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...

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...

Introdouction: Esthetic demands of patients have led to the introduction of tooth-colored restorations wherecomposite resins are bonded to the enamel using acid etch techniques. Total etch adhesion systems are still considered as the gold standard among bonding systems. However, clinicians have a tendency to use adhesive systems with simpler application procedures. The aim of the present stu...

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 ...

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...

The catalytic asymmetric three-component 1,3-dipolar cycloaddition of 3-amino oxindoles with aldehydes and nitroolefins under the catalysis of a chiral phosphoric acid is reported. The reaction provides a facile approach to synthesize a diverse array of spiro[pyrrolidine-2,3'-oxindoles] in high yields with excellent diastereo- and enantioselectivities under mild conditions.