"Evaluation of the Effectiveness and Longevity Post Whitening Carbamide Peroxide 10% in Smokers and Nonsmokers. Double-blind Multicenter Clinical Trial. "

This study will be conducted under the CONSORT recommendations and respecting the principles of Helsinsky convention and corresponds to a multicenter study in conjunction with the University of Ponta Grossa Brazil (Deputy resolution protocol and ethics committee (Appendix A and B ) . Will be invited to participate in the study to patients who come to the clinic through FOUCH public posters. Subsequently 120 volunteers will be selected on the criteria that qualify inclusion and exclusion from the study will be reported all volunteers were examined not qualify under the criteria for inclusion as part of the initial n , according to CONSORT recommendations .

After signing the informed ( TCLE ) consent (Appendix 3 ) shall be made prophylaxis teeth of the upper and lower teeth , for the removal of extrinsic stains jet sodium bicarbonate ( Profi class , Ribeirao Preto , Sao Paulo , Brazil) , two weeks before the beginning of tooth whitening.

Inclusion and exclusion criteria:

Patients included in this study must be over 18, in good general health and buccal, have teeth free of carious lesions and periodontal disease, which agree with the informed consent document . And the color of the anterior teeth higher is classified as A2 or greater value , according to the scale VITA Classical (Vita Zahnfabrik, Bad Sackingen, Germany) and the spectrophotometer Easyshade Vita (Vita Zahnfabrik, Bad Sackingen, Germany). Evaluation of color through the VITA scale Classical will be made independently by two calibrated investigators and blind.

Be excluded from the study patients: they have already made treatment tooth whitening, or dental prosthesis having options at the upper front teeth , who are pregnant or lactating , presenting gingival recession, sensitivity dental, endodontic treatment in anterior maxillary teeth, which have a coloring severe internal, if they have non-carious cervical lesions, are taking medications , using fixed orthodontic appliances, submit bruxism habits, which have visible teeth cranks and those who are not available to attend the controls.