【名词&注释】
根尖周炎(periapical periodontitis)、氟牙症(dental fluorosis)、间接盖髓术(indirect pulp capping)、牙髓摘除术(pulpectomy)、牙髓充血(hyperemic pulpitis)
[单选题]引起氟牙症的水源中含氟浓度是()
A. A.超过2ppm
B. B.低于1ppm,超过0.5ppm
C. C.超过1ppm,小于2.0ppm
D. D.超过0.2ppm,小于0.5ppm
E. E.超过0.1ppm,小于0.5ppm