Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Purpose: To evaluate a new method of simulated pulpal pressure in vitro in comparison with the conventional one. Materials and Methods: Four adhesives were analyzed: a three-step etch-and-rinse (Scotchbond Multi-Purpose [SBMP]), a two-step etch-and-rinse (Single Bond 2 [SB]), a two-step self-etching (Clearfil SE Bond [SE]) and a one-step self-etching (Clearfil S3 [S3]) system. Restorations were built up in flat, deep dentin from extracted molars. After two methods of simulated pulpal pressure or no pulpal pressure (control groups), the samples were cut into sticks and submitted to microtensile bond strength (mu TBS) testing and nanoleakage evaluation. Results were analyzed with two-way ANOVA and Tukey's test (p<0.05). Results: In general, statistical analysis of mu TBS showed SBMP>SB=SE>S3. For both methods of simulated pulpal pressure, the mu TBS of SB and S3 was lower than in control groups. For SBMP and SE, the mu TBS remained stable with simulated pulpal pressure. Conventional and experimental methods of simulating pulpal pressure resulted in similar mu TBS (p = 1.00) and nanoleakage patterns. Silver impregnation was higher with SB and S3, especially after simulated pulpal pressure with both methods. Conclusion: The experimental simulated pulpal-pressure method tested here was similar to the conventional method and can be an alternative to it. The simplified adhesives show reduction in bond strength after simulated pulpal pressure. The multistep adhesives have stable bond strengths under simulated pulpal pressure. Therefore, the separate application of hydrophobic resin can achieve resistance to bonding deterioration after hydrostatic pressure.146517524Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)