Objectives: This study’s objective was to evaluate restoration microleakage (ML) with confocal laser microscopy (CLM) comparing traditional vs. model simulating vital tooth pulpal pressure. Methods: Recently extracted molars (n=12) were sectioned 4mm below the CEJ using a slow-speed diamond saw with pulp tissue removed with a barbed broach. The sectioned crowns were mounted with cyanoacrylate on a Plexiglas plate penetrated with an 18G stainless steel tube connected to polyethylene tubing. The mounted specimen received a 2x4x6mm Class V preparation using a water-cooled handpiece and #330 carbide bur. Dentin fluid transport was verified via pressure then restored using Prompt-L-Pop adhesive/Heliomolar Flow following manufacturer directions with VLC curing (Valo). Restorations were finished to contour, and the apparatus was connected to a 0.2% rhodamine G (RG) reservoir 18cm above the tooth simulating pulpal pressure. After 48h specimens received 2 coats nail polish to within 1mm of restoration margins. Specimens then placed in 2% methylene blue (MB) dye 24h, rinsed, and embedded in epoxy resin. Cured resin sectioned with a diamond saw in 1mm thick slices. Controls were intact molars (n=12) with traditional microleakage techniques involving preparation/restoration as above, stored in DI water 48h, likewise nail polish coated and placed in MB due for 24h. Controls had same epoxy fixation/sectioning. Sliced specimens were evaluated under Zeiss LCM with 633nm (MB) and 561nm (RG) wavelengths. Exported images were measured by Image J; MB ML was determined as the preparation percentage of the dentin surface covered. Results: ML results are listed in the Table. MB dye penetrated almost all control preparation dentin surfaces. Pulpal pressure specimens demonstrated significantly less (p<0.0001) MB penetration. Conclusions: Under this study’s conditions, ML was significantly decreased, suggesting that future ML studies consider pulpal pressure simulations.