MMP-2, MMP-9, and iNOS expression in human dental pulp subjected to orthodontic traction.
OBJECTIVE
To test the hypothesis that some metalloproteinases (MMP-2, MMP-9) and inducible nitric oxide synthetase (iNOS) enzymes in dental pulp samples do not vary when subjected to orthodontic treatment.


METHODS
Human dental pulps were taken from male and female patients (N=10; age 10-14 years). A straight wire technique was used with nickel-titanium or steel archwires. The increase of pressure applied on teeth was gradual. Five patients were subjected to premolar extractions after 14 months of treatment and one after 24 months. Samples were Bouin-fixed, paraffin-embedded, and afterwards processed for immunohistochemistry using anti-MMP-2, anti-MMP-9, and anti-iNOS antibodies.


RESULTS
A reduction of MMP-2, MMP-9, and iNOS expression occurred in treated samples. This became more evident with increased treatment time.


CONCLUSIONS
The hypothesis is rejected. The reduction of expression of those proteins revealed a time-dependent relationship.
Department of Experimental Medicine, University of Palermo, Palermo, Italy. aleone.istologia@unipa.it
Angelo
A
Leone
Annamaria
A
Mauro
Giovanni Francesco
GF
Spatola
Salvatore
S
Provenzano
Carola
C
Caradonna
Aldo
A
Gerbino
Maria
M
Buscemi
D000293:Adolescent; D001641:Bicuspid / Q000201:enzymology; D001696:Biomechanical Phenomena; D002648:Child; D003722:Dental Alloys; D003782:Dental Pulp / Q000201:enzymology* / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008312:Malocclusion, Angle Class II / Q000628:therapy; D020778:Matrix Metalloproteinase 2 / Q000032:analysis*; D020780:Matrix Metalloproteinase 9 / Q000032:analysis*; D009532:Nickel; D052247:Nitric Oxide Synthase Type II / Q000032:analysis*; D009804:Odontoblasts / Q000201:enzymology; D009969:Orthodontic Wires; D011312:Pressure; D013232:Steel; D013314:Stress, Mechanical; D013997:Time Factors; D014025:Titanium; D014087:Tooth Movement Techniques
D003722:Dental Alloys; C040654:titanium nickelide; D013232:Steel; D009532:Nickel; D014025:Titanium; C496319:NOS2 protein, human; D052247:Nitric Oxide Synthase Type II; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9