Literature data attest to the adsorption of salivary glycoproteins on the resin substrate of denture bases. This layer increases the surface energy of the substrate though improving its wettability. An increased wettability associated with the perfect fit principle and the maximum physiological extension of the denture base provide better retention of the dentures. Artificial saliva should represent a mandatory part of the prosthetic treatment in xerostomic patients. Six denture base materials: Acry Pol (x2 thermo-cure cycles), Eco Cryl Hot, Polyan, Biodentaplast, BMS 014, Superacryl, were investigated regarding wettability change following immersion in natural and artificial salivas (Xerostom, Biocosmetics Laboratoires). Natural saliva was collected from a single healthy patient and stored in optimal conditions during the experiment. The resin specimens were fabricated following the manufacturer's indications, and the immersion conditions were standardised. Contact angle measurements (using CAM 101, KSV Instruments) were carried out to evaluate wettability modification. The liquid used for measurements was natural saliva for a more appropriate reproduction of the biological phenomenon. The samples were dried before the contact angle measurement, which were made after 1 and 7 days for immersion in natural saliva and after 1 day for immersion in artificial saliva. Both salivas improve the wettability of the substrate. Artificial saliva has an almost uniform effect on all materials. Natural saliva improves wettability with slight variations depending on the substrate and duration of immersion. Keywords: wettability, denture resin bases, saliva