The aims of this study were to evaluate the shear bond strength (SBS) of metal and ceramic brackets bonded to two different all-ceramic crowns, IPS Empress 2 and In-Ceram Alumina, to compare the SBS between hydrofluoric acid (HFA), phosphoric acid etched, and sandblasted, non-etched all-ceramic surfaces. Ninety-six all-ceramic crowns were fabricated resembling a maxillary left first premolar. T...

Key words phosphoric acid - deprotection tert-butoxycarbonyl group peptide synthesis

In a previous report (1) the isolation, toxicity and some chemical data concerning the lipopolysaccharide endotoxin of Neisseria gonorrhoeae was described. The present investigation includes the following: (a) an improved modification of lipopolysaccharide phosphoric acid ester preparation; (b) hydrolysis of lipopolysaccharide phosphoric acid ester and removal of fatty acids; (c) separation of ...

The present work deals with enzymatic hydrolysis of sweet sorghum bagasse to fermentable sugars. The bagasse was treated with phosphoric acid and sodium hydroxide prior to enzymatic hydrolysis by commercial cellulase and β-glucosidase. The phosphoric acid pretreatment was performed at 50°C for 30 min, while 12% NaOH was used for the alkali treatment at 0°C for 3 h. The phosphoric acid pretreatm...

BACKGROUND Based on contradictory findings concerning the use of lasers for enamel etching, the purpose of this study was to investigate the shear bond strength of teeth prepared for bonding with Er-YAG laser etching and compare them with phosphoric acid etching. MATERIALS AND METHODS In this in vitro study forty - eight premolars, extracted for orthodontic purposes were randomly divided in t...

The results of studies the physicochemical properties extraction phosphoric acids containing magnesium in presence ammonium nitrate are presented. A decrease heat vaporization H 3 PO 4 -H 2 O system was found range acid concentrations 20-30% and 37-45% P 5 . At an concentration 20, 35% 45% there is a minimum electrical conductivity, while at 30 40% , conductivity solutions reaches maximum value...

introduction in this study, we have investigated the effect of using phosphoric acid on bonding efficacy of an all-in-one adhesive system, after salivary contamination of dentin. methods and materials eighty-four extracted human molars were prepared for their superficial dentins to be exposed. the molars separated into 7 groups. group 1 specimens were not contaminated. in groups 2-4, samples we...

Introduction: Due to undeniable effect of surface treatment on restoration bond strength, this study was conducted to measure and compare the shear bond strength of hybrid ionomer and compomer using the three different methods of surface conditioning. Methods: In this in vitro experimental study, 72 samples were prepared from hybrid ionomer (Vitremer-3M) and compomer (Compoglass-Vivadent) re...