Objective: The aim of this study was to evaluate the remineralizing effect of Poly (amido amine) dendrimer, Gluteraldehyde and their combination on demineralized dentin at different time intervals. M ate rials and Methods: A total of one hundred and twenty dentin discs were prepared from extracted teeth (n=120), each dentin sample was immersed in 10% citric acid solution for 30 seconds. The samples were divided into two main groups (60 each) according to the assessment time, one week assessment, and four weeks assessment, These two groups were further subdivided into three groups according to the treatment materials; group (1), (n==10): pure G3.0 PAMAM dendrimer, group (II), (n=10): Gluteraldehyde was applied to the demineralized dentin, Group (III), (n=10): a combination of PAMAM dendrimer and Gluteraldehyde. Each group has its control group (n=10) which didn"t receive any treatment. Each treated group with its corresponding control one was placed in a separate container of artificial saliva for one and four weeks. The samples were subjected to microhardness test and Scanning Electron Microscope (SEM). Resu Its: after one week assessment, the results revealed that the highest mean value recorded for PAMAM group (10.9%) followed by PAMAMGluteraldehyde group (8.3%) while Gluteraldehyde group recorded the lowest mean value (5.26%). This difference was statistically insignificant. After four weeks assessment, the results revealed that the highest mean value recorded for PAMAM-Gluteraldehyde group (14.77%) followed by PAMAM group (14.34%) while Gluteraldehyde group recorded the lowest mean value (8%). This difference was statistically insignificant Conclusions: All treatment materials used were effective in increasing dentin microhardness and produced micromorphological changes of the dentin surface in terms of occluding the orificies of dentinal tubules to variable degree