the effects of closely adapting a prefabricated fiber to the post space remain unknown. the purpose of this study was to quantify the microleakages of a custom adapted fiber-reinforced post, a prefabricated quartz fiber post and a cast post using nondestructive methods.sixty-five extracted human premolars were endodontically treated and randomly divided into three groups (n=15), which were rest...

background: nowadays colonoscopy has a very important role in screening colorectal cancers. in addition, adequate bowel preparation is critical to colonoscopy, as a poor preparation may obscure pathology or prevent full colonoscopy. as it is estimated that unsuccessful colonoscopy leads to second procedures in up to 20% of patients, we sought to compare the effects of different doses of polyeth...

abstract— in the present study, genetic programming (gp) as a completely different approach in comparison with conventional methods, based on the imitation of natural evolution of living organism is proposed for the prediction of cellulose acetate (ca) polymeric membrane characteristics. the membrane preparation parameters of polymer concentration, additive concentration and coagulation bath te...

introduction: root canal preparation is an important process in endodontic therapy. nickel-titanium (niti) rotary file system can be used in single length technique (simultaneous technique) without early coronal enlargement, as well as in crown-down method. the purpose of this in vitro study was to compare single length with crown-down methods’ shaping ability using mtwo niti files . materials ...

introduction: 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. materials and methods: 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 ...

introduction: one of the most common complications of root canal treatment is postoperative pain. the aim of the present clinical trial was to compare the severity of postoperative pain after root canal preparation with race rotary system and hand k-flexofile. methods and materials: a total of 96 mandibular first and second molars were divided into two groups ( n =48) based on root canal prepar...

background: there are many preparation regimens for bowel cleansing. given their adverse effects, none of them have been considered perfect by the endoscopists. the aim of this study was to compare the effects of two bowel cleansing regimens on clean colonic preparation the subjects'well being and electrolyte balance. materials andmethods: atotal number of 280 patients were randomly assigned to...

introduction: the purpose of this study was to evaluate and compare canal preparation pattern of k3 and protaper rotary files in curved resin blocks. materials and methods: twenty-four resin blocks were used in this experimental study and randomly divided into two groups. their initial images were scanned. after preparation, their images were scanned again in the same position. pre and post pre...

background: sperm preparation is a fundamental step in art and attempt for developing new methods to be continued. objective: to evaluate the efficacy of upstream method for separation of human spermatozoa and its effects on sperm parameters including: motility morphology and concentration. materials and methods: semen samples from 17 men who referred to infertility clinic for evaluating their ...