This study will verify the effect of the application of a substance (10% sodium hypoclorite -NaOCL) in dentin on noncarious cervical lesions, with the aim of increasing the longevity of the restorations performed in this type of lesion.

The hypothesis of the present study is that the application of deproteinization solution after acid etching does not influence the failure rate of the restorations.

The purpose of this study will be to evaluate the failure rates of composite restorations of non-carious cervical lesions (NCCL) performed with or without the pre-treatment with 10% sodium hypochlorite (NaOCl) on etched dentin.

A randomized controlled split-mouth and double blind clinical trial will be carried out. Patients with at least two NCCL will be selected. Each patient will be received at least one pair of composite restorations (Filtek Z350/3M ESPE), bonded either with 2 techniques: control (acid etching + placebo solution for 60 seconds + Adper Single Bond 2/3M ESPE) or experimental (acid etching + 10% NaOCl for 60 seconds + Adper Single Bond 2). A calibrated examiner will be evaluated the restorations (baseline, 6-, 12-, 24- and 36-month) using the FDI criteria. The primary outcome is retention of the restoration.

Inclusion Criteria:

• Patients presenting at least two non-carious cervical lesions (NCL) in anterior, canine or pre-molars;
• Patients who had more than 20 teeth in the mouth;
• Patients who were at least 18 years of age at the time of treatment and capable to understand and sign the written informed consent;
• NCL in the facial surface of the teeth with sometimes a small part extending interproximally; Patients with good periodontal heath.

Exclusion Criteria:

• Patients with smoking habits, practicing bruxism, severe systemic diseases, using active orthodontic treatment, malocclusion (Angle Class II or Class III);
• Tooth with the NCL with the absent of antagonist;
• NCL wear facets upper than 50% of the incisal/occlusion surface, as a result of tooth attrition;
• Presence of caries or restorations in the area to be treated;
• Full-mouth visible plaque index (VPI) or full-mouth gingival bleeding index upper than 20%, probing depth and clinical attachment loss values exceeding 4 mm with bleeding on probing;
• Unwillingness to return for follow-ups or refuse to participate.

Double Blind