Patients with severe sensitivity will be immediately assisted by investigators to reverse the painful picture using desensitizing and / or analgesics and anti-inflammatories for pain relief, the patient will be removed from study. If sensitivity is used desensitizing FMG KF 2% ( nitrate Potassium and Sodium Fluoride 2%, Joinville, Brazil) , the literature does not present any report about RAM, if for any reason there is any Medical Adverse Event the research team will be responsible for any additional medical or dental treatment required and its follow-up, in the wake of whitening procedure ( restorations, endodontics, etc. )