atraumatic restorative treatment (art) is a minimal intervention technique in the management of carious lesions, which results in negligible discomfort to the patient. the aim of this study was to assess and compare the discomfort levels during atraumatic restorative treatment and minimal cavity preparation (mcp: a method using rotary instruments) treatment procedures in a sample of school chil...

the aim of this study was to assess the efficacy of apical negative pressure (anp), manual dynamic agitation (mda), passive ultrasonic irrigation (pui) and needle irrigation (ni) as final irrigation activation techniques for smear layer removal in curved root canals.mesiobuccal root canals of 80 freshly extracted maxillary first molars with curvatures ranging between 25° and 35° were used. a gl...

in this research different types of al2o3 were used as supports to prepare catalysts for dehydrogenation of isobutane to isobutene. these supports were al2o3 from merck, axen and gamma al2o3 synthesized from al(oh)3. sn/pt/al2o3 catalysts were prepared by sequential impregnation, at first pt and then sn was deposited. characterization of catalysts was performed by x-ray powder diffraction (xrd)...

the biologic width (bw) includes attached epithelial cells and connective tissue attachment complex being very important in the periodontal health during prosthetic treatments as invading this zone can cause bone resorption and gingival recession. the present study investigated biologic width values in the normal periodontium in anterior and posterior teeth. 30 patients that referred from resto...

introduction: this study investigated the influence of erbium-doped yttrium aluminum garnet (er:yag) laser on microhardness, chemical composition and subsurface morphology of dentin cavity walls. methods: forty sound human premolars were selected and randomly assigned into four groups. class v cavities were prepared either with an er:yag laser (groups 1 and 2; 15 hz, 250 mj for enamel, 10 hz, 2...

current ruminant feeding systems depend on knowledge of the composition of feeds and the rate and extent of degradation of feed organic matter (om) and crude protein (cp) in the rumen. the effect of storage and preparation of samples on in vitro gas production and fermentation characteristics of two common forage species, namely alfalfa and ryegrass werestudied. samples were prepared as fresh (...

objectives: different chelators may be used during root canal treatment, offering various advantages including lubricant effect inside the canal and smear layer removal. however, chelator residues in narrow root canals can lead to apical microleakage. the aim of this in-vitro study was to compare apical microleakage following the use of three root canal chelators via fluid filtration method in ...

introduction: disinfection and subsequent obturation of the root canal space require adequate mechanical enlargement of the canals. the purpose of this in vitro study was to compare the shaping ability of mtwo, race and medin rotary instruments during the preparation of curved root canals. materials and methods: sixty mesiobuccal root canals of mandibular molars with severe curvatures between 2...

introduction: root fracture is not an instant phenomenon but a result of gradual development of tiny craze lines in tooth structure. recent studies have shown that canal instrumentation has the potential to cause dentinal cracks. the purpose of this study was to evaluate and compare the formation of dentinal cracks caused by protaper rotary system to hand instrumentation. materials and methods:...

introduction: the aim of the present study was to compare hand stainless steel k-files and nickel-titanium profile 0.04 taper 29 series rotary instruments for their efficiency, procedural errors and time consumed in preparation of root canal system. materials and methods: a total of 46 maxillary and mandibular first premolars extracted for orthodontic purposes were collected (two contralateral ...