AVS 52nd International Symposium
    Biomaterial Interfaces Monday Sessions
       Session BI-MoP

Paper BI-MoP41
Nano-mechanical and Chemical Mapping Showing Remineralization of Incipient Carious Lesions in Human Dental Enamel

Monday, October 31, 2005, 5:00 pm, Room Exhibit Hall C&D

Session: Biomaterial Interfaces Poster Session
Presenter: M.E. Dickinson, Hysitron, Inc.
Authors: M.E. Dickinson, Hysitron, Inc.
A.B. Mann, Rutgers, The State University of New Jersey
Correspondent: Click to Email
Human dental enamel consists of hydroxyapatite crystals arranged in a complex nano-scale prism structure. This architecture can be altered by chemical variations originating from dietary components and their interactions within the oral cavity. Temporary localized fluctuations of pH on the enamel surface create a flux of minerals into and out of the enamel which normally remains at an overall equilibrium. However, at continually low pH a net loss of mineral from the enamel results, causing the formation of an incipient carious lesion. The lesion - a stage prior to caries formation, is reversible and with specialized care such as remineralization treatments, can become arrested. Many commercial remineralization treatments use topical solutions containing fluoride and calcium phosphates to aid in caries prevention. However, the effect of these treatments at different stages of lesion progression is poorly understood. This investigation uses nanoindentation and TOF-SIMS to create high resolution mechanical and chemical maps of the lesion cross-section at different stages of demineralization. These lesions were analyzed before and after treatment with a commercial remineralization solution to study the effectiveness of remineralization at different stages of lesion progression. The results showed that the treatment acted to remineralize the lesion body for all lesions. However, the most demineralized lesions which had a different structure (no detectable surface zone), resulted in a different, possibly fluoroapatite based material being deposited at the base of the lesion with mechanical properties much higher than that of enamel. The chemical data correlated with the mechanical data to relate the structural integrity of the enamel with the change in hardness and reduced elastic modulus. Visualizing this dependence of lesion structure for efficient remineralization allows further understanding into the effectiveness of commercial dental treatments.