Risk factors for early childhood caries in Canadian preschool children seeking care.

of Science of Literature Enamel Maturation of Permanent First Molars This study investigated the enamel maturation process in the occlusal pits of sound permanent fi rst molar teeth by measuring electrical resistance. Ninety-nine sound permanent fi rst molars in 34 Japanese children (mean age 6.47 + 0.51 years in a Japanese primary school) were measured electrically once every 6 months and were monitored for up to 66 months. These children had used a daily fl uoride mouth rinse (0.05% NaF) in nursery school and a weekly rinse (0.2% NaF) in primary school. Electrical resistance increased during the posteruptive period and had not yet reached the level of electrical resistance present in adult molars. Posteruptive enamel maturation was not completed by 66 months after tooth eruption. Comments: The highly porous enamel present on permanent molars at the time of eruption has been thought to mature 6-12 months after eruption. This study indicates that the maturation process for permanent fi rst molars is in excess of fi ve years post-eruption, which may impact treatment decisions. GEM Address correspondence to Dr. Shojiro Kataoka Division of Preventive Dentistry, Department of Oral Health Science Graduate School of Medical and Dental Sciences, Niigata University 2-5274, Gakkocho-Dori, Niigata, 951-8514 Japan); email: shojiro.kataoka@pref.toyama.lg.jp Kataoka S, Sakuma S, Wang J, Yoshihara A, Miyazaki H. Changes in electrical resistance of sound fi ssure enamel in fi rst molars for 66 Months from eruption. Caries Res 2007: 41:161-4.