Background: Children are the most sensitive and vulnerable group in terms of tooth decay. Any change or improvement in health-related knowledge and behavior in this group can have long-term and significant impacts on the health of the future generation. Thus, the present study was conducted with the aim to determine the relationship of knowledge of oral health-related issues with the decayed, missing, and filled teeth (DMFT) index in 12-year-old students of Rafsanjan, Iran, in 2016. Materials and Methods: This descriptive, cross-sectional study was performed on 460 students (230 boys and 230 girls) of 12 years of age from 10 elementary schools in Rafsanjan. The subjects were randomly selected. Data were collected through clinical examination, interviews, and a questionnaire. The questionnaire consisted of two parts; the first part contained a demographic characteristics form, and the second part contained the DMFT index and questions on knowledge of oral health-related issues. Data were analyzed using independent t-test, ANOVA, chi-square, and the Pearson correlation coefficient (α = 0.05). Results: Mean DMFT index and knowledge score of the students were 2.66 ± 1.40 and 5.43 ± 1.82, respectively. Students with higher knowledge had lower DMFT index. Moreover, mean knowledge score of students with homemaker mothers was significantly higher compared to students with working mothers. Conclusion: The results of this study suggested a positive significant relationship between knowledge of oral health-related issues and DMFT index in 12-year-old students of Rafsanjan.

Background: Streptococcus mutans and Streptococcus sanguis are two important bacteria of the oral microflora. S. mutans is the most important cause of dental caries and S. sanguis plays an important role in formation of microbial plaque. Objectives: The present study aimed to determine the effect of cigarettes and hookah on thebacterial growth of S. mutans and S. sanguis. Methods: The standard strains of S. mutans (PTCC = 1683) and S. sanguis (PTCC = 1449) were cultured on blood agar and incubated for 48 hours in different environments, including atmospheric air, carbon dioxide, three types of cigarette smoke (Winston, ultralight Winston, and Kent), and fruity tobacco. Then, the diameter of colonies was measured and data was compared using statistical tests, such as one-way ANOVA. Results: Bacterial growth was 80%, 100%, 61%, 48%, and 59% in carbon dioxide, Winston, Kent, Ultralight Winston, fruit tobacco, respectively, for S.mutans (P < 0.001) and 134%, 38%, 169%, 105%, and 61%, respectively, for S. sanguis, which were higher than ordinary air (P < 0.001), in addition, the growth of S. mutans was more than S. sanguis in the Winston group. Conclusions: These findings showed that the growth of S. sanguis was significantly greater than S. mutans in all groups, except in the Winston group.

Different surface treatments had different effects on µ TBS of aged CRCs to feldspathic ceramics. PF was significantly better than DL.

Background:The majority of individuals who visit the dentist are anxious. They are usually capable of controlling their anxiety. However, this fear sometimes creates great problems for the patient and dentist such as lack of visiting the dentist for treatment, incorrect diagnosis due to lack of appropriate communication between the patient and dentist, and finally, reduction of oral health level. The purpose of this study was to determine the level of dental fear and anxiety in students of Rafsanjan University of Medical Sciences, Rafsanjan, Iran, and its relationship with oral and dental health status in the 2010-2011 academic year. Materials and Methods: This descriptive study was conducted using the Dental Anxiety Scale-Revised (DAS-R), Dental fear Scale (DFS), and the decayed, missing, and filled teeth (DMFT) index checklist. The study was performed on 300 students of Rafsanjan University of Medical Sciences, enrolled during 2005-2011. The participants were selected through stratified random sampling based on the population of each department (medicine, nursing and midwifery, dentistry, and paramedicine). The DMFT, DAS-R, and DFS scores along with other gathered data were analyzed using chi-square test in SPSS software. Results: Among the participants, 82 individuals were medical students, 44 were dentistry students, 53 were nursing and midwifery students, and 121 were paramedical students. In addition, 173 subjects were women and 127 were men. Moreover, 49.3% of students had dental fear and 24.8% had dental anxiety. Among women, 32.4% had dental anxiety and 54.3% had dental fear, while among men, 14.2% had dental anxiety and 40.2% had dental fear. Conclusions: According to the obtained results, variables such as sex, marital status, field of education, history of dental visit, painful previous treatments, and dental anxiety in the family had an effect on DAS-R and DFS scores. Moreover, there was a significant relationship between DMFT index and level of fear and anxiety; with the increasing of dental fear and anxiety, DMFT also increased.