Advanced glycation end-products （AGEs） accumulate with aging or with diabetes. AGEs affect the physical properties of human dentin, resulting in fragility and browning. In particular, pentosidine, a cross-linked AGE, was found to be significantly increased in aged dentin or caries-affected dentin. The shorter fluorescence lifetime of dentinal collagen in carious teeth as compared to healthy teeth suggests that AGEs result in shortening of the fluorescence lifetime. AGEs are also thought to affect blood vessels in the pulp. In recent years, research has been conducted to mitigate the effects of AGEs with supplements or drugs. In this review, we present the details and latest findings of research related to glycation of dental tissue.

This study examines the cell proliferation and collagen-producing abilities, alkaline phosphatase （ALP） activity, and the production interleukin （IL）-6 and IL-8 of the nutritional functional food “Osteo AG” in a basic experimental system using Saos-2, a human osteoblastic osteosarcoma cell line. Cell proliferation was determined by 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyl tetrazolium bromide （MTT） assay；DNA synthesis by bromodeoxyuridine-incorporation. Production of collagen, IL-6, and IL-8 was analyzed by ELISA while ALP activity by a commercial assay kit. We found that cell proliferation, production of collagen type Ⅰ, and ALP activity increased in the presence of Osteo AG. Although lipopolysaccharide of the periodontopathic bacterium Aggregatibacter actinomycetemcomitans induced production of the aforementioned inflammatory cytokines, Osteo AG inhibited this effect. In conclusion, our study suggests that Osteo AG has bone-forming ability and anti-inflammatory effects in Saos-2.

The COVID-19 pandemic has made face-to-face classes difficult to be held. In response to this disaster, online classes have been launched to ensure learning opportunities for students in the university. However, it remains unknown how this shift of educational methods affects the learning outcome especially of the dental school. In this study, we evaluated the educational effectiveness of online classes of pharmacology on third- and fourth year of Nihon University School of Dentistry, in comparison to face-to-face classes. The scores on the examination questions （EQs） of online classes were compared to those of face-to-face classes. The EQs of online classes were consisted of both newly made EQs and the same EQs that were on the former examinations. The mean correct answer rate of the online classes was lower than that of the face-to-face classes, while the discrimination index, which reflects the validity of EQs, was higher in the online classes. This suggests a possibility that the difficulty of EQs is different between online and face-to-face classes. In the analysis of the same EQs, there was no significant difference in the correct answer rate and the discrimination index. We also evaluated students’ impression for both classes by questionnaire surveys, and found their high level satisfaction with online classes. These results suggest that online classes produce comparable students’ learning outcomes and satisfaction as well as face-to-face classes.