Clinical Performance of Different Adhesive Strategies With a Universal System in Sclerosed Dentin in NCCL: A Double-blind Randomized Clinical Trial.

The aim of this randomized, prospective, parallel, double-blind clinical trial will be to evaluate the clinical performance of restorations performed in non-carious cervical lesions (NCCL) using a soft ph universal adhesive system, varying the adhesive strategy (self-etching vs. selective etching of the enamel) and the sclerosis characteristics of the dentinal substrate over 24 months.

Two hundred restorations will be performed in NCCL of volunteers of both genders, by a single operator, using the Single Bond Universal(3M ESPE) adhesive system. The restorations will be randomly allocated into 4 groups (n-50): D-SE (absence of dentinal sclerosis and self-etching protocol); D-SELETIVE (absence of dentinal sclerosis and selective enamel etching protocol); SD-SE (sclerotic dentin and self-etching protocol); SD-SELETIVE (sclerotic dentin and selective enamel etching protocol). The randomization process within subject was performed by computer-generated tables by a staff member not involved in the research protocol. Details of the allocated group were recorded on cards contained in sequentially numbered, opaque, sealed envelopes. These were prepared by a staff member who was not involved in any of the phases of the clinical trial. The allocation assignment was revealed by opening the envelope on the day of the restorative procedure.The operator was not blinded to group assignment when administering.

The evaluations of the clinical performance of the restorations will be carried out by two previously calibrated examiners, adopting the criteria of the United States Public Health Service (USPHS) for the variables retention, marginal adaptation, marginal staining and postoperative sensitivity . The intragroup statistical analysis will be performed using the McNemar test for the variables retention and postoperative sensitivity; and by Wilcoxon for adaptation and marginal staining. To compare the clinical performance inter groups in the different assessment intervals, Fisher's exact test (retention and postoperative sensitivity) and Kruskal-Wallis (adaptation and marginal staining) will be used.

Eligibility Criteria:
Inclusion Criteria:

* Good general health status
* Good oral hygiene
* Absence of periodontal disease
* Minimum of 20 teeth in occlusion
* Presence at least one (01) non-carious cervical lesion in a tooth with pulp vitality.
* Non-carious cervical lesion greater than 1mm in depth.
* Non-carious cervical lesion involving enamel and dentin.

Exclusion Criteria:

* Non- carious cervical lesion cavo surface margin involving more than 50% of the enamel.
* NCCL in crack teeth.
* Absence of opposing teeth and/or adjacent to the lesion.
* Presence of occlusal trauma in the NCCL tooth
* Presence of orthodontic appliance or removable partial denture with retention in the tooth where the lesion is located
* Patients that underwent tooth whitening procedures within a period of less than 14 days from the date of restoration
* Patients with high risk of caries (presence of three or more active caries lesions)
* Xerostomia
* Bruxism
* Pregnant women
* Patients who do not accept the study conditions