title: [Effects of tooth whitening agents and acidic drinks on the surface properties of dental enamel].
abstract: OBJECTIVE
  Using tooth whitening agents (bleaching clip) in vitro and acidic drinks, we conducted a comparative study of the changes in enamel surface morphology, Ca/P content, and hardness.
  
  
  METHODS
  Tooth whitening glue pieces, cola, and orange juice were used to soak teeth in artificial saliva in vitro. Physiological saline was used as a control treatment. The morphology of the four groups was observed under a scanning electron microscope (SEM) immediately after the teeth were soaked for 7 and 14 d. The changes in Ca/P content and microhardness were analyzed.
  
  
  RESULTS
  The enamel surfaces of the teeth in the three test groups were demineralized. The Ca/P ratio and the average microhardness were significantly lower than those of the control group immediately after the teeth were soaked (P < 0.05). The Ca/P ratio and microhardness gradually increased after 7 d. No significant difference was observed between the control group and the test groups after 14 d (P > 0.05).
  
  
  CONCLUSIONS
  Bleaching agents caused transient demineralization of human enamel, but these agents could induce re-mineralization and repair of enamel over time. Demineralization caused by bleaching covered a relatively normal range compared with acidic drinks and daily drinking.
authors.affiliation: Dept. of Endodontics, Xiamen Stomatology Hospital, Teaching Hospital of Fujian Medical University, Xiamen 361003, China.
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Chen
authors.forename: Zhiqun
authors.initials: Z
authors.lastname: Chen
authors.forename: Yao
authors.initials: Y
authors.lastname: Lin
authors.forename: Jinquan
authors.initials: J
authors.lastname: Shao
authors.forename: Lu
authors.initials: L
authors.lastname: Yin
mesh_terms: D003743:Dental Enamel; D006244:Hardness; D006801:Humans; D006861:Hydrogen Peroxide; D012464:Saliva, Artificial; D013499:Surface Properties; D014073:Tooth Bleaching; D058205:Tooth Bleaching Agents
chemical_list: D012464:Saliva, Artificial; D058205:Tooth Bleaching Agents; D006861:Hydrogen Peroxide