such as limited long-term clinical data for certain materials, high initial equipment costs, and post-processing requirements, 3D printing offers substantial advantages in terms of customization, workflow efficiency, and clinical predictability of the final product. Future developments in advanced biomaterials, artificial intelligence-assisted workflows, bioprinting, and four-dimensional (4D) printing are expected to further expand the role of additive manufacturing in personalized and regenerative dentistry. Full article

Background/Objectives: This technical report introduces an innovative hybrid digital workflow that integrates diagnostic plaster-cast scanning with intraoral scanning to produce an accurate 3D-printed model for fabricating distal-extension removable dental prostheses (RDPs). Methods: The technique aims to overcome the challenges of reproducing the mobile mucosa in free-end saddles, a critical factor for denture base accuracy and stability. The workflow began with conventional clinical procedures, including clinical examination, impression-making, and cast surveying. After performing the required mouth preparations according to the prosthetic design, the diagnostic cast was digitized and selectively modified to allow intraoral rescanning. The prepared teeth were then scanned intraorally and merged with the digitalized cast, producing a refined virtual model for CAD-based metal framework design. The framework was digitally designed, 3D-printed to verify adaptation, and cast in cobalt–chromium. Standard RDP fabrication steps were followed, including intraoral framework try-in, fabrication of acrylic bases, occlusal registration, tooth arrangement, and functional and esthetic try-in. The final prosthesis was installed and adjusted without the need for an additional impression. Results: This hybrid workflow enabled a highly accurate reproduction of the distal extension region, outperforming models derived solely from direct intraoral scanning. By digitally capturing the physiological morphology of the mobile mucosa, the method eliminates the need for the traditional altered-cast technique, reducing clinical time, technical sensitivity, and material costs. Conclusions: The proposed approach enhances denture base accuracy, improves adaptation, and promotes more uniform occlusal load distribution in free-end RDPs. This streamlined and reproducible digital protocol offers a clinically relevant advancement, with potential to improve prosthesis stability and long-term outcomes. Full article

Additive manufacturing is now an integral part of digital prosthodontic workflows, and although stereolithography (SLA) is widely used for denture base fabrication, the dimensional accuracy of printed dentures remains highly dependent on manufacturing parameters, particularly build orientation. This study evaluated the influence of build orientation on the trueness and precision of SLA-printed maxillary and mandibular denture bases. Thirty complete denture bases were fabricated using SLA and divided into three groups according to build orientation: 0°, 45°, and 90° (n = 10). The intaglio surfaces of the printed dentures were scanned and compared with their corresponding digital reference models using three-dimensional inspection software. Trueness was quantified using root mean square error (RMSE) and directional deviations, while precision was assessed based on the variability of RMSE values within each group. Statistical analysis was performed using one-way ANOVA and Tukey’s post hoc test (p ≤ 0.05). Build orientation significantly affected the trueness of maxillary denture bases, with dentures printed at 90° demonstrating the lowest RMSE values. No statistically significant differences in trueness were observed among build orientations for mandibular denture bases. Precision was not influenced by build orientation for maxillary dentures, whereas mandibular dentures printed at 90° exhibited significantly greater variability compared with 0° and 45°. Build orientation is a critical factor influencing the dimensional accuracy of SLA-printed denture bases in an arch-dependent manner. Optimizing build orientation may enhance both accuracy and reproducibility, thereby improving the predictability and clinical reliability of additively manufactured denture bases. Full article

The increasing adoption of digital light processing (DLP) three-dimensional (3D) printing in prosthodontics has enabled the rapid fabrication of denture bases with improved dimensional accuracy and reproducibility. However, the mechanical performance and surface characteristics of 3D-printed denture base resins remain inferior to those of conventional heat-polymerized polymethyl methacrylate (PMMA), limiting their long-term clinical reliability. This study aimed to investigate the effect of incorporating zinc oxide (ZnO) and samarium oxide (Sm₂O₃) nanoparticles, individually and as hybrid nanofiller systems, on the mechanical and wettability properties of a DLP 3D-printed denture base resin. ZnO and Sm₂O₃ nanoparticles were incorporated into a photopolymerizable denture base resin at concentrations of 1 and 2 wt.%, producing seven experimental formulations, including a control group. A total of 280 specimens were fabricated using a DLP 3D printer and subjected to standardized post-processing. Nanoparticle dispersion and morphology were examined using field-emission scanning electron microscopy (FE-SEM), while Fourier-transform infrared spectroscopy (FTIR) was employed to assess possible chemical interactions between the nanofillers and the polymer matrix. Mechanical performance was evaluated through impact strength, transverse strength, and flexural strength tests, and surface wettability was assessed using static water contact angle measurements. Statistical analysis was conducted using one-way ANOVA followed by Tukey’s post hoc test (α = 0.05). The results demonstrated that all nanoparticle-reinforced groups exhibited significantly enhanced mechanical properties compared with the unmodified control resin. The incorporation of 1 wt.% nanofillers yielded the most pronounced improvements, with the 1 wt.% ZnO group achieving the highest transverse strength and the 1 wt.% ZnO–Sm₂O₃ hybrid group exhibiting the maximum flexural strength. Increasing the nanofiller concentration to 2 wt.% resulted in partial reductions in impact and flexural strength, which were attributed to nanoparticle agglomeration and increased light scattering during photopolymerization. FTIR analysis revealed no evidence of chemical bonding between the resin matrix and the nanofillers, indicating that the observed enhancements were primarily governed by physical reinforcement mechanisms. Wettability analysis showed that Sm₂O₃-containing formulations significantly reduced the water contact angle, indicating increased surface hydrophilicity, whereas ZnO incorporation produced more hydrophobic surfaces. Within the limitations of this in vitro study, the findings suggest that low-concentration incorporation of ZnO and Sm₂O₃ nanoparticles represents an effective strategy to enhance the mechanical integrity and tailor the surface properties of DLP 3D-printed denture base resins. These results suggest potential clinical relevance of nanoparticle-reinforced printed denture bases, emphasizing the importance of optimized filler loading to avoid agglomeration-induced performance degradation. Full article

Objectives: This study investigated the impact of age on the diagnostic accuracy and patient acceptance of two chewing efficiency tests: the digital Mini Dental Assessment (MDA) using carrots and the CHEW test by Slavicek using fruit gum, applied in both clinical and nursing home settings. Methods: Seventy participants aged 18 to 99 years from dental clinics and nursing homes were included. All participants received a standardized dental examination (reference standard) and performed the MDA and CHEW tests. Sensitivity, specificity, and AUC values were calculated using ROC analysis. Participants rated both tests in terms of taste, consistency, comprehensibility, required time, and subjective chewing sensation. Acceptance was analyzed across age groups and prosthesis types. Results: Both chewing efficiency tests showed good agreement with the clinical reference standard. The AUC was 0.72 for the MDA and 0.78 for the CHEW test (p = 0.192). Sensitivity was higher for the CHEW test (100%) compared to the MDA (83.3%), while the MDA demonstrated slightly higher specificity (59.6% vs. 55.8%). Age significantly influenced both diagnostic outcomes and test acceptance (p < 0.05). Younger participants (<70 years) were more often correctly classified as healthy and tended to prefer the MDA, whereas older participants (≥70 years) preferred the CHEW test, primarily due to taste. Misclassifications occurred most frequently among participants with complete dentures. Conclusions: Both the digital MDA and the CHEW chewing test demonstrated good diagnostic performance in identifying treatment need. Acceptance varied significantly with age, suggesting that test selection may be optimized based on patient characteristics. These simple and rapid assessments may support early detection of dental treatment needs in clinical and nursing home settings. Full article

Sjögren’s syndrome (SS) is a chronic autoimmune disease characterized by severe hyposalivation and mucosal fragility, conditions that significantly complicate prosthetic rehabilitation. Reduced salivary flow compromises denture retention, increases mucosal trauma, and predisposes patients to infections such as oral candidiasis, limiting the success of conventional tissue-supported prostheses. This work summarizes current evidence on prosthetic management strategies in SS, highlighting the role of optimized biomaterials, digital manufacturing technologies, and implant-supported solutions. Emphasis is placed on multidisciplinary care, adjunctive pharmacological management of xerostomia, and long-term maintenance protocols to improve function, comfort, and quality of life in this complex patient population. Full article

Background/Objectives: Artificial teeth in complete dentures are classified according to the materials used: porcelain (PO) or composite resin (CR). However, these materials’ effects on function, patient satisfaction, and quality of life (QOL), as well as occlusal wear, remain unclear. We compared PO and CR complete dentures in edentulous patients by assessing masticatory function, patient satisfaction, and oral health-related QOL at 3, 6, and 12 months post-insertion, as well as occlusal surface morphology owing to material differences. Methods: In this open-label, randomized, single-center, parallel-group study, participants were edentulous patients who visited our hospital and underwent treatment with new complete dentures. The outcomes were oral health-related QOL; subjective satisfaction, assessed using a visual analog scale; and masticatory performance, evaluated with gummy jelly and were assessed at baseline and 3, 6, and 12 months post-denture insertion. Occlusal surface impressions were taken twice, digitized as STL models, superimposed, and analyzed for wear. The Wilcoxon rank-sum test was used to compare between groups. Results: All evaluated items showed improvement. However, no significant differences were observed between the PO and CR groups, including between the amount of wear observed in the two groups. However, the PO group showed a tendency toward less wear. Extended observation may be required to clarify the long-term effects of artificial tooth materials. Conclusions: In the short term, the artificial tooth material did not influence masticatory function, oral health-related QOL, or patient satisfaction. Full article

Background: Three-dimensional (3D) facial scanning is an objective, non-invasive method for quantifying facial soft-tissue changes following complete denture (CD) rehabilitation. Reliable quantification of these changes in completely edentulous patients can support more predictable aesthetic and functional outcomes. Methods: This prospective before–after observational study included 30 completely edentulous patients (12 men, 18 women; age 48–87 years; mean ± SD: 67.8 ± 9.2 years) who received new maxillary and mandibular CDs. Structured-light 3D facial scans were obtained at baseline (edentulous, without dentures) and post-rehabilitation with dentures in place, in relaxed posture (RP) and maximal intercuspation (MI). Sixty-five validated anthropometric landmarks were analyzed. Primary outcomes were lower facial height (Sn-Gn), nasolabial angle (Cm-Sn-Ls), lower facial convexity (Ls-Li-Pg), mouth width (Ch-Ch), and upper vermilion height (Ls-Sto). Pre–post changes were assessed using paired-sample tests (p < 0.05). Results: Thirty-four of 65 parameters (52.3%) demonstrated significant post-treatment changes (p < 0.05), mainly in the perioral and lower facial regions. The reported parameters were selected due to their clinical relevance in evaluating perioral support and facial profile changes after complete denture treatment. In RP, upper lip thickness increased from 3.69 ± 0.97 mm to 4.96 ± 1.11 mm (Δ = +1.27 mm; p < 0.0001) and lower lip thickness from 6.18 ± 2.69 mm to 7.36 ± 1.52 mm (Δ = +1.18 mm; p = 0.0408). The nasolabial angle decreased from 116.08 ± 9.17° to 108.06 ± 9.56° (Δ = −8.02°; p = 0.0016). In MI, mouth width increased from 55.72 ± 3.43 mm to 57.97 ± 3.13 mm (Δ = +2.25 mm; p = 0.0102). Conclusions: Complete denture rehabilitation produces measurable, clinically relevant improvements in facial soft-tissue morphology in completely edentulous patients, particularly affecting lip support, mouth width, and the nasolabial profile. Structured-light 3D facial scanning provides a reproducible approach to objective outcome assessment and may support individualized denture design. Full article

Background/Objectives: The purpose of this in vitro study is to evaluate the effect varying palatal vault depths have on the accuracy of complete maxillary denture bases fabricated using additive manufacturing technology. Methods: One hundred complete maxillary denture bases were manufactured on two different digital light processing (DLP) dental 3D printers at five different palatal depths. After manufacturing, the denture bases were post-cured, scanned, and then analyzed in metrology software. Statistically significant differences were determined using two-way ANOVA tests for normally distributed data and the Kruskal–Wallis test for non-normally distributed data. Color deviation maps were used to give clinical relevance to the results. Results: Significant differences were found for both printers among some groups for the different palatal depths. In relation to the negative mean deviation, the data revealed that the NextDent printers were the least accurate (0.047 ± 0.004) in the group with the deepest palate. The positive mean deviation revealed the most deviation (0.077 ± 0.009) in the group with the deepest palate, which was also mirrored in the Asiga printer (0.050 ± 0.002). The color deviation maps revealed areas of positive and negative average deviation in all groups. The effect of the printer model (p = 0.007) and palatal depth (p = 0.04) on negative average deviation was significant. The effect of the interaction of printer and palatal depth was also significant (p = 0.001). Conclusion: Deeper palatal vaults are associated with higher deviation in DLP 3D-printed complete maxillary denture bases manufactured through additive manufacturing. Full article