فهرست مطالب حسین عصارزاده

The present study was conducted with the aim of evaluating the effects of Er:YAG laser (λ=2940 nm) and acidulated phosphate fluoride (APF) gel on the acid resistance of enamel white spot lesions, when applied alone or combined together.
This laboratory study was conducted on 90buccal and lingual slabs of human molar teeth. The samples were submitted to pH-cycling model to create white spot lesions. Subsequently, they were randomly assigned into six groups of positive control (without enamel white spot lesion), negative control (with enamel white spot lesion), enamel treated with APF gel, enamel irradiated with Er:YAG laser, pre-treated with APF gel followed by Er:YAG laser irradiation, and pre-irradiated with Er:YAG followed by APF gel application. Before and after the treatments, the samples were analyzed using potentiometer in order to evaluate the fluoride contents. Statistical analysis was performed using Kruskal-Wallis and ANOVA tests (P=0.05).
According to the results, the application of APF gel before or after laser irradiation resulted in the highest enamel resistance to acid and fluoride uptake (P As the findings indicated,Er:YAG laser changes the chemical combination of the enamel, and improves enamel hardness, especially when combined with topical fluoride, suggesting its anticaries potential

Oral malodor can be used as a motivational tool to improve oral health-related behaviors. The present study aimed to compare oral health training on the dental plaque index.
In the current study, 161 ( 76 females, 85 male) grade-one high school students from public schools of Yazd were divided into three groups : 1 – Oral health training oral malodor training ( halitosis group), 2– oral health training training of dental caries and periodontal diseases ( traditional groups), 3- oral health training (control group ). Two weeks and two months after the intervention, plaque index was measured. Positive and negative changes were recorded over time, and then, the study data were analyzed using Chi-square (bonferroni adjustment), McNemar, Kruskal-Wallis and Paired t-Test.
The study results revealed no significant differences between the halitosis group and the traditional group, though both had a significant difference with the control group. Positive changes in halitosis group especially within girls were held to be more durable compared to the other groups.
Oral health training accompanging training of oral malodor, tooth decay and periodontal disease seems to be more effective on health promotion of senior high school students in Yazd. Furthermore, oral malodor training produces more durable effects. As a result, this training style is recommended in regard with eductional programs of schools.

In spite of improvements in composite function, marginal microleakage in deep composite restoration is still considered as a challenge due to unstable bond between composite and dentin. Therefore, this study aimed to investigate effect of applying different materials on marginal microleakage in posterior composite restoration.

A standard distal box was prepared on 80 human premolar. The gingival floors were 1 millimeter under CEJ. The specimens were divided to four groups. In the first group, 1 millimeter amalgam was used as the first increment in proximal box on gingival floor, in the second group flow able composite, and in the third group, RMGI were used. Other cavities were filled by condensable composite. In the fourth group (control), all the cavities were filled only by condensable composite. The specimens, after 6 months of storage, were placed under cyclic load (10000 cycle- 80 N- 1 Hz), and then were immersed in 2% methylene blue for 6 hours. Afterwards, the specimens were sectioned in the middle of restoration. Extension of dye penetration at the cervical margin was examined under a stereo microscope at 25x magnification and the leakage was evaluated by Fuks degree. The study data were statistically analyzed using the Mann- Whitney U-test (p<0.05).

Microleakage was observed in all the groups. The third group demonstrated the most leakage and the least was for the first group. No statistically significant difference was observed between the groups.)p-value =0.689)

In cavities with gingival floor under CEJ, different filling methods have no effect on marginal sealing.