فهرست مطالب ss hashemi kamangar

Fluorescence of natural teeth and its alterations due to environmental factors should also be taken into account in restorations. This study aims to assess fluorescence changes of three types of dental ceramics. 36 Ceramics of Feldspathic, Emax, and Enamic in 10 mm diameter and the thicknesses of 0.5 and 1mm with glaze and polish finishes were studied. Fluorescence was measured before and after aging and were analyzed using Anova test. The results showed that ceramics became opaque as the result of aging. This was more noticeable for Enamic ceramic  with the lightness increase of 4.10 and 4.86 for the UV excited and non-excited measurements, respectively. Moreover, Enamic ceramic experienced significant changes in its fluorescence due to aging (Average Fluoresence ChangeEnamic=-10.2) while Emax (Average Fluoresence ChangeEmax=-3.6) and feldspathic (Average Fluoresence ChangeFeldspathic=-0.4) ceramics were superior to Enamic in this respect. In Feldspathic ceramic, due to the presence of feldspar phase, high resistance to aging process was observed. While, severe shifts in fluorescence due to aging were observed in Enamic ceramic. Several factors affect color and fluorescence change of ceramics due to aging. Preparations stresses, adhesion of glazes and the formation of micro cracks on the ceramic surfaces are among the factors can influence on this behavior. In case on Enamic ceramic caveat should be taken as it can change its appearance due to fluorescence hue shift probably as a result of surface scattering of UV light. According to the findings of this study Feldspathic, Emax and Enamic are respectively preferable in terms of fluorescence stability during aging process.

Using smart phone and social media in medical education  get popular. This study aimed to evaluate the effect of providing a study guide and rules of endodontics department with smart phone based on Tritapp application as one of the special medical social networks on general dentistry students' satisfaction and self- reporting of their capabilites in fundamental endodontics course.

This quasi- experimental study was performed on fourth year general dentistry students of Tehran University of Medical Sciences in Endodontics Basics course. The students were divided into two equal random groups. In the control group, the rules and textbook of practical endodontics basics were presented in the relevant common method, while in the experimental group, in addition to the usual method of endo department, the rules of endo department were presented using the social network Tritapp.Then, in order to assess satisfaction, at the end of the course, a valid and reliable questionnaire for measuring satisfaction was provided to students. Finally, the obtained data were analyzed using Chi- square, t- test and Mann- Whitney statistical tests through SPSS.

The evaluation of students' satisfaction with Tritapp software showed that in the field of TritApp design 44.5%, in the field of easy application and use of the software, 55.5%, in the field of receiving appropriate and complete answers from the support system, 27.8%, and in the field of this software being helpful in the corona pandemic period, 83.4% answered in the affirmative and strongly agreed state.Despite the overall level of satisfaction with the study guide and department rules between the intervention group and the control group there was no statistically significant difference (p>0.05), but descriptively, in the intervention group, higher satisfaction was observed than the control group, in a way that all the students in the intervention group (100%) believed that the use of TritApp software as a teaching application helps to provide a study guide and endodontic department rules that will prevent the students from going astray and wasting time. Also, there was no statistically significant difference between students in the intervention group and the control group in the field of self- expression of competence (p>0.05).

In both groups, satisfaction of providing a study guide and self-expression of competency were the same. It seems that the student support in conventional mode and by social media affect similar on satisfaction of dental students in fundamental endodontic course.

Caries is a multifactorial disease with a microbial nature. Thus, more concentration on its operative treatment will lead to failure in annihilating its origin. On the other hand, because of known side effects of antibiotics and world attraction to traditional treatment and importance of drug extraction of natural material and plants, this study was done to compare the antibacterial effect of hydroalcoholic extract of Salvia officinalis, Pimpinella anisum, Mentha longifolia and Achillea millefolium against Streptococcus mutans, Lactobacillus rhamnosus and Actinomyces viscosus with two in vitro methods. In this experimental study, hydroalcoholic extracts have been prepared from Salvia officinalis, Pimpinella anisum, Mentha longifolia and Achillea millefolium with maceration method. Their antibacterial activity against Streptococcus mutans, Lactobacillus rhamnosus and Actinomyces viscosus have been evaluated with Broth macrodilution (the method in which amounts of antimicrobial agents is diluted in broth environment serially) (0.18-200 µg/ml) and Agar diffusion (the method in which antimicrobial effect is assessed in solid environment) (0.78-400 µg/ml) methods. In Broth macrodilution method MIC (Minimum Inhibitory Concentration) for Pimpinella anisum, Salvia officinalis, Mentha longifolia and Achillea millefolium for Streptococcus mutans were respectively 12.5, 6.25, 12.5 and 50 µg/ml, for Lactobacillus rhamnosus 12.5,1.56, 3.12 and 12.5 µg/ml and for Actinomyces viscosus 50, 12.5, 100 and 50 µg/ml. In Agar diffusion method Pimpinella anisum and Salvia officinalis against Streptococcus mutans, Pimpinella anisum against Lactobacillus rhamnosus and Mentha longifolia against Actinomyces viscosus had antibacterial effect. According to the results of this study, four extracts had growth inhibitory effect on all three bacteria. Salvia officinalis had greater effect on inhibition of growth of all three bacteria. All of the extracts had bactericidal effect in the range of concentration