Study Visit #1 (Baseline) After obtaining consent, subjects will be randomly assigned to receive fluoride therapy with either custom trays (Tray group) or by application with a toothbrush (Brush group). Each subject will undergo a basic dental examination for identification of new carious lesions. Visit #1 is the baseline, with a new caries score of zero. Photographs will be taken of the subject's mouth and instructions for fluoride therapy will be given.