title: Effect of Galla chinensis extract and chemical fractions on demineralization of bovine enamel in vitro.
abstract: OBJECTIVE
  To evaluate the demineralization inhibition property of extracts and chemical fractions of Galla chinensis in vitro.
  
  
  METHODS
  Seventy sound bovine enamels blocks were prepared and randomly divided into seven groups. These samples were pH-cycled for 12 times in 6 days. Each daily cycle included 2x 5 min application with one of the seven treatments: 1000 ppmFaq. (as NaF, positive control); deionized water (negative control); or 4000 ppm aqueous solutions of five G. chinensis extracts (GCEs): GCE, GCE-A, GCE-B, GCE-C or GCE-D. Surface enamel microhardness was measured on the enamel blocks before and after pH-cycling, and the reduction of surface microhardness (DeltaSMH) was calculated. The acidic buffers were retained for calcium analysis.
  
  
  RESULTS
  There were significant differences between the GCE groups and the two controls (p<0.01). Among all the GCE groups, the reduction of surface microhardness (DeltaSMH) in GCE group was the least (p<0.01). No significant differences were found between the GCE group and GCE-C group in CDR, as well as the other three GCE groups (GCE-A, GCE-B and GCE-D) (p>0.05).
  
  
  CONCLUSIONS
  The present study has demonstrated the potential of the GCE to effect the demineralization under dynamic pH-cycling conditions. None of the chemical fractions was as effective as GCE. Combined with its anti-bacterial properties, the demineralization inhibition of GCE suggests that this material could be a useful source for the development of promising anti-cariogenic agents.
authors.affiliation: State Key Laboratory of Oral Diseases, West China College of Stomatology, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Zou
authors.forename: LingLin
authors.initials: L
authors.lastname: Zhang
authors.forename: JiYao
authors.initials: J
authors.lastname: Li
authors.forename: YuQing
authors.initials: Y
authors.lastname: Hao
authors.forename: Lei
authors.initials: L
authors.lastname: Cheng
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Xuedong
authors.initials: X
authors.lastname: Zhou
mesh_terms: D000818:Animals; D002021:Buffers; D002118:Calcium / Q000032:analysis; D002327:Cariostatic Agents / Q000627:therapeutic use*; D002417:Cattle; D003743:Dental Enamel / Q000187:drug effects*; D003747:Dental Enamel Solubility / Q000187:drug effects; D004365:Drugs, Chinese Herbal / Q000627:therapeutic use*; D006244:Hardness; D006863:Hydrogen-Ion Concentration; D010936:Plant Extracts / Q000032:analysis / Q000627:therapeutic use*; D011897:Random Allocation; D029045:Rhus; D012969:Sodium Fluoride / Q000627:therapeutic use; D017001:Tooth Demineralization / Q000517:prevention & control*
chemical_list: D002021:Buffers; D002327:Cariostatic Agents; D004365:Drugs, Chinese Herbal; D010936:Plant Extracts; D012969:Sodium Fluoride; D002118:Calcium