The effect of a feldspathic porcelain coating applied before or after zirconia sintering on the shear bond strength between a resin luting agent and zirconia was evaluated. Pre-sintered and fully sintered zirconia specimens were coated with feldspathic porcelain and divided into three surface treatment groups: no treatment, airborne-particle abrasion, and hydrofluoric acid etching. The specimens were bonded using a dual-polymerizing resin luting agent and subjected to 0 or 5,000 thermocycles. The shear bond strength was measured. The fracture modes were analyzed microscopically. The surface morphology and composition were examined by scanning electron microscopy (SEM) and X-ray diffraction. Before thermocycling, both airborne-particle abrasion and hydrofluoric acid etching significantly increased the bond strength compared with no treatment. After thermocycling, airborne-particle abrasion maintained the highest bond durability, while hydrofluoric acid etching showed a marked decrease. SEM revealed that airborne-particle abrasion produced a rough surface favorable for micromechanical retention, whereas hydrofluoric acid etching resulted in smoother morphology. Airborne-particle abrasion effectively enhanced and preserved the bond strength between the resin luting agent and feldspathic porcelain-coated zirconia, regardless of the coating sequence. Hydrofluoric acid etching was ineffective after thermocycling, likely due to surface precipitation that occurred during firing.

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. 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). 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. 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.

As the anatomy of proximal contact areas affects the risk of dental caries in primary molars, this study aimed to assess the impact of different resin and matrix systems on the geometry of reproduced proximal surfaces in primary molars. Sixty mandibular primary first molar typodont teeth were prepared with standardized disto-occlusal cavities. Two experimental groups were created: Group I utilized GC UniFil Flow and Filtek Z250 XT; Group II utilized SDR Plus Bulk Fill Flowable Composite and Ceram.x Spectra ST. Each group was further subdivided into the Palodent V3 sectional matrix system (P) and the Tofflemire matrix system (T). Digital evaluations were then performed to calculate discrepancies. Significant discrepancies were found only between Group IT and Group IIP in the middle third (P < 0.05). Average root mean square values at proximal contact surfaces did not differ significantly among the groups. The proximal surface shape was also not significantly different. Within the limits of this study, the reproduced proximal surface geometry was not significantly affected by the type of resin and matrix system.

This study investigated the synergistic effects of reduced graphene oxide (RGO) on the antibacterial activity of three calcium hydroxide-based intracanal medicaments with different vehicles. Multispecies biofilms were cultured in a bovine root canal model. Intracanal medicaments containing nonaqueous vehicles, including N-methyl-2-pyrrolidone (NMP; CleaniCal), propylene glycol (PG; UltraCal XS), and polyethylene glycol (PEG; Calcipex II), were placed in the model. The synergistic effects of RGO were evaluated by analyzing colony-forming units, extracellular deoxyribonucleic acid (eDNA) levels, and findings from confocal laser-scanning microscopy (CLSM) and scanning electron microscopy. To evaluate the cytotoxicity of each vehicle, a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed. To determine whether RGO altered the physicochemical properties of the medicaments, flowability and pH were measured. A P-value of <0.05 was considered to indicate statistical significance. In the CleaniCal group, bacterial viability, eDNA levels, and extracellular polymeric substrate (EPS) were significantly lower in the presence of RGO. However, only bacterial viability significantly differed in the other groups. PEG resulted in the highest cell viability among the vehicles. Furthermore, there was no significant difference in flowability or pH in relation to the inclusion of RGO. The results suggest that RGO enhances the antibacterial effect of intracanal medicaments containing NMP.

This study used descriptive and inferential statistics to evaluate healing complications and survival time of avulsed permanent teeth. Records of children and adolescents with avulsion injury were identified, and data on age, gender, cause of trauma, number of affected teeth, and status of other teeth and supporting tissues were analyzed. In addition, data on root formation status, duration and medium of extraoral storage, and healing complications of avulsed and replanted permanent teeth were obtained for patients who attended follow-up appointments. During a period of almost 20 years, 187 permanent teeth of 138 patients were avulsed. Avulsion injuries were more frequent in males and at 10-12 years of age. Falls were the main cause of avulsion, and the teeth most frequently affected were the maxillary central incisors. Seventeen of 51 replanted and followed teeth were retained. Retention was shorter for teeth stored in dry medium. Duration of tooth retention was positively correlated with patient age at the time of trauma. The most common healing complications were ankylosis (70.6%) and inflammatory root resorption (54.9%). Outcomes of traumatic injuries are multifactorial, and favorable storage conditions, shorter duration of extraoral storage, and biological response are important for survival of avulsed teeth.

Using multivariate analysis, this study investigated the effectiveness of maxillofacial prosthetic treatment in relation to oral health-related quality of life (OHR-QoL), masticatory ability (food intake status score and gum-jelly test score) and related factors in patients who had undergone surgery for head and neck tumors. The study cohort comprised 112 patients who underwent surgical resection and prosthetic treatment among 224 patients with head and neck tumors seen at the Maxillofacial Prosthetics Clinic of Tohoku University Hospital in a 2-year period. Correlations between OHR-QoL, food intake status score, and gum-jelly test score (criterion variables), and age, sex, maxillary defect, tongue/soft tissue defect, reconstructive surgery, and chemoradiotherapy (explanatory variables) were investigated, and the data were examined statistically. Maxillary defect, tongue and soft palate tissue defect, and chemoradiotherapy were identified as factors that hindered the effectiveness of maxillofacial prosthetic treatment for improvement of the OHR-QoL, food intake status score, and gum-jelly test score. On the other hand, reconstructive surgery was a factor that facilitated the improvement of OHR-QoL and masticatory ability with maxillofacial prosthetic treatment. The factors identified to be related to the success or failure of maxillofacial prosthetic treatment suggest the importance of combining prosthetic intervention with surgical reconstruction.

To assess the sensitivity and the effect of topical lidocaine on the tongue by quantitative sensory testing, comparing healthy middle-aged female subjects with healthy young female subjects. Sixteen healthy female subjects including eight in their fifties and eight in their twenties participated. They participated in two sessions at a 2-week interval in randomized order: lidocaine (experimental session) or placebo gel (placebo session) was applied on the tongue tip for 5min. The following parameters were taken on the tongue tip before and after application of the gel in each session: tactile detection threshold (TDT), filament-prick pain detection threshold (FPT), and numerical rating scale (NRS). An increase of both TDT and FPT and a decrease of NRS were found after lidocaine application in both middle-aged and young female subjects. In the elder females, an increase of TDT, FPT, and NRS was also found after placebo gel application. However, the changes were not statistically significant, except for FPT in middle-aged subjects. The reactions found after lidocaine application in middle-aged female subjects could be due to habituation as well as to the post-application effect of placebo gel. Placebo-induced changes appeared more pronounced in the elder females.

To evaluate the flexural properties of repaired poly(methylmethacrylate) (PMMA) denture base materials for computer-aided design/computer-aided manufacturing (CAD-CAM) and to compare them with heat-activated polymerized PMMA. A total of 288 specimens (65 × 10 × 2.5 mm) were prepared using both CAD-CAM and conventional blocks and repaired using autopolymerizing and visible-light polymerizing (VLC) materials. Microwave energy, water storage and hydroflask polymerization were applied as additional post-polymerization cycles after the repair process. The flexural strength (FS) of the specimens was evaluated using the three-point bending test. Data were evaluated statistically using 2-way ANOVA followed by Bonferroni's correction to determine the significance of differences between the groups (P ≤ 0.05). The FS of the denture base materials for CAD-CAM was significantly higher than that for the heat-activated group (P ≤ 0.05). The FS was significantly highest when microwave energy was used for the post-polymerization cycle. The FS values for all groups repaired with VLC resin were significantly lower than for the autopolymerization group (P ≤ 0.05). The flexural properties of denture base materials for CAD-CAM repaired using autopolymerizing acrylic resins can recover by 50-70%. Additional post-polymerization cycles for autopolymerizing repair resin can be suggested to improve the clinical service properties of repaired dentures.

This study was designed to investigate the distribution of the main occluding area in adolescents. Furthermore, the importance of the main occluding area was clarified by examining its interrelationship with oral function and craniofacial morphology. A total of 102 patients were included in this study. The main occluding area was identified using a previously described method. Maximum occlusal force, occlusal contact area, lip-closing force, tongue pressure, and masticatory efficiency were measured to evaluate oral function. Craniofacial morphology was assessed using lateral cephalography. In terms of the degree of consistency of the main occluding area, the proportion of cases in which two matches were obtained among three trials was the highest. The most common main occluding area was the first molar. Regarding the anteroposterior position of the hyoid bone, the anteroposterior distance between the hyoid bone and the menton (Me-H) was significantly shorter in the group where the first molar was used for occlusion, relative to the group in which second premolar was used. The main occluding area in adolescents was less stable than that in adults and older adults; however, first molars accounted for most of the main occlusion areas, suggesting that the position of the hyoid bone might play a role in establishing their location.

To identify and measure the distance from the dental apices to the mandibular (MC) and mandibular incisive (MIC) canals, the diameter of the MC and the distances of the mental foramen (MF). In this retrospective study, cone-beam computed tomography scans of 144 adult patients (males and females) from a dental school in South Brazil were evaluated. Cross-sections were selected on the MC and the MIC paths, perpendicular to the mandibular base, and measurements were taken from the dental apices to the mandibular cortices. The measurement and location of the mandibular and mental foramen on both sides were compared. Paired t-tests compared sides, while Student's t-tests compared sexes (P < 0.05). The distance from the dental apices to the upper wall of the MC was closest in the third molar and farthest in the central incisor region. In both sexes and sides, the path of the MC is in most cases lingually in the molar regions and moves to the buccal region from the second premolar. The MF emerges in the regions between the premolars or near the second premolar. The results of this study highlight the importance of evaluating specific individual characteristics of a given population.