Calcium hypochlorite commercially known as bleaching powder is used as a bleaching agent in shrimp processing industries in many countries and known to effect biochemical alteration in shrimp muscle. Studies were, therefore, undertaken to determine their effect in different concentrations viz., 10, 20, 30, 40 and 50 ppm with different time intervals on the quality of head-on, headless shell-on ...

The aim of this study was to evaluate the effects of bleaching and delayed bonding on the shear bond strengths of metal and ceramic brackets bonded with light and chemically cure composite resin to human enamel. One hundred and twenty extracted human premolar teeth were randomly divided into three groups of 40 each. The first two groups were bleached with 20 per cent carbamide peroxide (CP) at-...

Three selected alkali-based organosolv pulps (alkali-sulfite-anthraquinone-methanol (ASAM), alkali-anthraquinone-methanol (organocell) and ethanol-soda) from agrofibre crop giant reed (Arundo donax L.) were bleached by an ozone-based TCF (totally chlorine- free) bleaching sequence AZE(R)QP (where A is an acidic pulp pre-treatment, Z is an ozone stage, (E(R)) is an alkaline extraction in the pre...

Introdouction: Bleaching has become a common treatment for improving the appearance of natural teeth. However, the need to protect dental restorations from bleaching agent exposure is inevitable, as these agents may change the color of restorative materials by oxidation. Filtek P90 composite resin has recently been introduced with the aim of decreasing polymerization shrinkage. The purpose of...

The aim of this work was to evaluate the concentration of carbamide peroxide compounded at different dispensing pharmacies. Immediate concentration analysis was made of bleaching gels dispensed by specialized pharmacies, and of a commercially available gel (control group) (n=20). The carbamide peroxide concentration was determined by titration and the results were analyzed statistically by the ...

(HP) penetration in teeth with incipient lesions submitted to bleaching treatment. For analysis of HP penetration, sound and demineralized enamel/dentin discs were placed in artificial pulp chambers containing acetate buffer solution. After bleaching treatment, this solution was subjected for analysis of optical density by spectrophotometry and the disc surfaces were analyzed with scanning elec...

OBJECTIVE This study evaluates the effect of calcium hydroxide dressing on microleakage of composite restorations following non-vital bleaching. METHODS A total of 45 sound extracted human maxillary central incisors underwent endodontic treatment. The teeth were randomly divided into three groups (n=15). In group 1, access cavities were restored with composite. In group 2, the teeth underwent...

Most investigators studying rhodopsin in solution have used digitonin as the solubilizing agent. In solutions of this detergent, one can observe the bleaching of rhodopsin, as well as the reversal of bleaching by resynthesis from 11 cis retinal and opsin (e.g. see ref. 1) or by photoreversal from the intermediates of bleaching (e.g., see ref. 2). Other detergents can also solubilize rhodopsin (...

This study determined the degradation of nine bleaching agents with different concentrations after two hours in vivo following the manufacturers' recommendations. The nine carbamide peroxide products are 10%, 15% and 20% Opalescence, 10%, 15% and 22% Rembrandt and 10%, 16% and 22% Nite White Excel 2. Each subject wore the tray with the bleaching agent for two hours on three separate occasions. ...