STUDY PROTOCOL Open Access Tooth whitening with hyd o

Full list of author information is available at the end of the articleBackground Technological innovations in dental materials have been fueled by the desire of patients to improve the esthetics of their teeth, which many consider to be an important aspect of quality of life [1,2]. This emphasis on esthetics has led dentists to seek resources that respect the stan-dards established by society, but without compromising the integrity of the teeth, as the treatment philosophy should be the maximum preservation of sound dental tissues [3,4]. Tooth discoloration is classified based on the etiology. Extrinsic factors cause superficial changes in color, such as staining due to the consumption of coffee, tea, soft drinks, etc. Intrinsic factors, whether congenital or ac-quired, cause more complicated discoloration that is dif-ficult to treat, as such discoloration is incorporated into the structure of the teeth and generally only removed through the use of more aggressive procedures that can have a negative effect on sound dental tissues [3,5,6]