ABSTRACT
To assess the prevalence and severity of dental caries amongst Egyptian adolescents and the prevalence of carious lesions treatable through the atraumatic restorative treatment [ART] approach. Using a convenient sample procedure, two secondary schools with a dental clinic were selected [967 students, average age: 13.7 +/- 0.8 years, range: 12-15]. Dental caries was diagnosed using the ART caries criteria, and plaque and calculus were assessed using the Green and Vermillion criteria amongst students grades 1-3 in the dental clinic by 3 calibrated examiners. The effect of the independent variables gender, age, tooth surface, jaw side [left or right] and type of jaw [mandible/maxilla] on dependent caries experience variables and D2 and D3 variables were tested using ANOVA. The prevalence of dental caries including enamel lesion [D2MFT] amongst the 967 students was 51.4% and that of dental caries excluding enamel lesions [D3MFT] was 38.1%. The mean D2MFT and D3MFT scores were 1.5 and 0.8, respectively. The percentage of teeth filled and extracted was low. Female students had statistically significantly higher mean D3MFT/S and D2MFT/S scores than males [p < 0.0001]. The prevalence of cavitated carious lesions [D3] treatable through ART was 48% for score 2 and 28% for score 3. Most of the cavitated lesions were found untreated despite the presence of a dental clinic and a dentist on the school premises. The majority of cavitated lesions without pulp involvement could be treated using the preventive and restorative components of the ART approach
ABSTRACT
In this study, a system for in vitro selection of salt tolerant canola clones [plantlets] was developed. The developed system relies on somaclonal variation and the high regenerative capacity of hypocotyl explants of the Egyptian canola cultivar Serw 4 via direct and indirect shoot organogenesis. The optimized regeneration system involves callus formation from hypocotyl explants of 4 day-old seedlings on MS medium supplemented with 1.5 mg/l 2,4-D and shoot proliferation from proliferated microcalli colonies on MS + 4.0 mg/l BA. Shoot organogenesis frequecny ranged from 35 to 40%. This system was used for in vitro selection of salt tolerant plantlets from hypocotyl explants of seedlings germinated on salt containing medium. Under selection pressure, shoot organogenesis frequencey dropped to 5% for selected cell lines and zero for non-selected cell lines onto 0.3% NaCl. The biochemical and molecular characterization of the selected and non-selected clones were performed using: proline accumulation, total protein content, SDS-PAGE and RAPD analysis. The salt-tolerant plantlets were characterized by improved growth on saline media, rapid accumulation of proline, high content of total protein, synthesis of new set of high molecular weight proteins [38 and 94 KD] and unique RAPD banding profiles. The criteria of the selected clones outlined above may be a part of biochemical make up performed by these canola clones to tolerate extreme salt stress