Subclinical concentrations of chlorhexidine inhibit gelatinase activity of carious dentine in vitro.
BACKGROUND
There is evidence that dentine matrix gelatinases are involved in the destruction of carious dentine after demineralization by bacterial acids. It has also been observed that chlorhexidine, in very low concentrations, inhibits the activity of these enzymes in mammalian cells. The goal of this study was to determine if the gelatinase activity of carious dentine may be inhibited by chlorhexidine in clinical use concentrations.


METHODS
Gelatinolytic activity was evaluated through zymography and identified by Western blot. The inhibitory effects of chlorhexidine at concentrations of 0.01%, 0.04%, 0.08% and 1% on the enzymatic activity of softened carious dentine samples were determined.


RESULTS
In carious dentine, five bands of gelatinolytic activity were detected, with molecular sizes of 86, 75, 38, 33 and 32 kDa. The two bands of the greatest molecular size corresponded to latent and active metalloproteinase-9, respectively. Concentrations of chlorhexidine that were greater than or equal to 0.04% were sufficient to inhibit gelatinolytic activity in the observed bands of carious dentine.


CONCLUSIONS
These results support the use of chlorhexidine in clinical use concentrations for the treatment and control of dentine caries. Our study demonstrates for the first time the inhibitory effect of chlorhexidine on gelatinases from carious human dentine.
Department of Community and Basic Sciences, Faculty of Dentistry, University of Chile, Santiago, Chile.
A Mustakis
AM
Trufello
B Urzúa
BU
Orellana
C Lozano
CL
Moraga
C Lefimil
CL
Puente
I
I
Morales-Bozo
D015153:Blotting, Western; D002710:Chlorhexidine / Q000008:administration & dosage / Q000494:pharmacology*; D003731:Dental Caries / Q000201:enzymology* / Q000382:microbiology; D003804:Dentin / Q000201:enzymology / Q000382:microbiology; D018093:Gelatinases / Q000037:antagonists & inhibitors*; D006801:Humans; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D061965:Matrix Metalloproteinase Inhibitors / Q000494:pharmacology*
D061965:Matrix Metalloproteinase Inhibitors; D018093:Gelatinases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D002710:Chlorhexidine
Caries; chlorhexidine; dentine; gelatinases; metalloproteases