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Background and Objectives: This study aimed to evaluate the effects of hard, soft, and semi-soft splints on TMJ vibrations in bruxers with JVA and to compare them with data obtained from asymptomatic individuals. Materials and Methods: A total of 64 individuals were divided into four subgroups: control (n = 15); and hard (n = 17), soft (n = 16), and semi-soft (n = 16) splints. Electrovibratography records from all individuals included in the study before and after the 3-month splint treatment were obtained with the Biopak® System. Joint vibration analysis was used to evaluate TMJ sounds. Data normality was examined with the Kolmogorov–Smirnov and Levene tests. The significance of the differences was investigated by One-Way ANOVA and by the Kruskal–Wallis test. Conover’s multiple comparison test was used in post hoc tests. (ClinicalTrials.gov identifier: NCT06893744, on 24 March 2025, titled; Effects of Different Occlusal Splints). Results: After 3 months of treatment, for I < 300 Hz right opening, the control group was statistically lower than both semi-soft (p < 0.001) and hard (p < 0.001) splint groups. The difference between semi-soft and hard splints in post-treatment I < 300 Hz right opening is not statistically significant. After 3 months of treatment compared with the beginning, the increases in left-opening Ti (p = 0.004), I < 300 Hz (p = 0.004), and PA (p = 0.007) values in the soft splint group were statistically significant. Conclusions: All three kinds of splints improved clinical symptoms and complaints of bruxers. For joint vibrations in bruxers, hard and semi-soft splints are more beneficial than soft splints.

Backround : It has been considered that the preclinical education may be inadequate in the development of preparation skills of dental students. With technological developments, there is an increase in the use of computer-aided simulations in dental education. Virtual reality (VR) patient simulators promise practice in a realistic environment with detailed, frequent and objective feedback, but it remains unclear whether these features lead to better or faster skill acquisition. This study aims to investigate the impact of virtual reality simulations on students’ clinical preparation skills. Methods In this study, tooth preparation data of 100 fourth-year students who practiced preparation with a virtual reality device and had real patient experience, as well as a group of 100 fifth-year students who had no prior virtual reality experience but had real patient experience, were transferred to the exocad ® DentalCAD program, a CAD software, for the measurement of TOC (Total Occlusal Convergence) angles. The data obtained from these measurements were analyzed using the SPSS program. In addition to this study, 25 random individuals from both groups underwent preparation in a phantom model in order to make a comparison between different experience environments. Finally, a questionnaire was administered to the group trained in the simulator to evaluate the students’ perspective on this new training method. Independent sample T test and single sample analysis of variance (ANOVA), which are parametric test methods, and Tukey HSD, which is a post hoc test, were used in statistical analyses. With the t test, which is used to investigate whether there is a difference between two sample groups in terms of averages, we aimed to investigate the significance between class level and tooth cutting surface by using group statistics and descriptive analysis data of the preparations. With the ANOVA test, which is a statistical analysis method used to compare the averages between at least three groups, we looked at whether the preparations we made in 3 different experience environments produced a significant result according to the tooth cutting surface, and then we investigated which experience group was the source of the significance with the tukey test. Results In the descriptive statistical analysis, it was determined that the average preparation angles of the 4th-year students were lower than those of the 5th-year students. Accordingly, it is possible to say that grade levels affect all surface preparation results in a statistically significant way. In descriptive statistics regarding patient preparation experience, the averages of the preparation angles taken according to the tooth surfaces of the 4th and 5th Grades are; The averages of the mesial, distal and buccal surfaces are close to each other, but only on the palatal surfaces, there is a significant difference between the averages of the 4th Grade (12.46) and the current average of the 5th Grade (15.22). The results of the Independent Samples T-Test conducted in the context of grade levels and four surface areas, is examined, it is seen that there are statistically significant differences between grade levels and the preparation results of all surfaces ( p  < 0.05). Conclusions According to the results of this study, students who used virtual reality simulators were more successful in terms of tooth preparation angles compared to students who did not use virtual reality simulators. This study demonstrated that the use of virtual reality simulators contributes to tooth prepartion skills.

Background and Objectives: CBCT images have been successfully used for CAD/CAM crown restorations; however, their use for ceramic inlay restorations remains unclear. This study aimed to evaluate the marginal and internal fit of CAD/CAM ceramic inlay restorations fabricated using intraoral scanner, model scanner, and CBCT data. Materials and Methods: Inlay preparations were performed on 11 mandibular molar typodont teeth. The teeth were scanned using an intraoral scanner, an extraoral scanner, and CBCT (0.075 mm voxel size). CBCT-generated DICOM data were converted to STL format with dedicated software. All scan data were transferred to CAD software, and a total of 33 restorations were designed. Feldspathic ceramic blocks were used for milling. Micro-CT was employed to measure marginal and internal gaps, with 60 measurement points taken from three cross-sections per sample. Data were analyzed using ANOVA and Bonferroni tests (p < 0.05). Results: CBCT exhibited greater marginal and internal gap dimensions (mean: 169.27 ± 38.64 μm), which were approximately 60–70 μm higher than those of the intraoral (97.00 ± 10.1 μm) and model scanner groups (109.67 ± 9.72 μm), exceeding clinically acceptable limits (≤120 μm) (p < 0.05). Intraoral and model scanners showed similar, clinically acceptable results. Conclusions: CBCT was less accurate for inlay restorations, likely due to their complex geometry. Nevertheless, fabrication was possible, and further research may improve its clinical applicability.

In the original publication [...]

(1) Background: This study aimed to evaluate the marginal and internal fit of ceramic crowns produced by various digital methods using microcomputed tomography (MCT) imaging. (2) Methods: The ceramic crown preparation was performed on typodont maxillary first premolar. The crown preparation was scanned with an intraoral scanner and a model scanner, and cone-beam computed tomography (CBCT) scans were performed with three different voxel sizes (0.075 mm, 0.1 mm, and 0.15 mm). The space between the crown and prepared teeth was measured at nine different points in both coronal and sagittal sections. Three different digital model acquisition techniques, namely, intraoral scanning, model scanning, and CBCT-based standard tessellation language (STL) reconstruction, were compared in terms of marginal and internal fit. (3) Results: Quantitative analyses revealed that model scanners exhibited the lowest marginal and internal gap values, indicating superior fit compared to intraoral scanners and CBCT-based models. The highest gap values were observed in the CBCT group with a voxel size of 0.15 mm. Overall, crowns obtained from model scanners demonstrated the highest success rates in both marginal and internal fit. (4) Conclusions: In conclusion, this study highlights the critical role of digital scanning accuracy in achieving clinically acceptable prosthetic fits and emphasizes the need for continued technological advancement.

This in vitro study aimed to evaluate and compare the shear bond strength (SBS) between monolithic zirconia (MZ) and different core build-up materials. Sixty cylindrical MZ specimens were fabricated and divided into three groups (n = 20) based on the type of core build-up material: nanohybrid composite resin (NHCR), glass ionomer cement (GIC), and zirconia-reinforced glass ionomer cement (zirconomer). All specimens were subjected to airborne-particle abrasion with aluminum oxide and bonded using a self-adhesive dual-cure resin cement. After 24 h of storage in distilled water at 37 °C, SBS testing was performed using a universal testing machine. Failure modes were examined under a stereomicroscope and classified as adhesive, cohesive, or mixed. The NHCR group exhibited the highest SBS values (48.32 ± 12.49 MPa), followed by the Zirkonomer group (14.19 ± 3.66 MPa), and the GIC group (10.37 ± 4.21 MPa). The SBS of NHCR was significantly higher than that of both Zirconomer and GIC (p < 0.001). Although no significant difference was found between Zirconomer and GIC, Zirconomer demonstrated higher mean bond strength. Within the limitations of this study, NHCR showed the highest bond strength to monolithic zirconia. Zirconomer performed better than conventional GIC; however, further investigations involving different surface treatments and long-term clinical conditions are recommended to enhance its bonding efficacy.

Reliable bonding between zirconia and PEEK surfaces is crucial for ensuring the long-term success of hybrid prosthetic restorations. This study aimed to evaluate the tensile bond strength of zirconia–PEEK specimens prepared using different primer strategies to determine the most effective adhesive protocol. One hundred bonded specimens were divided into four groups (n = 25): control (no primer), zirconia primer (MKZ Primer), PEEK primer (Visio.link), and dual primer application. Specimens underwent sandblasting with 110 µm Al2O3 particles at 2 bar pressure for 15 s, and the PEEK primer was light-cured using a Valo Grand LED curing unit (1000 mW/cm2, 90 s). All samples were bonded using the same universal adhesive and resin cement, and tensile bond strength was measured with a micro-tensile testing device. Data were analyzed using one-way ANOVA and Tukey’s HSD test (α = 0.05). The mean bond strengths were 12.83 MPa (control), 15.05 MPa (zirconia primer), 90.50 MPa (PEEK primer), and 102.09 MPa (dual primer). Application of PEEK primer significantly enhanced adhesion compared to zirconia primer or control (p < 0.001), while dual primer use yielded the highest values, indicating a synergistic effect. These findings suggest that surface-specific priming of both zirconia and PEEK surfaces effectively improves polymer–ceramic bonding performance and may contribute to the clinical durability of hybrid prosthetic restorations.

ObjectiveTo evaluate changes in the masseter muscle after orthognathic surgery using electromyography (EMG), ultrasonography (US), and ultrasound elastography (USE) in individuals with skeletal class III anomaly over long-term follow-up and compare with a control group.Materials and methodsThe study group included 29 patients with class III dentofacial deformities scheduled to undergo orthodontic treatment and orthognathic surgery. The control group included 20 individuals with dental class I occlusion. Assessment of the masseter muscles using EMG, US, and USE was performed before orthognathic surgery (T1) and at postoperative 3 months (T2) and 1 year (T3) in the study group, and at a single time point in the control group. All assessments were performed at rest and during maximum clenching. Masseter muscle activity, dimension, and hardness were analyzed.ResultsElectromyographic activity of the masseter muscle during maximum clenching was increased at postoperative 1 year but did not reach control group values. On ultrasonography, the masseter muscle showed minimal changes in dimension at postoperative 1 year compared to preoperative values and remained below control group values. The postoperative increase in masseter muscle hardness at rest and during maximum clenching persisted at postoperative 1 year.ConclusionThe results of this study suggest that after orthognathic surgery, additional interventions and much longer follow-up are needed to ensure better muscle adaptation to the new occlusion and skeletal morphology.Clinical relevanceAll assessment methods are useful for comprehensively evaluating changes in the masticatory muscles after orthognathic surgery.

While zirconia implants exhibit osseointegration comparable to that of titanium, concerns arise regarding low-temperature degradation and its potential impact on fracture strength. This study investigated the phase transformation and fracture characteristics of zirconia dental implants after aging through chewing simulation and subsequent static loading. The experimental setup involved 48 one-piece monobloc zirconia implants with diameters of 3.0 mm and 3.7 mm that had straight or angled abutments, with crown restorations, which were divided into six groups based on intraoral regions. The specimens underwent chewing simulation equal to five years of oral service, which was followed by static loading. Statistical analyses were performed for the data obtained from the tests. After dynamic and static loadings, the fractured samples were investigated by Raman spectroscopy to analyze the phase composition and micro-CT to evaluate fracture surfaces and volume changes. According to the results, narrow-diameter zirconia implants have low mechanical durability. The fracture levels, fracture patterns, total porosity, and implant fracture volume values varied according to the implant diameter and phase transformation grade. It was concluded that phase transformation initially guides the propagation of microcracks in zirconia implants, enhancing fracture toughness up to a specific threshold; however, beyond that point, it leads to destructive consequences.