Effect of Energy Drinks on Discoloration of Silorane- and Dimethacrylate-Based Composite Resins

Objectives: This study aimed to assess the effects of two energy drinks on color change (∆E) of two methacrylate-based and a silorane-based composite resin after one week and one month. Materials and Methods: Thirty cubic samples were fabricated from Filtek P90, Filtek Z250 and Filtek Z350XT composite resins. All the specimens were stored in distilled water at 37°C for 24 hours. Baseline color values (L*a*b*) of each specimen were measured using a spectrophotometer according to the CIEL*a*b* color system. Ten randomly selected specimens from each composite were then immersed in the two energy drinks (Hype, Red Bull) and artificial saliva (control) for one week and one month. Color was re-assessed after each storage period and ∆E values were calculated. The data were analyzed using the Kruskal Wallis and Mann–Whitney U tests. Results: Filtek Z250 composite showed the highest ∆E irrespective of the solutions at both time points. After seven days and one month, the lowest ∆E values were observed in Filtek Z350XT and Filtek P90 composites immersed in artificial saliva, respectively. The ∆E values of Filtek Z250 and Z350XT composites induced by Red Bull and Hype energy drinks were not significantly different. Discoloration of Filtek P90 was higher in Red Bull energy drink at both time points. Conclusions: Prolonged immersion time in all three solutions increased ∆E values of all composites. However, the ∆E values were within the clinically acceptable range (<3.3) at both time points.

The effect of two training methods on the dental students\' ability in shade matching

Background and Aims: Color is the most important and complicated part of aesthetic dentistry. The tooth color matching of restorations is considered as one of the most difficult tasks in the restorative dentistry. The aim of this study to evaluate the effect of two training methods on the dental students’ ability in determining tooth color matching. Materials and Methods: In this study, 40 dentistry students participated which randomly allocated into two groups. The first group consisted of students who learned teeth color matching methods practically. In the second group, training booklet was used for learning. Using Vita Classic shade guide series, 4 color samples were chosen and the students of each group were asked to determine samples’ color, before, after and one month after the training. Results: Booklet learning group was more successful in determining fourth color sample. However, in no studied group and no used samples, the results of one month after learning were not better than that of before learning. Also generally, no significant relationship was found between the color matching accuracy, using glasses, and sex of participants. Conclusion: The use of booklet learning was more effective than practical learning in color matching accuracy for dental students. Also, using glasses and sex were not effective on their color matching accuracy