The purpose of the present study was to assess the bond strength of composite resin repairs subjected to different surface treatments and accelerated artificial aging. 192 cylindrical samples (CSs) were prepared and divided into 24 groups (n = 8). Half of the CSs were stored in water for 24 h, and the other half were subjected to C-UV accelerated aging for non-metallic specimens. The treatments...

Glucose-l-phosphoric acid was first isolated from minced and washed frog muscle which had been incubated for 3 hour in phosphate buffer containing small amounts of adenylic acid (2). Under these conditions part of the glucose-l-phosphoric acid (l-ester) was converted to hexose-6-phosphoric acid (8ester), so that fractional crystallization of the brucine salts had to be resorted to as a means of...

Multi-mode universal adhesives (UA) are indicated as either self-etch or etch-and-rinse adhesives, and manufacturers also recommend an alternative ‘selective enamel etch’ technique. Currently available laboratory data support phosphoric acid selective etching of enamel prior to use of UA to improve bond strength. In another way to improve adhesion to enamel of UA without the use of phosphoric a...

AIM To evaluate and compare ex vivo the decalcifying effect of 15% EDTA, 15% citric acid, 5% phosphoric acid and 2.5% sodium hypochlorite on root canal dentine. METHODOLOGY Two 2-mm-thick slices were cut from the coronal third of the root of 10 human incisors. Each slice was sectioned into two equal parts. Specimens were assigned to one of four groups (n = 10) for immersion in 20 mL of either...

Contradictory evidence exists as to the acid necessary for producing optimum enamel etching on buccal tooth surfaces. The aims of this study were to (1) compare the etching abilities of four different acids; (2) identify the acid concentrations required for optimum etching; and (3) determine the concentration stability of phosphoric acid solutions. Crowns of caries-free molar teeth were pumiced...

The purpose of this study was to examine the feasibility of a conditioner for treating enamel and dentin simultaneously for MMA-TBB resin bonding. Various phosphoric acid solutions containing copper salts were prepared and used as conditioners before bonding MMA-TBB resin to bovine teeth. Their effects on the surface morphology and bonding were studied by scanning electron microscopy and tensil...

Solvent extraction using organic solvents is an important technology for the purification of wet process phosphoric acid (WPA). In this study, the purification process of WPA, using a new type of solvent extraction system, cyclohexanol diluted in kerosene, was investigated. The equilibrium phase diagram of the system H3PO4 H2Osolvent mixtures at 313.2K was obtained. The effects of extraction ...

A reinvestigation of a chiral phosphoric-acid-catalyzed four-component Hantzsch enantioselective synthesis polyhydroquinolines reported in 2009 is presented. In our hands, when the reaction was performed with fidelity to original report using enantiopure phosphoric acid catalyst, no enantioselectivity observed. Unlike report, results are backed by baseline separation enantiomers HPLC analyses o...