To investigate the effect of complete denture wearing on residual ridge resorption in edentulous patient compared with edentulous patient who never wore dentures. Patients who had been edentulous for at least five year who had never worn dentures successfully were matched to edentulous denture wearing control patients. To control for factors possibly associated with alveolar ridge resorption patients who had been rendered edentulous in one arch before the other, smokers, those taking steroids, bisphosphonates, with histories of autoimmune diseases, diabetes mellitus or osteoporosis at any time during their period of edentulousness were excluded. Case and control groups were matched for age, sex and time since being rendered edentulous. Statistical analyses were undertaken using Person's Chi squared (X2) test and Fisher's exact test. 30 edentulous patients who had not worn dentures for at least five years were identified and matched with 30 controls. All control patients were the same age ± 2 years and had been edentulous for the same number of years ± 2 years of their respective controls. There was no significant difference between age and time since being rendered edentulous between case and control. Denture wearers had significantly more maxillary and mandibular residual alveolar ridge resorption than did non denture wearers. Severe ridge resorption was mostly confined to the denture wearing group. Patients wearing complete dentures for more than 5 years had significantly more residual alveolar ridge resorption than was found in non-denture wearing edentulous patients.