Biological markers for evaluation of root resorption.
BACKGROUND
External apical root resorption is a pathologic consequence of orthodontic tooth movement. Cementum and dentin are removed from the root surface while active force is present.


OBJECTIVE
The aim of this study was to identify and quantify extracellular matrix proteins, dentin matrix protein 1 (DMP1), dentin phosphophoryn (PP), and dentin sialoprotein (DSP) in the gingival crevicular fluid (GCF) of subjects undergoing orthodontic treatment.


METHODS
Subjects with mild (less than 2mm) and severe (more than 2mm) root resorption during orthodontic treatment were identified by radiographs. A control group of subjects with neither signs of root loss nor undergoing orthodontic treatment was also identified. GCF was collected from the upper incisors by using filter paper strips (Periopaper). The absorbed GCF was eluted and the proteins were separated by SDS-PAGE analysis and stained. Western blot and ELISA were also performed. One-way ANOVA and Scheffé test were used for statistical analysis.


RESULTS
SDS-PAGE analysis identified proteins at 77, 66, 55, 50 and 26kDa. Immunoblotting did not show any differential expression pattern between control and study groups. ELISA results revealed a significant difference in the concentrations of DMP1, PP and DSP between control and root resorption groups. Concentration of PP and DSP in severe root resorption group was also statistically higher than in mild root resorption group.


CONCLUSIONS
DSP and PP could be suitable biological markers for monitoring root resorption during orthodontic treatment, since a significant difference in the level of these dentin specific proteins is detected in all groups.
Balducci
Laura
L
Department of Orthodontics, College of Dentistry, University of Illinois at Chicago, Chicago, IL 60612, USA.
Ramachandran
Amsaveni
A
Hao
Jianjun
J
Narayanan
Karthikeyan
K
Evans
Carla
C
George
Anne
A
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D015415:Biomarkers / Q000032:analysis; D015153:Blotting, Western / Q000379:methods; D002648:Child; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D016326:Extracellular Matrix Proteins / Q000032:analysis*; D005260:Female; D005883:Gingival Crevicular Fluid / Q000378:metabolism; D006801:Humans; D008297:Male; D010750:Phosphoproteins / Q000032:analysis; D012391:Root Resorption / Q000378:metabolism*; D012795:Sialoglycoproteins / Q000032:analysis; D000099311:Dentin Sialophosphoprotein
D015415:Biomarkers; D016326:Extracellular Matrix Proteins; D010750:Phosphoproteins; D012795:Sialoglycoproteins; D000099311:Dentin Sialophosphoprotein; C513309:DMP1 protein, human