Search Results (3,381)

Background: Zirconia ceramics are generally used in monolithic restorations, and their microstructural, mechanical, and optical properties continue to improve. Several factors affect the mechanical properties of these restorations; however, the combined effects of yttria content and margin design on the fracture resistance remain unclear. Methods: Sixty monolithic zirconia crowns were fabricated and assigned to six groups (n = 10) based on three different yttria contents (strength-gradient multilayer zirconia containing 3 mol% yttria tetragonal zirconia polycrystals in the dentin region and 5 mol% yttria-partially stabilized zirconia in the occlusal region: 3Y-TZP/5Y-PSZ [ZP], 3 mol% yttria tetragonal zirconia polycrystals: 3Y-TZP [HTML], and 4 mol% yttria-partially stabilized zirconia: 4Y-PSZ [STML]), and two different margin designs (chamfer and rounded shoulder). Crowns were adhesively bonded to standardized 3-dimensional-printed resin dies and subjected to thermal and mechanical aging (10,000 thermocycles at 5–55 °C, and 1.2 million mechanical cycles at 50 N, 1.6 Hz). Fracture resistance values were recorded in Newtons, and fracture types were evaluated. Data were analyzed using a two-way analysis of variance (ANOVA), and Bonferroni adjustment was used for multiple comparisons (α = 0.05). Results: A significant interaction between yttria content and margin design was found (p = 0.005). In the chamfer margin design groups, ZP (2208.5 ± 501.9 N) and HTML (2069.6 ± 463.3 N) showed significantly higher fracture resistance than STML (1444 ± 303.2 N) (p < 0.05). In the rounded shoulder margin design groups, no significant differences were observed among ZP (1662.8 ± 293.8 N), HTML (1940.9 ± 341.6 N), and STML (1795.6 ± 529.6 N) (p > 0.05). ZP and HTML showed higher fracture resistance values with the chamfer margin design, while STML showed higher fracture resistance with the rounded shoulder margin design. Conclusions: The fracture resistance of zirconia restorations is influenced by both the margin design and the yttria content. Designing the margin geometry based on the type of zirconia to be used can enhance the mechanical properties of the restorations and support clinical decision-making. Full article

Objective: This cross-sectional study investigated whether the frequency of waking-state and sleep-related bruxism is associated with sensitivity to occlusal tactile stimuli (i.e., occlusal tactile acuity) in healthy individuals. Methods: Forty healthy participants (20 females and 20 males) completed the Oral Behavioural Checklist to assess the frequency of waking-state and sleep-related bruxism. Participants were stratified into groups representing low, medium, and high bruxism frequency. Occlusal tactile acuity was evaluated using articulating foils of different thicknesses (8–56 μm) and sham trials presented in random order. Each stimulus was tested six times. Participants indicated whether they perceived a foil between their teeth. Signal detection theory was applied to distinguish perceptual sensitivity from response strategy. Results: Detection accuracy increased with foil thickness. Individuals with a high frequency of sleep-related bruxism exhibited reduced detection of thinner foils (8–24 μm) compared with those with low frequency of sleep-related bruxism (p = 0.029). Additionally, participants with high-frequency waking-state or sleep-related bruxism were more reluctant to report occlusal contact, indicating a more conservative reporting strategy (p = 0.045 and p = 0.002, respectively). Conclusions: Higher frequency of sleep-related bruxism was associated with reduced detection of low-intensity occlusal stimuli and a more conservative reporting strategy. These findings indicate an association between sleep-related bruxism frequency and differences in occlusal tactile detection. However, as the bruxism assessment was based on self-reports, these findings should be interpreted with caution. Full article

Two hemostatic bionanocomposite dressings were developed using natural, semi-natural (or semi-synthetic) and synthetic polymers. The first system consisted of chitosan (CS), polyvinyl alcohol (PVA), and carboxymethyl cellulose (CMC) (CS/PVA/CMC), while the second was based on CS, PVA, and starch (SR) (CS/PVA/SR). Zinc oxide (ZnO) nanoparticles and bicyclic monoterpene camphor (CP) ketone were incorporated as bioactive agents in order to enhance antimicrobial and hemostatic performance. FTIR spectroscopy confirmed the successful solvent casting synthesis of the dressings and the interactions between the biopolymers and additives. XRD analysis indicated a predominantly amorphous structure, while SEM images and EDS analysis revealed uniform dispersion of ZnO particles within the polymer matrices without aggregation. Furthermore, the CS/PVA/CMC-1ZnO/CP sample exhibited a water sorption of 12,666 ± 126%, while CS/PVA/SR-1ZnO/CP reached 7013 ± 215%. ZnO incorporation also improved mechanical performance, with CS/PVA/SR-2ZnO/CP displaying the highest tensile strength (39.18 ± 0.2 MPa) and elongation at break (9.54 ± 1.04%). ZnO incorporation also led to a concentration-dependent increase in antibacterial activity, with SR-based dressings achieving near-complete bacterial reduction at higher ZnO loadings. All the dressings demonstrated good biocompatibility, while CS/PVA/SR-1ZnOCP showed the fastest clotting time (420s ± 40), highlighting its potential for hemostatic applications. Full article

Coaggregation by bridging bacteria such as Fusobacterium nucleatum is considered a key element in dental biofilm development and maturation. Previous studies showed that sublethal exposure to blue light caused damage to cell membrane integrity. The aim of the present study was to test the effect of blue light phototoxicity on this bacterium’s ability to coaggregate with the early colonizer Streptococcus sanguinis. Fusobacterium nucleatum bacterial cells were suspended in coaggregation buffer (CAB) and exposed to blue light (400–500 nm) for 0, 70, 140 and 280 s (i.e., fluences of 0, 96, 192 and 384 J/cm², respectively). Following blue light exposure, samples were mixed with Streptococcus sanguinis suspensions and coaggregation was measured using a visual scale, spectrophotometric analysis and light microscopy. Results showed that blue light exposure significantly reduced the ability of Fusobacterium nucleatum to coaggregate with Streptococcus sanguinis. These results suggest that blue light antibacterial phototoxicity may be considered as a viable option in preventing dental biofilm-related conditions. Full article

Nesfatin-1 and ghrelin O-acyltransferase (GOAT) have established roles in metabolic regulation and neuronal excitability, yet their relationship in epilepsy remains conflicted. This cross-sectional study compared 22 adolescent epilepsy patients (13.1 ± 2.0 years; 11 women/11 men) with 20 age-matched healthy controls (HCs) (12.3 ± 2.2 years; 8 women/12 men). Serum and salivary nesfatin-1 and GOAT levels were measured by enzyme-linked immunosorbent assay; Spearman’s rank correlation assessed inter-neuropeptide relationships. Serum nesfatin-1 was markedly elevated in patients with epilepsy compared to HCs (44.04 (interquartile range 38.19–76.72) vs. 8.65 (interquartile range 7.82–9.01) ng/mL, p < 0.001; ~5-fold). Serum GOAT was similarly elevated (4.90 (interquartile range 4.17–6.66) vs. 1.41 (interquartile range 1.21–1.79) ng/mL, p < 0.001; 3.5-fold). A significant inverse correlation between serum nesfatin-1 and GOAT levels was identified in patients with epilepsy (rho = −0.68, 95% CI [−0.86, −0.36], p < 0.001) but not in HCs (p = 0.53) and remained independent of age, sex, body mass index and epilepsy type. This inverse correlation was significant in women (rho = −0.68, p = 0.021) with a similar trend in men (rho = −0.53, p = 0.096). Salivary nesfatin-1 mirrored serum patterns (2.3-fold increase; p < 0.001), while salivary GOAT showed a 9-fold reduction (p < 0.001). This study provides the first evidence of an inverse nesfatin-1/GOAT correlation in adolescent epilepsy, suggesting disease-specific neuroendocrine dysregulation. These exploratory findings support the potential of these neuropeptides as candidate biomarkers warranting further validation and offer new insights into the metabolic-excitability axis in epilepsy. Full article

This study evaluated the physical and mechanical properties of acrylic resins used for interim fixed prostheses, with and without metal reinforcement, before and after aging. A total of 138 samples were divided into three groups: VIPI + Wire (control), VIPI, and Diamond D. Samples were assessed for microhardness, porosity, roughness, and flexural strength. Aging was simulated using 500 thermocycling cycles at 5 and 55 ± 1 °C. Data were analyzed using ANOVA and Tukey’s test. Group Diamond D did not fracture during flexural testing, but it exhibited significantly lower microhardness at both baseline and after aging. Before aging, Group Diamond D had higher roughness than Group VIPI, which exhibited greater porosity. Aging increased the microhardness of Group VIPI and the roughness of Group Diamond D. The percentage of porosity decreased significantly for Groups VIPI + Wire and VIPI, and pore size was reduced in all groups. Based on the results obtained from Diamond D material, this resin does not meet the required properties for the proposed indication for temporary fixed prostheses, whereas VIPI with reinforcement showed superior properties and greater stability after aging. Full article

Objectives: This study aimed to evaluate the masking ability of different thicknesses of advanced lithium disilicate (ALDS) ceramic used for implant-supported crowns compared to conventional lithium disilicate (LDS) and to assess the influence of their combination with various implant abutment materials. Methods: Two types of high-translucency computer-aided design/computer-aided manufacturing (CAD/CAM) glass–ceramics in shade A2 were tested: IPS e.max CAD (LDS) and CEREC Tessera (ALDS). Each material was sectioned into four thicknesses (n = 8 per group). Four implant abutments were evaluated: titanium (Ti), yellow-anodized titanium (TiY), pink-anodized titanium (TiP), and white zirconia (Zir). The translucency parameter (TP₀₀) and color difference (∆E₀₀) between the glass–ceramic and abutment were calculated using the CIEDE2000 formula. Results: Significant differences were observed between 1.0 mm and 2.5 mm thicknesses in all groups except for ALDS on TiY. Both glass–ceramics on TiY and TiP showed lower ∆E00 values than those on Ti, except for 2.0 mm and 2.5 mm ALDS. Additionally, their ∆E00 values were lower than those on Zir. Clinically acceptable ∆E₀₀ values occurred for 2.5 mm LDS on TiP, 2.0 mm ALDS on TiY and TiP, and 2.5 mm ALDS on TiY and TiP. ALDS demonstrated lower TP₀₀ values than LDS at corresponding thicknesses. Conclusions: Greater restoration thickness and titanium anodization improved color masking. Anodized titanium enhanced the glass–ceramic masking ability. ALDS at 2.0–2.5 mm on TiY or TiP and 2.5 mm LDS on TiP achieved clinically acceptable masking, with ALDS showing lower translucency than LDS. Full article

Objectives: To evaluate the influence of two surface finishing procedures—mechanical polishing and glaze firing—on the color stability and wear behavior of lithium aluminium disilicate (LAD) hybrid abutment crowns over a three-year clinical observation period. Methods: Twenty-four patients requiring 34 implant-supported single crowns were included in this prospective clinical study. LAD abutment crowns were fabricated using n!ce ceramic and a CAD/CAM workflow and finished either by mechanical polishing (P, n = 17) or glaze firing (G, n = 17). After insertion as well as after one and three years (P: n = 9, G: n = 9) of clinical use color measurements were performed using spectrophotometry, and color differences (ΔE00) were calculated. Wear was assessed by digital surface comparison of baseline and the two follow-up scans using three-dimensional analysis software. Reference teeth (R) were defined and evaluated comparable to the P and F groups. Biological and technical complications were recorded throughout the observation period. Results: Color deviations increased over time in all groups (P, G, R). After three years, G showed lower mean color differences (ΔE00 ≈ 2.77) compared with F (ΔE00 ≈ 5.40), although the difference was not statistically significant. No significant differences in vertical height loss were observed between P and G. One adhesive fracture occurred both in the P and G group, five crowns (P: n = 3, G: n = 2) developed periimplantitis. Conclusions: Both polishing and glazing resulted in comparable clinical outcomes regarding color stability, wear behavior, and complication rates. Clinical Significance: Both finishing protocols might be a reliable option for LAD hybrid abutment crowns. Full article

Accurate, standardized dental model measurements remain labor-intensive and difficult to scale in orthodontics. This technical development study aimed to develop and preliminarily evaluate a semiautomated three-dimensional (3D) dental cast measurement system using standardized measurement templates (patent pending). The workflow integrates robotic handling of models, X-ray CT acquisition of volumetric data, optional intraoral-scan polygonal data (e.g., STL), template generation from 3D data, and orthodontist-guided landmark placement, after which dedicated software retrieves 3D coordinates and performs automated measurements and visualization. The system was demonstrated on four standard models scanned by X-ray CT. It produced automated aggregation of measurements and 3D visual outputs, and enabled calculation of conventional indices as well as template-based metrics such as palatal volume and cusp height variation. This semiautomated approach combines mechanical efficiency with expert oversight, providing a standardized alternative to manual measurement and a foundation for broader applications in orthodontic, prosthodontic, and forensic contexts. Full article

Background/Objectives: The quality of intraoral scanner-derived digital models depends not only on deviation-based accuracy, but also on how scanned surfaces are reconstructed into a polygonal mesh. The aim of this prospective within-subject observational study was to evaluate whether tooth morphology influences local mesh density distribution in intraoral scanner-derived STL models of selected maxillary teeth. Methods: Twenty participants underwent maxillary intraoral scanning using a Medit i900 wired intraoral scanner under standardized clinical conditions. For each participant, the buccal surfaces of the maxillary right central incisor (11), canine (13), first premolar (15), and first molar (16) were selected as regions of interest. Surface area (A), number of vertices (V), and number of faces (F) were recorded, and the surface-normalized mesh density parameters vertices per unit area (V/A) and faces per unit area (F/A) were calculated. Comparisons among tooth types were performed using repeated-measures analysis of variance (ANOVA) with Bonferroni post hoc correction. Results: Significant differences were found among tooth types for both V/A and F/A (p < 0.001). Mean V/A values were 18.2 ± 1.9 for tooth 11, 19.8 ± 1.4 for tooth 13, 23.8 ± 1.7 for tooth 15, and 22.9 ± 2.0 vertices/mm² for tooth 16. Mean F/A values were 34.3 ± 3.6, 37.5 ± 2.7, 44.4 ± 3.3, and 42.9 ± 3.8 faces/mm², respectively. Post hoc comparisons showed significant differences between teeth 11 and 13, 11 and 15, 11 and 16, 13 and 15, and 13 and 16, whereas no significant difference was observed between teeth 15 and 16. Conclusions: Tooth morphology significantly influenced local mesh density distribution in intraoral scanner-derived STL models of selected maxillary teeth. These findings suggest that local anatomical form affects STL mesh reconstruction under standardized in vivo scanning conditions and support local mesh density analysis as a useful complementary approach to conventional deviation-based digital assessment. Full article

Background/Objectives: Dental caries is one of the most prevalent chronic diseases in childhood, disproportionately affecting socially vulnerable populations. This scoping review aimed to analyze the clinical effects of selected minimally invasive materials and approaches, specifically mouthrinses, fluoride varnishes, silver diamine fluoride, and glass ionomer-based interventions, for the prevention and management of dental caries in pediatric patients, with emphasis on public health and community-based settings. Methods: This scoping review followed the Population, Concept, and Context (PCC) framework. Electronic searches were conducted up to 23 January 2026, using tailored strategies for mouthrinses, fluoride varnishes, silver diamine fluoride (SDF), and glass ionomer cements (GICs). Randomized clinical trials (RCTs) were included. Data extraction and qualitative synthesis focused on clinical outcomes and applicability in public health contexts. Results: Fifty-five RCTs were included. Fluoride- or chlorhexidine-based mouthrinses showed potential in controlling cariogenic biofilm, with evidence primarily based on microbiological outcomes. Fluoride varnishes were associated with enamel remineralization and control of early white spot lesions, particularly in supervised programs. SDF was reported to achieve high caries’ arrest rates in cavitated dentin lesions of primary teeth, while its preventive effect on sound surfaces appeared comparable to other fluoride-based interventions. GICs were associated with acceptable clinical performance as pit-and-fissure sealants and in atraumatic restorative treatment. Conclusions: Minimally invasive dentistry (MID) approaches show promise for the prevention and management of childhood dental caries in public health and community-based settings. However, these findings should be interpreted with caution due to the heterogeneity of interventions and outcome measures, the predominance of short-term and surrogate (microbiological) outcomes, and the absence of a formal risk-of-bias assessment. As a scoping review, the synthesis is narrative in nature, which limits the ability to draw definitive conclusions. Further studies with standardized clinical outcomes and longer follow-up are needed to strengthen the evidence. Full article

Background: Alterations of the vertical dimension of occlusion may affect masticatory muscle function, which is critical in pre-prosthetic planning, especially in Class II division 2 malocclusions. This study aimed to evaluate the impact of increasing VDO on the myoelectric activity of masticatory muscles using surface electromyography (EMG). The null hypothesis was that a 2–4 mm increase in VDO does not significantly influence muscle activity. Methods: Nine patients with Class II division 2 malocclusion were evaluated. EMG recordings of the masseter and anterior digastric muscles were obtained using the BioEMG II system (BioResearch Asoc., Milwaukee, WI, USA) and Biopak™ software (AcqKnowledge 4.x). VDO was increased using the Dupas universal jig. EMG was recorded for 30 s under six conditions: resting posture, intercuspal position (IM), swallowing, resting posture after VDO increase, IM with increased VDO (IM2), and swallowing with increased VDO (swallowing 2). Results: Most EMG variables showed no statistically significant differences after short-term VDO increase. Significant differences were observed only in the resting activity of both masseter muscles and in the right masseter during maximum intercuspation. No significant changes were identified during swallowing. Conclusions: Within the limitations of this pilot study, a 2–4 mm increase in VDO appears to produce minimal short-term changes in masticatory muscle activity in Class II division 2 patients. These findings should be interpreted with caution due to the small sample size and short observation period, and further studies are required to evaluate long-term neuromuscular adaptation. Full article

Additive manufacturing enables the fabrication of patient-specific zirconia devices with integrated surface features; however, the biological effects of meso-scale topographies remain insufficiently understood. This in vitro study evaluated the influence of defined meso-scale surface modifications on osteoblast behavior using Digital Light Processing (DLP)-fabricated 3Y tetragonal zirconia polycrystal (3Y-TZP) and 5Y partially stabilized zirconia (5Y-PSZ). Planar control specimens and surfaces incorporating regularly distributed columnar structures (height: 100 µm; width: 40 µm; center-to-center spacing: 80, 120, and 160 µm; Mod-80, Mod-120, Mod-160) were fabricated and characterized after sintering. Cytotoxicity was assessed by elution testing and showed cell viability >98% for all groups. Osteoblast adhesion and proliferation (hFOB 1.19) were quantified using metabolic assays. Meso-scale modifications significantly increased early cell adhesion compared to planar controls (p < 0.05), with the strongest effect observed for Mod-160. No significant differences in proliferation rates were detected between groups (p > 0.05). Osteogenic differentiation was evaluated by RT-qPCR (RUNX2, ALPL, COL1A1, BGLAP), revealing material- and geometry-dependent responses. On 3Y-TZP, meso-scale structures, particularly Mod-160, were associated with sustained upregulation of BGLAP, whereas 5Y-PSZ exhibited less pronounced effects. Within the limitations of this in vitro study, meso-scale surface structuring of additively manufactured zirconia enhances early osteoblast adhesion without affecting proliferation and may influence osteogenic differentiation in a material-dependent manner. Full article

This study comparatively evaluated the influence of processing routes on the optical stability of three dental resin composites: a light-cured direct composite—G-ænial A’CHORD (LCC), a CAD-CAM milled composite—BreCAM.HIPC (MC), and a 3D-printed composite—Saremco Print Crowntec (PC). Specimens were analyzed before (T0) and after hydrothermal aging for 5000 (T1), 10,000 (T2), and 30,000 cycles (T3). Optical stability was assessed through the change in color (ΔE₀₀) and translucency parameter (TP) after aging and immersion in beverages. Surface topography was evaluated using atomic force microscopy (AFM), while Raman spectroscopy was employed to detect aging-induced molecular changes. After aging and staining, all composites exceeded the acceptability threshold for color change. ΔE₀₀ values of 6.8 ± 1.1 (PC), 4.6 ± 0.9 (MC), and 2.1 ± 0.9 (LCC), obtained after initial aging, further increased following prolonged immersion in coffee. After 1 day of immersion in Coca-Cola, MC exhibited the highest ΔE₀₀ values, which slightly exceeded the clinically acceptable threshold. Prolonged immersion (7 days) significantly increased staining for all materials. TP values significantly differed among materials, with the highest values detected for LCC (20.6 ± 3.6) and PC (19.1 ± 1.5) and the lowest values detected for MC (4.9 ± 0.8). Overall, the results demonstrated that ΔE₀₀ was strongly influenced by the processing route and surface topography, whereas changes in translucency parameter (TP) were predominantly governed by the intrinsic properties of the resin composites. Full article

Background/Objectives: This study aimed to compare AI-generated educational material with faculty-authored content in Dental Prostheses Technology, evaluating perceived clarity, accuracy, structure, usefulness, and overall instructional quality across different age and professional groups. Methods: An analytical cross-sectional study was conducted using two versions of the first three chapters of a prosthodontics textbook: the original faculty-authored text and a reformulated version generated by ChatGPT 5.2 (OpenAI). Images were removed and formatting standardized to ensure a text-only comparison. An anonymized online questionnaire based on a five-point Likert scale assessed clarity, accuracy, readability, usefulness and structure. To reduce potential bias, participants were unaware of the authorship of the evaluated materials (human-authored vs. AI-generated). A total of 130 participants independently reviewed both documents. Data were analyzed using Wilcoxon signed-rank, Mann–Whitney U, and Friedman tests. Results: Both materials received favorable evaluations across all dimensions. The AI-generated version demonstrated a statistically significant advantage in clarity (Z = −2.107, p = 0.035; r = 0.19), while no significant differences were observed for structure, accuracy, readability, or usefulness. Generational differences emerged: younger participants valued improved clarity but reported reduced usefulness, mid-career participants showed the greatest improvement in perceived accuracy, and senior professionals reported substantial gains in usefulness and readability. Conclusions: AI-generated educational material demonstrates pedagogical equivalence to faculty-authored content, with clarity representing its principal advantage. Large language models may serve as effective complementary tools in dental education, particularly for restructuring complex content. Full article