All participants will be informed (Written and verbal information) about the trial conditions and purposes, but will not be aware of what tooth will received the adhesion treatment strategy under evaluation. Written informed consent, according to World Medical Association Declaration of Helsinki (3), will be obtained from all participants prior to starting the treatment. University Fernando Pessoa Ethics Committee review and approved the present protocol. This clinical trial is done according to the National Law 21/2014, of 16 April, and was analysed, approved and authorized by the National Competent Authorities: