PURPOSE:This study aimed to evaluate and compare the flow characteristics and wall shear stress (WSS) generated by the XP-Endo Finisher, sonic, and ultrasonic activation systems using computational fluid dynamics (CFD) analysis. METHODS:A three-dimensional model of a resin-based prepared mandibular premolar was generated from a high-resolution micro-computed tomography (Micro-CT) scan and used for CFD analysis of different irrigation activation systems. Following image segmentation and stereolithography (STL) reconstruction, high-quality tetrahedral meshes with inflation layers were generated and imported into ANSYS Fluent. Irrigant flow during needle irrigation was simulated under steady-state laminar conditions. For the sonic, ultrasonic, and mechanical activation systems, dynamic mesh techniques and user-defined functions were employed to model device-specific oscillatory tip motions based on their respective frequencies and amplitudes. Deterministic CFD outputs, including velocity magnitude and WSS, were compared descriptively among the activation systems. RESULTS:The highest intracanal flow velocity was observed with the EDDY system, followed by ultrasonic activation, EndoActivator, XP-Endo Finisher, and side-vented needle irrigation. A similar trend was observed for maximum WSS, with the EDDY system producing the highest values. Ultrasonic activation ranked second, while EndoActivator, XP-Endo Finisher, and side-vented needle generated progressively lower WSS values. CONCLUSION:All activation techniques demonstrated improved flow dynamics compared to conventional side-vented needle irrigation.
PURPOSE:Calcium (Ca) and magnesium (Mg) ions enhance the osteoconductivity of titanium oral implants, yet their effects on clinically established complex topographies remain under-explored. This study evaluated the effects of Ca and Mg incorporation into sandblasted, large-grit-, acid-etched (SLA) surfaces on the osteogenic differentiation of human mesenchymal stem cells (MSCs). METHODS:Ca or Mg ions were incorporated into SLA-treated titanium via wet chemical treatment. Primary human MSC responses on these modified surfaces were assessed, with unmodified SLA surfaces serving as controls. RESULTS:Ion incorporation facilitated successful formation of nanostructured oxide layers while preserving the underlying microscale SLA topography. Both Ca- and Mg-modified surfaces significantly upregulated adhesion-related genes (integrin subunits, ACTA2, and TLN1), osteogenic transcription factors (RUNX2 and CTNNB1) and differentiation markers (ALPL and BGLAP) relative to the control (P < 0.05). Notably, in comparison to Ca modification, Mg modification induced higher expression of the integrin subunit beta gene and BGLAP production than at early time points; overall, however, cellular behaviors in the two groups remained comparable. CONCLUSION:Surface chemistry modification with Ca or Mg ions enhances the osteogenic capacity of complex-structured titanium implants by modulating early adhesion signaling and accelerating MSC differentiation. Such bioactive surface modifications represent a promising strategy for improving the clinical performance of contemporary oral implants.
This report describes a 74-year-old postmenopausal woman with painful oral mucous membrane pemphigoid and generalized periodontitis who, as an equol non-producer, received adjunctive equol supplementation for 24 months. During follow-up, gingival pain decreased, plaque control improved, and bleeding on probing decreased, accompanied by improvement in gingival inflammation and mucosal appearance. This case is notable because the effects of long-term (24-month) follow-up with adjunctive equol supplementation with oral mucous membrane pemphigoid have rarely been documented. Although causality cannot be established, the report suggests a potential supportive role for equol in facilitating periodontal management in painful oral mucous membrane pemphigoid.
PURPOSE:This study aimed to compare the knowledge and reliability of endodontists and artificial intelligence (AI) chatbots (ChatGPT 4o and DeepSeek-R1) in relation to regenerative endodontic procedures (REPs). METHODS:A 19-item survey addressing case selection, materials, complications, success criteria, and follow-up in REPs was administered to endodontists and AI chatbots. Four clinical case scenarios with sub-questions required participants to rank treatment options by preference. Responses were analyzed for knowledge and reliability using Kruskal-Wallis, chi-square, and Fisher's exact tests; Cronbach's alpha assessed internal consistency. RESULTS:ChatGPT 4o demonstrated a significantly higher knowledge rate for REPs (100%) than endodontists (61.5%) and DeepSeek-R1 (56.9%) (P < 0.05). It also achieved the greatest reliability (Cronbach's alpha = 0.852). In the first three case scenarios, ChatGPT-4o most frequently favored REPs, while in the fourth scenario, apexification or conventional root canal therapy was more often preferred. CONCLUSION:ChatGPT 4o exhibited superior knowledge of REPs and reliability compared to endodontists and DeepSeek-R1, which showed moderate and low reliability, respectively. ChatGPT 4o consistently favored REPs for managing immature permanent teeth. As AI use expands in healthcare, optimizing its integration into clinical endodontic decision-making is essential to maximize patient benefit.
This study used multiple methods in the same cohort to assess oral hypofunction, namely, poor oral hygiene, oral dryness, and diminished occlusal force, tongue-lip motor function, tongue pressure, masticatory function, and swallowing function. Oral hypofunction diagnoses differed in relation to the method used to assess oral dryness (in 6 patients) and poor oral hygiene (in 24 patients). Accurate diagnosis of oral hypofunction enables appropriate management of oral function. Future studies should evaluate other assessment items.
PURPOSE:This study aimed to evaluate how immobilizing tilapia fish scale type 1 collagen onto poly(lactic acid) (PLA), following chemical modification with hexamethylenediamine (HMDA), affects the adhesion and proliferation of mouse osteoblast-like cells (OLCs). METHODS:PLA films were chemically modified by HMDA immersion to introduce amino groups (-NH2) (PLA-NH2). Tilapia fish scale type 1 collagen was subsequently immobilized onto the PLA-NH2 surface via a water-soluble carbodiimide condensation reaction, producing (TFColl-PLA-NH2). Surface properties of the films were characterized using contact angle measurements and X-ray photoelectron spectroscopy (XPS). Biological evaluation was conducted by culturing OLCs on PLA, PLA-NH2, and TFColl-PLA-NH2 films, followed by quantification of cell numbers. RESULTS:The contact angles of PLA-NH2 and TFColl-PLA-NH2 were significantly lower than PLA (P < 0.05). XPS confirmed successful immobilization of tilapia collagen onto the PLA surface. At all time points, TFColl-PLA-NH2 showed the highest cell numbers, followed by PLA-NH2, while PLA had the lowest (P < 0.05). PLA-NH2 promoted calcification more effectively than PLA (P < 0.05), and TFColl- PLA-NH2 further enhanced calcification compared with PLA-NH2 (P < 0.05). CONCLUSION:PLA surface treatment with HMDA is an effective and straightforward method. Tilapia fish scale type 1 collagen has potential for application as a novel biomaterial source.
A case of a patient with left maxillary molar pain unresponsive to standard dental treatment is presented. Advanced imaging revealed an aggressive lesion in the maxillary sinus with associated bone destruction, soft tissue extension, and diffusion restriction suggestive of malignancy. The lesion was subsequently confirmed as maxillary sinus carcinoma. This case highlights the diagnostic challenges associated with nonspecific temporomandibular disorder-like symptoms and emphasizes the importance of recognizing red flags as prompts for cross-sectional imaging and specialist referral, which are essential for ensuring an accurate diagnosis and improving clinical outcomes in patients with atypical or refractory orofacial pain.
PURPOSE:This study investigated the dose-dependent impact of smoking intensity on marginal bone loss (MBL) and the rates of implant survival and failure in patients undergoing implant placement with simultaneous guided bone regeneration (GBR) over a 5-year follow-up period. METHODS:A retrospective cohort analysis was performed on 55 patients (130 implants) who were stratified by smoking intensity (10 or 20 cigarettes/day). MBL was assessed radiographically, and clinical outcomes were analyzed using Kaplan-Meier survival curves and multivariate logistic regression. RESULTS:At 5 years, smokers consuming >10 cigarettes/day exhibited significantly greater MBL than did non-smokers and light smokers (2.67 mm vs. 1.34-1.40 mm; P < 0.001). Heavy smokers (>20 cigarettes/day) showed the highest MBL (2.88 mm). Multivariate analysis identified smoking ≥20 cigarettes/day (odds ratio = 16.7) and the use of non-resorbable membranes (odds ratio = 10.4) as primary independent risk factors for failure. The 5-year survival rate remained 100% for non-smokers and light smokers (≤10 cigarettes/day) but decreased significantly to 88.1% for those exceeding 10 cigarettes/day. CONCLUSION:Smoking intensity has a profound, dose-dependent negative effect on GBR-supported implants. Consumption of more than 10 cigarettes/day significantly accelerates bone loss and diminishes implant survival, identifying heavy smoking as a critical risk factor for long-term biological complications in patients receiving implants along with concurrent GBR.
PURPOSE:This study compares the marginal and internal gaps for four restorative materials produced by two fabrication methods in both minimally invasive occlusal veneer and conventional onlay cavities. METHODS:Eighty mandibular molars prepared as occlusal veneer and mesial-occlusal-distal-lingual onlays and restorations were produced using lithium disilicate glass ceramic, hybrid ceramic, nanohybrid composite, and laboratory composite materials. A silicone replica method was used to examine the marginal gap and internal gap with a stereomicroscope. Two-way analysis of variance (ANOVA) was used to analyze the effects of the material and design, and one-way ANOVA was used to analyze the effect of the fabrication method. RESULTS:The marginal gap significantly differed in relation to the material, and the internal gap significantly differed in relation to the material and design. Gaps were significantly smaller for the laboratory composite groups than for the other groups. Comparison of fabrication methods showed that internal and marginal gaps were significantly smaller for the conventional procedure. CONCLUSION:The less complicated designs yielded a better fit. In particular, because of the greater number of intaglio surfaces, internal gap values were worse when cavity design complexity increased.
Electrochemical surface treatment (ET) was applied to Ti-6Al-7Nb and Ti-6Al-4V alloys to enhance their corrosion resistance for biomedical applications. Disk-shaped specimens were treated in a water-glycerin-lactic acid electrolyte under a constant voltage of 50 V. Corrosion behavior was evaluated by anodic polarization in 0.9% saline, and the surface chemistry was analyzed using X-ray photoelectron spectroscopy (XPS). ET shifted the corrosion potential toward more noble values and reduced the passive current density for both alloys. XPS revealed a marked increase in the Ti4+ fraction, indicating the formation of a TiO2-enriched surface layer. Overall, ET enhanced the passivation of high-strength titanium alloys used in medical and dental prostheses.
PURPOSE:Dentin hypersensitivity, caused by exposed dentinal tubules, remains a significant clinical challenge. Conventional biomineralization using hydroxyapatite (HAP) often fails to achieve rapid nucleation and durable tubule occlusion. This study aims to develop a biomimetic mineralization strategy that leverages the synergistic interplay of specific polar amino acids to actively direct HAP deposition and enhance dentin occlusion efficacy. METHODS:Mineralization kinetics of isolated and combined polar amino acids were quantitatively evaluated to identify the optimal templating conditions for HAP nucleation. The optimized combination of (tyrosine and lysine) with HAP was applied in vitro to demineralized dentin models for 1 to 7 days. The efficacy of tubule occlusion, structural integration, and chemical stability was systematically characterized using scanning electron microscopy, focused ion beam-transmission electron microscopy, and rigorous acid-challenge assays. RESULTS:The combination of positively charged and neutral polar amino acids synergistically accelerated HAP nucleation kinetics. In vitro application promoted rapid, dense, and deep occlusion of dentinal tubules. Crystallographic analysis confirmed the formation of a structurally integrated mineralized layer with strong chemical homology to native dentin (Ca/P ratio: 1.67 vs. 1.72). Moreover, the layer maintained significant occlusion integrity following prolonged acid challenges. CONCLUSION:This biomimetic mineralization paradigm, driven by a synergistic combination of polar amino acids, overcomes the limitations of passive HAP filling by achieving rapid, deeply integrated, and chemically stable dentinal tubule occlusion. It provides a highly translatable foundation for the development of advanced desensitizing biomaterials.
PURPOSE:This study was designed to investigate the effects of increased exposure time and different levels of irradiance on the repair bond strength (µTBS) and degree of conversion (DoC) of two universal adhesives. METHODS:Computer-aided design-computeraided manufacturing (CAD-CAM) composite blocks were prepared and subjected to thermal cycling. They were randomly divided into two groups based on the adhesive agent used: Clearfil S3 Bond Universal (CSU) or Gluma Bond Universal (GBU). Within each group, the specimens were further classified into six subgroups (n = 6 blocks) according to irradiance (1,000 or 1,400 mW/cm2) and exposure time (10, 15, or 20 s). The bonded specimens were then repaired using nano-hybrid resin composite. Sticks measuring 0.9 mm2 were obtained from the repaired blocks and subsequently tested in a micro-tensile testing machine. Additionally, the DoC was assessed using micro-Raman spectroscopy. RESULTS:The 1400*10 group of GBU and CSU demonstrated higher µTBS than the 1000*10 and 1400*15 groups, regardless of thermal cycling (P = 0.000). For CSU, the 1400*10 group showed the highest DoC (P < 0.05). However, the DoC of GBU did not differ significantly among the various irradiation/exposure times (P > 0.05). CONCLUSION:The polymerization of adhesives at an irradiance level of 1,400 mW/cm2 for 10 s (14 J/cm2) increases the repair µTBS and DoC regardless of thermal cycling.
PURPOSE:This study aimed to evaluate the effects of scan body splinting material types and heights on scanning accuracy and duration for a completely edentulous mandible. METHODS:Scan bodies on multi-unit abutments were splinted at heights of 2 mm and 6 mm using orthodontic elastic ligatures (OELs) and three-dimensionally printed attachments (3D-As). Forty scans were obtained (n = 10 per combination) and analyzed with Geomagic Control X software. The Shapiro-Wilk test was used to assess normality, and nonparametric data were analyzed using the Kruskal-Wallis and Mann-Whitney U tests (P < 0.05). RESULTS:Scanning time varied significantly among groups (P = 0.000), being longest in the 2-mm-OEL and shortest in the 6-mm-3D-A group. Greater splinting height significantly reduced scan time (P < 0.001), and 3D-A showed shorter durations than OELs (P = 0.008). Angular deviation differed significantly among the groups (P = 0.012), although height and material alone had no significant effect (P > 0.05). Linear deviation did not differ significantly overall (P = 0.062), but lower values were observed in OEL groups (P = 0.018). CONCLUSION:Splint height and material type significantly influence scanning time. The potential impact of splinting material type and height on accuracy should be carefully considered when planning digital impression protocols.
PURPOSE:From a life-course perspective, adolescent socioeconomic status (SES) can have long-term effects. This study investigated the association between SES in adolescence and older age SES, as well as their mobility, and routine oral health behaviors among older adults. METHODS:This cross-sectional study analyzed data of individuals aged 65 years or older from the 2019 wave of the Japan Gerontological Evaluation Study (JAGES). SES mobility from adolescence to old age was defined based on combinations of economic status at age 15 and in older adulthood. Oral health behaviors, such as tooth brushing, toothpaste use, and flossing or interdental brushing, were also assessed. Poisson regression analysis was used to estimate prevalence ratios (PRs). RESULTS:Among 21,197 participants with a mean age of 74.0 years (SD = 5.9), 47.2% were male. Compared to individuals with consistently low SES, those with upward SES mobility and consistently high SES were more likely to use dental floss or interdental brushes (PR = 1.21, 95% CI: 1.12-1.30 and 1.22, 95% CI: 1.14-1.31, respectively). In contrast, neither tooth brushing nor toothpaste use was significantly associated with SES mobility. CONCLUSION:Inequalities in the use of dental floss and interdental brushes based on SES and SES mobility were observed.
PURPOSE:This study aimed to establish an in vitro model using Calu-3 human lung adenocarcinoma cells stimulated with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) envelope (E) protein to evaluate the anti-inflammatory effects of oren (Coptis rhizome), a traditional Kampo medicine. METHODS:Calu-3 cells were treated with the E protein in the presence or absence of oren extract. Interleukin (IL)-6 production was quantified using ELISA. Reporter gene assays were used to measure IL-6 promoter activity and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation. The involvement of Toll-like receptor (TLR) signaling pathways was also investigated. RESULTS:The E protein increased IL-6 production in Calu-3 cells by approximately fourfold; however, co-treatment with oren significantly suppressed this effect (P < 0.001). In 293-TLR2/CD14 cells, the E protein enhanced IL-6 promoter activity by approximately 2.8-fold, but this activation was significantly inhibited by oren (P < 0.001). The E protein also increased NF-κB-dependent transcriptional activity by approximately fourfold in 293-TLR2/CD14 and 2.4-fold in Calu-3 cells, and these effects were significantly suppressed by oren (P < 0.001). CONCLUSION:Oren significantly suppressed SARS-CoV-2 E protein-induced IL-6 production and NF-κB pathway activation, with effects extending to the transcriptional level through inhibition of IL-6 promoter activity.
PURPOSE:This study aimed to assess whether masseter, suprahyoid, and trapezius muscle activities during mastication differed with changes in sitting posture. METHODS:Thirteen healthy young adults chewed gummy candies under three conditions: sitting with sole-ground contact, sitting without sole-ground contact, and sitting on an unstable balance board. Electromyographic electrodes were attached to the masseter, suprahyoid, and trapezius muscles to evaluate muscle activity. The examiner also evaluated the mastication time, total integral values for each muscle, and number of chewing cycles from start of mastication to swallowing. RESULTS:The total integral values for masseter and suprahyoid muscles were significantly higher for the no sole-ground contact and balance-board conditions than those under the sole contact condition. The total integral value for the right trapezius muscle was also significantly greater for the no sole-ground contact and balance-board conditions than that under the sole contact condition. CONCLUSION:Increased masseter and suprahyoid muscle activity under unstable sitting conditions suggests that a stable sitting posture is necessary for efficient mastication. The right trapezius muscle also exhibited greater activity under unstable sitting conditions, which may have been a compensatory response to enhance postural stability alongside the masticatory muscles.
PURPOSE:Teachers frequently serve as primary first responders when traumatic dental injuries (TDIs) occur in schools. Immediate management is critical for prognosis, particularly in avulsion cases. This study aimed to assess preschool and primary school teachers' knowledge of emergency TDI management and their awareness of the ToothSOS mobile application, a resource providing evidence-based guidance. METHODS:A descriptive cross-sectional study was conducted among 427 preschool and primary school teachers in Turkey between May and June 2025. An online questionnaire, based on international guidelines and validated by expert review, collected data on demographics, TDI management knowledge, and ToothSOS awareness. Statistical analyses were performed using non-parametric tests (P < 0.05). RESULTS:The median knowledge score was 3 (range: 0-8). Few teachers correctly identified immediate replantation or storage in milk as appropriate actions for avulsed permanent teeth. Although awareness of the ToothSOS was extremely low, over half of the participants expressed willingness to use it. Significantly higher knowledge scores were observed among teachers with prior trauma education. CONCLUSION:Teachers demonstrated insufficient knowledge of emergency management of TDIs and limited awareness of digital support tools. Incorporating structured trauma education and accessible educational technologies into teacher training may support teachers' preparedness and decision-making in dental trauma emergencies.
PURPOSE:This in vitro study evaluated the effects of different chelating agents on dentin properties influencing the adhesion of calcium silicate-based biomaterials. The effects of 9% etidronic acid and 0.2% chitosan nanoparticles on the microhardness, surface roughness, and push-out bond strength of Biodentine were assessed. METHODS:Seventy-five extracted maxillary incisors were divided into three groups according to the final irrigation protocol: 9% 1-hydroxyethylidene-1,1-bisphosphonate (HEBP), 0.2% chitosan, or 0.9% saline (control). Dentin microhardness (Vickers hardness number) and surface roughness (Ra, µm) were measured before and after irrigation. For push-out testing, standardized cavities in 60 dentin discs were filled with Biodentine and stored for 24 h at 37°C and 100% humidity. Failure modes were examined under a stereomicroscope. Data were analyzed using one-way Analysis of Variance (ANOVA), Tukey Honestly Significant Difference (HSD), Kruskal-Wallis, and paired t-tests (P < 0.05). RESULTS:All groups showed a significant reduction in microhardness (P < 0.001), with the greatest reduction observed in HEBP. Surface roughness increased significantly and was highest in HEBP (P < 0.001). Push-out bond strength was higher in HEBP than control (P < 0.01), with no difference between HEBP and chitosan (P > 0.05). CONCLUSION:Both agents improved Biodentine adhesion; however, chitosan caused milder dentin alterations, indicating greater potential for dentin preservation.
PURPOSE:This study attempted to compare frictional resistance among three-dimensional (3D) printed resin brackets, and also with conventional metal and ceramic brackets under in vitro conditions. METHODS:3D bracket designs were created digitally and converted to stereolithography (STL) file format. Subsequently, brackets were produced using a FormLabs 3B+ printer using Permanent Crown and Biomed Clear resins. Half of these 3D-printed brackets were aged by thermal cycling, and then the frictional resistances of aged resin, non-aged resin, ceramic and metal brackets were measured using a universal testing machine. RESULTS:Shrinkage was 5.41% for Permanent Crown brackets and 7.84% for Biomed Clear brackets. Resin-based brackets produced by 3D printing demonstrated the highest frictional resistance. After the aging process, the frictional resistance of the 3D-printed brackets was reduced. Frictional resistance was lowest for the stainless steel wire and stainless steel bracket combination, and highest for the beta-titanium wire and resin bracket combinations (P < 0.05). CONCLUSION:As the Permanent Crown resin bracket demonstrated frictional resistance comparable to ceramic brackets after aging, advances in more durable 3D printing materials with improved surface properties are expected to further enhance the clinical applicability of 3D-printed brackets.
PURPOSE:To propose and validate the residual ratio of the metal artifact area (ResRaMAA) as an objective and practical metric for quantitative evaluation of the effectiveness of metal artifact reduction (MAR) in cone-beam computed tomography (CBCT) using a dedicated phantom. METHODS:A phantom enabling variation in the number and positioning of titanium rods was scanned under four rod configurations using three CBCT systems. The metal artifact area (MAA) was measured with MAR turned off (MAR-Off) and on (MAR-On), and the two values were used to determine the ResRaMAA. RESULTS:MAA values indicated a proportional relationship between MAR-Off and MAR-On. The proportionality coefficient, total ResRaMAA, ranged from 14% to 18%, significantly differing from 0% and 100%. Lower and upper ResRaMAA distributions differed significantly within the same device. Device-related differences were suggested, but not confirmed statistically. Additionally, titanium rod shapes in MAR-On data varied by device and metal rod configuration. CONCLUSION:ResRaMAA was able to quantify MAR effectiveness in reducing metal artifacts (MAs) caused by titanium rods and revealed significant differences between the lower and upper MA regions. ResRaMAA provides a simple, practical metric for objective evaluation of MAR performance.
