title: [Effect of topical iron, fluoride application on eroded enamel in vitro].
abstract: OBJECTIVE
  To evaluate the effect of supplementation containing iron and/or fluoride on eroded enamel in vitro.
  
  
  METHODS
  Eighty enamel specimens collected in orthodontic treatments were randomly allocated into 4 groups of 20 samples each: C (control,deionized water); Fe(2+)(15 mmol/L FeSO(4)); F(-)(1.23% NaF) and Fe(2+)+ F(-)(15 mmol/L FeSO(4) and 1.23% NaF ). Before all samples submitted to 6 alternating demineralization and remineralization cycles, they were pre-treated with one of the experimental solutions for 1 minute. One complete cycle consisted of the following steps: ①demineralization in 5 mL beverage (Coca-Cola, pH=2.58) for 5 minutes under gentle agitation; ②remineralization in 5 mL artificial saliva for 1 hour at 37°C. The effect of erosion was observed by enamel surface morphology and measured by superficial micro-hardness (SMH). One-way ANOVA was performed using SPSS18.0 software package for analysis of the data.
  
  
  RESULTS
  The SMH of enamel after erosion by carbonated drinks was significantly lower than the SMH before erosion. When ferrous sulfate with or without fluoride was tested for the prevention of enamel demineralization, there was statistically significant increase in the SMH of enamel in comparison with the control (P<0.001). However, the experimental solutions did not differ significantly among them. Scanning election microscope showed the deposition on the enamel surface after iron or fluorine treatment ,and the damage degree of the enamel surface were reduced compared with the control.
  
  
  CONCLUSIONS
  Iron and/or fluoride was shown to be effective to enhance the acid resistance of enamel,while the combined use of fluoride and iron in group Fe(2+)+F(-)had no cumulative effects.
authors.affiliation: Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, Clinical Research Center of Shaanxi Province for Dental and Maxillofacial Diseases, College of Stomatology, Xi'an Jiaotong University. Xi'an 710004, China. E-mail:zhangyue198717@sina.com.
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Stomatology, Second Hospital of Xi'an City. Xi'an 710003, Shaanxi Province,China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Chong
authors.affiliation: Department of Preventive Dentistry, School of Stomatology, Xi'an Jiaotong University. Xi'an 710004, China.
authors.forename: Rui-zhe
authors.initials: RZ
authors.lastname: Huang
mesh_terms: D002253:Carbonated Beverages; D003743:Dental Enamel; D005459:Fluorides; D005461:Fluorine; D006244:Hardness; D006801:Humans; D007501:Iron; D010710:Phosphates; D012464:Saliva, Artificial; D014077:Tooth Erosion
chemical_list: D010710:Phosphates; D012464:Saliva, Artificial; C012980:fluorophosphate; D005461:Fluorine; D007501:Iron; D005459:Fluorides