To assess the effect of silver diamine fluoride (SDF) treatment on microorganisms present in root caries or cervical lesions by collecting microbial deposits before and 1 month after SDF application. Bacterial samples will be collected from 20 adult subjects at the initial visit before application of SDF and one month after. At the 1 month recall, examination for caries arrest will be performed. All 40 bacterial samples will be sent to the Forsyth Institute to verify bacterial composition using HOMINGS technology.