title: Comparison between electrochemical ELISA and spectrophotometric ELISA for the detection of dentine sialophosphoprotein for root resorption.
abstract: BACKGROUND
  Root resorption is an undesirable sequela of orthodontic treatment. It is necessary to establish sensitive methods for identification of teeth at risk for resorption. The x-ray is the traditional method to diagnose root resorption, which is often at a late stage. Some researchers used enzyme-linked immunosorbent immunoassay (ELISA) combined with spectrophotometry to study some biochemical markers of root resorption. However, spectrophotometric detection often has a poor detection limit. Electrochemical detection has inherent advantages over spectrophotometric detection, which is especially suitable for small biologic samples.
  
  
  METHODS
  We used ELISA combined with electrochemistry and ELISA combined with spectrophotometry to measure the biochemical marker dentine sialophosphoprotein in gingival crevicular fluid of orthodontic patients (treated for 8-12 months).
  
  
  RESULTS
  Standard dentine sialophosphoprotein was used to calculate the linear regression equation. No significant difference was found between the electrochemical outcome and the spectrophotometric outcome. But the electrochemical results extended the lower end of detection from 5 pg per milliliter (by spectrophotometry) to 0.5 pg per milliliter.
  
  
  CONCLUSIONS
  These results showed that ELISA combined with electrochemistry is a reliable and sensitive method to detect dentine sialophosphoprotein in gingival crevicular fluid.
authors.affiliation: Associate chief physician, Department of Orthodontics, School of Dentistry, Capital Medical University, Beijing, China.
authors.forename: Hailiang
authors.initials: H
authors.lastname: Sha
authors.affiliation: Professor, Department of Orthodontics, School of Dentistry, Capital Medical University, Beijing, China. Electronic address: byuxing@263.net.
authors.forename: Yuxing
authors.initials: Y
authors.lastname: Bai
authors.affiliation: Associate professor, Department of Orthodontics, School of Dentistry, Capital Medical University, Beijing, China.
authors.forename: Song
authors.initials: S
authors.lastname: Li
authors.affiliation: Associate professor, Department of Precision Instruments, Tsinghua University, Beijing, China.
authors.forename: Xiofeng
authors.initials: X
authors.lastname: Wang
authors.affiliation: Postgraduate student, Department of Precision Instruments, Tsinghua University, Beijing, China.
authors.forename: Yajiang
authors.initials: Y
authors.lastname: Yin
mesh_terms: D000293:Adolescent; D015415:Biomarkers / Q000032:analysis; D055664:Electrochemical Techniques; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D016326:Extracellular Matrix Proteins / Q000032:analysis*; D005260:Female; D005883:Gingival Crevicular Fluid / Q000737:chemistry; D006801:Humans; D007180:Incisor / Q000473:pathology; D008297:Male; D009971:Orthodontics, Corrective; D010750:Phosphoproteins / Q000032:analysis*; D015203:Reproducibility of Results; D012391:Root Resorption / Q000378:metabolism / Q000473:pathology*; D012680:Sensitivity and Specificity; D012795:Sialoglycoproteins / Q000032:analysis*; D013053:Spectrophotometry / Q000379:methods; D055815:Young Adult; D000099311:Dentin Sialophosphoprotein
chemical_list: D015415:Biomarkers; D016326:Extracellular Matrix Proteins; D010750:Phosphoproteins; D012795:Sialoglycoproteins; D000099311:Dentin Sialophosphoprotein