فهرست مطالب rezaei far m

Human Papillomavirus (HPV) plays an important role in the genesis of cancers of cervix and oral cavity. Squamous epithelium of esophagus is an appropriate site for HPV infection. The aim of this study was to determine the correlation of this infection with esophageal squamous cell carcinoma (ESCC). In a case-control study forty cases of ESCC and forty controls with nonmalignant specimens from the patients referred to Imam Khomeini hospital–Sari (Mazandaran, Iran) during eight years (2001-2008) were enrolled. Extracted DNAs from the specimens were analyzed for HPV DNA with the commercial kits available for HPV. Fifteen (37.5%) cases of ESCC and 5 (12.5%) specimens of controls were positive for HPV DNA (p=0.03). The most common genotypes in the ESCC patients and control group were HPV16 & HPV45 (each 15% for ESCC patients; HPV16 7.5% and HPV45 five percent for the controls). There was no significant difference for HPV genotype and patient’s age, sex or tumor’s stage and grade. HPV may be counted as an important risk factor for ESCC in northern region of Iran.

Complete obturation of the prepared root canal is an essential step in endodontic treatment. Combination of gutta-percha and a sealer is widely used in clinical practice for root canal obturation, thus microleakage studies on sealing properties of these materials constitute an important part of endodontic researches. The aim of this study was to evaluate the microleakage of three root canal sealers: Apexit, AH26 and Dorifill by electrochemical method. In this experimental study, 55 extracted human maxillary and mandibular cuspids were used. The coronal part of teeth were removed and the root canals were prepared using the step-back technique. The specimens were randomly divided into 3 groups of 17 samples each. Teeth in each group were filled with one of the sealers and gutta-percha by lateral condensation technique. 4 specimens served as positive and negative controls. An electrochemical method was used for evaluation of apical leakage with the electrical source potential of 10 V. Measurements of current flow through the test system were recorded every 72 hours. Data were analyzed by Kruskall Wallis and Mann Whitney tests. P<0.05 was considered as the level of significance. All specimens of the three groups showed low initial leakage that increased during the test period. The mean leakage in Apexit group was higher than AH26 and Dorifill groups. The lowest mean leakage was related to Dorifill group. Although no statistically significant difference was observed between this sealer and AH26. The results of this study revealed that the best apical seal was obtained using Dorifill and AH26 sealers. The poorest result was observed in Apexit.