Due to its excellent biocompatibility and good mechanical properties, titanium has been used successfully in dentistry for many years. In this study, complete dentures with titanium palatal plates were applied to 10 patients who were in need of upper dentures. The clinical performance of cast titanium palatal plates was determined over a period of 6 months. No increase in accumulation of denture plaque nor mucosa irritation was observed. After the above period, the electrochemical corrosion behaviour of cast titanium and chromium-cobalt palatal plates were compared with the titanium plates that were not left in an oral environment after casting. For the electrochemical corrosion tests, a corrosion cell was designed and artificial saliva with lactic acid was used, with the temperature during the tests being about 37 degrees C. The potential difference between the test sample and the saturated calomel electrode was measured, and after the determination of the rest potentials, the anodic potentiodynamic polarization curves were traced at a rate of 1 mV/s. From the standpoint of corrosion, the titanium plates used by the patients for a 6-month period corroded more than the titanium not used by the patients. This may be due to the casting and processing conditions and the effect of the oral environment.