This study aimed to evaluate the depth of cure (DoC) of bulk-fill composite resins, measured by the bottom-to-top Vickers microhardness ratio, using different light-curing units (LCUs): single-wave LED, polywave LED, and halogen. Six bulk-fill composites—Tetric EvoCeram Bulk Fill, X-tra base, SonicFill, Venus Bulk Fill, SDR, and Filtek Bulk Fill—were tested. Four LCUs, including one halogen (Elipar Trilight) and three LEDs (Demi Ultra, Valo, and Bluephase style), were employed for polymerization. Vickers hardness measurements were taken at depths of 1 mm to 5 mm. One- and two-way ANOVA (α = 0.05) were used for data analysis. The results revealed significant differences in microhardness and microhardness ratios among the composites at depths of 4 mm and beyond, depending on the LCU used. It was observed that most bulk-fill composites showed an adequate DoC up to 4 mm, but the effectiveness varied with different LCUs. Importantly, polywave LED LCUs did not exhibit a superior advantage in achieving depth of cure compared to monowave LED LCUs for composites containing multiple photoinitiators. These findings suggest that while several factors affect the DoC, the type of LCU plays a crucial role, and polywave LEDs may not offer additional benefits over monowave LEDs.

Objective: To compare the fracture toughness of CAD/CAM resin-based restorative materials and direct composite resins. Materials and Methods: A systematic search was conducted in July 2025 across PubMed/MEDLINE, EBSCO, Scopus, ISI Web of Science, and grey literature. Eligible studies were only in vitro investigations evaluating fracture toughness of direct composite resins and CAD/CAM hybrid materials. Study selection, data extraction, and risk-of-bias assessment were performed independently by two reviewers. A systematic review and meta-analysis were not performed due to methodological heterogeneity, and findings were synthesized qualitatively. Results: Fifty-two studies met the inclusion criteria, including 16 assessing CAD/CAM restorative materials. Considerable variability in fracture toughness values was observed, even within the same material type. Most studies were judged to present a medium risk of bias. Short fiber-reinforced composites exhibited higher fracture toughness, whereas other CAD/CAM resin-based materials showed values comparable to direct composites. Conclusions: Current evidence does not confirm superior fracture toughness of CAD/CAM resin-based materials compared with direct composites. Short fiber-reinforced composites appear to offer improved resistance to crack propagation. Standardized testing protocols are needed to enable more reliable comparisons.

Objective: This systematic review aimed to analyze if polywave light curing units can polymerize Bulk Fill resin composites better than monowave. Materials and methods: Inclusion criteria were in vitro studies that evaluated the polymerization of Bulk Fill resin composites by monowave and/or polywave light curing units. Selection of studies, data extraction, and risk-of-bias analysis were performed. Data from selected studies were qualitatively analyzed. A systematic search was performed in May 2025 using PubMed/Medline, EBSCO/Medline, Scopus, and ISI Web of Science databases and grey literature in English, and 788 studies were found. Results: A total of 65 studies were included in the qualitative analysis. Seventeen of them were investigating both monowave and polywave light-curing units for the polymerization of Bulk Fill resin composites. The evidence was graded as medium quality due to the medium risk of bias for most studies. Polywave LED LCUs improved the microhardness ratio, or DC, of Bulk Fill resin composite compared to monowave in 3 of the included studies, while 3 studies revealed that monowave LED LCUs demonstrated a favorable microhardness ratio, or DC, compared to polywave, and the rest of the 11 studies presented material-dependent results. Due to the heterogeneity of the studies included, a meta-analysis was not performed. Conclusion: The existing studies, with their limitations, revealed that polywave light curing units do not seem to have an advantage over monowave in the polymerization of Bulk Fill resin composites.

Implant screw loosening remains among the most frequently reported technical complications in implant-supported prostheses and may compromise prosthetic stability, maintenance requirements, and long-term clinical outcomes. Etiology is multifactorial and involves biomechanical, prosthetic, occlusal, and patient-related factors. This narrative review aimed to synthesize medium- and long-term clinical evidence (>5 years whenever available) regarding mechanisms, prevalence, and risk factors associated with screw loosening in implant-supported restorations. A structured literature search was conducted in PubMed, Web of Science, Cochrane Library, and EBSCOhost to identify clinical studies, randomized controlled trials, systematic reviews, and meta-analyses. Evidence regarding preload, implant–abutment connection design, retention type, implant splinting, framework fit, abutment angulation, implant dimensions, occlusal loading, parafunction, full-arch restorations, and torque protocols was critically interpreted. Current evidence indicates that screw loosening is influenced by inadequate preload, unfavorable occlusal forces, cantilevers, angulated abutments, framework misfit, and parafunctional habits. Single-unit and screw-retained restorations appear to exhibit higher complication rates in several studies, although findings remain inconsistent. Internal connections and splinting may improve mechanical stability; however, superiority has not been conclusively demonstrated. Most screw loosening events occur during the early functional period, emphasizing the importance of preload optimization, occlusal control, maintenance, and follow-up. High-quality long-term comparative studies remain limited.

This observational study evaluated changes in selected performance parameters of 15 new high-speed dental handpieces after eight months of routine clinical use in a routine educational undergraduate environment (two 4 h daily clinical shifts, five days per week, with repeated sterilization cycles). All handpieces underwent routine cleaning, lubrication, and autoclave sterilization as instructed. The turbine components from the handpieces were disassembled and examined by stereomicroscopy before and after use, while free-running speed and friction grip force were assessed at the same intervals. Two handpieces were no longer operational at follow-up due to ball bearing failure. Paired t-test was performed for free-running speed and friction grip force. Among the remaining handpieces, statistically significant reductions were observed in both free-running speed and friction grip force (p < 0.01). Microscopic examination of the rotors revealed surface alterations consistent with corrosion and wear. Within the limitations of this study, routine clinical use over an eight-month period was associated with measurable changes in key performance characteristics of high-speed dental handpieces in educational clinical settings.

Background and Clinical Significance: Implant impressions can present inaccuracies, affected by many factors, such as impression technique, impression material, and parallelism or lack thereof among the implants. The use of a verification index can assess the accuracy of the mastercast and can be used in order to adjust the inaccuracy of the mastercast. This article presents a technical variation in established verification-index procedures, followed by implant analog repositioning, which can be used in case of an impression inaccuracy; Case Presentation: A patient with a moderate gag reflex received an implant. The impression of an implant and a prepared tooth was made. At the metal try-in, an inaccuracy of the mastercast was found, attributed to the final impression. A technique was illustrated, describing a polymethyl methacrylate (PMMA) verification index fabrication, followed by implant analog repositioning in the removable die of the master cast with the use of acrylic resin. This method may be used as an alternative to repeating the impression in selected clinical situations, but it is time-consuming, technique-sensitive, and needs meticulous handling; Conclusions: This is a viable technique and may represent an alternative to repeating the impression in selected clinical situations. Therefore, the clinical workflow can be reduced by one appointment. It can be helpful for patients with a moderate to severe gag reflex, since it can minimize the discomfort and stress for the patient and the dentist.