OBJECTIVES: This study examined the relationship between exposure to teacher violence and mental health problems.
PARTICIPANTS AND SETTING: An international sample of young adults aged 18 to 24 (N = 283).
METHODS: Participants completed self-report measures of childhood trauma, exposure to teacher violence, depressive symptoms, post-traumatic stress, and alcohol misuse.
RESULTS: Exposure to teacher violence could be reliably and validly measured using the Teacher Violence Scale (TVS). Current mental health problems - including depressive symptoms, post-traumatic stress, and alcohol misuse - were associated with exposure to teacher violence during high school years, but not with childhood non-betrayal trauma.
CONCLUSIONS: Our findings expand the application of the betrayal trauma theory to school settings and point to the importance of preventing and managing teacher violence. It is important to provide more support and training to teachers and enhance monitoring measures in schools. More research on the prevalence and correlates of exposure to teacher violence is needed. We also provided first evidence supporting the reliability and validity of the English version of the TVS to facilitate future research.
OBJECTIVES: The objectives of this study were to evaluate the degradation effects of each dietary solvent on the microhardness of the different CAD/CAM dental composites and to observe the degradation effects of dietary solvent on the inorganic elements of the dental composites investigated.
METHODS: Fifty specimens with dimensions 12 mm x 14 mm x 1.5 mm were prepared for direct composite (Filtek Z350 XT [FZ]), indirect composite (Shofu Ceramage [CM]), and three CAD/CAM composites (Lava Ultimate [LU], Cerasmart [CS], and Vita Enamic [VE]). The specimens were randomly divided into 5 groups (n = 10) and conditioned for 1-week at 37°C in the following: air (control), distilled water, 0.02 N citric acid, 0.02 N lactic acid and 50% ethanol-water solution. Subsequently, the specimens were subjected to microhardness test (KHN) using Knoop hardness indenter. Air (control) and representative postconditioning specimens with the lowest mean KHN value for each material were analyzed using energy dispersive X-ray spectroscopy (EDX). Statistical analysis was done using one-way ANOVA and post hoc Bonferroni test at a significance level of p = 0.05.
RESULTS: Mean KHN values ranged from 39.7 ± 2.7 kg/mm2 for FZ conditioned in 50% ethanol-water solution to 79.2 ± 3.4 kg/mm2 for VE conditioned in air (control). With exception to LU, significant differences were observed between materials and dietary solvents for other dental composites investigated. EDX showed stable peaks of the inorganic elements between air (control) and representative postconditioning specimens.
CONCLUSIONS: The microhardness of dental composites was significantly affected by dietary solvents, except for one CAD/CAM composite [LU]. However, no changes were observed in the inorganic elemental composition of dental composites between air (control) and 1-week postconditioning.