4. Group: [Fluoride + calcium varnish] + polipeptide solution combination ( The investigators will do polipeptide ( Curodont repair) solution and fluoride + calcium varnish (Clinpro white varnish) application on white spot lesions) First day,the investigators will collect stimulated saliva from each volunteer before any application. Saliva samples will transport to the microbiology laboratory. After any application 6 weeks, 3 months and 6 months later we will collect stimulated saliva again for microbiological assessment.