Comparative Evaluation of Changes in Brain Activity Among Edentulous Patients Rehabilitated With Conventional Complete Dentures and Tooth-Supported Overdentures Using Electroencephalography: An In Vivo Study

Introduction: Edentulism is associated with impaired masticatory function and reduced sensory stimulation that may adversely affect cortical activity and cognitive health. However, evidence comparing the effects of different removable prosthetic rehabilitation modalities on brain activity is limited. Our study aimed to evaluate and compare changes in brain activity using electroencephalography among completely edentulous patients rehabilitated with conventional complete dentures, tooth-supported overdentures without attachments, and tooth-supported overdentures with stud attachments. Materials and methods: This prospective observational study included 36 participants aged 60-80 years who fulfilled the eligibility criteria. The participants received routine prosthodontic treatment based on their clinical condition, were non-randomized, and were categorized into three groups (n = 12 each): conventional complete dentures, tooth-supported overdentures without attachments, and tooth-supported overdentures with stud attachments. Baseline electroencephalographic recordings were obtained before treatment and repeated after two months of prosthesis use under standardized recording conditions. Baseline demographic characteristics were compared using one-way analysis of variance (ANOVA) and the chi-square test. Changes in brain activity over time were evaluated using a mixed-design repeated-measures ANOVA, with supplementary independent-samples and paired-samples t-tests for pairwise and within-group comparisons. Statistical significance was set at p < 0.05. Results: The three groups were comparable in terms of age and sex at baseline. Significant changes were noticed in the measured electroencephalographic parameter after prosthodontic rehabilitation in all three groups (p ≤ 0.001). The observed increase in the EEG-derived measure following prosthodontic rehabilitation is interpreted as reflecting enhanced cortical electrical activity associated with restoration of masticatory function. However, because EEG provides an indirect measure of neural activity, these findings should not be interpreted as definitive evidence of improved cortical or cognitive function without complementary neuropsychological or functional assessments. Mixed-design repeated-measures analysis demonstrated a significant effect of time (p < 0.001), indicating that cortical activity increased following rehabilitation, irrespective of prosthesis type. Although the tooth-supported overdenture with stud attachment group demonstrated the greatest numerical increase in brain activity, neither the overall group effect nor the group-by-time interaction was significant (p > 0.05). Pairwise intergroup comparisons at baseline and after two months also revealed no significant differences. Conclusion: Prosthodontic rehabilitation was associated with a significant increase in EEG-derived cortical brain activity after two months of functional use. Although attachment-retained tooth-supported overdentures showed the highest numerical increase, they were not statistically superior to the other treatment modalities. These findings suggest that restoration of masticatory function is associated with enhanced cortical electrical activity, irrespective of prosthesis design.