Double-layer Application of an Enamel Protector for Bleached Teeth

Abstract

Bleaching treatment has been becoming more popular for discolored teeth, as it does not require any cutting of enamel and dentine. However, the problem of color relapse after bleaching treatment remains unsolved. One of its causes is the rough enamel surface that is caused by chemical agents for bleaching. Thus, coating of the rough enamel surface with appropriate materials after bleaching treatment may be effective in preventing color relapse. In this study, seeking to protect the surface of bleached teeth, several properties of two types of experimental materials as enamel protectors, were examined as follows: 1. Evaluation of application methods: three kinds of application methods were compared. 2. Evaluation of discoloration: color changes after using strong staining solutions (coffee and artificial saliva) were measured. 3. Resistance to abrasing was evaluated following brushing with an electric toothbrush. 4. Observation of coated surfaces after thermal cycling. According to the results of color measurements and SEM observations, the following conclusions were obtained: 1. The best application method of the enamel protector on the teeth surface was a brush-on technique with sonic vibration. 2. Discoloration of the bleached tooth surface was reduced by using an enamel protector. 3. Double-layer application of enamel protectors gave better results in the abrasion test. 4. There was no difference between single- and double-layer applications in the thermal cycling test. There results suggest that the two kinds of enamel protector, applied with the double-layer methods, could reduce the color relapse of bleached teeth.