Treatment clinical trial, randomized, controled, parallel, double-blinded, with four groups, that aims to evaluate the best application strategy when using a Universal Adhesive system, Single Bond Universal (3M ESPE, USA), in self-etch application mode, with or without enamel etching, associated wity a Bulk Fill Composite (Filtek Bulk Fill, 3M ESPE, USA), or with a conventional nanofilled composite (Filtek Z350 XT, 3M ESPE). Volunteers will be selected and recruited,following inclusion criteria and pre-established exclusion. All volunteers will be informed and sign a term of clarification and consent. 50 enrolled patients will receive 200 Class I or Class II dental restorations, made in four different ways, one from each experimental group, using the same universal self-etching adhesive system, with two application strategies, under the restorations that will use two different composites, a bulk fill composite, used in the bulk strategy, or a nanofilled composite, used in the traditional incremental strategy. Occlusal or Proximo-occlusal lesions will receive the selected adhesive system in 2 different protocols separated by groups. Group Self Etching and Bulk Fill (SETB), Group Selective enamel etching and Bulk Fill (SEEB), Group Self Etching and Filtek Z350XT (SETI), and Group Selective enamel etching and Filtek Z350XT (SEEI).Total time used in the restorations will be evaluated during the restorations. Immediate post-operative tooth sensitivity will be evaluated after one week. Restorations will be evaluated every 6 months for pain assessment, shape, fractures, staining or recurrent caries, using scores. To determine in which group each tooth will be enrolled, the authors will randomize the teeth.

This is a Treatment clinical trial, randomized, controlled, parallel, double-blinded, with four groups, that aims to evaluate the best application strategy when using a Universal Adhesive system, Single Bond Universal (3M ESPE, USA), in self-etch application mode, with or without enamel etching, associated wity a Bulk Fill Composite (Filtek Bulk Fill, 3M ESPE, USA), or with a conventional nanofilled composite (Filtek Z350 XT, 3M ESPE). Volunteers will be selected and recruited, following inclusion criteria and pre-established exclusion. All volunteers will be informed and sign a term of clarification and consent. All 50 enrolled patients will receive 200 Class I or Class II dental restorations, made in four different ways, one from each experimental group, using the same universal self-etching adhesive system, with two application strategies, under the restorations that will use two different composites, a bulk fill composite, used in the bulk strategy, or a nanofilled composite, used in the traditional incremental strategy. All patients must have at only 20 teeth in function, must have at only 4 carious lesion in occlusal or proximo-occlusal face in posterior teeth or old restorations in the same faces, with problems, that need to be changed. Those lesions must be more than 2 mm deep, should have exposed dentin, and must have at only 50% of margins in enamel. Teeth should not present periodontal mobility. Firstly, the patient will be anesthetized locally with 3% Mepivacaine solution, followed by prophylaxis with pumice powder and water. All cavities will be washed and dried after these procedures for optimal selection of color, using a color scale. Then, the rubber dam isolation of the teeth to be restored will be held. Occlusal or Proximo-occlusal lesions will receive the selected adhesive system in 2 different protocols separated by groups. Group Self Etching and Bulk Fill (SETB): no conditioning, the adhesive system will be used in 50 teeth, according to the manufacturer's instructions, in the self-etching mode. The adhesive system will be brushed during 20 seconds in the cavity, will be air-dried during 5 seconds, and photoactivated during 10 seconds with Light Emission Diode (LED) light. Then, the Filtek Bulk Fill composite will be used in increments of 4 mm, using the bulk restoration technique, and photoactivated for 40 seconds; Group Selective enamel etching and Bulk Fill (SEEB): 37% phosphoric acid will be applied during 30 seconds, only in enamel in 50 teeth. This acid will be removed using water, the cavity will be air-dried, and then, the adhesive will be applied according to the manufacturer's instructions, as described in group SETB. Restorations will also be made as described in group SETB; Group Self Etching and Filtek Z350XT (SETI): no conditioning, the adhesive system will be used in 50 teeth, according to the manufacturer's instructions, in the self-etching mode. The adhesive system will be brushed during 20 seconds in the cavity, will be air-dried during 5 seconds, and photoactivated during 10 seconds with Light Emission Diode (LED) light. Then, the Filtek Z350XT composite will be used in increments of no more than 2 mm, using the incremental restoration technique, and each increment will be photoactivated for 40 seconds.; Group Selective enamel etching and Filtek Z350XT (SEEI): 37% phosphoric acid will be applied during 30 seconds, only in enamel in 50 teeth. This acid will be removed using water, the cavity will be air-dried, and then, the adhesive will be applied according to the manufacturer's instructions, as described in group SETI. Restorations will also be made as described in group SETI. Total time used in the restorations will be evaluated during the restorations. Immediate post-operative tooth sensitivity will be evaluated after one week. Restorations will be evaluated every 6 months for pain assessment, shape, fractures, staining or recurrent caries, using scores. To determine in which group each tooth will be enrolled, the authors will randomize the teeth.

Inclusion Criteria:

• All patients must have at only 20 teeth in function, must have at only 4 carious occlusal or proximo-occlusal lesions, or old restorations that need to be changed, in different teeth. Those lesions must be more than 2 mm deep, should have exposed dentin, and must have at only 50% of margins in enamel. Teeth should not present periodontal mobility.

Exclusion Criteria:

• Volunteers with periodontal disease; with gingival bleeding; use of anti-inflammatory drugs in the last 30 days.