Purpose: Osseointegration begins at the initial blood–implant contact; however, titanium-adhesive blood proteins remain incompletely defined. We used a structure-free, nano-smooth titanium substrate (Ra ≈ 0.6 nm) to identify titanium-adhesive blood proteins and determine whether coating such proteins modulates cell adhesion, osteogenic differentiation, and peri-implant bone formation.

Methods: Whole blood from Sprague–Dawley rats was seeded on nano-smooth titanium, followed by stringent washing. Adherent proteins were recovered and analyzed using LC–MS/MS and STRING-based bioinformatics screening. Vitronectin was identified as a major titanium-adhesive protein and functionally evaluated using a recombinant protein. Bone marrow stromal cell (BMSC) adhesion, osteogenic gene expression, mineralization, and peri-implant bone formation were assessed in a rat model. Phosphate-buffered saline (PBS)-treated, albumin-coated, and fibronectin-coated titanium surfaces were used as controls.

Results: The vitronectin coating significantly enhanced early BMSC adhesion compared to all control surfaces, whereas fibronectin and albumin demonstrated no effect. Vitronectin did not alter osteogenic gene expression or mineralization in vitro but significantly accelerated peri-implant bone formation in vivo.

Conclusions: Vitronectin exhibits physicochemical affinity for nano-smooth titanium and promotes peri-implant bone formation, primarily by accelerating early cell adhesion rather than by directly stimulating osteogenic differentiation.

Purpose: This study evaluates and compares the flexural properties of computer-aided design-computer-aided manufacturing (CAD-CAM) resin composite and polyetheretherketone (PEEK) blocks used for molar crowns under three storage conditions. Furthermore, the relationship between the inorganic filler content (>70 wt. %) and the flexural properties of the resin composite blocks was clarified.

Methods: Five commercially available resin composite blocks and one PEEK block were subjected to three storage conditions: dry storage, water immersion for 7 d at 37 °C, and 10,000 thermal cycles between 5 and 55 °C. The flexural strength and flexural modulus were analyzed using two-way ANOVA, followed by Tukey’s post-hoc comparisons. The inorganic filler content and water sorption were analyzed via one-way ANOVA and the Tukey–Kramer post-hoc test, with the level of significance set at 5%.

Results: The resin composite blocks exhibited a significantly higher flexural strength and flexural modulus than the PEEK block. A positive correlation was observed between the inorganic filler content and the flexural properties of the CAD-CAM blocks, specifically for the flexural strength (r = 0.49) and flexural modulus (r = 0.63). However, the PEEK block exhibited the lowest water sorption and minimal flexural properties changes across all conditions, as compared to the resin composite blocks.

Conclusions: Both the inorganic filler content and matrix resin composition influenced the flexural properties of the CAD-CAM crown materials. PEEK demonstrated superior durability under thermal and humid conditions, indicating its potential as a long-term restorative material for posterior crowns.

Purpose: We evaluated the influence of multiple uses of scan bodies after reprocessing cycles—steam sterilization and thermal disinfection—on the precision of implant position transfer.

Methods: Six mandibular models with two implants in regions 34 and 36 were fabricated. The implants were scanned with an intraoral scanner using pairs of titanium (SB_T_Pr) and polyether ether ketone (PEEK) (SB_P_Pr) scan bodies according to the manufacturers’ recommendations. The scan body group underwent up to 15 standardized reprocessing cycles. The unreprocessed titanium group (SB_T_NPr) served as a control. Three-dimensional deviations (R) between the implant positions were calculated from the scanned STL datasets and statistically analyzed (P < 0.05).

Results: A preliminary investigation demonstrated that 15 cycles of screwing in and out of the titanium or PEEK scan bodies did not influence subsequent measurements (P = 0.129, P = 0.215). The mean ΔR values were 38.9 ± 18.7 µm for SB_T_NPr and 42.6 ± 19.5 µm for SB_T_Pr. No significant differences in precision were found between the unprocessed and reprocessed titanium scan bodies within 15 cycles (P = 0.174). The mean ΔR value for SB_P_Pr was 27.1 ± 12.5 µm. In contrast, the PEEK scan bodies consistently showed significantly lower deviations than the titanium scan bodies (P < 0.001).

Conclusions: PEEK scan bodies demonstrate higher precision but may be limited by lower mechanical stability and their single-use concept. Titanium scan bodies, although slightly less precise, have proven to be mechanically robust and suitable for multiple reuses after the conducted reprocessing. Further clinical studies with extended re-processing cycles are required to confirm these findings.

Purpose: To examine the association between dentition status and frailty across different age groups, and explore the mitigating role of dietary intake.

Methods: This cross-sectional study involved data on participants aged ≥60 years from the National Health and Nutrition Examination Surveys (NHANES) in the United States (2011–2018). Dentition status was assessed by:1) dento-occlusal support pattern (according to Miyachi’s Triangular Classification), which combines the number of remaining natural teeth and occlusal supports, and 2) number of functional teeth. Frailty and dietary intake were assessed using the Frailty Index (FI) and the 2015 Healthy Eating Index 2015 (HEI-2015). Covariates included age, sex, education, ethnicity, smoking status, income, marital status, and physical activity. Beta regression analysis was used to examine these associations.

Results: Among the 6,859 older participants, the mean age was 69.9 years (SD 6.9), diet according to HEI-2015 was 58.1 (SD 13.5) and FI was 0.24 (SD 0.15). Regarding the triangular classification, compared to those in Zone A (mild level), the estimate for FI was significantly higher in Zone B (1.16; 95% confidence interval [CI],1.09–1.23), Zone C (1.30; 95% CI,1.22–1.38), and Zone D (severe level) (1.27; 95% CI,1.16–1.39). For each additional functional tooth, the estimate for FI score was 0.985 (95% CI, 0.981–0.989). Adjusting for dietary intake mitigated the association between dentition status and frailty, which was attenuated with increasing age.

Conclusions: There is an association between dentition status and frailty among adults in the United States, with dietary intake slightly mitigating this association.

Purpose: Tooth extraction due to root fractures has recently been increasing. Preserving fractured teeth is clinically important to prevent progressive tooth loss and subsequent occlusal collapse. In this retrospective cohort study, we aimed to evaluate long-term tooth retention after root fracture repair and identify prognostic factors associated with retention outcomes.

Methods: The participants were patients who were treated for fractured teeth at Niigata University Hospital in Niigata, Japan from 2003 to 2022. Tooth extraction was defined as the study endpoint. The effects of age, sex, location of teeth, presence of adjacent teeth, Eichner’s classification, Miyachi’s occlusal triangle, and fracture type were analyzed.

Results: In total, 330 root-fractured teeth of 264 patients were analyzed. Kaplan–Meier analysis demonstrated retention rates of 82.4% at 3 years and 70.1% at 5 years after repair, with a median retention period of 8.1 years. Log-rank tests showed that the absence of adjacent teeth (P = 0.01), Eichner’s classifications of B and C (P < 0.01), and Miyachi’s occlusal triangles II, III, and IV (P = 0.03) were significantly associated with worse retention. Cox proportional hazards analysis identified the absence of adjacent teeth (HR = 1.78; 95% CI: 1.05–3.08; P = 0.03) and Eichner’s classification B or C (HR = 2.27; 95% CI: 1.14–4.62; P = 0.02) as significant risk factors for the loss of root-fracture–treated teeth.

Conclusions: Root fracture repair may represent an effective strategy to delay tooth extraction and prevent occlusal collapse. Favorable retention outcomes were observed in patients with stable occlusal support, particularly those with adjacent teeth and an Eichner’s classification of A.

Purpose: This study retrospectively investigated the clinical outcomes of computer-aided design/computer-aided manufacturing (CAD-CAM) resin composite crowns for molars and analyzed the morphological factors contributing to crown failure using three-dimensional (3D) digital data.

Methods: The clinical outcomes of 117 crowns in 101 patients treated at Osaka University Dental Hospital were analyzed. 3D digital data were evaluated to identify factors influencing crown debonding, focusing on luting methods, abutment morphology, and crown parameters. Survival analyses, multivariate analyses, and regression modeling were performed.

Results: During an observation period of up to 1281 days, the cumulative success and survival rates were 83.3% and 95.5%, respectively. Debonding (12.0%) was the most frequent complication and was significantly associated with the choice of luting materials (P < 0.001). In addition, 3D analysis identified greater buccolingual taper, insufficient occlusal thickness, smaller abutment surface area, and reduced abutment height as predictors of debonding. Nonlinear regression analysis revealed significant differences in the abutment parameters between SA Luting and PANAVIA V5 at the lower percentiles (P = 0.02).

Conclusions: Combining clinical outcomes with 3D data highlights the importance of precise abutment preparation and material selection to reduce the risk of crown debonding.

Purpose: To develop a newly designed root-extended overlay (REO) for adolescents’ permanent mandibular first molars (M1Ms) with a 4-wall defect and to analyze the stress distribution of REOs using finite element analysis (FEA).

Methods: A post-endodontic M1M was 3D reconstructed from Cone-Beam Computed Tomography, and the model was then modified to simulate a 4-wall defect located 2 mm above the enamel-dentinal junction. Subsequently, REOs with 0–2 mm distal root extensions were designed using Ti-6Al-4V (3D printed), lithium disilicate (IPS e.max Press), and composite resin. In FEA, vertical (400 N) and lateral (225 N) loads were applied to evaluate the maximum von Mises stress (mVMS) and principal stress.

Results: Ti-6Al-4V, lithium disilicate, and composite resin exhibited similar stress distribution. Under vertical loading, the 2-mm group showed the highest mVMS in the restorations. Additionally, the 2-mm group exhibited the minimal tensile stress in the alveolar bone. The 2-mm group with Ti-6Al-4V minimized tensile stress in the cement layer and tooth structure under lateral loading.

Conclusions: The REO design was feasible for M1Ms with a 4-wall defect. The stress distribution of 3D printed Ti-6Al-4V was comparable to that of lithium disilicate. A 2-mm root extension exhibited optimal stress distribution across the restoration, cement layer, tooth structure, and periodontal tissues. This optimized stress distribution may reduce root fracture, debonding, and periodontal overload, supporting long-term preservation of mandibular first molars during occlusal and craniofacial development.

Purpose: This scoping review aimed to map and summarize existing evidence on the association between dental prosthesis use and cardiovascular events, highlighting current trends, methodological heterogeneity, and knowledge gaps to guide future research.

Study selection: This scoping review followed the methodologies described by the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) and the Joanna Briggs Institute (JBI). Literature searches were performed using the PubMed, Cochrane Library, and Google Scholar databases on November 10, 2024. Eligible studies included observational studies involving adults with diagnosed or undiagnosed cardiovascular disease (CVD) who use dental prostheses (removable, fixed, or implant-supported). Data were extracted and synthesized descriptively to map existing evidence.

Results: Seven studies were included: six cohort studies and one cross-sectional study. A cross-sectional study reported higher odds of angina, heart failure, and stroke among prosthesis users, whereas another cohort study found no significant association between recurrent myocardial infarction and stroke. Among the cohort studies assessing cardiovascular-related mortality, four reported a lower mortality risk among prosthesis users, while two observed a higher risk, particularly among complete or mixed-prosthesis users. Overall, the findings were inconsistent owing to methodological and population differences across studies.

Conclusions: This review mapped and summarized existing evidence on the association between dental prosthesis use and cardiovascular events. The available evidence remains limited, inconclusive, and heterogeneous, with variations in study design and confounder adjustments hindering clear interpretation. Further longitudinal studies using standardized methods are required to clarify these associations through interdisciplinary research.

Purpose: Oral hypofunction (OHF) is defined as a multidimensional impairment of oral function that may contribute to the development of geriatric syndromes. This cross-sectional study aimed to assess the relative importance of seven OHF components in relation to physical frailty, sarcopenia, and nutritional impairment, using machine learning methods that are robust to multicollinearity.

Methods: Data were pooled from two observational studies involving community-dwelling adults aged ≥65 years. Light Gradient Boosting Machine (LightGBM) algorithm was used to calculate the SHapley Additive exPlanation (SHAP) values, reflecting the relative contribution of each OHF component in the identification of three outcomes: physical frailty, sarcopenia, and nutritional impairment. Incremental contributions were further evaluated using integrated discrimination improvement (IDI) and C-statistics, weighted by the SHAP magnitudes.

Results: A total of 1,133 participants (mean age 74.4 years) were included. Low tongue pressure had the highest composite SHAP value among the three outcomes (5.20), followed by low masticatory performance, occlusal force, and articulatory oral motor skills. The IDI analysis confirmed that these four components provided incremental value in identifying frailty and sarcopenia. A simplified “OHF-4” model consisting of these four components alone demonstrated comparable discriminatory performance to the full seven-component model across all outcomes based on the C-statistics comparisons.

Conclusions: Four OHF components—low tongue pressure, masticatory performance, occlusal force, and articulatory oral motor skills —were the most informative indicators of geriatric syndromes. Targeting these specific functions may aid the development of effective oral function management strategies to mitigate the risk of geriatric syndromes.

Purpose: Open-source environments offer interesting opportunities to democratize digital workflows in dentistry, thereby reducing dependency on costly proprietary systems. This proof of concept aimed to demonstrate a method for creating a semi-adjustable virtual articulator by integrating intraoral, facial, and cone-beam computed tomography (CBCT) scans into freeware software.

Methods: CBCT-derived mandibular segmentation was combined with intraoral and facial scans within Meshmixer (v. 3.5; Autodesk Inc, San Francisco, USA), with anatomical condylar pivots defining the hinge axis. Alignment was achieved using dental surfaces as common references. The workflow enabled simulation of mandibular opening, closure, protrusion, and lateral excursions based on patient-specific anatomy in a virtual semi-adjustable articulator.

Conclusions: This proof of concept demonstrated how freeware environments can democratize access to virtual patient simulation, serving as a stepping-stone toward validated, cost-effective clinical workflows, fostering innovation beyond proprietary constraints and traditional facebows.

Patients: Two female patients aged 55 and 65 presented with persistent occlusal discomfort diagnosed as phantom bite syndrome (PBS) despite multiple prosthetic interventions. Neither had significant psychiatric comorbidity. Both underwent psychosomatic evaluation after non-pharmacological approaches proved insufficient. Pharmacotherapy included low-dose amitriptyline at 10–35 mg/day with aripiprazole augmentation at 1 mg/day in Case 1, and low-dose aripiprazole monotherapy at 1 mg/day in Case 2 after amitriptyline intolerance. Both patients showed marked improvement on the Oral Discomfort/Dysesthesia Rating Scale misalignment subscale, achieved stable occlusion without excessive adjustments, and reported no severe adverse effects during 27–33 months of follow-up.

Discussion: These cases show that pharmacotherapy targeting central hypersensitivity can facilitate successful prosthetic rehabilitation, even in patients without major psychiatric comorbidity. Continued medication during definitive prosthetic procedures helped prevent relapse, highlighting the value of integrated psychopharmacological and prosthodontic management. Clear communication, reframing the condition as hypersensitivity, and shared decision-making further improved adherence and long-term stability.

Conclusions: Maintaining pharmacotherapy throughout prosthetic treatment stabilized PBS symptoms, reduced relapse risk, and improved acceptance of definitive restorations. Recognition of possible central nervous system involvement, even without overt psychiatric comorbidity, broadens therapeutic options and supports better outcomes. Future studies should expand clinical case data, refine medication strategies, define optimal treatment timing, and strengthen interdisciplinary collaboration in PBS management.

Purpose: The aim of the current systematic review was to compare the internal fit of lithium disilicate crowns, fabricated using conventional heat-pressing versus CAD-CAM milling techniques.

Study selection: A comprehensive literature search was conducted in PubMed, Embase, Scopus, and the Cochrane Library up to December 2025, following PRISMA guidelines and registered in the Open Science Framework. Eleven studies met the inclusion criteria (nine in vitro studies and two clinical trials), of which nine were included in the quantitative synthesis.

Results: The random-effects meta-analysis demonstrated no statistically significant difference in internal fit between heat-pressed and CAD-CAM-milled crowns, although substantial heterogeneity was observed (I²=95%). Sensitivity analysis excluding five methodologically heterogeneous studies revealed a statistically significant pooled effect favoring heat-pressed crowns (MD=−18.92 μm; 95% CI: −29.77 to −8.07; P = 0.008), with markedly reduced heterogeneity (I²=19%). Subgroup analysis suggested that elastomeric impressions may be associated with better internal fit compared with digital workflows, although heterogeneity remained high.

Conclusions: The current evidence does not demonstrate a consistent difference in internal fit between heat-pressed and CAD-CAM-milled lithium disilicate crowns. Further well-designed, standardized clinical studies are needed to confirm these findings.

Purpose: Commercially pure titanium (CP-Ti) is ideal for removable partial denture (RPD) frameworks owing to its biocompatibility and corrosion resistance; however, conventional casting can introduce defects and dimensional errors. This study compared the shape accuracy, surface roughness, microstructure, and internal pores of CP-Ti RPD frameworks prepared using four CAD-CAM fabrication methods: (1) Ti-resin: casting from a three-dimensional (3D)-printed resin pattern; (2) Ti-wax: casting from a milled wax pattern; (3) Ti-milling: direct milling from a CP-Ti disc; and (4) Ti-SLM: selective laser melting.

Methods: Forty frameworks were prepared for each group (N = 10). Shape accuracy was assessed using 3D data-inspection software, surface roughness was analyzed using laser microscopy, the microstructure was determined using X-ray diffraction, and internal pores were examined using micro-computed tomography. Nonparametric statistics (Kruskal–Wallis and Steel–Dwass tests) were used (P < 0.05).

Results: Ti-SLM achieved the highest trueness (median: 0.00 mm; IQR: 0.09 mm) and precision (median: 0.01 mm; IQR: 0.02 mm), while Ti-milling yielded the lowest surface roughness (median arithmetic mean height: 0.61 µm; IQR: 0.05 µm). Internal pores were absent in Ti-milling and minimal in Ti-SLM (0–1), whereas Ti-resin and Ti-wax produced 319 and 171 pores (median), respectively. Significant inter-method differences were found in shape accuracy, surface roughness, and pore counts (P < 0.05).

Conclusions: The fabrication method affected the dimensional accuracy, surface conditions, crystalline features, and internal pores of the CP-Ti frameworks. Ti-milling and Ti-SLM outperformed the casting-based methods (Ti-resin and Ti-wax) in terms of accuracy and defect reduction. These digital approaches may improve the reproducibility and precision of clinical fabrication of CP-Ti RPD frameworks.

Purpose: The molecular mechanisms guiding osseointegration and soft tissue sealing remain poorly understood. Additionally, conventional assays provide limited insight. RNA sequencing (RNA-seq) offers an unbiased, genome-wide profiling of biological events. This review summarizes RNA-seq applications in implant research, highlighting current evidence and future opportunities.

Study selection: A structured search was conducted in PubMed to identify studies that included RNA-seq analyses with titanium surface experiments, including in vitro experiments with osteoblasts/mesenchymal stem cells, fibroblasts, macrophages, soft tissue cells, and in vivo animal models. An overview of the RNA-seq methodology and emerging applications of biomaterials was also included in the search.

Results: RNA-seq contributions comprised three categories: (1) confirmation of known responses, such as upregulation of osteogenic differentiation genes on microrough surfaces; (2) discovery of novel functions, including non-canonical Wnt signaling, oxidative stress regulators, and non-coding RNAs mediating osteogenesis and immune modulation; and (3) mechanistic explanations of paradoxes, such as the osteoblast “dilemma” of reduced proliferation but enhanced differentiation. Fibroblast studies linked ultraviolet-activated titanium to proteoglycan/glycosaminoglycan signaling, and macrophage analyses identified zinc-induced metallothioneins as immunomodulatory biomarkers. In vivo, RNA-seq revealed strontium-driven CDH2/β-catenin signaling, age-related suppression of Wnt/angiogenesis, and keratin-mediated soft tissue sealing. Notably, we presented new RNA-seq data demonstrating distinct osteoblast reprogramming on microrough titanium, including the activation of oxidative stress defense, lipid metabolism, and immune-osteoblast crosstalk.

Conclusions: RNA-seq is highly useful for establishing implant–tissue interactions, validating clinical observations, and revealing mechanistic explanations. Despite limited studies and protocol heterogeneity, RNA-seq offers a transformative framework for biologically informed and immune-smart implants.

Purpose: We evaluated the stress distribution patterns in inlay, onlay, and overlay restorations fabricated from different CAD-CAM materials, including current 3D-printed resins and 3D-printed zirconia, under 300 N vertical loading using finite element analysis (FEA).

Methods: A 3D solid model of a mandibular first molar was generated based on standard anatomical dimensions. Fifteen finite element models were constructed by combining three preparation designs with five restorative materials. A static vertical load of 300 N was applied and distributed across the multipoint occlusal contacts to simulate physiological masticatory forces. The stress distribution was analyzed using the von Mises and Maximum Principal Stress criteria to evaluate both the restoration and the surrounding dental tissues.

Results: Restoration design and material stiffness significantly influenced stress distribution. Among the designs, the overlay preparations exhibited the most favorable biomechanical behavior, showing lower stress transmission to the tooth structure than inlay and onlay designs. Materials with a high elastic modulus (205.000 MPa LithaCon 3Y-210) demonstrated a stress-shielding effect, absorbing higher internal stress while protecting the underlying dentin. Conversely, low-modulus materials (4.030 MPa VarseoSmile Crown Plus) exhibited lower internal stress, but transferred higher stress loads to the tooth-restoration interface and dentin.

Conclusions: The use of overlay designs combined with high-elastic modulus materials offers a biomechanically superior configuration for reinforcing compromised posterior teeth because this combination minimizes stress transmission to the remaining tooth structure. Although low-modulus materials reduce internal restoration stress, they require careful consideration because of the increased stress transfer to the dentin.

Purpose: We functionalized a three-dimensionally (3D) printed denture base resin with α-Ag₂WO₄ microcrystals and evaluated its chemical and surface properties, flexural strength, antimicrobial activity, biocompatibility, and inflammatory response.

Methods: Resin specimens were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The surface roughness was evaluated by profilometry and wettability, whereas the surface free energy was determined using a goniometer. The flexural strength of the resin was assessed by three-point mechanical flexural testing. Antimicrobial activity was evaluated against Candida albicans, Staphylococcus aureus, and Escherichia coli in the adhesion and biofilm formation phases by counting colony-forming units (CFU)/mL and using confocal laser scanning microscopy (CLSM). Time–kill curve assays were performed using the Alamar Blue (AB) reagent, and the biocompatibility of the materials was evaluated in a 3D organotypic model of the oral mucosa using AB and CLSM. Inflammatory response was assessed by measuring cytokine production using flow cytometry.

Results: XRD, FTIR, and SEM analyses demonstrated that α-Ag₂WO₄ was incorporated into the resin with its structure preserved. The surface roughness did not change, and the surface free energy increased; however, the flexural strength decreased slightly. The evaluated resins exhibited antifungal and antibacterial effects at both the adhesion and biofilm formation stages. Functionalization did not alter the biocompatibility of the resins and did not cause an exacerbated inflammatory response.

Conclusions: Functionalization of a 3D-printed denture base resin with α-Ag₂WO₄ demonstrated antimicrobial activity without any detrimental effects to the surface, mechanical, and biocompatibility properties of the material.

Purpose: We elucidated the relationships and differences between mandibular movement (MM) and complementary mandibular movement (cMM), defined as the relative motion of the maxilla with respect to the mandible, by analyzing their spatial characteristics, symmetry, and associated rotational axes.

Methods: Twenty-seven healthy participants (mean age, 53.0 years) were examined. Jaw movements, including sagittal border (SAG), lateral excursion–incursion (LAT), and protrusion–retrusion (PRO), were recorded using a six-degree-of-freedom electromagnetic jaw-tracking device. The cMM data were obtained as the inverse matrices of the MM data. The kinematic (KA) and complementary kinematic axes (cKA) were calculated using Shigemoto’s method. The symmetry between the MM and cMM was evaluated at the incisal point, kinematic axis point (KAP), and complementary kinematic axis point (cKAP). Furthermore, the spatial relationship between KA and cKA was analyzed.

Results: The MM and cMM displayed partial symmetry near the intercuspal position (ICP); however, none of the movements exhibited complete correspondence. The PRO, which consists of translational motion, demonstrated significantly greater symmetry than the SAG and LAT. The cKA was located 14.14 mm antero-superior to the KA. The maximum displacement at the cKAP (22.68 mm) was significantly larger than that at the KAP (17.85 mm), whereas no significant difference was observed in path thickness (KA: 0.47 mm; cKA: 0.50 mm).

Conclusions: The MM and cMM were not strictly point-symmetric, and their rotational axes (KA and cKA) did not coincide. The accurate recognition of both MM and cMM is essential when applying jaw movement data to CAD-CAM workflows for prosthetic designs.

Purpose: This narrative review aims to provide dental professionals and researchers with a comprehensive overview of YOLO applications in dentistry.

Study Selection: A narrative review approach was used in this study. Literature relevant to YOLO models in dentistry was identified and organized thematically into dental domains such as dental caries detection, tooth numbering, dental biomaterials and restorative evaluation, prosthodontics and implant planning and treatment, dental education, salivary biomarker analysis, and oral cancer detection.

Results: YOLO-based models consistently achieved high precision and efficiency across diverse applications. Notable successes include reliable caries detection, automated restoration evaluation, support for prosthodontic and implant planning through cone-beam computed tomography analysis, and enhanced educational platforms that provide real-time feedback to students. Emerging studies have further demonstrated YOLO’s role in point-of-care diagnostics through salivary biomarker analysis and the early detection of potentially malignant oral disorders and cancer. Despite these advances, challenges persist, particularly regarding small datasets, variability in imaging protocols, and limited external validation.

Conclusions: YOLO algorithms are a transformative tool in dentistry that enable rapid, accurate, and reproducible image interpretation. Although further validation and standardization are required, YOLO has a strong potential to enhance diagnostics, prosthodontic treatment planning, education, patient-oriented care, and advance dentistry towards greater precision and efficiency.

Purpose: We evaluated the effects of zirconia tubes on fracture resistance and microleakage of endodontically treated premolars with flared root canals under cyclic loading.

Methods: Sixty-four bovine mandibular incisors were prepared to simulate human premolars and randomly assigned to four core build-up groups (n = 16 per group): composite resin core only (RC), glass-fiber post (FC), zirconia tube (ZC), and zirconia tube with glass-fiber post (ZFC). After crown fabrication and cementation, specimens underwent cyclic loading (10,000 cycles, 50 N, 2 Hz). In each group, eight specimens (n = 8) were evaluated for fracture resistance under 45 degree oblique loading, and eight (n = 8) were evaluated for microleakage using micro-computed tomography (micro-CT) after silver nitrate immersion.

Results: ZC and ZFC exhibited significantly higher fracture resistance than RC (P = 0.004, 0.022) and FC (P = 0.001, 0.047), with no difference between RC and FC or between ZC and ZFC. Microleakage was significantly lower in ZC and ZFC than in RC and FC (all P < 0.001). Leakage in zirconia tube groups was largely confined to the cervical area, whereas RC and FC showed penetration into the root canal. All specimens in each group exhibited fractures extending below the simulated alveolar bone level, corresponding to unfavorable fracture modes.

Conclusions: Zirconia tubes enhanced fracture resistance and reduced microleakage under cyclic loading in endodontically treated premolars. Foundation restorations using zirconia tubes may be a reliable reinforcement option for structurally weakened roots. Further clinical and long-term studies are required to confirm these findings.

Purpose: Sleep bruxism (SB) presents diverse clinical manifestations; however, phenotypic classification is limited by a lack of large-scale standardized data. We established a multicenter clinical registry for SB in Japan and explored SB subgroups using the explanatory latent class analysis (LCA).

Methods: We established a multicenter Sleep Bruxism Clinical Registry in seven dental schools across Japan. The registry enrolls adults (≥18 years) who underwent standardized electromyography (EMG) recordings of masticatory muscle activity during sleep, including both dental patients and healthy volunteers. In addition, clinical characteristics related to orofacial conditions, psychosocial factors, and sleep-related symptoms were registered for the enrolled individuals. Participants with EMG-confirmed SB were included in the exploratory LCA to identify the data-driven subgroups.

Results: In total, 910 individuals, including 524 SB-positive cases, were registered. The LCA identified four SB subgroups: younger individuals with few signs and symptoms (subgroup I, 35.3%), middle-aged women with frequent morning symptoms and high self-awareness (subgroup II, 16.2%), middle-aged individuals with marked tooth wear but low grinding-sound reports and self-awareness (subgroup III, 22.3%), and younger individuals with frequent signs and symptoms (subgroup IV, 26.2%). Individuals in subgroups II and IV exhibited significantly more tonic episodes than those in subgroup I, whereas those in subgroup IV exhibited more phasic episodes than subgroups I and II.

Conclusions: A novel multicenter Sleep Bruxism Clinical Registry was successfully established to enable the collection of comprehensive clinical and physiological data. Exploratory LCA revealed four clinical SB subgroups with distinct EMG episode patterns, suggesting an underlying heterogeneity in SB pathophysiology.

Purpose: This study evaluated the effects of build orientation on the mechanical and surface properties of polyetheretherketone (PEEK) fabricated using fused deposition modeling (FDM).

Methods: Rectangular and six disc-shaped specimens were fabricated in three build orientations (0, 45, and 90°) using an FDM printer with a PEEK filament (PP) (n = 6 per group). Three-point bending tests were conducted on the rectangular specimens to assess the flexural strength (FS) and flexural modulus (FM), whereas Vickers hardness (HV) and surface roughness (Ra) tests were performed on the disc specimens. A scanning electron microscope (SEM) was employed to observe the cross-section of the deformed and undeformed parts of the rectangular specimen after a three-point bending test. The mean FS, FM, HV, and Ra of PP were analyzed using a one-way analysis of variance. Tukey’s multiple comparison test was also performed (α = 0.05).

Results: The 90° PP had the highest FS and FM, followed by the 45° PP; the 0° PP had the lowest FS and FM. The surface of the 0° PP had no connecting surfaces between the layers, suggesting that its HV was the highest for the PP groups. For the 45° PP, the surface roughness may have increased because of the addition of a support structure to the specimen.

Conclusions: Build orientation affects the mechanical and surface properties of the FDM-fabricated PEEK. Overall, the 90° PP demonstrated the most reasonable build orientation.

Purpose: This study evaluated the effects of auxiliary devices on the scanning accuracy of scan bodies and implant positioning accuracy for dental prosthetic design.

Methods: Four implants were placed in an edentulous maxillary model and fitted with scan bodies. Two types of removable auxiliary devices were designed and 3D-printed for intraoral scanning, categorized into three groups: non-auxiliary device (NAD), geometric-shaped device (GAD), and tooth-shaped device (TAD) groups. Scanning was performed using three intraoral scanners (i700, i500, and Primescan), with ten scans acquired per group. The scanning accuracy of scan bodies was assessed using 3D inspection software (Zeiss Inspect; Zeiss), whereas implant positioning accuracy after scan body library alignment was analyzed using Geomagic Control X (3D Systems) and Zeiss Inspect. Statistical analyses were performed using one-way and two-way ANOVA followed by Tukey HSD tests to compare the performance among the three groups (α = 0.05).

Results: The TAD group demonstrated significantly lower linear discrepancy in the anterior and posterior scan body distance for the i700 and i500 (P < 0.001). However, in terms of implant position accuracy after scan body library alignment, the NAD group with the i700 system showed significantly lower root mean square (RMS) values (P = 0.001) and also demonstrated significantly lower deviation in the apical region (P = 0.005).

Conclusions: The use of auxiliary devices for intraoral scanning improved the accuracy of the scan body; however, these devices had little or even a detrimental effect on implant positioning accuracy after scan body library alignment in the CAD process.

Purpose: To evaluate whether Candida albicans adhesion differs between denture base resins fabricated using computer-aided design/computer-aided manufacturing (CAD/CAM; milled or 3D-printed) systems and those fabricated using conventional heat-polymerized resin (HPAR).

Study selection: This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and PRISMA-Network Meta-Analyses (PRISMA-NMA) guidelines. The research question was, “For the fabrication of denture bases, are resins from the CAD/CAM system more prone to Candida albicans adhesion compared with conventional resins?” Searches were conducted in PubMed/MEDLINE, Scopus, Web of Science, Lilacs, and Embase, as well as through manual searches up to May 2025, with no language or date restrictions. The risk of bias was assessed using RoBDEMAT software. Surface roughness and contact angle were assessed using NMA.

Results: The search identified 2960 records, of which 16 in vitro studies met the eligibility criteria. In four studies, HPAR was compared with milled resins; in ten, HPAR was compared with milled and 3D-printed resins, and only 3D-printed resins were evaluated in two. Overall, the milled resins exhibited lower C. albicans adhesion, whereas the 3D-printed resins exhibited higher adhesion in five studies. NMA did not significantly differ in surface roughness or contact angle between the resin types.

Conclusions: Within the limitations of the in vitro evidence, CAD/CAM milled resins were less prone to Candida albicans adhesion than conventional and 3D-printed resins. NMA indicated that the resin type did not significantly influence the surface roughness or contact angle. Further clinical studies are required to validate these findings.

Patients: This report describes the digital workflow for the design and fabrication of a telescopic prosthesis that incorporates a polyetherketoneketone (PEKK) primary crown and PEKK framework to restore multiple teeth in the mandible of a 56-year-old female patient. The process includes intraoral scanning, computer-aided design, digital milling of the telescopic crown and PEKK framework, and 3D printing of the casts. Good retention, mastication, aesthetics, and biological outcomes are observed in the four-year follow-up.

Discussion: Two clinical outcomes are observed. (1) A PEKK telescopic prosthesis can be fabricated using digital workflows, which demonstrates an initial retention value sufficient for intraoral function. (2) No significant wear or decline in the retention force is observed over a four-year follow-up period.

Conclusions: The PEKK telescopic prosthesis facilitated favorable outcomes when restoring extensive mandibular tooth loss. We suggest that PEKK can be effectively used in the fabrication of telescopic prostheses supported by natural teeth.

Purpose: This study aimed to develop an artificial intelligence (AI) system using a convolutional neural network (CNN) to design major connectors for removable partial denture (RPD) frameworks. Unlike rule-based or case-matching expert systems, the proposed model automatically generated RPD designs from comprehensive oral data using gradient-weighted class activation mapping (Grad-CAM) enhancing explainability.

Methods: Data were obtained from 1000 RPDs (457 maxillary, 543 mandibular) designed by prosthodontic specialists, including 255 dental variables from oral examinations. Ten CNN models were constructed sequentially to predict denture type (resin/metal), unilateral/bilateral design, absence/presence of a major connector, and four and two connector types for the maxilla and mandible, respectively. This sequential prediction followed clinical logic. Model performance was assessed by accuracy, sensitivity, specificity, positive and negative predictive values, and F1 score. Grad-CAM was employed to visualize input factors influencing predictions.

Results: The CNN models predicted major connector types with high accuracy (maxilla: palatal bar/strap, 93.0%; palatal plate, 87.1%; horseshoe bar, 89.5%; and mandible: lingual bar or plate, 87.3%). Heatmaps highlighted clinically relevant features including periodontal condition, dentition defects, and occlusal relationships as key determinants.

Conclusions: This study demonstrated the feasibility of an AI-based system for predicting RPD major connector types with acceptable performance. The system is expected to provide valuable support to dentists by minimizing the variability owing to differences in clinical skills and experience. Grad-CAM visualization enhances interpretability, enabling both clinicians and patients to better understand the reasoning behind the RPD design process. Ultimately, this approach could improve consistency, efficiency, and training in prosthodontics.

Purpose: Titanium dental implants are widely regarded as the gold standard for tooth replacement because of their mechanical strength and biocompatibility. However, cases of titanium hypersensitivity have been reported, raising concerns about immune-mediated complications in susceptible patients. This systematic review aimed to provide an updated synthesis of the available clinical evidence on titanium hypersensitivity, including diagnostic methods, and management strategies.

Study selection: A systematic search was conducted in PubMed, Scopus, Web of Science, and EBSCO databases following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. The Population, Exposure, and Outcome (PEO) framework was used to identify primary studies published until July 14, 2025, reporting titanium hypersensitivity related to dental implants, diagnostic modalities, and case outcomes.

Results: Of 1,761 retrieved studies, 9 met the inclusion criteria. These comprised one prospective study and eight case reports involving 21 patients and 33 titanium implants, 20 of which were diagnosed as titanium hypersensitivity cases based on skin testing, immunological assays, histological or immunohistochemical analysis, or clinical symptoms. In 17 cases, implant removal was required, whereas three were managed by abutment replacement.

Conclusions: Despite the limited evidence, current data indicate that titanium hypersensitivity is rare but clinically relevant. Titanium micro-particles often originating from early mechanical wear may act as immunological co-factors in susceptible patients, underscoring the need for standardized and sensitive diagnostic protocols to support early and accurate identification.

Purpose: This study compared the mechanical properties, wear behavior, and shear bond strength (SBS) of resin luting agents in additive-manufactured composite crown materials intended for definitive restorations with those of conventional computer-aided design/computer-aided manufacturing (CAD-CAM) hybrid composite resin (HCR) block materials.

Methods: Sprintray Ceramic Crown (SP) was used as the representative vat photopolymerization (VPP)-fabricated material based on additive manufacturing, whereas Shofu Block HC Hard II (HC) and Cerasmart Prime (CS) were selected as CAD-CAM HCR block materials. The mechanical properties were evaluated using three-point flexural strength and Vickers hardness tests. The wear behavior was examined via a reciprocating sliding test using an alumina ball antagonist. The SBS was measured between each material and various resin-luting agents.

Results: SP showed ~50–60% of the flexural strength and 30–40% of the Vickers hardness of HC and CS. Wear testing revealed that SP exhibited greater wear loss than those of CAD-CAM HCRs. The SBS values of SP with each resin cement were slightly lower than those of HC and CS under most conditions; however, all values exceeded 15 MPa, indicating a clinically acceptable bond strength.

Conclusions: The VPP-fabricated definitive crown material (SP) demonstrated inferior mechanical properties and wear resistance compared to those of conventional CAD-CAM HCRs. However, the acceptable levels of bond strength were observed, highlighting the importance of careful case selection for definitive restorations.

Purpose: This study proposes the development of “Motion-DSD”, an artificial intelligence-assisted workflow for digital smile design (DSD), which enables a dynamic 2-dimensional (2D) simulation of digital diagnostic waxing by transferring an intraoral design onto a frontal facial video, and validates its clinical feasibility.

Methods: A total of 2,000 facial and 190 intraoral images were used to fine-tune the pre-trained neural network, Segment Anything model (SAM), via two sets of low-rank adaptation (LoRA) modules for facial structures and teeth segmentation respectively. A transformation algorithm incorporating a “standard” facial image was developed to align intraoral and facial structures. A Flask-based web user interface (web-UI) was developed for clinical deployment. A participant sample set was prepared to validate the workflow’s performance in a clinical setting.

Results: Two fine-tuned SAMs achieved robust segmentation performance, with a mean Dice score coefficient of 0.886 for the facial dataset and 0.969 for the intraoral dataset. The alignment algorithm effectively transferred the intraoral DSD design onto the participant’s frontal facial video and enabled a 2D simulation of digital diagnostic waxing under various facial expressions, demonstrating its clinical feasibility. The web-UI allows dentists to interactively refine the design and preview simulation results in real time.

Conclusions: Motion-DSD enables the 2D simulation of digital diagnostic waxing from intraoral DSD designs in a dynamic facial context. The workflow overcomes the limitations of static imaging methods and manual alignment, bringing dynamics prior to the physical mockup phase. Further investigations are warranted to quantitatively validate the simulation accuracy and demonstrate its potential advantages over conventional static methods.

Purpose: Polyetheretherketone (PEEK), a high-performance thermoplastic polymer, has been explored as a dental material because of its excellent mechanical strength and biocompatibility. Composite resin has been reported as a viable prosthetic material when appropriate surface treatment is applied to PEEK. We evaluated the effects of ultraviolet and ozone (UV/ozone) irradiation on the bond strength of PEEK.

Methods: Eighty-six rectangular PEEK specimens were fabricated and divided into two surface-pretreatment groups: untreated (CO) and UV/ozone-treated (UV). The contact angle, surface roughness, and chemical composition were analyzed using contact angle goniometry, laser scanning microscopy, and X-ray photoelectron spectroscopy (XPS), respectively. The remaining specimens were assigned to two conditioning groups: no conditioning (NT) and primer conditioning (AD). Cylindrical specimens fabricated by Computer-Aided Design, Computer-Aided Manufacturing (CAD-CAM) composite resin blocks were bonded to the PEEK surface using resin cement. Half of the specimens in each group were subjected to 5000 thermal cycles. The shear bond strength was tested using a universal testing machine and the fracture surfaces were examined under a stereomicroscope. Statistical analyses were performed using t-tests (α = 0.05).

Results: UV/ozone treatment significantly reduced the contact angle, improved the surface wettability, and caused slight changes in the surface roughness. XPS analysis revealed a decrease in the C=O bonds and an increase in the C-OH bonds in the UV/ozone-treated group. The shear bond strength improved significantly, particularly in the AD group.

Conclusions: UV/ozone treatment of PEEK surfaces increased the wettability and significantly improved the shear bond strength of the composite resin blocks.

Purpose: To evaluate the trueness of denture bases fabricated using digital light processing (DLP) and milling methods using three-dimensional (3D) models with varying residual ridge morphologies.

Methods: Edentulous mandibular 3D models representing a well-rounded ridge (WR), knife-edge ridge (KR), and flat ridge (FR) were designed using computer-aided design (CAD) software. Denture bases for these models were created using dental CAD software and fabricated via DLP 3D printing at build angles of 0 and 45 degrees (DLP0 and DLP45) and by milling (MIL). A total of 90 denture bases were fabricated, with 10 bases per model–method combination. These bases were digitized and compared to their original CAD data to assess the adaptation across three regions: denture border, alveolar ridge, and retromolar pad. Measurements were performed at three time points: before water storage, after 1 day of water storage, and after 7 days of water storage.

Results: The MIL bases exhibited significantly lower 3D surface deviations than the DLP0 and DLP45 bases. The KR models generally exhibited greater 3D surface deviations than the WR and FR models. Temporal changes in the denture bases were significant across almost all ridge types and manufacturing methods.

Conclusions: The trueness of digitally fabricated denture bases is influenced by the residual ridge morphology and manufacturing method. Milling demonstrated superior trueness compared to DLP. Temporal dimensional changes were observed in almost all the bases.

Purpose: This systematic review aimed to investigate and compare peri-implant soft-tissue responses to tooth-colored abutment materials frequently used in implant dentistry.

Study selection: A comprehensive electronic search was performed in three databases (MEDLINE via PubMed, Google Scholar, and Scopus) to identify relevant literature. The study-selection criteria included original research articles written in English that investigated the effects of various tooth-colored abutment materials on peri-implant soft-tissue responses.

Results: In total, 136 articles were included in this systematic review. Tooth-colored abutment materials, particularly zirconia and polyetheretherketone (PEEK), facilitated favorable soft-tissue adaptation, enhanced esthetics, and contributed to long-term implant success. Zirconia demonstrated excellent biocompatibility, enhanced cell viability and attachment, and lower inflammatory responses compared to titanium, suggesting improved soft-tissue integration and reduced biofilm-related risks. PEEK exhibited favorable mechanical properties and biocompatibility but limited cell attachment due to its hydrophobicity, indicating the need for surface modification. Titanium remains the clinical standard for integration but is associated with greater inflammation and biofilm formation than tooth-colored materials.

Conclusions: This review highlights the effects of tooth-colored abutment materials on peri-implant soft-tissue responses and emphasizes the importance of selecting appropriate materials for successful dental implants. Zirconia represents a promising biological alternative to titanium, promoting a stable soft-tissue barrier that contributes to minimizing inflammation and maintaining long-term tissue health. Conversely, while PEEK offers strong mechanical properties, it faces challenges regarding cell proliferation and matrix production, limiting its optimal biological performance. Further research will provide deeper insights into the best options for enhancing patient and esthetic outcomes.

Purpose: We aimed to verify the hypothesis that patients who undergo prosthetic treatment with a definitive obturator following maxillectomy for oral tumors show decreased oral functions when the maxillary defects are extensive.

Methods: This study comprised 77 patients (46 men, 31 women; mean age, 71.0 years) who underwent prosthetic treatment with definitive obturators designed to restore maxillary defects following maxillectomy owing to an oral tumor. Oral function, masticatory performance, maximum bite force, tongue pressure, and tongue-lip motor function (oral diadochokinesis /pa/, /ta/, /ka/) were evaluated. The extent of maxillary defects was evaluated based on Aramany’s classification. The maxillary defects were classified into three groups, namely, no oroantral communication (NOC), small oroantral communication (SOC), and large oroantral communication (LOC) groups. Multiple regression analyses were performed with each oral function as the objective variable and age, sex, maximal mouth opening, history of radiotherapy, number of functional teeth, and the extent of the maxillary defect as explanatory variables.

Results: The number of functional teeth and LOC were significant as explanatory variables for masticatory performance, while sex, number of functional teeth, and LOC were significant as explanatory variables for maximum bite force. Regarding other oral functions, the extent of the jaw defect was not significant as an explanatory variable.

Conclusions: In patients with maxillary defects wearing definitive obturators, a defect exceeding half of the palate and communicating with the nasal cavity was significantly associated with lower masticatory performance and maximum bite force.

Purpose: To investigate the effects of coffee and orange juice on 3 different esthetic ceramic materials regarding color changes, Vickers microhardness, and solubility & sorption changes among patients with reflux.

Methods: A glass-ceramic material (IPS Emax CAD), a polymer-infiltrated ceramic material (Vita Enamic), and a nano-hybrid ceramic material (Cerasmart) were selected for this study (n=32/group). Following the polishing procedure, all the samples were immersed in artificial saliva for 21 days. Half the samples were assigned to the control group and exposed only to artificial saliva (pH 7.3). The remaining 16 samples were exposed to saliva or simulated gastric acid. Sixteen samples from each group were exposed to gastric acid 3 times daily for 30 seconds. The color, Vickers microhardness, and solubility & sorption were then measured. Following this procedure, the samples were exposed to coffee and orange juice (n=8/per group). The samples were exposed to the solutions for 16 hours and 48 minutes to simulate 21 days of consumption. Final measurements were then obtained. Statistical significance was determined using Levene’s test to compare variances, and three-way analysis of variance (ANOVA) followed by Tukey’s post-hoc test, Welch’s ANOVA, and Games–Howell’s test were applied to reveal differences between groups.

Results: According to ANOVA, restorative material type and immersion media had a significant effect on color change (P < 0.001), microhardness (P < 0.001), and solubility & sorption (P < 0.001).

Conclusions: The choice of material is crucial for erosion-prone patients.

Purpose: We evaluated the effects of the particle size and content of surface pre-reacted glass-ionomer (S-PRG) filler on the mechanical properties and antimicrobial efficacy of a hard denture relining material.

Methods: S-PRG microfiller (0.8–1 μm; 5, 10, and 20 wt%) and nanofiller (0.3–0.5 μm; 2.5, 5, and 10 wt%) were incorporated into a Shofu denture liner. The control group did not contain S-PRG fillers. The surface morphology (scanning electron microscopy), roughness (confocal scanning laser microscopy; Shapiro–Wilk’s test followed by Dunnett or Steel’s test), ion release after 24 h immersion in ultrapure water (fluoride, aluminum, borate, sodium, silicate, strontium ions; Shapiro–Wilk’s test followed by one-way ANOVA with Tukey’s test or Kruskal–Wallis and Dunn’s tests), three-point flexural strength (Weibull analysis), shear bond strength after 24 h water immersion or 10,000 thermal cycles (linear mixed-effects model), and antimicrobial activity against Candida albicans (confocal microscopy, Shapiro–Wilk’s test followed by Dunnett’s or Steel’s test) were analyzed and compared. The significance level was set at α = 0.05.

Results: Although a higher S-PRG filler content reduced the flexural and bond strengths, it increased the surface roughness and ion release. Groups treated with 10 wt% nanofiller or 20 wt% microfiller displayed significantly inhibited C. albicans adhesion. The nanofiller-containing groups maintained flexural strength comparable to that of the control.

Conclusions: The incorporation of 10 wt% S-PRG nanofiller provided the best balance between antimicrobial efficacy and mechanical performance, indicating that this formulation may be clinically acceptable for use in hard denture relining materials.

Purpose: This study evaluates the effects of different abutment screw tightening protocols and implant materials on screw loosening and morphological changes after cyclic torsional loading of two-piece implants.

Methods: Titanium (T) and zirconia (Z) two-piece implants were used. Abutment screws were tightened to 35 Ncm. Three protocols were tested: (A) retightening after 5 min, (B) immediate retightening, and (C) no retightening (n = 6 each). All samples underwent 100,000 cycles of cyclic torsional loading. Removal torque values before and after loading (RT-pre and RT-post) and torque loss percentage (TL) were calculated. Surface morphology was assessed using scanning electron microscopy (SEM), and dimensional changes were quantified using root mean square (RMS) values from three-dimensional data.

Results: In the titanium group, protocol A (TA) had lower RT-post values than protocols B (TB) and C (TC) (P < 0.001), and TB was lower than TC (P < 0.05). In the zirconia group, protocol A (ZA) was significantly lower than protocols B (ZB) and C (ZC) (P < 0.05, P < 0.001, respectively). RT-post and RT-pre were significantly lower in the zirconia group than in the titanium group under all conditions (P < 0.001). No differences were observed in TL. SEM revealed wear on the screw heads and threads in all groups. RMS values were significantly lower in the zirconia group (P < 0.05).

Conclusions: Abutment screw retightening does not consistently enhance torque maintenance under torsional loading. The implant material affects torque retention and deformation, where titanium implants demonstrating greater stability than zirconia implants.

Purpose: Masticatory exercise promotes systemic health and cognitive function. Although acute masticatory stimuli enhance prefrontal cortical activity, the effects of increased habitual chewing on cortical activity remain unclear. This study evaluated the effects of habitual chewing on cortical activity in young adults.

Methods: Forty-one young adults (aged 21-31 years) were randomly assigned to an intervention group, which used a wearable device to increase attentional chewing strokes during meals for 1 month, or a control group that did not use the device. We monitored the cortical activity during gum chewing using functional near-infrared spectroscopy at baseline and immediately after intervention. We recorded the number of chews per rice ball at baseline, immediately after intervention, and at 3 months post-intervention. Changes across different time points in each group were compared using one-sample t-tests with Bonferroni correction.

Results: The intervention group showed a significant increase in the number of chews after the intervention and at the 3-month follow-up, whereas the control group exhibited no changes. Moreover, the intervention group demonstrated significantly higher activity in the dorsolateral prefrontal cortex (DLPFC) and premotor cortex compared with the control group. A voxel-based correlation analysis revealed a positive correlation between increase in chewing strokes and activity in these brain regions in the intervention group (family-wise error-corrected, P < 0.05).

Conclusions: Intentional chewing, enhanced through an attentional intervention, led to increased activation in the DLPFC and premotor cortex during mastication. These results demonstrated the objective neural effects of interventions targeting habitual masticatory behavior.

Purpose: Extensive maxillectomy may result in rapid contour changes in the unsupported facial tissue, causing irreversible and severe aesthetic deformities. This technical report details a novel digital workflow for the fabrication of obturators with immediate facial support consistent with the existing maxillary contour.

Methods: Preoperative digital impressions were obtained using an intraoral scanner (IOS). A three-dimensional (3D) model of the presurgical maxillofacial hard tissue was constructed using cone-beam computed tomography (CBCT) and aligned with the IOS data. Surgical planning data were used to guide the separation and fusion of anatomical reference data for obturator design from the CBCT and IOS data. The obturator was designed using dental design software, and the existing maxillary morphology for facial support was transferred to the obturator. After the surgical resection, an immediate obturator with a surgical pack was placed at the defect site.

Conclusions: The implementation of a fully digital workflow demonstrated the potential to streamline the complex procedure traditionally required to restore harmonious facial contour support through the transfer of maxillary morphology to the immediate obturator. This method offers a promising and viable alternative to conventional techniques, with the potential to minimize long-term aesthetic compromise, facilitate adaptation and functional restoration, and simplify postoperative prosthetic care.

Purpose: This study aimed to determine whether the maximum compressive force exerted on denture base materials by test foods varies depending on the presence and type of resilient denture liners.

Methods: The maximum compressive forces of gummy jelly and peanuts were measured using a texture analyzer equipped with a 500 N load cell, operating at a crosshead speed of 9.78 mm/s. Tests were conducted on rectangular prism-shaped specimens (30 mm × 30 mm × 4 mm) fabricated from various denture base materials. Three commercial silicone-based resilient denture liners—Sofreliner Supersoft (SS), Sofreliner Mediumsoft (MS), and Sofreliner Tough Medium (TM)—and a conventional heat-cured acrylic resin (Urban, UR) were used. Additionally, the Shore A hardness of each material was measured using a hardness tester.

Results: The maximum compressive forces applied to gummy jelly and peanuts on UR specimens were significantly higher than those on TM, MS, and SS specimens. Similarly, the Shore A hardness of UR was higher than that of the other materials. A statistically significant positive correlation was observed between the maximum compressive force of the test foods and the Shore A hardness of the denture base materials.

Conclusions: The maximum compressive force applied to food varied according to the type of denture base materials. In particular, resilient denture liners effectively reduced the force transmitted to the food compared with conventional hard acrylic resin.

Patients: This report presents a minimally invasive, adhesive-friendly approach for the esthetic rehabilitation of multiple anterior teeth using a modified direct-indirect technique with ultrathin composite resin veneers. A 43-year-old woman presented with esthetic concerns and disharmony of the maxillary anterior region. The treatment comprised ultrathin composite resin veneers fabricated using a modified direct-indirect technique, incorporating a fully digital workflow with a smile design and a three-dimensional-printed model used to create a translucent silicone index. Without tooth preparation, the index was filled with composite resin and intraorally positioned to replicate the planned morphology. The veneers were removed, post-cured, and extraorally completed before definitive adhesive cementation.

Discussion: Traditionally, the direct-indirect technique has been limited to single restorations that require enamel reduction and freehand stratification. This report describes a modified approach that enables the fabrication of multiple ultrathin veneers without tooth preparation, thereby preserving the enamel and promoting adhesive longevity. The innovative aspect lies in the integration of a fully digital workflow, ensuring precise replication of the morphology and control of the restoration thickness. Extraoral finishing of proximal contacts and margins before cementation improves clinical efficiency and esthetic predictability.

Conclusions: For patients requiring multiple composite veneers, the modified direct-indirect technique provides a conservative, precise, and predictable solution. It preserves sound tooth structure, optimizes adhesive performance, and enhances efficiency and esthetic outcomes through digital integration.

Purpose: To elucidate how the combination of acidic and sulfur-based monomers enhances bonding to oxidized noble metal alloy surfaces.

Methods: Two types of gold alloys were used: one with a low copper content (DG) and the other with a high copper content (IV). Three primers were used: a sulfur-based monomer primer (VP), a phosphate-based acidic monomer primer (PZ), and a combination of both (MC). Two conditions were used: heated and non-heated. The shear bond strengths before and after thermocycling were determined and compared for each condition. Surface chemical analysis was performed using X-ray photoelectron spectroscopy (XPS).

Results: After thermocycling, the bond strength of MC was significantly higher than that of the VP under all conditions. In the comparison of alloys under heating conditions, IV showed a significantly higher bond strength than that of DG for the PZ and MC groups. XPS revealed peaks attributed to copper oxide (CuO) formation on the heated IV surface.

Conclusions: Multipurpose primers are effective for bonding oxidized noble metal alloys and acrylic resins. The formation of CuO improves the performance of 10-methacryloyloxydecyl dihydrogen phosphate, and its combination with sulfur-based monomers is particularly effective for noble metal alloy surfaces with high copper content.

Purpose: The purpose of this study was to establish chevron-notched beam (CNB) finite element analysis (FEA) models to investigate the fracture toughness of zirconia ceramics.

Methods: Experimental four-point flexural strength data (n = 9; previously published) for 3 mol% yttria-stabilized tetragonal zirconia polycrystals (3Y-TZP; 3M Oral Care, Seefeld, Germany) were combined with numerical data (calculated using the inverse finite element method) to evaluate the input material properties of the CNB-FEA models. These models (n = 8) were then simulated and validated against the CNB test data of specimens with the same geometries (n = 8). The validation criteria included the margin of error, coefficient of determination, and linear regression. FEA was used to evaluate the volumetric strain distribution during deformation.

Results: 3Y-TZP has static elastic modulus and fracture strain values of 144.5 GPa and 0.0056, respectively. The fracture toughness of the CNB-FEA models closely matched those of the corresponding test specimens (±3% error). Linear regression yielded a coefficient of determination (R²) of 0.94 (P < 0.05), demonstrating an excellent predictive performance. The CNB-FEA models accurately reflected the actual fracture behaviors of the zirconia ceramics, with the volumetric strain localized at the notch tip.

Conclusions: The volumetric strains of the CNB-FEA models could be determined using the FEA and measured four-point flexural strength data. Thus, CNB-FEA was found to be a valuable method for predicting the fracture toughness of zirconia ceramics.

Purpose: This study evaluated the wear behavior of dental materials for definitive fixed prostheses, including computer-aided design (CAD)- and manufacturing (CAM) composite resins, polyether-ether-ketone (PEEK), Ag-Pd-Au alloys, titanium, and zirconia, under standardized experimental conditions.

Methods: Three CAD-CAM-produced composite resins (HC, HCH, and CS), PEEK (SPE), Ag-Pd-Au alloys (CW), pure titanium class II (TJ), and zirconia (ZL) were tested. Two-body wear tests were conducted using an abrasion-testing machine under wet conditions using stainless-steel styluses as antagonists. Wear traces were examined using laser confocal scanning microscopy and scanning electron microscopy (SEM). Wear depths and heights were analyzed by one-way analysis of variance with Tukey’s multiple comparison test.

Results: The wear depths of CS and TJ were significantly greater than those of the other materials (P < 0.05), whereas ZL exhibited the lowest wear depth. No significant differences were found among HC, HCH, SPE, and CW. The stylus opposing the SPE exhibited the smallest wear height, whereas TJ caused the most antagonist wear. SEM revealed distinct wear mechanisms, including adhesive and abrasive wear, depending on the material.

Conclusions: The SPE and CW showed similar wear behavior. CAD/CAM composite resins demonstrated variable wear rates, which was likely attributable to variations in the composition and morphology of the constituent fillers. The TJ exhibited excessive antagonist wear, suggesting the need for improved tribological properties. These findings provide guidance for selecting materials that preserve occlusion and prevent excessive wear.

Purpose: This review examined clinical and technological factors that influence implant placement accuracy in computer-assisted implant surgery (CAIS) systems.

Study selection: A systematic search of PubMed, Scopus, and Embase identified English-language studies published between January 2015 and January 2025. The eligible studies included randomized controlled trials, observational studies, systematic reviews, in vitro investigations, and case reports. Data extraction focused on the coronal, apical, and angular deviations. Methodological quality was appraised using the Oxford Centre for Evidence-Based Medicine (CEBM) framework and validated bias assessment tools.

Results: Fifty-three studies were included. Accuracy was influenced by patient-related factors (arch type, bone density, and edentulous span), surgical variables (flap design, operator experience, and guide protocol), and technological parameters (imaging modality, fiducial markers, and calibration). Static systems achieved high accuracy in dentate cases with stable guide support, but were less reliable in posterior or edentulous jaws. Dynamic navigation provided intraoperative flexibility and consistent performance across arches, although outcomes depended on calibration precision and operator learning curves. Robotic-assisted systems achieved the lowest mean deviations through trajectory control and haptic feedback, although evidence remains limited to early clinical and in vitro studies.

Conclusions: Although all CAIS systems achieve high accuracy, their performance varies according to the design of the system and clinical context. Static systems are effective when stabilization is ensured, while dynamic navigation offers adaptable accuracy across scenarios, and robotics exhibit the greatest consistency by reducing operator variability. Further multicenter randomized trials and standardized reporting are needed to strengthen the available evidence and guide clinical selection.

Purpose: To assess the time efficiency of an innovative workflow (SafetyCrown) for implant-supported rehabilitation of posterior single-tooth sites against the standard workflow. The hypothesis was that there is no difference in treatment duration and accuracy, as represented by the number of clinical adjustments and additional visits required.

Methods: 31 participants (16 females, 15 males) were included in this analysis from a randomized clinical trial. Participants were randomly assigned to the test group (SafetyCrown workflow, three visits) or control group (conventional digital workflow, six visits). The SafetyCrown workflow combined immediate restoration with a prefabricated definitive abutment and chairside provisional restoration. The control group followed a conventional digital approach in six visits. Treatment times per visit were recorded with a stopwatch; clinical adjustments and additional visits were documented.

Results: The SafetyCrown workflow was completed in three visits in 53% of cases, with a mean of 3.5 visits compared with 6.1 visits in the control group. The total treatment time differed insignificantly by 10 minutes (test: 126.4 minutes; 95% CI: 116.4–136.5; control: 116.8 minutes; 95% CI: 104.4–129.3; P = 0.232), and individual visits lasted longer in the test group (e.g., surgical visit: 62 minutes vs. 33 minutes in control). Clinical adjustments were common in both groups when using model-free workflows.

Conclusions: Limitations aside, the SafetyCrown workflow reduced the total visits while maintaining the overall treatment time despite longer individual appointments, thus increasing efficiency. Both fully digital workflows were feasible, although frequent adjustments highlight the need to investigate sources of inaccuracy to improve the precision and efficiency further.

Purpose: Conventional handheld pH meters have measurement limitations. Therefore, this study aimed to continuously measure the salivary pH at two intraoral locations using a newly developed sensor system.

Methods: In this pilot study, we developed custom-made intraoral mouthguards (MG) with two pH sensors in the anterior region (Channel 1: Ch1) and the buccal side of the maxillary molar (Channel 2: Ch2) to continuously monitor salivary pH at two different locations in the oral cavity.

Results: The coefficient of determination (R²) for all MG sensor measurements was ≥0.99, with a high level of accuracy. Both sensor channels exhibited similar mean pH values for standard solutions, with small and constant variations. However, notable unstable differences in intraoral measurements were observed during rehydration owing to positional differences. Nonetheless, the MG sensors demonstrated excellent reliability with consistently high Intraclass Correlation Coefficients ranging from 0.977 to 0.999.

Conclusions: This pilot study provides valuable insights into salivary pH fluctuations, particularly during exercise, through continuous measurements using a sensor system for the simultaneous acquisition of real-time data from different anatomical sites. These results emphasize the potential of developing an intraoral sensor system that can detect subtle variations in salivary pH.

Purpose: Hard reline procedures are commonly used to improve denture fit; however, the long-term durability of reline materials remains unclear. This study evaluated time-dependent changes in the surface properties and biofilm adhesion of light- and auto-polymerizing hard reline materials following long-term immersion in artificial saliva. The findings may help determine optimal timing for clinical intervention and enhance prosthesis longevity.

Methods: Specimens of three materials—light-polymerizing reline, auto-polymerizing reline, and heat-polymerizing denture base polymethyl methacrylate—were immersed in artificial saliva for up to 180 days. Auto-polymerizing materials continue to polymerize over time, whereas light-polymerizing materials require light irradiation. The surface properties were evaluated based on Vickers hardness, surface roughness, color stability, contact angle, and Candida albicans (C. albicans) biofilm adhesion.

Results: After 180 days, the light-polymerizing material exhibited a significant increase in hardness (P < 0.001), whereas the auto-polymerizing material exhibited an increase from day 120 (P < 0.001). Contrastingly, the heat-polymerizing PMMA exhibited a significant decrease in hardness. The surface roughness increased nearly threefold for the auto-polymerizing material, indicating pronounced degradation. Color changes in the light-polymerizing material were weaker than those in the auto-polymerizing material at all time points except at 60 and 150 days. C. albicans adhesion increased significantly in the auto-polymerizing material (P = 0.034), whereas the light-polymerized material showed no significant change (P = 0.258).

Conclusions: Time-dependent changes in surface characteristics were observed in both reline materials. The light-polymerizing material superior stability throughout the immersion period compared with that of the auto-polymerizing material, indicating superior long-term performance.

Purpose: To clarify the intra- and inter-examiner reliability of an occlusal force-measuring device equipped with a capacitive-type pressure-mapping sensor sheet in older adults.

Methods: Thirty-eight individuals (23 women) aged ≥65 (mean ± SD: 79.3±6.1) years were included. The numbers of present and functional teeth were visually examined. Occlusal force was measured using the Oramo-bf device (Sumitomo Riko Co., Aichi, Japan). To evaluate intra-examiner reliability, one dentist measured each participant’s occlusal force thrice and calculated the intraclass correlation coefficient (ICC; case 1) and the coefficient of variation (CV). To examine inter-examiner reliability, three dentists measured the occlusal force once per participant and calculated the ICC case 2.

Results: The median (first quartile–third quartile [Q1–Q3]) numbers of present and functional teeth were 22.5 (18–27) and 28 (26–28), respectively. The median (Q1-Q3) occlusal force measured by a single examiner across the measurements was 604.8 (261.7–731.5) N. The ICC for a single measurement by one examiner based on all three measurements per participant was 0.982 (95% confidence interval [CI]: 0.969–0.990). The ICC (1,3) for the mean of three repeated measurements by one examiner was 0.994 (95% CI: 0.990–0.997). The mean ± SD CV was 0.052 ± 0.046. The ICC (2,1) for inter-examiner reliability was 0.950 (95% CI: 0.917–0.972).

Conclusions: This study revealed high intra- and inter-examiner reliability of measurements obtained using an occlusal force-measuring device equipped with a capacitive-type pressure-mapping sensor sheet. This device may provide reliable results with a single measurement, regardless of the examiner.

Purpose: This was a prospective study conducted alongside a randomized controlled trial (RCT) that evaluated the incidence of fractures and associated risk factors in single-implant overdentures (1-IOD) compared with two-implant overdentures (2-IOD).

Methods: The participants received either a mandibular 1-IOD or 2-IOD (attachments: Straumann® retentive anchor and elliptical titanium matrix with gold insert; implants: 4.1 mm diameter, Straumann® Standard Plus SLActive® Regular Neck), within the context of a randomized clinical trial. The primary outcome of interest was the incidence of IOD fractures at 5-year follow-up. Prosthetic factors, such as area and cervico-incisal height in the attachment region, and volume at the inter-canine region, were measured. Patient-related factors including age, sex, handgrip strength, manual dexterity, bite force, and chewing performance were assessed. Data analysis included descriptive statistics, bivariate tests, Kaplan-Meier plots, and linear discriminant analysis with log₁₀ transformation for variable normalization.

Results: A total of 47 patients were recruited, and 34 (n = 34, 1-IOD = 16, 2-IOD = 18; mean-age: 63.9 ± 8.6 years; 79.4% women) completed the 5-year follow-up. There were no differences in the incidence of fractures between the 1-IOD and 2-IOD groups (P < 0.05). Fractures were more frequent in younger patients, and reduced cervico-incisal IOD height was significantly associated with fractures (P = 0.040). Linear discriminant analysis predicted fractures with 84.4% accuracy and identified cervico-incisal height and age as key predictors.

Conclusions: There were no significant differences in the incidence of overdenture fractures between groups. Reduced cervico-incisal denture height in the attachment region of ball-retained IODs was associated with mandibular IOD fractures. Further studies with larger cohorts are recommended to identify additional risk factors for mandibular IODs.

Purpose: Evaluation of the impact of ultraviolet (UV) photofunctionalization on titanium–cement interfaces, specifically its ability to transform titanium into a high-energy surface and enhance crown retention.

Methods: Commercial titanium abutments (standard: 4.0 mm; long: 5.5 mm) were treated with vacuum UV (VUV) light at 172 nm for 1 min. Milled polymethyl methacrylate crowns were cemented using resin-modified glass ionomer cement. Tensile testing quantified the maximum tensile load and interfacial energy. Surface changes were analyzed using contact angle measurements and X-ray photoelectron spectroscopy (XPS). Post-failure interfaces were examined via scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX).

Results: UV-treated standard-length abutments exhibited a 4.1-fold increase in maximum tensile load and 27-fold increase in bonding energy compared with untreated control counterparts. UV-treated long abutments showed a 4.6-fold increase in maximum tensile load and 54-fold increase in bonding energy. UV treatment rendered the titanium surface superhydrophilic and low in carbon, whereas untreated specimens remained carbon-rich and hydrophobic. UV-treated long abutments exhibited 3.1-fold higher energy than UV-treated standard abutments. Notably, long abutments without UV treatment did not outperform standard untreated abutments. SEM and EDX confirmed extensive residual cement on UV-treated abutments, indicating cohesive failure and strong interfacial bonding.

Conclusions: A 1-min UV photofunctionalization transforms titanium into a superhydrophilic, high-energy surface that significantly enhances cement bonding. This physicochemical surface strategy outperforms geometric modifications alone. As a rapid, non-invasive approach, UV photofunctionalization may establish a new standard for durable implant-supported restorations, reducing prosthetic failure and influencing both material selection and clinical and laboratory workflows.