Z-100

The early socio-economic differences in smoking build on the interplay between individual-, family-, peer-, and school-related factors. The present study aimed to add knowledge to this by examining susceptibility to smoking (S-SM), electronic cigarette (e-cigarette) use (S-EC), and smokeless tobacco (snus) use (S-SN) by educational aspirations in a country with advanced tobacco control policies. National cross-sectional School Health Promotion study survey was conducted among 8.–9. grade students (av. 15-year-olds) in 2017 with no prior smoking (n = 47 589), e-cigarette use (n = 49 382), or snus use (n = 53 335). Gender-stratified, age-adjusted multilevel logistic regression analyses with S-SM, S-EC, and S-SN were considered as outcomes and student- and school-level (aggregated) factors were considered as independent variables. The highest prevalence was observed for S-EC (girls 29%, boys 35%), followed by S-SM (16%, 15%) and S-SN (10%, 16%). Compared to those planning for general upper secondary education, S-SM was the highest for those without educational aspirations (OR = 1.20, 95% CI = 1.04–1.40), S-EC for those planning for vocational education [1.15 (1.05–1.25)], and S-SN for those planning for extra year/discontinuation [1.65 (1.04–2.60)] among girls. Among boys, both S-SM [1.37 (1.23–1.52)] and S-EC [1.19 (1.09–1.29)] were the highest among those planning for vocational education, with no clear associations with S-SN. Current other tobacco/e-cigarette use [OR range 1.27–8.87], positive attitude towards product use in one’s age group [3.55–6.63], and liking school [0.58–0.68] consistently associated with susceptibility. Students not planning for academically oriented education had higher susceptibility to different nicotine products. High S-EC warrants monitoring to strengthen policy evaluation and prevention.

To determine the effects of time and temperature on the viscosity of preheated composite resins.

Eleven composite resins were heated to 60°C, and temperature analyses were performed at intervals of 1 min until they had cooled to 25°C. The permanent oscillatory shear test was performed at 25°C, 35°C, 50°C, and 60°C for three composite resins under a shear rate of 1s−1. One- and two-way analysis of variance were used for the analysis (α = 0.05).

There was no significant interaction between the composite resin and time (P = 0.9304), and only the main effect time was significantly different (P < 0.0001). A difference was observed between T0 and T6 (P < 0.001), but not after T7. The increase in temperature resulted in a viscosity reduction (P < 0.05). At 25°C, Beautifil II presented higher viscosity. Palfique LX5 showed a significant viscosity reduction with increasing temperature compared with the others (P < 0.05). For Beautifil II and Z100, there was no difference at temperatures of 50°C and 60°C, while for Palfique LX5, no statistical difference was observed at 35°C, 50°C, and 60°C.

Ten minutes of preheating were sufficient to reach a temperature of 60°C, reducing viscosity by at least 84%. However, 5 min after removal, the composite resin cooled to room temperature.

Preheating composite resin has potential benefits. To determine how this approach will work in clinical practice, it is important to define the effects of time and temperature in the protocol of this technique and understand its limitations.