• The Journal of Advanced Prosthodontics
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• v.6 no.5
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• pp.333-345
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• 2014

PURPOSE. Bonding agents (BA) are the crucial weak link of composite restorations. Since the commercial materials' compositions are not disclosed, studies to formulize the optimum ratios of different components are of value. The aim of this study was to find a proper formula of BAs. MATERIALS AND METHODS. This explorative experimental in vitro study was composed of 4 different sets of extensive experiments. A commercial BA and 7 experimental formulas were compared in terms of degree of conversion (5 experimental formulas), shear bond strength, mode of failure, and microleakage (3 experimental formulas). Statistical analyses were performed (${\alpha}$=.05). The DC of selected formula was tested one year later. RESULTS. The two-way ANOVA indicated a significant difference between the shear bond strength (SBS) of two tissues (dentin vs. enamel, P=.0001) in a way that dentinal bonds were weaker. However, there was no difference between the four materials (P=.283). The adhesive mode of failure was predominant in all groups. No differences between the microleakage of the four materials at occlusal (P=.788) or gingival (P=.508) sites were detected (Kruskal-Wallis). The Mann-Whitney U test showed a significant difference between the microleakage of all materials (3 experimental formulas and a commercial material) together at the occlusal site versus the gingival site (P=.041). CONCLUSION. A formula with 62% bisphenol A-glycidyl methacrylate (Bis-GMA), 37% hydroxy ethyl methacrylate (HEMA), 0.3% camphorquinone (CQ), and 0.7% dimethyl-para-toluidine (DMPT) seems a proper formula for mass production. The microleakage and SBS might be respectively higher and lower on dentin compared to enamel.

• Korean Journal of Health Education and Promotion
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• v.25 no.1
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• pp.1-12
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• 2008

Objectives: The researchers investigated the relationship among fun seeking, self-efficacy, interest in physical activity and actual physical activities of male college students, in orders to provide valuable information to professionals in health promotion. Methods: The participants were 316 male college students whose ages ranged from 18 to 30(M=22.53, SD=2.09). The questionnaires and psychological tests used in this research included the following: sub-scale of Korean Version of BAS/BIS Scale, The General Self-Efficacy Scale, International Physical Activity Questionnaires, & sub-scale of The Intrinsic Motivation Inventory for physical activity. Results: Results indicated that male students who had moderate level of fun seeking were more likely to engage in physical activities than those who showed low or high level of fun seeking. And students with the strong self-efficacy were more likely to do physical activity than with the weak self-efficacy, especially high level of physical activity. Male students who had greater interest in physical activity were more likely to engage in physical activities than those who were not interested in physical activity. A regression analysis revealed that interest in physical activity accounted for the most variance; it accounted for around 14.5% variance of actual physical activity with self-efficacy. The interaction effect of self-efficacy and interest in physical activity was significant for actual physical activity. Conclusion: This study reiterates the roles of self-efficacy and the interest in physical activity on physical activity, and found that non-linear relation of fun seeking to physical activity. These results may provide useful information for health practitioners.