Introduction: The risk of being affected by infectious diseases in dentistry directly depends upon the degree of contact with body liquids, such as blood and saliva, as well as the working tools. Different micro-organisms including the viruses causing AIDS and Hepatitis B as well as oral thrush are possible to be transferred in dentistry. According to the Dental intervention (FDI), it is suggested that all dental patients, in spite of the healthy look, are considered to be infective. Therefore, the health principles and protective and safety methods must be observed in all the sequences to prevent cross-INFECTION. Thus, the present study seeks to investigate the degree to which the dentists in Isfahan respect and approach to such standards.Materials and Methods: This is a cross-sectional descriptive study. In order to answer the questions of the study (as found in tables 1&2), the data related to the participants’ attitudes and performance were collected by having them fill out a questionnaire and a checklist. A total of 140 dentists in Isfahan were selected through a random sampling in 1385 (HS). The data collected was then evaluated with SPSS.Results: The mean score obtained from the attitude-related questions was 5.36. Also, the mean score of performance-related questions was found to be 8.03. No significant relation was found between the dentists` attitudes and the years of service (P=0.092, r=0.17). No significant relation was found between the dentists` performance and the years of service (P=0.12, r=0.15). No significant relation was found between the dentists` attitudes and their performance (P=0.1, r=0.16).

Hepatitis B virus (HBV) INFECTION is a global public health problem. In endemic areas, HBV INFECTION occurs mainly during infancy and early childhood, with mother to child TRANSMISSION (MTCT) accounting for approximately half of the TRANSMISSION routes of chronic HBV INFECTIONs. Prevention of MTCT is an essential step in reducing the global burden of chronic HBV. Natal TRANSMISSION accounts for most of MTCT, and providing immunoprophylaxis to newborns is an excellent way to block natal TRANSMISSION. Prenatal TRANSMISSION is responsible for the minority of MTCT not preventable by immunoprophylaxis. Because of the correlation between prenatal TRANSMISSION and the level of maternal viremia, some authors find it sound to offer lamivudine in women who have a high viral load (more than 8 to 9 log 10 copies/mL). In addition to considerations regarding the TRANSMISSION of HBV to the child, the combination of HBV INFECTION and pregnancy raises several unique management issues. Chronic HBV INFECTION during pregnancy is usually mild but may flare after delivery or with discontinuing therapy. Management of chronic HBV INFECTION in pregnancy is mostly supportive with antiviral medications indicated in a small subset of HBV infected women with rapidly progressive chronic liver disease.

In this article, an attempt has been made to estimate the amount of sound TRANSMISSION loss in a flat oval channel by applying the approach of statistical energy analysis. Correct estimation of sound TRANSMISSION loss in an air conditioning channel is of great importance due to the harmful effects of noise pollution in the environment on human health. Simulation with the statistical energy analysis method is a powerful approach to estimate sound and vibration in problems in which we deal with complex and multi-part systems; is considered. In this method, first, a system is divided into several subsystems, and then by writing a matrix equation that includes the energy exchanges between subsystems and energy loss coefficients; It is investigated from the perspective of vibration and sound estimation.On average, the model presented in this research is able to estimate the sound TRANSMISSION loss in different dimensions of the air conditioning channels according to the experimental results in the accuracy range of ± 2.5 dB. Considering that it seems that the results obtained from modeling with this method are in good agreement with the experimental data; The results of this research can be used as an efficient approach to estimate noise in oval shaped channels stretched in different lengths.

Background: Hepatitis C virus (HCV) is a major cause of chronic liver disease worldwide. The role of intra familial HCV TRANSMISSION is still controversial. The aim of the present study is to determine intra familial TRANSMISSION (sexual and non sexual contacts) of HCV in a group of Iranian population.Patients and methods: In this historical cohort study, 270 first degree relatives of hepatitis C patients were enrolled as the exposed group and compared to 270 first degree relatives of normal subjects (with negative HCV) as the unexposed group. Antibodies to HCV were detected by commercially available fourth-generation enzyme immunoassay. Positive serum specimens were retested using a second generation recombinant immunoblot assay. Fisher's exact test was used to detect association between the exposure and out come of the study.Results: The mean age of exposed group was 27.1±19.8 years and 38.1% were male. The mean age of unexposed group was 29.4±16.7 years and 51.9% were male. Regarding gender, age, familial relation and condom use, there were not statistically significant differences between exposed and unexposed subjects. Only 2 HCV-infected subjects were detected in the unexposed group, both of whom were intravenous drug users. The frequency of positive HCV antibody among household contacts of two groups was not significantly different (NS). Conclusion: Our results revealed that house hold contact TRANSMISSION of HCV is not a significant TRANSMISSION route and sexual TRANSMISSION does not seem to play a role in the intra familial spread of HCV INFECTION.

Background: The household TRANSMISSION of hepatitis B virus (HBV) is a major health problem. The prevalence rate of this INFECTION is reported about 11% to 57% among family members of HBsAg carriers.Objectives: This study was conducted to evaluate serological determinants of chronic hepatitis B INFECTION, especially HBsAg positivity, among family members of asymptomatic HBsAg positive carriers in Zahedan (Southeast of Iran).Patients and Methods: In a cross-sectional study, data were collected from the total number of 454 HBsAg positive cases and 1817 members of their family by trained interviewers and a validated questionnaire. In addition, blood samples were obtained and titrated to detect serologic markers of hepatitis B. All subjects were recruited following informed consent to the study.Results: In total, 454 chronic HBsAg carriers (66% male) with mean age of 36±10 years and 1817 of their family members were included in the study. The prevalence rate of HBsAg and HBcAb positivity among household members were 19.3% (n=351) and 51% (n=573), respectively. The frequency of HBV markers was different by age groups. The highest prevalence rate of HBsAg (34.9%) and HBcAb (31.9%) positivity were found in the age group of 21-30 years old. Importantly, the mothers of index cases had the highest prevalence of HBsAg positivity compared to their spouses who had the lowest proportion (53.2% vs. 8.4%, P<0.001).Conclusions: In family members, HBsAg positivity was four times greater than the general indigenous population. Considering the importance of close contacts for TRANSMISSION, it was more prevalent in mothers of index cases compared to their spouses, suggesting more efficient mother-to-child than sexually TRANSMISSION of HBV. It was also more prevalent in those having a history of hepatitis B in their maternal family compared to those with paternal one, probably due to more efficient TRANSMISSION from infected mothers to children. The lower prevalence of HBsAg positivity in lower age groups could be attributed to vaccination of Iranian infants since 1993 and the screening of HBsAg positive mothers during the last two decades.