Introduction:Progressive ridge resorption is one of the main causes of loss of stability and retention of mandibular complete dentures with subsequent loss of masticatory efficiency and patient discomfort. Aim: This study was conducted to evaluate radiographically the effect of nano-hybrid composite resin teeth on mandibular residual ridge using cone beam computerized tomography (CBCT). A comparative study. Materials and Methods: Twelve completely edentulous male patients were randomly divided into two groups according to the artificial tooth material used in complete denture construction. One group received complete dentures with nano-hybrid composite resin teeth and the other group received complete dentures with cross-linked acrylic resin teeth. CBCT was taken at the delivery, 6 months and 12 months follow -up appointments. The evaluation was done for height and width changes of the mandibular residual alveolar ridge at different anatomical sites either in the anterior or posterior part of the mandible. Results: Analysis was done by using two-tailed t-test revealed that increase in amount of bone loss in both groups which is in favor to patients wearing dentures with nano-hybrid composite resin teeth, with no statistically significant difference between the two groups. Conclusion: Despite of introduction of new denture tooth material as nano-hybrid composite resin teeth, the cross-linked acrylic resin teeth still considered the gold standard denture teeth regarding the degree of occlusal force transmission and preservation of residual alveolar ridge.