Efficacy of E-Learning via the Website of Tehran University of Medical Sciences for Diagnosing Tooth Discolorations and Treatment Planning by Senior Dental Students

The efficacy of methods like e-learning as a supplement to traditional face-to-face instruction needs to be evaluated in dental courses. This study aimed to assess the efficacy of posting case presentations on one of the educational websites of  the virtual school of Tehran University of Medical Sciences called "SARMAD" to enhance the ability of senior dental students to diagnose tooth discolorations and offer treatment plans. This experimental study had a pre-test/post-test control group design and was conducted on 63 senior dental students. After filling out the primary questionnaire and obtaining a written informed consent, students participated in a pre-test and were then randomly divided into two groups of intervention and control. Fifteen case presentations were posted on the university website (SARMAD) during 6 weeks and discussed. Then, students participated in a post-test. Students' perspectives and their satisfaction with the website were assessed by a questionnaire. For ethical purposes, the same program was also offered to the controls. The post-test score was significantly higher than the pre-test score in the intervention group (P<0.001); but in the control group, the post-test score was only slightly higher than the pre-test score (P=0.128). In the intervention group, 70% stated that they would suggest this method as an efficient educational modality; 93.3% stated that this method would be beneficial as a supplement to conventional education; 16.7% ranked the SARMAD website excellent, 30% ranked it good, 33.3% acceptable, 16.7% moderate and 3.3 poor. It appears that this instructional modality may be efficiently used as a supplement to traditional instruction in undergraduate dental curricula.

Comparison of the Effects of Two Different Drinks on Microhardness of a Silorane-based Composite Resin

STATEMENT OF THE PROBLEM

Acidic foods and drinks can erode composite resins. Silorane-based composite is a new low shrinkage composite with higher hydrophobicity which might resist the erosive effect of beverages.

PURPOSE

The aim of this study was to determine the effects of 100% orange juice and non-alcoholic carbonated beer on microhardness of a silorane-based composite in comparison with two methacrylate-based composite resins.

MATERIALS AND METHOD

Ninety disc-shaped composite specimens were fabricated of Filtek P90, Filtek Z350 XT Enamel and Filtek Z250 (3M-ESPE) (n=30) and randomly divided into 3 subgroups of 10.Group 1 was immersed in distilled water, group 2 in 100% orange juice, and group 3 in non-alcoholic beer for 3 h/day. Primary, secondary and final Vickers microhardness tests were performed at the beginning of the study and 7 and 28 days later. Surface of 2 specimens in each group was evaluated under scanning electron microscope on day 28. Data were analyzed using repeated measures of ANOVA model (α=0.05).

RESULTS

The primary and secondary microhardness of P90 was significantly lower than that of Z350, and Z250 (p< 0.001). Microhardness of Z350 was also lower than that of Z250 (p= 0.002). On day 28, microhardness of P90 was lower than Z250 and Z350 (p< 0.001); however, microhardness values of Z250 and Z350 were not significantly different (p= 0.054). Microhardness of specimens subjected to non-alcoholic beer was significantly lower than that of controls (p= 0.003). Meanwhile, the microhardness value of resins in orange juice was somewhere between the two mentioned values with no significant difference with any of them (p> 0.05).

CONCLUSION

Although 28 days of immersion in 100% orange juice and non-alcoholic beer decreased the microhardness of all specimens, P90 experienced the greatest reduction of microhardness and non-alcoholic beer had the highest effect on reducing microhardness.