European Journal of Dentistry最新文献

Dentists routinely adopt forward-lean postures that can lead to chronic spinal musculoskeletal disorders. Wearable real-time feedback may prompt microadjustments that preserve spinal health. This article aims to develop a wearable device for real-time detection of forwardleaning posture in dentistry, to assess its usability and alert rate during standardized student tasks, and to estimate cervical-disc fatigue lifetime from the measured headflexion profile using a simplified S-N model.An assistive device was constructed around an Arduino Uno interfaced with a three-axis FC-51 tilt-switch module, calibrated to trigger at > 30 degrees of head flexion. A piezo buzzer emitted pulsatile alerts when tilt exceeded the threshold. Twenty-four dental students (12 fourth year, 12 fifth year) wore the device during 30-minute simulated operative sessions. A research assistant logged each alert in real time. Postsession questionnaires (5-point Likert scale) assessed comfort, intrusiveness, distraction, workflow impact, and posture awareness. Qualitative feedback on power, alert modalities, and design refinements was collected. A fatigue model based on an S-N curve framework used measured angles to estimate years to cervical-disc fatigue under typical clinical exposure.Head flexion averaged 42.7 degrees (standard deviation 9.4). The device generated a mean of 7.9 alerts per session, with no significant difference between year levels. Likert ratings indicated high comfort, low intrusiveness and distraction, minimal workflow disruption, and enhanced posture awareness; 79% of participants expressed willingness to adopt the device. Common suggestions included rechargeable power, multimodal alerts, slimmer enclosures, and customizable thresholds. The S-N fatigue model predicted disc fatigue onset at approximately 20.6 years for pure flexion and 16.0 years when lateral tilt was also considered, aligning with clinical data from the literature. Simulated use of the device, limiting "bad posture" to 1 minute per day, extended the model's fatigue lifetime to over 900 years.The goggle-mounted tilt-sensor device effectively detected and interrupted excessive forward-lean postures, was well accepted by users, and provided insights for ergonomic design improvements. Coupled with an S-N fatigue model, this approach offers both a practical intervention and a quantitative framework for mitigating career-long spinal risk in dentistry. Future work should validate long-term musculoskeletal outcomes and explore integration into clinical training.

To assess and compare the trueness (dimensional discrepancy and degree of deviation) of various methods of impressions for All-on-4 implants.This investigation employed a single-piece artificial mandibular jaw with four implants arranged in an All-on-4 configuration. Three impression methods were compared: one open-tray conventional impression digitized after pouring, and two intraoral scanners, TRIOS 5 and Runyes 3DS 3.0. A reference scan (control) was conducted with a laboratory-based scanner. All scans were performed using scan bodies and exported as Standard Tessellation Language (STL) files. A total of 30 STL scans were produced (n = 10). The dimensional discrepancy (along the X, Y, and Z axes) and the overall degree of deviation in the position were assessed. Data analysis was conducted using Brown-Forsythe one-way analysis of variance and Tamhane's post hoc tests (p < 0.05).The mean degree of deviation for scan bodies was as follows: TRIOS 5 (1.11 ± 0.06 mm), Runyes 3DS (1.02 ± 0.05 mm), and conventional (0.82 ± 0.16 mm). Statistically significant differences were found among all impression methods (p < 0.05). While the conventional method showed the highest trueness, it had the greatest standard deviation (SD, 0.16), which was the least consistent among them. The Runyes 3DS scans displayed the highest precision with the degree of deviation of 0.05 (± SD). Dimensional discrepancies mainly occur on the Z-axis across all three impression methods. Conventional impressions showed statistically significant discrepancies in the Y- and Z-axes, while TRIOS 5 images had statistically significant discrepancies in the X- and Z-axes. Runyes 3DS readings were statistically significantly discrepant in the Z-axis.While both conventional methods and digital scans have their merits, traditional impression methods may offer improved trueness in full-arch implant cases. Utilizing the open-tray system with suitable materials and methods can enhance precision and lead to more reliable outcomes.

High-fat diet (HFD) consumption induces metabolic diseases, which lead to salivary gland alteration. However, the alteration in salivary gland remains inconclusive, and the potential protective effect of simvastatin is limited. Therefore, our study aimed to investigate the effect of HFD consumption and the protective effect of simvastatin on submandibular and sublingual glands in rats.Eighteen male Wistar rats were divided into three groups (n = 6 per group): a control group (C) fed a standard diet, a HFD group (H), and a HFD with simvastatin group (S). After 12 weeks, blood was collected for lipid parameter analysis. Submandibular and sublingual glands were stained with hematoxylin and eosin (H&E), Masson's trichrome, periodic acid-Schiff, and alcian blue to evaluate gland architecture, fibrosis, and mucin content. Image analysis was done using imageJ software.Parametric data were analyzed using one-way ANOVA followed by Tukey's post hoc test. Nonparametric data were analyzed using the Kruskal-Wallis test, followed by Dunn's test. A p-value <0.05 was considered statistically significant.The low-density lipoprotein cholesterol (LDL-C) level significantly increases in the H group compared with the C group (p = 0.004). Acinar cells in both submandibular and sublingual glands were significantly smaller in the H and S groups compared with the C group (p < 0.05). Vacuole-like clear structures were more frequent in the H group. Collagen deposition in the submandibular gland was significantly higher in the H and S groups compared with controls (p = 0.005 and p = 0.011, respectively). Slightly altered mucin staining is seen in both glands.HFD increased LDL-C levels and induced acinar atrophy and fibrosis in the submandibular and sublingual glands. Simvastatin did not protect against salivary gland damage from HFD consumption.

Bone grafts derived from natural hydroxyapatite (HA) are increasingly being explored because they are more economical in terms of production costs compared with commercial HA. HA can be obtained from local cattle slaughter waste in Aceh, Indonesia, which has not been widely studied for its potential for dental applications. This study examines the synthesis and characterization of bovine HA (BHA) derived from Aceh cattle femur through calcination for applications in dentistry.This research began with the cleaning of fresh bones by boiling and soaking them in acetone for 2 hours before 3-hour calcination at varying temperatures. The BHA samples were characterized using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction, scanning electron microscopy with energy dispersive X-ray (SEM-EDX), and particle size analyzer (PSA).Data were analyzed using SPSS with a one-way analysis of variance to assess the impact of calcination temperature on the yield and particle size of BHA.BHA obtained from calcination at 900°C and 1,000°C showed the highest crystallinity, with values above 84%, and uniform particle distribution. PSA and SEM analysis showed that BHA particles were spherical in submicron size, which became smaller and more uniform but agglomeration did not occur significantly between each increase in calcination temperature. FTIR analysis showed the presence of phosphate, carbonate, and hydroxyl functional groups. Elemental composition analysis using EDX confirmed that essential elements such as calcium and phosphorus were distributed consistently at all temperatures with a Ca/P ratio of 1.7 to 2.3.Based on the characteristics of crystallinity, particle size, and chemical composition of the obtained BHA, it is considered optimal for bioactivity, which allows stimulation of new bone tissue formation and promotes osseointegration while balancing structural stability. This makes BHA derived from Aceh cattle bones a suitable bone filler candidate for treating alveolar bone defects in hard tissue regeneration. These findings highlight the potential use of cattle bone waste as a sustainable source of HA in dental applications.These findings suggest that Aceh bovine bones are a viable source for producing quality BHA, potentially contributing to more sustainable and ecofriendly biomaterials for dental applications.

This article evaluates the marginal and internal gap, interfacial volume, and fatigue behavior in computer-aided design-computer-aided manufacturing (CAD-CAM) restorations with different designs (crowns or endocrowns) made from lithium disilicate-based ceramic (LD, IPS e.max CAD, Ivoclar AG) or resin composite (RC, Tetric CAD, Ivoclar AG).Simplified LD and RC crowns (-C) and endocrowns (-E) were produced (n = 10) using CAD-CAM technology, through scanning (CEREC Primescan, Dentsply Sirona) and milling (CEREC MC XL, Dentsply Sirona), and then adhesively bonded to fiberglass-reinforced epoxy resin. Computed microtomography was used to assess the marginal and internal gap and interfacial volume. A cyclic fatigue test (20 Hz, initial load = 100 N/5,000 cycles; step-size = 50 N/10,000 cycles until 1,500 N, if specimens survived, the step-size = 100 N/10,000 cycles until failure) was performed. Topography, finite element analysis (FEA), and fractography were also executed.Two-way analysis of variance and Tukey's post hoc tests were employed (α = 0.05) for marginal and internal gap and interfacial volume. Survival analysis based on Kaplan-Meier and Mantel-Cox tests (α = 0.05) was used for fatigue data.RC crowns demonstrated the smallest marginal gap, LD crowns the largest. Endocrowns presented intermediary marginal gap values. Internal gaps were all above the planned 120 µm space. The lowest gap was seen at the cervical-axial angle at crowns, regardless of material. At the axio-occlusal angle, LD crowns presented a lower gap than RC; meanwhile, there was no difference among endocrowns. When comparing occlusal/pulpal space, LD crowns showed the lowest values, and RC-C, LD-E, and RC-E were statistically similar. Fatigue testing revealed superior behavior for RC restorations, withstanding higher loads and more cycles before failure compared to LD. FEA indicated that the crowns required higher stress concentration to unleash their failure than endocrowns. Fractographic features confirm failure origin at surface defects located at the restoration/cement intaglio surface, where it concentrated the highest maximum principal stress.RC crowns and endocrowns presented lower marginal gaps than LD ones. Differences in other internal gap outcomes exist but within a nonclinically relevant threshold. The restoration fatigue behavior was influenced by the CAD-CAM material, but not by its design.

This study aims to explore the beliefs and attitudes related to the adoption of teledentistry among Pakistani dental professionals, focusing on data security, practice enhancement, and patient benefits.A cross-sectional study on a 5-point Likert scale assessed four domains of teledentistry: data security and patient consent, practice improvement capabilities, usefulness for dental practice, and patient benefits, among dental professionals through electronic forms. Demographic data and items from four domains were analyzed by descriptive statistics, analysis of variance and Pearson's correlation tests, respectively, using SPSS, with a p-value of < 0.05 set as statistically significant.A large percentage (59.8%) of the 408 dental professionals raised issues related to data security with 52% showing concerns about securing patient consent. Most professionals (61.8%) acknowledged the potential of teledentistry in reducing waiting times. Gender, age, qualifications, and work experience were found to be associated with individual perceptions of teledentistry. Females were more skeptical on teledentistry capabilities (p < 0.000) while younger, more than the older professionals had heightened worries about data security (p < 0.000). Specialists viewed teledentistry favorably compared with other professionals (p < 0.000). Professionals with more than 5 years of experience expressed optimism, on how teledentistry could improve practice efficiency and patient outcomes (p < 0.000).This report on the views and attitudes of Pakistani dental professionals toward teledentistry indicates their positive perception of teledentistry, citing its potential to enhance practice and benefit patients. Overcoming data security concerns and improving education on teledentistry benefits could foster broader acceptance and utilization of this technology.

This study compares the color change of non-vital anterior teeth after laser-activated bleaching and conventional walking bleaching technique.Sixty extracted teeth were endodontically treated, stained in a black tea solution, and the baseline shade was measured using a spectrophotometer (Easyshade, VITA). Bleaching was done using either: internal bleaching with 35% H₂O₂ (Opalescence Endo) and then tooth sealed for 5 days (Gr1), 35% H₂O₂ (JW Next) for 7 minutes (Gr2), internal and external bleaching for 7 minutes (Gr3), diode laser-activated internal bleaching for 30 seconds (940 nm, continuous wave, 2 W, noncontact mode, 300 um, non-initiated tip), wait for 7 minutes, second laser application for 30 seconds, tooth sealed for 5 days (Gr4), diode laser-activated internal bleaching for 24 hours (Gr5), or diode laser-activated internal and external bleaching for 24 hours (Gr6) (n = 10). The color change (ΔE₀₀) was measured and data were analyzed using one-way analysis of variance followed by Tukey post hoc test (a = 0.05). The inner dentin of the samples was inspected using scanning electron microscopy.All the tested bleaching techniques were able to change the color. All the laser-activated bleaching protocols, namely, Gr4, Gr5, and Gr6, showed higher mean ΔE₀₀ values than the non-laser-activated bleaching Gr2 and Gr3 (p < 0.05) and were statistically similar (p > 0.05) to the control group Gr1. Laser-activated bleaching caused surface modification and dentinal tubule opening.All the tested laser-activated bleaching protocols showed faster and more efficient color change, comparable to the conventional 5-day walking bleaching protocol.

Regenerative periodontal surgical approaches require scaffolds in a form that can fill narrow and irregular defects. Each scaffold must be specially designed to conform to the shape of the specific defect. The aim of this study was to fabricate nanohydroxyapatite chitosan-gelatin (nHA/KG) pastes with different composition percentages and to analyze the differences in physical, chemical, and biological characteristics in response to periodontal tissue regeneration in vitro.The nHA/KG paste was prepared at three different concentrations of inorganic and organic contents (70/30; 75/25; and 80/20) by mixing nHA powder, chitosan flakes, and gelatin powder. The ratio of chitosan and gelatin on all nHA/KG pastes is 1:1. The three nHA/KG pastes were tested for the following rheology and bioactivity properties in simulated body fluid (SBF): pH value, swelling, degradability, surface morphology, and cell attachment by scanning electron microscopy and chemical structure by Fourier transform infrared (FTIR). Osteoblasts and fibroblasts were analyzed for proliferation using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay and for cell proliferation by reverse transcription quantitative real-time polymerase chain reaction of COL1, alkaline phosphatase (ALP), osteocalcin (OCN), and RUNX2.Analysis of variance followed by Tukey's post hoc, Kruskal-Wallis, Wilcoxon, and paired sample t-tests were performed according to each data type.The nHA/KG paste showed gel-like physical characteristics. The pH value after SBF immersion was stable at pH ± 7.0, although the pH of the nHA/KG 80/20 paste decreased to pH 6.3 on day 14. The three paste preparations showed significant differences in swelling (p < 0.05) on days 1 and 14 and in the degradability ratio on days 1, 2, and 7 (p < 0.05). The three-dimensional scaffold surface morphology differed depending on the immersion time. The FTIR test showed the presence of PO₄ ^3-, CO₃ ^2-, -OH, amide I, and amide II functional groups in all paste variants. The nHA/KG 75/25 paste had the most stable structure during the immersion period. Biological tests showed a viability ratio of osteoblasts and fibroblasts ≥ 70%. The paste could stimulate the messenger ribonucleic acid expression of the COL1, ALP, OCN, and RUNX2.The nHA/KG bone graft paste showed good potential as an injectable scaffold, with the nHA/KG 75/25 paste being the best of the three pastes tested here.

The search for an ideal obturating material has taken precedence due to the revolution of the materials used in pediatric endodontics. With zinc oxide, calcium hydroxide, and metronidazole as its core constituents, an unique obturating material was developed. To aid in the healing process, the material should be biocompatible and most importantly it should not have any negative consequences. Thus, using embryonic toxicology, brine shrimp lethality, and methylthiazol tetrazolium (MTT) assay, the current investigation sought to determine the cytotoxicity of the newly developed obturating material, which contained calcium hydroxide, zinc oxide, and metronidazole at 2% 60-40 concentrations.In zebrafish embryonic toxicology method and brine shrimp lethality assay, five distinct concentrations of the new obturating material was tested and compared with the control in a 24-well plate containing fertilized zebrafish eggs and in 6-well plate containing nauplii, respectively. The hatching and the viability rate of the zebrafish embryos and survival rate of nauplii were calculated. In MTT assay, the percentage of fibroblast cell viability and the cell morphology was documented. A statistical analysis was performed on all of the collected data.The hatching and the viability rate of the zebrafish embryos falls as the concentration of the new obturating material rises. The survival rate of the nauplii also falls with rise in the concentration of the obturating material. No cytotoxic effect was demonstrated by the novel obturating material on the human gingival fibroblasts up to 200 μg/mL concentration.The novel obturating material exhibits minimal cytotoxic effects even at increased concentrations.

The challenge of endodontic regeneration requires scaffold that can facilitate dentin and pulp regeneration by providing structural support and promoting initial cell adherence to regenerate new tissue. This study explores characterization of a novel carbonate apatite-bovine gelatin (CA-BG) scaffold for endodontic regeneration that was fabricated using a lyophilization technique. CA, recognized for its biocompatibility and osteoconductive capabilities as a scaffold, was expected to provide structural support in complex biological environments such as pulp tissues. BG, a natural polymer with cell attachment substrates, was incorporated into the scaffold to enhance bioactivity, promoting cell attachment, proliferation, and differentiation.Scaffolds were fabricated with varying liquid-to-powder (L/P) ratios (0.5, 0.8, and 1) using freeze drying, and then their chemical and structural properties were evaluated using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM).FTIR analysis confirmed the presence of carbonate and phosphate groups, with slight peak shifts indicating CA-BG interaction. XRD analysis showed crystallinity differences, which were affected by the liquid ratio in each group. SEM results demonstrated that the L/P 1 scaffold exhibited surface roughness, which is expected to represent BG incorporation to CA. The L/P 1 scaffold was identified as the optimal candidate, balancing bioactivity and structural properties, to be able to promote dentin and pulp tissue regeneration.The findings contribute significantly to developing biocompatible, bioactive scaffolds for endodontic regeneration and broader tissue engineering applications, offering insights to achieve a balance between a scaffold structure and its biological functionality.