The effect of brushing with two abrasive levels on the fluoride release of high-viscosity glass ionomers (GIs) was investigated. Forty-eight GI discs were fabricated and randomly assigned to one of the four groups. Treatments, performed for 30 days, included exposure to a carboxymethylcellulose (CMC) solution without fluoride (CMC-F), CMC with 275 ppm fluoride (CMC+F), CMC with fluoride plus br...

This study compared the traditional radiotracer method (Rt) for determination of dentifrice abrasivity to the recently introduced surface profile (Sp) method (ISO 11609). Specimens from human root dentin were prepared for each method and randomly assigned to 8 dentifrice/abrasive groups (n1⁄48), of wide abrasivity range. Aqueous dentifrice slurries or abrasive suspensions were used to brush spe...

One of the most crucial factors involved in the optimum design and cost estimation of rock sawing process is the rock abrasivity that could result in a significant cost increase. Various methods including direct and indirect tests have been introduced in order to measure rock abrasivity. The Schimazek’s F-abrasiveness factor ( ) is one of the most common indices to assess rock abrasivity.  is t...

Polycrystalline diamond compact (PDC) bits have been widely used in oil and gas well drilling recently also begun to be geothermal drilling. In the present study, performance wear of a PDC bit were assessed by laboratory tests. The correlation between progress some indexes rock abrasivity was discussed referring test results. rate penetration formulated as function weight on using results for o...

graph 5100, Micromeritics) and the specific surface area was measured by nitrogen adsorption, the BET-method (ASAP 2000, Micromeritics). The particle size distribution (PSD), a narrow or broad distribution, was determined by using the equation: PSD slope=[75% (ESD)-25% (ESD)]/2.APS, where ESD means equivalent spherical diameter and APS means average particle size. Oil absorption, packing index,...

INTRODUCTION The study was designed to explore the mechanical properties of the self-adjusting file (SAF) and its application in the root canal using continuous irrigation. METHODS The compressibility of the SAF file and the resulting peripheral force were measured using specially designed systems. The abrasivity of the file was tested on dentin blocks representing a flat root canal. The dura...