Comparative Evaluation of Changes in Brain Activity and Cognitive Function of Edentulous Patients, with Dentures and Two-Implant Supported Mandibular Overdenture-Pilot Study.

BACKGROUND The relationship between brain and prosthesis was previously assessed either by improving denture function or in fixed implant retained, wherein brain function was assessed only after crown placement. PURPOSE To prospectively analyze the changes in brain activity and cognitive function of completely edentulous patients in edentulous state, with dentures and two-implant supported mandibular overdenture before and after loading, along with the effect of mastication in the change - a pilot study. MATERIALS AND METHOD Ten completely edentulous (CE) non-denture wearers were selected. The mandibular prosthesis was loaded with two 3.3 mm × 13 mm myriad snap fit implants. To assess the brain activity and cognitive function, Electroencephalogram (Neurofax EEG 1000 Ver 05-90, Nihon Kohden corporation, Tokyo, Japan) and Mini-Mental State Examination (MMSE) questionnaire, respectively, were taken during the process of rehabilitation. EEG assessment was analyzed using Matlab 2011A 7.9 signal processing tool box. The results were statistically analyzed with SPSS 17.0 version using Wilcoxon signed rank and Friedman test RESULTS Amplitude, power of alpha waves and cognitive scores increased gradually with highest mean rank for implant supported overdenture (IOD). The bivariate analysis between two groups showed there was significant difference between all the groups (p < 0.05) except for groups CE-I (completely edentulous - implant placement) and CD- I (complete denture insertion - implant placement) in amplitude of alpha waves while in group CD-I with respect to power of alpha waves. MMSE revealed the mean of cognitive scores in Complete Edentulous was 17.40, Complete Denture was 18.30 and finally with Implant Overdenture was 23.80. CONCLUSION The present study has enlightened the significance of two implant supported mandibular overdenture in improving the mental state of an individual and that the enhancement was due to functional improvement with prosthesis when loaded with implants and not due to mere existence of implant without any function.