objective: a clinically feasible convergence angle in full-coverage crown preparations, meeting the requirements for proper retention and resistance forms, has always been a matter of interest for laboratory and clinical researches. this study aims to evaluate the angle in teeth prepared by both under- and post-graduate students at tehran university of medical sciences, faculty of dentistry, de...

background. efficient canal preparation is the key to successful root canal treatment. this study aimed to assess the cleaning and shaping ability, preparation time and file deformation of rotary, reciprocating and manual instrumentation in canal preparation of primary molars. methods. the mesiobuccal canals of 64 extracted primary mandibular second molars were injected with india ink. the samp...

objective: one of the major problems of all ceramic restorations is their probable fracture against the occlusal force. the aim of the present in-vitro study is was to compare the effect of two marginal designs (chamfer & shoulder) on the fracture resistance of zirconia copings, cercon (cad/cam). materials and methods : this in vitro study was done with single blind experimental technique. one ...

introduction: radiolabeled antibiotics are being used for the specific diagnosis of infection by exploiting their specific binding properties to the bacterial components, thereby making it possible to differentiate infection from sterile lesions. the aim of this work was to prepare and evaluate a freeze-dried kit of ciprofloxacin designed for the labeling with 99mtc. methods: factors like amou...

introduction: full crown preparation may have adverse effects on pulp tissue. in this study, the effect of full-crown preparation on intact versus inflamed pulp tissue was studied. methods: fifteen healthy mature cats were randomly selected for this study. the study was performed on four canine teeth of each cat. cats were anesthetized and then radiographs were taken from the canine teeth. clas...

production of fe-c alloy powders by mechanical alloying was studied. fe and graphite elemental powdermixtures containing 0.8 and 1.5wt.% graphite were mechanically alloyed using a planetary ball mill. thestructural changes of powder particles during mechanical alloying were studied by x-ray diffractometery,scanning electron microscopy and microhardness measurements. for both compositions, mecha...

objectives : cleaning and shaping of the root canal system is an important step in endodontic therapy. new instruments incorporate new preparation techniques that can improve the efficacy of cleaning and shaping. the aim of this study was to compare the efficacy of mtwo and race rotary file systems in straightening the canal curvature using only one file or the conventional method. materials an...

1 ABSTRACT The dissemination of critical information and the synchronization of coordinated activities are critical problems in geographically separated, large-scale, software development. While these problems are not insurmountable, their solutions have varying trade-oos in terms of time, cost and eeectiveness. Our previous studies have shown that the inspection interval is typically lengthene...

the aim of ideal canal preparation is to prevent iatrogenic aberrations such as transportation. the aim of this study was to evaluate the root canal transportation by reciproc file with and without glide path.thirty acrylic-resin blocks with a curvature of 60° and size#10 (2% taper) were assigned into two groups (n= 15). in group 1, the glide path was performed using stainless steel k-files siz...