Casein phosphopeptides (CPP) have been shown to stabilise amorphous calcium phosphate (CPP-ACP). CPP-ACP has been associated with anticariogenicity and remineralization in in vitro and in vivo models. CPP has also been shown to stabilise amorphous calcium fluoride phosphate (CPP-ACFP) which had an additive effect compared with the separate remineralization effects of fluoride or CPP-ACP.
Objectives: The aim of this study was to examine the remineralization potential of two concentrations of CPP-ACFP in terms of mineral and visual change. The mineral formed was subsequently analysed using wavelength dispersive microprobe spectrometry.
Methods: Enamel subsurface lesions were created using the Carbopol method and remineralized using CPP-ACFP solutions (0.5, 1.0%w/v) at pH 5.5 (2mL, 37oC, 10 days, daily solution changes, n=10 lesions per group). The lesions were then digitally photographed, analysed using quantitative light induced fluorescence (QLF) to determine percentage fluorescent loss integrated over area (%Q), embedded, sectioned, lapped and analysed using transverse microradiography (TMR) to determine percentage mineral change (%R). Elemental maps and quantitative line scans for calcium, phosphorous, fluoride, oxygen and chlorine were collected across the lesions using wavelength dispersive spectrometry on a JEOL 8900 SuperProbe Microprobe.
Results: The 0.5 and 1% CPP-ACFP solutions both produced statistically similar levels of remineralization as measured by TMR and QLF respectively, however there was more variation in the 0.5% lesions.
|
|
0.5% |
1% |
P value |
|
%R |
56.3±17.7 |
58.7±5.9 |
0.85 |
|
%Q |
83.4±16.0 |
93.1±6.6 |
0.36 |
All white spot lesions became more translucent after remineralization treatment. Microprobe analysis of remineralized enamel showed a single calcium phosphate phase with the ratio matching apatite. Fluoride was found evenly throughout the body of the lesions supporting fluorapatite formation.
Conclusion: CPP-ACFP solutions remineralized enamel subsurface lesions in vitro by the deposition of fluorapatite increasing mineral content and improving translucency.
Supported by the NHMRC and the Cooperative Research Centre for Oral Health Science.