Evaluation of the effect of nanofilled resin-based coatings on water sorption and solubility of glass ionomer restorations

Background and Aims: Glass ionomer cements are among direct restorative materials which are used in an environment saturated with moisture. Therefore, having the ability to prevent water contamination is crucial. The aim of this study was to determine the water sorption and solubility of five glass ionomer restoratives with and without two nanofilled resin coating agents. Materials and Methods: Five glass ionomer cements (Fuji BULK/GC, EQUIA Forte Fil/GC, Fuji II LC/GC, riva self cure/SDI, riva light cure/SDI) and two resin-based coating (G-COAT PLUS/GC and EQUIA Forte Coat/GC) were used in this study. Water sorption and solubility were measured in accordance with the ISO 4049's. For each material, 15 disc-shaped specimens were prepared using a polyethelyn mould. The specimens of each material were randomly divided into two groups: 10 coated and 5 uncoated. For the coated groups of each material, 5 specimens were coated with G-COAT PLUS, and 5 with EQUIA Forte Coat. Data were analyzed using SPSS software version 18 (SPSS Inc., Chicago, IL, USA). Two-way ANOVA was applied to investigate if there were any interactions between materials and coatings. One-way ANOVA was used to compare different variables between the materials, and post-hoc Tukey’s test was performed to show significant differences in subgroup comparisons. Results: A significant interaction effect was obsevred between materials and coatings (P<0.05) using two-way ANOVA. The uncoated groups showed higher mean sorption and solubility values compared to the coated groups, and the groups coated by G-COAT PLUS showed less mean sorption and solubility values than that of EQUIA Forte Coat. In general, the lowest mean sorption and solubility values among glass ionomer cements belonged to Fuji BULK. Conclusion: The water sorption and solubility values of glass ionomer cements could be reduced by the use of a protective coating

General Self-Efficacy and Self-Perceived Confidence of Dental Students in Performing Orthodontic Clinical Skills

Background Evaluating the self-perceived confidence of students in their abilities to provide orthodontic services is crucial to measuring the effectiveness of the orthodontic curriculum. Objectives The purpose of this study was to investigate the relationship between general self-efficacy (GSE) in dental students and self-perceived confidence in performing orthodontic clinical skills. Methods A total of 100 dental students in their final-year at Shiraz University of Medical Sciences participated in the study in February 2017. They responded to a multiple-choice questionnaire consisting of two parts. The first part evaluated the students’ self-perceived confidence in performing orthodontic clinical skills and the second part evaluated the students’ GSE. The correlation between the two parameters was evaluated using the Spearman correlation test with an alpha level set at 0.05. Results More than 20% of the students reported being “not yet confident” in 8 out of the 18 skills evaluated. There was a medium correlation between the students’ confidence in performing clinical skills and their GSE. There was no correlation between the students’ grades in theoretical courses and their GSE scores (P > 0.05). The students’ confidence in all aspects of clinical skills, however, was correlated with their grades. Conclusions The students’ self-perceived confidence in performing orthodontic clinical skills is moderately correlated with their GSE; other factors such as exposure to orthodontic cases, and teaching methods seem to play a more influential part in their confidence