study of carcinogenicity test [Ames test] in forensic medicine laboratories of Tehran and comparison with Tehran University Medical Sciences Laboratories

cancer is one of the most frequent disease in the world and mutation has an important role in etiology of cancer [approximately 90%of mutagens are carcinogen]. Therefore Lab assistances that are working with mutagenic agents such as: Benzene, Xylazine and Formaldehyde for long period of time may be exposed to overload of these carcinogens. In Previous study, Mutagenicity test on urine sample of laboratory pathology technician of Tehran university medical sciences determined mutagenic agents activity. In regards to results, Mutagenicity assay was considered on forensic medicine laboratory of Tehran. Urine samples were collected at the end of the work shift and then were extracted by c18 column for the maximum concentration of pollutants. Then extracts were tested by TA100 and TA98 standard strains as well both with and without metabolic activator. Levels of toxicity and mutagenicity were detected by TA98 strain with activator in two personnel of pathology lab. Our results shows that forensic medicine pathology lab. worker have the same risk of cancer as the TUMS pathology lab. personals. I loecause smoking and other confounding factors not recorder false positive result is probably diseregarded in this study

comparative study of apical microleakage using the conventional lateral condensation and mechanical lateral condensation techniques

This study compared apical dye penetration using lateral condensation technique [LC] and LC technique with a reciprocal handpiece [mechanical lateral condensation or MLC] as a new method. Forty-eight human extracted straight canine teeth were used. After crown amputation, the teeth were randomly divided into four experimental groups of 10 teeth each and two negative and positive control groups of 4 teeth each. The groups were as follows: IA, 10 obturations completed by operator A using the LC technique; Group IB, 10 obturations completed by operator B using the LC technique; Group IIA, 10 obturations completed by operator A using the MLC technique; and Group IIB, 10 obturations completed by operator B using the MLC technique. All roots were placed in 2% methylene blue dye and centrifuged at 3000 rpm for 3 minutes. Following centrifugation, the roots were cut along their long axis and evaluated under a stereomicroscope to measure the depth of dye penetration. A t-test showed that the teeth which were filled by the MLC technique had less dye penetration in comparison with LC technique [P<0.05]. This in vitro study illustrates that canals obturated with the MLC technique had superior apical seal than canals filled with the LC technique