Introduction: Air-powder polishing devices are increasingly used for stain and plaque removal. However, besides cleaning the tooth surface, they may increase the surface roughness of the dental tissues. This in turn may result in plaque accumulation and superficial degradation. Thus the aim of this study was to assess the influence of three different abrasive agents: Pumice, Sodium bicarbonate ...

In this research the potential of aluminum-coated pumice and zeolite in arsenic, As (V) removal was investigated and compared. Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and X-Ray Flaorescence Spectrometry (XRF) were carried out to determine the properties of the adsorbents. Several parameters including adsorbent dosage] pH, contact time, and initial As(V) concentration were st...

OBJECTIVES Acrylic resins, used in the manufacturing of different types of intra-oral prostheses, are vulnerable to colonisation by microorganisms which potentially endanger the general health of the prostheses, wearers. The aim of this study was to investigate the influence of a novel coating (Parylene) on surface roughness of poly-methyl-methacrylate (PMMA) samples after simulated cleansing u...

In this study, pumice stone was used for the removal of tetracyline (TC) from aqueous solutions. It was characterized by XRD, FT-IR, SEM and BET analyses. Cation exchange capacity of pumice stone was found to be 9.9 meq/100 g. Effect of various parameters such as solution pH (2-11), adsorbent dosage (0.5-10 g/L), contact time (2.5-120 min), initial TC concentration (5-300 mg/L) and temperature ...

In the current study two methods are evaluated for predicting the compressive strength of concrete containing metakaolin. Adaptive neuro-fuzzy inference system (ANFIS) model and stepwise regression (SR) model are developed as a reliable modeling method for simulating and predicting the compressive strength of concrete containing metakaolin at the different ages. The required data in training an...

The 1285 m thick MIS core offers an invaluable opportunity to obtain a detailed record of volcanism in McMurdo Sound. Volcanic stratigraphy and preliminary petrologic data on volcanic rocks in the AND-1B core are reported here. Remarkable volcanic deposits include: a) a phonolitic pumice layer found at ≈85 mbsf which is not correlated to any known vent onshore; b) a black well sorted volcanic s...

Background & Aims of the Study: Azo dyes are used in industrial processes such as textile industry to produce large quantities of colored effluents that contain organic and non-organic materials. So, effective and efficient treatment of them is important for the environmental protection. The aim of this study was to evaluate the efficiency of powder and granular pumice for the ...

statement of the problem: demineralization of enamel adjacent to orthodontic appliances frequently occurs, commonly due to insufficient oral hygiene. purpose: the aim of this study was to compare two microabrasion techniques on improving the white spot lesions as well as subsequent enamel discoloration. materials and method: sixty extracted premolar teeth without caries and hypoplasia were sele...