OBJECTIVE The objective of this study was to assess, in vitro, the influence of bleaching gel and the use of desensitizing agent over bond strength of ceramic brackets bonded to bovine enamel. METHODS One hundred bovine incisors were selected and randomly divided into five groups (n = 20): Group 1, control group (without bleaching); Group 2, bleached with 35% hydrogen peroxide; Group 3, bleac...

The adsorption of xylan on pulp fibers improves the strength properties of paper. However, the optical properties are decreased significantly. The objective of our research was to bleach hardwood kraft pulp with adsorbed birch xylan by hydrogen peroxide and study the effect of bleaching parameters on paper properties. The bleaching parameters studied included bleaching temperature, time, initia...

OBJECTIVES This study evaluated the effectiveness of low- and high-concentration bleaching agents on enamel and deep dentin. STUDY DESIGN Stained bovine incisors fragments were randomized placed into 10 groups (n=5), according to the sample thicknesses (2.0 mm or 3.5 mm) and bleaching agent: 10% carbamide peroxide (CP) (4 h a day/21 days); 6% hydrogen peroxide (HP) with calcium (1:30 h a day/...

Sickle cell disease (SCD) is a monogenic disease that affects millions of people worldwide. This study analyzed the effectiveness of bleaching and tooth sensitivity after in-office bleaching in patients with SCD. Forty volunteers were randomly assigned to four groups of 10 patients each (five with the SCD and five healthy controls) and treated using in-office bleaching with 35% hydrogen peroxid...

AIM This in vitro study evaluated the effect of calcium hydroxide on pH changes of the external medium after intracoronal bleaching. MATERIALS AND METHODS A total of 50 extracted human premolars were prepared and filled with gutta-percha and endodontic sealer. The teeth were randomly divided into five groups according to the bleaching agents employed: (a) Sterile cotton pellet with distilled ...

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 ...

Considering the importance of bleaching earth with activated carbon in reduction of impurities in vegetable oils, this study was conducted to investigate the effects of bleaching process on physicochemical properties of the bleached soybean oil. The bleaching process was carried out with bleaching earth (1 % w/w) containing different concentrations of activated carbon (0.1 % up to 0.5 % w/w). T...

AIM The aim of this study was to compare the effects of solution and different sodium ascorbate hydrogels on dentin-resin composite shear bond strength subsequent to a bleaching procedure with 10% carbamide peroxide. METHODS AND MATERIALS Sixty buccal dentin surfaces obtained from intact human third molars were randomly divided into five groups (n=12). Dentin surfaces received different treat...

The purpose of our study was to determine the effect of a 35% hydrogen peroxide bleaching agent on the shear bond strength of metallic orthodontic brackets. Sixty premolars were randomly divided into 3 groups of 20 each. Teeth in group A were etched with 37% phosphoric acid before bonding metallic premolar brackets. Teeth in the other 2 groups were bleached with a 35% hydrogen peroxide in-offic...

Two industrial elemental chlorine free (ECF) bleaching sequences, D0(EOP)D1(EP)D2 and OQ(PO)DP, are compared with respect to the bulk content of lignin, carboxyl, hexeneuronic acids (HexA), and reducing groups after each bleaching stage. HexA groups contribute significantly to the total content of carboxyl groups, and their degradation during chlorine dioxide bleaching is reflected by a decreas...