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 ...

objectives: the purpose of this study was to evaluate the resistance to fatigue failure of five different nickel-titanium rotary files in three different curved trajectories. materials and methods: a total of 150 neoniti a1, race 25.06, mtwo 25.06, twisted file 25.06 and protaper next x2 files with the tip size of 25 were tested (n=30 for each group). three groove types simulating curved canals...

introduction: marginal seal integrity is important for a successful adhesive dental restoration. alterations caused by laser irradiation in the enamel and dentin surface can affect the marginal integrity of adhesive restorations. the aim of this study was to evaluate the microleakage of a composite resin restoration in primary teeth following laser irradiation of enamel and dentin. methods: for...

objective: lack of a dental material with optimal adhesion and sealability is an important challenge in modern dentistry leading to marginal leakage. there are controversies on the necessity of enamel preparation in pit and fissure sealant therapy and its effect on decreasing the microleakage therefore, the present in vitro study aimed to assess the amount of microleakage with and without ename...

Functionalized polymeric microspheres based on a modifed polyether ether keetone (PEEK-WC) using immersion precipitation techniques were successfully prepared by doping initial polymeric solutions with DEHPA. The viscosity of the doping solution was measured for determining the optimal value for obtaining reproducible capsules. The modifed microspheres were characterize...

The possibility of using water insoluble fraction from biomass pyrolysis oil as additive in synthesis of Wood-Plastic novolac has been proved by using Differential Scanning Calorimetry (DSC) and Fourier Transformed Infra Red (FT-IR) spectroscopy. Synthesis of novolac with different concentrations (10, 20 and 30 wt %) of water insoluble fraction were performed. It was found that mechanical p...