 This study aimed to evaluate the clinical performance of a novel vitro-ceramic biomaterial Biosilicate as treatment of caries-affected dentin in posterior resin restorations. A total of 94 restorations of 66 participants were selected and assigned at random into four groups: 1 Biosilicate Two-step etch and rinse system, 2 Control Two-step etch and rinse system, 3 Biosilicate Two-step self-etching system and 4 Control Two-step self-etching system. Two operators carried out the adhesive protocols and restored the cavities with a nano-hybrid resin composite IPS Empress, Ivoclar using the incremental technique. Participants were recalled at one week, 6, 12 and 18 months for clinical evaluation performed by two blinders and calibrated examiners according FDI criteria. 