Do bonding agents protect the bracket-periphery?—Evaluation by consecutive μCT scans and fluorescence measurements
December 2014
Abstract
Objectives
The
aim of this in vitro study was to consecutively determine the effect of
three bonding agents on the prevention of enamel demineralisation at
the bracket-periphery and to compare the suitability of micro-computed
tomography (μCT) scans and quantitative light-induced fluorescence (QLF)
to detect changes within subsurface lesions.
Materials and methods
The effect of a resin-modified glass ionomer cement (RMGI) (Fuji Ortho
LC), a compomer (Assure) and a composite (Transbond XT) on the
prevention of enamel demineralisation at the bracket-periphery was
examined. After 7, 14, 21 and 28 days of pH cycling, the teeth (N = 45) were examined by consecutive μCT scans and by using a customised QLF set-up.
Results
Particularly
for the RMGI and for the compomer, the QLF and μCT scans showed that
the formation and the body of the lesion were not precisely located at
the enamel next to the bracket margin. There was an area that was almost
protected. The progression of demineralisation was decreased for the
RMGI and the compomer-treated teeth.
Conclusion
For
bonding orthodontic brackets, the RMGI and compomer were comparably
able to decrease the progression of white spot lesions (WSL), although
the RMGI showed marginally superior protection. Both methods (QLF and
μCT scans) were suitable for investigating the longitudinal fluoride
effects on WSL, though these effects were more accurately described by
mineral (fluorescence) loss or volume changes than by lesion depth.
Clinical relevance
The
progression of WSL at the bracket-periphery could be altered by using
fluoride-releasing bonding agents for bracket application. This approach
represents a minimally invasive preventive measure.
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