introduction: the aim of this study was to evaluate the amount of dentine removed after canal preparation using stainless steel (ss) hand instruments or rotary profile instruments. materials and methods: thirty-six extracted human teeth with root canal curvatures less than 30º were embedded in clear polyester resin. the roots were cut horizontally at apical 2, 4 and 7 mm. dentin thickness was m...

introduction: this study compared the cleaning efficiency of mtwo, race and medin nickel-titanium (niti) rotary instruments. materials and methods: sixty mandibular molar mesial roots were selected with angle curvatures between 25-35 degrees and divided into three groups; each containing 20 teeth. canals were prepared with the rotary files and irrigated with 2.5% naocl solution after each instr...

so42-/zno-tio2 catalyst was prepared by sulfating zno-tio2 powders with h2so4 solution. the catalyst was characterized by xrd, ir and hammett indicator. the catalyst showed strong acidity(h0 ≦-16.0). the optimum conditions are found that the calcination temperature is 823k and the soaked consistency of h2so4 is 1 mol/dm3. then so42-/zno-tio2 was applied as the catalyst in the catalytic synthesi...

this study was conducted to compare the methods of seed bedpreparation in rangelands of khash region in sistan and baluchestan province iniran. a split plot design was conducted based on randomized complete blockdesign with three replications in 1999. five seed bed preparation methods wereused as main plot as: 1) seed sown by passing livestock. 2) seed sown machinery.3) seeds sown as drilled in...

polyacrylonitrile (pan) membranes with nano-porous surface and high hydrophilicity were fabricated by addition of polyoxyethylene (40) nonylphenyl ether (igepal) as an additive in the casting solution. the membranes were prepared from pan/igepal/1-methyl-2-pyrrolidone (nmp) via phase inversion induced by immersion precipitation technique. pure water was used as coagulation medium. the effects o...

fenugreek (trigonella foeum-graecum l.) has been used in iranian traditional medicine for treatment of different kinds of inflammation disorders. in the present study, anti- inflammatory activity of the methanolic extract of the plant (at doses of 100, 200 and 400 mg/kg) were studied using carrageenan-induced edema method and compared with the effects of dexamethasone and ibuprofen. various con...

o bjectives: bond strength of composite resin to enamel and dentin of primary teeth is lower than that to permanent teeth; therefore, it may compromise the ad- hesive bonding. new methods, such as laser application have been recently intro- duced for tooth preparation. the purpose of this study was to evaluate the effect of tooth preparation with bur and er:yag laser on shear bond strength of c...

the effect of test on teachers, students, and their classroom behaviors has ever been amenable to scholarly studies. to explore such an effect, 20 professors offering ma tefl preparation courses and 30 candidates received plsp and apals inventories. paired-sample t-tests revealed significant differences. however, the respective componential multivariate anova revealed non-significant and signif...

the 2-(methylamino) pyridine, l, reacts with cucl in thf to give hexameric copper (i) complex, [cucl(l)]6. the molecular structure has been determined by using single-crystal x-ray diffraction method. the complex crustallizes in the monoclinic space group p21/n with four molecules per unit cell. the unit cell dimensions are a = 8.3495 (15), b = 15.622 (6), and c = 17.030(4) å with b= 98.55 (2)°...