title: [Clinical investigation of six cases with mandibular first premolars with three canals].
authors.forename: Bing-zhen
authors.initials: BZ
authors.lastname: He
authors.forename: Xing-zhe
authors.initials: XZ
authors.lastname: Yin
authors.forename: Qian-qian
authors.initials: QQ
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008963:Molar; D012390:Root Canal Therapy / Q000379:methods*