Xylitol-induced changes of enamel microhardness paralleled by microradiographic observations

The study, aimed to analyze the feasibility of a prospective field study, was carried out in Polynesian children with rampant untreated caries. Slabs of bovine enamel were inserted for 8-12 days in cavities and subsequently replaced by permanent fillings. Before use, the surface of the slab was polished, and one half predemineralized and tested for microhardness. The follow-up in 30 subjects involved 54 slabs, 30 from negative controls with no added sweets and 24 from subjects receiving 20 g/day of xylitol in candy. The microhardness of the slabs was reassessed, and the difference between measurements calculated and tested for significance. The differences between the groups were highly significant, the predemineralized halves showing pronounced rehardening at exposure to xylitol. Parallel microradiographic observations conformed with the above findings. The results indicate that the use of a noncariogenic sweetener might be of value in high caries risk subjects.