This in vitro study evaluated the surface microhardness of human enamel submitted to bleaching with 10% carbamide peroxide (CP) containing calcium or fluoride. Ninety-eight dental blocks (5 x 5 mm2) with polished enamel surfaces were randomly assigned to 7 treatment groups (n=14), as follows: without bleaching and storage in artificial saliva (control); 10% CP; 10% CP + 0.05% calcium; 10% CP + ...

Reprinted from Dentistry Today (2000:19(4):44-53), c2000, Dentistry Today, Inc. Introduction In-office bleaching of teeth has been in use for approximately 125 years, with little change in science or technique during that time. When at-home "nightguard" bleaching using carbamide peroxide was introduced in 1989, it appeared that the in-office approach would quickly become extinct. However, there...

Urea as chemical substance Urea is a natural chemical compound, produced in human organism as a metabolite of proteins and other nitrogencontaining compounds [4]. It is released in urine and sweat in amount 20–30 mg per day. Urea is a carbonic acid diamide (carbamide, CAS number: 57–13–6). It occurs in the form of odourless, colourless crystals whose melting point is 133oC, highly soluble in wa...

A crescente demanda por clareamento dental vem acompanhada de queixas em relação a seus efeitos adversos. Sendo sensibilidade dentária um desses principais efeitos, o objetivo dessa revisão foi avaliar entre tempo exposição ao agente clareador, presença e intensidade da dentária, independente do protocolo clareador ser caseiro ou consultório. Trata-se uma integrativa realizada nas bases dados P...

The aim of this study was to evaluate by micro-shear bond strength test, the bond strength of composite resin restoration to enamel submitted to whitening dentifrices. Forty bovine teeth were embedded in polystyrene resin and polished. The specimens were randomly divided into eight groups (n=5), according to the dentifrice (carbamide peroxide, hydrogen peroxide and conventional dentifrice) and ...

Objective. The purpose of this study was to compare the color changes and microhardness of a nanocomposite after four bleaching regimens. Materials. Twenty-five specimens (n = 25) were made with a nanocomposite resin (Filtek Supreme XT). The specimens were divided into five groups equally (n = 5): bleaching groups and control group, as follows: G1: artificial saliva at 37 degrees C; (control) G...

OBJECTIVE To evaluate the influence of bonding and debonding of orthodontic brackets on dental in-home bleaching, taking into account three different adhesive systems. METHODS Forty-four bovine incisors were divided into four groups according to the primer system used for orthodontic bracket bonding. Following the debonding of orthodontic brackets, the teeth were stored in staining solution f...

Sodium ascorbate has recently been suggested to compensate decreased bond strength of composite resin to bleached tooth surfaces. The aim of present study was to evaluate the effect of 10% sodium ascorbate on bleached bovine enamel morphology and microhardness considering the possibility of its effect on enamel surface characteristics. A total of 69 bovine enamel slabs were prepared and mounted...