introduction: the purpose of this study is the evaluation of the amount of surface roughness (ra) of zirconia ceramic following different surface treatments as well as the assessment of its shear bond strength to composite resin. methods: 40 sintered zirconia ceramic block samples were randomly divided in 4 groups of 10 and underwent the following surface treatments: a) control group without tr...

Minimally invasive dentistry is not a very new concept but still many dental practitioners do not know its importance. Many novel dental materials and techniques now work on the principle of minimal invasion. One such technique is air abrasion. Air abrasion was first described by Black (1945).1 His aim was to develop a technique that is effective, works on the principles of minimal invasion and...

Grain size distributions in eolian settings are the result of both sorting and abrasion of grains by saltation. The two are tightly coupled because mobility of particles determines abrasion rate, while abrasion affects the mobility of particles by changing their mass and shape; few field studies have examined this quantitatively. We measured grain size and shape over a 9 km transect downwind of...

UNLABELLED BACKGROUND Excessive shoe heel abrasion is of concern to patients, parents and shoe manufacturers, but little scientific information is available. The purpose of this study was to describe the phenomenon in a group of infantry recruits performing similar physical activity, and search for biomechanical factors that might be related. METHODS Seventy-six subjects (median age 19) en...

This paper focuses on effect of abrasion process on color and reflectance factor changes of dyed woven fabrics containing 100% acrylic chenille yarns in weft and cotton warp yarns. Three fabrics having 12, 14 and 16 weft per centimeter were dyed with three basic dyes in different hues. Four different abrasion levels, i.e. 50,200,400 and 650 were selected to abrade samples. The obtained results ...