Background: The effects of topical fluoride applications on the release of monomer ingredients from resin-based dental materials by immersion in various extraction solutions are unclear. The aim of this study was to determine the effect of topical fluorides (APF and NaF) on the elution of residual monomers (Bis-GMA, TEGDMA, UDMA, and HEMA) from resin-based materials. Methods: Ninety specimens were prepared, 30 bulk-fill composite resin, 30 nanohybrid universal composite resin, and 30 polyacid-modified composite resin (compomer). These were randomly divided into three groups based on fluoride application procedures. Each specimen was kept in 75% ethanol solution, and residual monomers released from materials were analyzed using high-performance liquid chromatography (HPLC) after 10 min, 1 h, 24 h, and 30 days. The groups were compared using the Mann Whitney U and Kruskal Wallis tests. Measurements were analyzed using the Friedman and Wilcoxon signed-rank tests. Results: Fluoride applications generally had no considerable effect on the amount of residual monomer released from resin-based restorative materials. The amount of monomer release after topical APF application was similar to the release in the control group and was lower than the release in the NaF group. The release of monomers from the resin-based material used in the study did not approach toxic levels at the applied time intervals. The compomer released lower amounts of monomer than other resin-based materials. Conclusions: Fluoride applications do not increase monomer release from resin-based restorative materials. However, compomers should be employed by clinicians due to their lower monomer release compared to other resin restorative materials. The release of monomers from all the resin-based materials did not approach toxic levels at the applied time intervals.

It is not known whether the coronavirus disease 2019 (COVID-19) pandemic has affected dentistry education. This study aimed to determine the satisfaction and stress levels of dentistry students in Turkey regarding distance education during the COVID-19 pandemic, and to evaluate their opinions on this matter. This cross-sectional research study was conducted from October to November 2020 with the use of a web-based questionnaire consisting of 3 sections. The 1st section focused on demographic data. The 2nd section evaluated dentistry students' opinions regarding distance education during the pandemic; it comprised 8 multiple-choice questions and 1 open-ended question. The 3rd section referred to the 10-item Perceived Stress Scale (PSS-10), which is intended to assess the stress levels. The data was subjected to the descriptive statistical analysis, the χ2 tests and the logistic regression analysis. The sample consisted of 919 dentistry students, reflecting a response rate of 84%. Of the total sample, 81.6% of the participants were studying at state universities and more than half were female. These students' perceived stress levels were significantly increased due to the following factors: education at a state school; insufficient technical opportunities at home/dormitory facilities; decreased support from the academic staff of the universities during distance education; and a low level of knowledge of online document usage (p < 0.05). The evaluation of the responses to the open-ended question indicated that the difficulties encountered by highly stressed students during distance education were mostly adaptationrelated (p = 0.011). The logistic regression analysis showed that gender was significantly associated with high stress levels (p < 0.05). The data showed that dentistry students preferred hybrid education and were unsatisfied with their experience with distance education.

The aim of this study was to evaluate the effects of various whitening agents on the surface roughness and optical characteristics of different types of resin composite restorations. Fifty specimens were prepared for each resin [G‐ænial Posterior (GP), SonicFill‐2 (SF), Solidex (SDX), and Nova Compo HF (NC)]. Following baseline color and surface roughness (Ra) measurements, the specimens were randomly divided into 5 groups (n = 10/group) according to whitening concepts: control (distilled water), in‐office bleaching [OB‐(Opalescence Boost)], at‐home bleaching [HB‐(Opalescence PF)], whitening toothpaste [WT‐(Signal White Now)], and whitening mouthwash [WM‐(Listerine Advanced White)]. ∆E₀₀, ∆TP₀₀, and ∆WI_D values were calculated before and after the whitening procedure with a spectrophotometer using the CIEDE2000 formula. Surface roughness measurements were repeated. The surface topography was determined using atomic force microscopy. Two‐ and three‐way analyses of variance and Tukey's post‐hoc test were performed, with p < 0.05 regarded as indicative of significance. No significant differences were detected among the resin composite materials in terms of the ΔE₀₀ values (p > 0.05). Color change of all resin materials was above the AT threshold (>1.8) and the PT threshold (>0.8). All restorative materials presented acceptable (AT<2.62) TP₀₀ values. Solidex specimens demonstrated the lowest W_ID values compared to the other composites. There were significant differences among the whitening procedures with respect to ΔE₀₀, ΔTP₀₀, and W_ID values (p < 0.001). SF/WT combination showed the highest and clinically unacceptable ΔE₀₀ values. The highest roughness values were observed in the SDX specimens and the combination of SDX/OB. The effect of whitening agents on the optical characteristics and surface roughness of restorative materials depends on the type of material, agent, and time.Research Highlights: Clinicians should be aware that long‐term use of over‐the‐counter products due to the abrasive effects of their ingredients and repeated bleaching session applications may affect the color stability and surface roughness of resin composites.