The degree of conversion (DC) and the released bisphenol A diglycidyl ether dimethacrylate (BisGMA), triethylene glycol dimethacrylate (TEGDMA) and urethane dimethacrylate (UDMA) monomers of bulk-fill composites compared to that of conventional flowable ones were assessed using micro-Raman spectroscopy and high performance liquid chromatography (HPLC). Four millimeter-thick samples were prepared from SureFil SDR Flow (SDR), X-tra Base (XB), Filtek Bulk Fill (FBF) and two and four millimeter samples from Filtek Ultimate Flow (FUF). They were measured with micro-Raman spectroscopy to determine the DC% of the top and the bottom surfaces. The amount of released monomers in 75% ethanol extraction media was measured with HPLC. The differences between the top and bottom DC% were significant for each material. The mean DC values were in the following order for the bottom surfaces: SDR_4mm_20s > FUF_2mm_20s > XB_4mm_20s > FBF_4mm_20s > XB_4mm_10s > FBF_4mm_10s > FUF_4mm_20s. The highest rate in the amount of released BisGMA and TEGDMA was found from the 4 mm-thick conventional flowable FUF. Among bulk-fills, FBF showed a twenty times higher amount of eluted UDMA and twice more BisGMA; meanwhile, SDR released a significantly higher amount of TEGDMA. SDR bulk-fill showed significantly higher DC%; meanwhile XB, FBF did not reach the same level DC, as that of the 2 mm-thick conventional composite at the bottom surface. Conventional flowable composites showed a higher rate of monomer elution compared to the bulk-fills, except FBF, which showed a high amount of UDMA release.

Multiple studies have investigated the positive effects of human–animal interactions and showed that animal-assisted activities can be successfully used to better human physical and mental health. Equine-assisted activities have also raised considerable attention within the field. Our research focuses on healthy students (aged 14–18) without deviations or special educational needs. We analyze the occurrence of behavior problems and prosocial behavior among adolescents who regularly have interactions with horses, and those who have no connection to horses at all. The subjects of our investigation completed the strengths and difficulties questionnaire (SDQ), and we use a ‘quasi’ 2 × 2 before-after control-impact design to analyze the data. Students studying equine-related vocations and students of other vocations are compared, at the beginning and at the end of their studies. Our results indicate that students of equine-related vocations are more helpful and empathetic, and have fewer behavior problems, than those studying other vocations. There is a negative correlation between prosocial behavior and behavior problems. The development of the prosocial behaviors of students with regular horse–human interactions is more remarkable than of those who have no connection to horses. With these results, we are going to confirm the hypothesis that equine-assisted activities correlate with positive behavioral traits among healthy adolescents.

The COVID-19 pandemic has caused extreme deviations from everyday life. The aim of this study was to investigate how these deviations affected adolescents’ sense of coherence and their level of aggression, and whether this was influenced by their relationship with animals, especially horses. In two random samples of students from vocational schools in Hungary, taken in June 2018 and June 2020 (n1 = 525, n2 = 412), separate groups were drawn from those who had regularly engaged in equine-assisted activities (ES) and those who had not (OS) before the pandemic. Data were collected using an anonymous, paper-based questionnaire, and during the pandemic an online version of the Sense of Coherence (SOC13) and Bryant–Smith (B12) scales. During the pandemic, boys’ sense of coherence weakened and their aggressiveness increased. Multiple linear regression analyses showed that, regardless of gender and age group, increased time spent using the internet (p < 0.001), a lack of classmates (p = 0.017), reduced time spent outdoors (p = 0.026) and reduced physical activity (p < 0.038) during the pandemic significantly increased the tendency for aggressive behavior, whereas being with a horse or pet was beneficial (p < 0.001). The changes imposed by the curfew were rated as bad by 90% of the pupils, however, those with a strong sense of coherence felt less negatively about them. Schools should place a great emphasis on strengthening the students’ sense of coherence.