The specific aim of this research program is the development of a low-cost, laser-based caries prevention and treatment system to effectively reduce or eliminate caries in children and adults. Even with the substantial decline in caries that has occurred over the last several decades, a substantial percentage of children and adults have evidence of untreated caries in their permanent teeth. Furthermore, the decline in caries reached a plateau during the 1990s. Many methods are currently available for caries prevention and treatment. However, they are limited by their high cost, limited availability or effectiveness, or lack of long- term caries resistance. Hence, new approaches are needed to address these key issues and provide a low- cost, long-term solution that can prevent caries altogether. Creare's innovation is the Caries Prevention and Treatment System (CRTS). This novel system combines a standard fluoride treatment with a low-power, low-cost, continuous-wave laser to almost completely inhibit enamel demineralization. Novel methodologies to measure the real-time enamel temperature will be integral to the system. This hardware will be combined with model-based adaptive control software to precisely control the enamel temperature. In so doing, our innovation will maximize the effectiveness of treatment while improving ease of use and eliminating the risk of damage to sensitive tissues. The low cost of our innovation will enable increased access to critical caries management and treatment, which is of particular importance to high-risk children and adults. Our novel system will improve the affordability, access, effectiveness, practicality, and safety of caries prevention. ? ?