OBJECTIVE: In the Maillard reaction, reducing sugars bind to proteins in a non-enzymatic manner, and the final products are collectively named, advanced glycation end products (AGEs). AGEs accumulate in the human body with age and cause various disorders in tissues and cells. In this study, pentosidine, an AGE that can be stably measured, was used to investigate the differences in pentosidine accumulation within dentin, and whether the results can indicate age. METHODS: High-performance liquid chromatography was used to measure pentosidine, an AGE that accumulates in dentin collagen, in extracted teeth with no caries and a clear history. RESULTS: The dentin pentosidine concentration increased with age, with a higher pentosidine concentration observed at the enamel-dentin junction aspect than at the pulp cavity aspect. A close correlation was observed between the dentin pentosidine level and age. CONCLUSIONS: These findings suggest the utility of measuring accumulation of AGEs in dentin collagen as an indicator of age.