background: it is thought that the transmission of hepatitis b virus (hbv) through the endoscopic procedures is a very rare event. the aim of this study is to evaluate the effect of the standard disinfection procedure of the endoscopes and accessories versus conventional disinfection in the transmission of hbv. materials and methods: a prospective survey, comprising 520 consecutive upper gastro...

\ INTRODUCTION Utilization of adsorption on solid surfaces was exercised for the first time in 1785. Practical application of unactivated carbon filters, and powdered carbon were first demonstrated in the American water treatment plant, and a municipal treatment plant in New Jersey, in 1883 and 1930, respectively. The use of activated carbon became widespread in the next few decades. At present...

The purpose of this study is to evaluate calcium hydroxide as a root canal dressing in presence apical lesion due pulpal necrosis, after chemomechanical preparation. Culture test were done 19 patients wich 80% all teeth treated with remained negative and 100% PMCC. Under the present experimental conditions, PMCC well mantained desinfection status pursued during preparation therefore indicated a...