The Journal of Adhesive Dentistry, Volume 27/2025

Objective: To evaluate the effect of pre-procedural antiseptic mouthwashes on dentin bond strength of different adhesive systems. Methods: Flat occlusal dentin surfaces from 120 extracted human molars were randomly divided into four groups according to mouthwashes (0.12% chlorhexidine = CHX, 1% hydrogen peroxide = HP, 0.2% povidone-iodine = PI, and no mouthwash/control) and three subgroups of adhesives used (Clearfil SE Bond; CSE, Single Bond Universal = SBU in etch-and-rinse (ER) or self-etch (SE) modes) (n = 8). Composite resin was built up, and all bonded teeth were stored in 37°C distilled water for 24 h. Stick-shaped specimens were prepared and subjected to microtensile bond strength (µTBS) test. Failure mode analysis was determined using a light microscope. A resin-dentin interface was observed using scanning electron microscopy (SEM, n = 2). Elemental analysis in the PI group was further examined by SEM with energy-dispersive X-ray spectroscopy. The µTBS data were statistically analyzed by two-way analysis of variance (ANOVA) and Duncan’s multiple comparison (P < 0.05). Results: Rinsing with PI followed by SBU-SE demonstrated significantly higher µTBS than the control group (P < 0.05). Rinsing with HP showed significantly lower bond strength for CSE (P < 0.05). However, the effect of adhesive systems was not observed for all mouthwashes used (P > 0.05). SEM/EDX revealed the iodine deposition in the underlying dentin, where the highest amount of iodine was found for SBU-SE. Conclusion: CHX and PI can be recommended as pre-procedural antiseptic mouthwashes since they show no negative impact on µTBS for all tested adhesives. The dentin bond strength of CSE is hampered in the HP mouthwash group, and this should be a concern for the use of self-etching adhesive afterward. Schlagwörter: adhesion to dentin, adhesive, dentin, microtensile bond strength, pre-procedural antiseptic mouthwash

Purpose: The aim of this study was to evaluate the marginal quality and wear of bulk-fill composite resins (BFs) for Class-II restorations of primary and permanent molars in comparison to a conventionally layered composite resin (RC) and to compare the results of the two dentitions. Materials and Methods: Eighty (40 primary and 40 permanent) extracted molars received standardized Class-II cavity preparations and were restored with either one of two flowable BFs, one of two high viscous BFs, or a composite resin (RC). Thermomechanical loading (TML; 2,500 cycles +5°C/+55°C; 100,000 cycles, 50N, 1.67Hz) followed. A quantitative marginal analysis using SEM images and a profilometric quantification of two-body wear were carried out using replicas. ANOVA, Kruskal–Wallis, Mann–Whitney U, and Wilcoxon signed-rank tests were used for statistical analysis (P < 0.05). Results: For both dentitions, a significant reduction of perfect margins was observed after TML (P < 0.02). For the primary dentition, the flowable BFs showed significantly less perfect margins than all high viscous materials (P < 0.005). For the permanent dentition, RC showed significantly fewer gaps than the flowable BFs (P < 0.04). Regarding wear, within the dentitions, no significant differences could be computed between groups with regard to the maximum height loss (P < 0.05). Conclusion: All of the investigated bulk-fill composite resins showed satisfactory in-vitro results for both tested parameters in primary and permanent teeth, with a superiority of the high-viscosity materials in terms of marginal quality. Schlagwörter: bulk-fill composite resins, marginal quality, permanent teeth, primary teeth, restoration materials, wear

Purpose: The current trend in denture adhesives is shifting toward zinc-free formulations due to the significant health concerns associated with zinc. Studies have focused on the retention of these zinc-free denture adhesives; however, there is a dearth of literature regarding their damping performance. This study analyzes the impact of oral cavity physiological parameters: temperature, pH, and swelling ratio on the mechanical properties of zinc-stabilized and zinc-free denture adhesives and examines the role zinc plays in influencing the adhesive behavior. This study investigates how underlying mechanical properties of adhesive cream change for zinc-stabilized and zinc-free denture adhesives. The relative damping and its variation from exposure to physiological conditions in the oral cavity can significantly assist in the design of dentures to reduce the discomfort experienced by denture wearers. Materials and Methods: The relative damping of the zinc-stabilized and zinc-free denture adhesives was investigated with the loss modulus values, which were evaluated using rheological frequency sweep tests. The tests were performed by maintaining the denture adhesives at specified values of temperature, pH, and swelling ratio, and over a frequency range of 0.01 Hz to 10 Hz, which included the average frequencies of human chewing / bite forces reported in existing literature. Results: Zinc-stabilized denture adhesive showed a larger fluctuation of loss modulus values compared to the zinc-free formulation with respect to pH, temperature, and swelling ratios. The zinc-free denture adhesive showed higher damping behavior at frequencies below 0.7 Hz, whereas the zinc-stabilized denture adhesive showed higher damping behavior above loading frequencies of 0.7–1 Hz. Both the adhesives showed varying behavior on either side of the bite force spectrum in terms of relative damping of the applied bite. Conclusions: The damping or cushioning effect provided by denture adhesives can reduce pain experienced and assist dental practitioners in better supporting denture wearers. Schlagwörter: bite force, damping, denture retention, physiological parameters, zinc-free denture adhesive