Remineralization effects when using different methods to apply fluoride varnish in vitro
Abstract
Background/purpose
Remineralization efficacy for early caries lesion may change when fluoride varnish (FV) is applied directly or indirectly to the lesion. This in vitro
study compared direct and indirect remineralization efficacies of FV on
artificial caries lesions and evaluated acid-resistance of lesion
remineralized by FV and artificial saliva.
Materials and methods
One hundred and twenty-six bovine demineralized specimens were allocated to four varnish groups (Duraphat®, EnamelPro®, MI™, and ClinproWhite™, n = 28 each) and a negative-control group (n = 14).
Half of specimens from each varnish group had the FV applied and the
other specimens didn't. The specimens treated and not treated with the
FV were immersed together in 20 mL of artificial saliva at 37 °C for
24 h. Then the applied FV was removed carefully from the specimen, and
immersion process was continued in fresh artificial saliva for 48 h. The
negative-control group was immersed in artificial saliva for same time
as in varnish groups. The acid resistance of remineralized specimens
from varnish groups was compared to negative-control group. Vickers
microhardness number (VHN) was measured to evaluate re-demineralization
effect.
Results
The
ΔVHN was significantly higher for indirect remineralization
(134.4 ± 31.5, mean ± SD) than for direct remineralization
(66.8 ± 27.9). All varnish groups showed significant differences between
the direct and indirect application methods. The acid resistance of
remineralized specimens was higher in the all FV groups than in the
negative-control.
Conclusion
This in vitro
study confirmed that the remineralization effect of fluoride varnishes
would be higher in the vicinity than the underneath of the varnish
treated surface.
Comments