Background: The demonstration of moderately simple sterilization-disinfection measures in daily practice is very serious to decrease the probabilities of cross-infection as prosthetic appliances have to be sterilized prior to be transferred to the technician and patient. The used disinfection method should be properly selected due to its great effect on the physical and mechanical properties of denture bases. Aim: This research was conducted to study the consequences of chemical and electromagnetic radiation disinfection methods on dimensional stability and oral health impact on daily performance. Also, to evaluate the effect of repeated microwave disinfection under different conditions. Materials and Methods: Group I: Denture disinfection using (1%) sodium hypochlorite for 10 minutes. Group II: Denture disinfection using electromagnetic radiation (650 W for 3 minutes / once per week) and divided into 2 subgroups: Group II-A: Dentures kept dry during microwave disinfection. Group II-B: Dentures kept wet in distilled water during microwave disinfection. Group III: Denture disinfection using electromagnetic radiation (650 W for 3 minutes / twice per week) and divided into 2 subgroups: Group III-A: Dentures kept dry during microwave disinfection. Group III-B: Dentures kept wet in distilled water during microwave disinfection. Dimensional stability and patient satisfaction using (OIDP) questionnaire were evaluated after one- and three-weeks follow-up periods. Results: Comparison between dimensional changes after 1st & 3rd week revealed insignificant difference in dimensional changes regarding Group I (expansion) & GII-A & GII-B (Shrinkage) after 3rd week as P > 0.05. On the other hand, there was a significant difference (shrinkage) in GIII-A & GIII-B after the 3rd week as P<0.05. Oral health impact on daily performance (OIDP) revealed insignificantly decreased after 3rd week in all groups except GIII-B as OIDP significantly decreased. Conclusion: Complete denture disinfection with sodium hypochlorite preparation showed the least dimensional change (Expansion) with higher patient satisfaction, while electromagnetic radiation treatment (microwave) of complete dentures showed higher dimensional change with lower patient satisfaction especially in wet conditions.