Purpose: This study sought to investigate the acceptance rate and associated factors of COVID-19 vaccines among dentists and dental students in seven countries. Material and Methods: A structured questionnaire prepared and guided by the report of the SAGE Working Group on Vaccine Hesitancy was distributed among groups of dentists and dental students in seven countries across four continents. Results: A total of 1527 subjects (850 dentists and 677 dental students) participated in this survey. Although 72.5% of the respondents reported their intention to accept COVID-19 vaccines (dentists: 74.4%, dental students: 70.2%), there was a significant difference in agreement between dentists/dental students across countries; generally, respondents in upper-middle-, and high-income countries (UM-HICs) showed significantly higher acceptance rates compared to those in low- and lower-middle income countries (L-LMICs). Potential predictors of higher vaccine acceptance included being a dentist, being free of comorbidity, being well-informed about COVID-19 vaccines, having better knowledge about COVID-19 complications, having anxiety about COVID-19 infection, having no concerns about the side effects of the produced vaccines and being a resident of an UM-HIC. Conclusion: The results of our survey indicate a relatively good acceptance rate of COVID-19 among the surveyed dentists and dental students. However, dentists and dental students in L-LMICs showed significantly lower vaccine acceptance rates and trust in COVID-19 vaccines compared to their counterparts in UM-HICs. Our results provide important information to policymakers, highlighting the need for implementation of country-specific vaccine promotion strategies, with special focus on L-LMICs.

Background: Improved Lithium Disilicate Ceramic has been highly valued in dentistry for over two decades, owing to its durability and aesthetic qualities, making it a preferred choice for both anterior and posterior crowns. Objective: This study aimed to evaluate the flexural strength of two types of lithium disilicate blocks post-chewing simulation. Materials and Methods: Seventy-six lithium disilicate specimens were utilized in this study. They were divided into two primary groups (n=38) based on two brands: IPS Emax CAD LT (Ivoclar Vivadent) designated as (E), and Initial Lisi LT/B1 (GC America) designated as (L). Each primary group was further split into two subgroups (n=19) based on surface treatment: group E into (E0 & E1) and group L into (L0 & L1). Half of the specimens were subjected to flexural testing without chewing simulation cycles and designated as (E0 and L0), while the remainder were tested after 24× 10⁴ cycles of chewing simulation and designated as (E1 and L1). The ceramic surfaces were examined using SEM before and after loading. Statistical Analysis: Data were gathered, organized, and subjected to Shapiro–Wilk’s and Levene’s tests (p-value < 0.05), followed by analysis with Brown-Forsythe two-way ANOVA and Tamhane’s post hoc tests to assess group differences (p-value < 0.05). Results: There were significant statistical differences in the flexural strength values between the different brand groups before and after chewing simulation (p-value < 0.05). The IPS Emax CAD group showed values approximately twice that of the Initial Lisi group (307.2– 310.5 MPa ± 48.5– 67 vs 148.1– 158.5 MPa ± 24.6– 25.6). Conclusion: Within the limitation of the current study, the following may be concluded: 1. The study’s findings suggest that Initial Lisi blocks should not be used for posterior teeth restorations. 2. This study can provide valuable insights for dental professionals to make informed decisions about which material is most appropriate for various clinical situations.

Objectives The aim of this research is to evaluate/compare the use of traditional versus sleeve fixed partial denture (PD) designs made from different materials on supporting structures. The comparison included three- and four-unit PD cases. Materials and Methods Four finite element models are used in the research. The three-unit PD consists of the mandibular second premolar, first molar (as a pontic), and second molar. The four-unit PD includes the first premolar. The PD materials assessed were zirconia, E-max, and Celtra Duo. Bone has been simplified representing it as two cuboids. Each PD has been loaded to two cases over the pontic's central fossa: 300 N compressive, 150 N obliquely applied with 45 degrees forming 24 cases. Results The three-unit traditional and sleeve PDs material change showed a slight change in cortical bone stress under vertical loading. Under oblique loading, cortical bone Von Mises stresses were higher by about 12 to 15% more than vertical loading. On the other hand, the four-unit PDs showed minor effect by changing PD material, while using sleeve design PD can reduce the cortical bone stresses up to 20% in comparison to traditional PD design. The mucosa and spongy bone were negligibly affected by changing PD material, and the traditional and sleeve designs showed close values to each other. Superiority of sleeve design appeared by reducing cement layer stresses dramatically, while PD body material rigidity affects its response. Conclusion Within the limitations of this study, the higher rigid PD material can dissipate loadings over it more preferably regarding its effect on the underlying structures. Sleeve PD design is equivalent to the traditional one for three-unit PDs, while it showed better performance with four-unit PDs. Zirconia three-unit PDs' bodies received the lowest stresses and redistributed and transferred the applied load to the underneath structures better than the other two tested materials. This finding was reversed with four-unit PDs.

Objective The objective of this study was to compare types of veneer preparations and their combination with three materials. Materials and Methods Two finite element models were specially prepared used representing window and wrap around preparation for veneers. The “central incisor” tooth geometry was acquired using a laser scanner, and then its surface was adjusted to form a solid model prior to the removal of each preparation separately. Three materials (Lava Ultimate, IPS e-max, and Celtra) were tested in combination with the preparation type. Bone geometry was simplified as two coaxial cylinders in all models. Each model was subjected to two loading conditions of occlusion (edge-to-edge bite and normal bite). Statistical Analysis and Results It was observed that cortical, cancellous bone, and periodontal ligament are insensitive to preparation or materials. Their stresses and deformation were within physiological limits. Significant changes appeared on the central incisor tooth structure, cement layer, and veneer layer stresses and deformations under loading cases. Conclusions Edge-to-edge bite stresses are severe with window-type preparation, and normal bite did not show any critical values on tooth structure, cement layer, or veneer layer. Veneer layer finish line and its contact with the cement layer and tooth structure play a role in the loading transfer mechanism. Preparation type alters the values of stresses on tooth structure, cement, and veneer layers. With window preparation, extreme stresses appear at finish line, while stresses appear under the loading site with wrap around preparation. Veneer and cement layers withstand the load energy with wrap around preparation and reduce tooth structure stresses. Thus, the lifetime of veneer and cement layers might be longer with window preparation.

The marginal fit of all-ceramic fixed restorations is critical to long-term success. This comprehensive study and meta-analysis assessed the marginal fit of restorations manufactured using digital versus conventional impression procedures. We conducted a comprehensive search of electronic databases such as PubMed, Cochrane CENTRAL, Web of Science, and Scopus for publications published up to 2023. Eligible papers comparing the marginal fit of all-ceramic permanent restorations made using digital and conventional impressions were considered. A total of 19 studies met the inclusion criteria. The pooled analysis revealed that restorations fabricated from digital impressions exhibited a significantly better marginal fit than those from conventional impressions and showed a mean marginal gap of –13.76 µm (95% confidence interval: [–24.77, –2.76], p-value = 0.01). Subgroup analysis by type of digital impression system demonstrated consistent superiority of zironica material over other ones. However, high heterogeneity was observed among the included studies (I ² = 90.74%). Digital impression restorations show superior marginal fit compared with conventional impressions, but high heterogeneity requires cautious interpretation and further well-designed studies to validate results. Article published online: 02 May 2025 © 2025. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/) Thieme Medical and Scientific Publishers Pvt. Ltd. A-12, 2nd Floor, Sector 2, Noida-201301 UP, India

Objective: The current investigation aims to assess the clinical efficacy of intraoral photographic assessment in detecting dental caries of varying severity and to assess different variables, such as the type of dentition, examiner experience, and the type of imaging equipment, on evaluative clarity. Methods: This meta-analysis of the PRISMA-DTA systematic review and diagnostic test accuracy was conducted. They searched electronic databases such as PubMed, Web of Science, Scopus, Embase, and Cochrane Library from the beginning of time up to January 2025. The studies had to have evaluated intraoral photographic caries because they were required to have compared it with clinical intraoral examination and provide extractable tooth-level 2 × 2 data. Enamel (ICDAS 1 3), dentine (ICDAS 4 6), and any caries (ICDAS 1 6) were analyzed separately in a meta-analysis. A random-effects model was used to compute pooled sensitivity, specificity, diagnostic odds ratio (DOR), and summary receiver operating characteristic (SROC) curves. Subgroup analysis was done on a pre-specified basis according to dentition, type of examiner, and imaging device. This study has been registered in PROSPERO with reference number 2026 CRD420261330820. Results: Twenty-three studies were retrieved through a comprehensive search and were stratified by severity into three categories. In the case of enamel caries, sensitivity was 0.65 (95% CI: 0.62–0.68), specificity was 0.95 (95% CI: 0.94–0.95), DOR was 36.74 (95% CI: 12.44–108.49), and the AUC was 0.87. In the case of dentine caries, the pooled sensitivity and specificity were 0.86 (95% CI: 0.85–0.87) and 0.96 (95% CI: 0.96–0.97), respectively, which produced the DOR of 176 (95% CI: 91.2–339.6) and the AUC of 0.94. Any caries had a pooled sensitivity of 0.81 (95% CI: 0.80–0.83), specificity of 0.97 (95% CI: 0.96–0.97), DOR of 64.04 (95% CI: 11.65–351.94), and AUC of 0.888. Subgroup analyses revealed that diagnostic accuracy was greater when the lesions were severe. Conclusions: Intraoral photographic assessment has a moderate level of accuracy in detecting enamel lesions and has a clinically acceptable level of accuracy in detecting dentine caries. The clinical efficacy increased with the severity of lesions and was consistent with high specificity at all levels of threshold. Imaging on smartphones could be a promising method for caries screening.