In vitro remineralisation of carious lesions by casein phosphopeptide

Objectives:  To compare any remineralisation (R) of sub-surface caries like lesions made by casein phosphopeptide (CPP) product (Tooth Mousse, GC Corporation, Tokyo) and fluoride toothpaste slurries. 

Methods:  Twelve bovine incisors were sectioned into five and varnished to leave a 5x5 mm window.  Each section was exposed to a demineralising solution (pH 4.5) for 18 hours.  Sections were imaged with quantitative light induced fluorescence (QLF) following demineralisation (D). One section of each tooth was analysed with TMR.  None showed evidence of erosion.  The slabs were allocated by structured randomisation into regimen W,X,Y or Z.  W distilled water (control); X artificial saliva, 0.05 ppmF, pH 7.2; Y 10% weight volume (w/v) CPP in artificial saliva 0.05 ppmF; and Z 10% w/v 1000 ppmF NaH₂PO₄ in artificial saliva 0.05 ppmF.  Samples were stored in artificial saliva between dippings for 84 days with a total of 10 hours test time.  The 48 sections each had 13 QLF images and TMR for one sample per group.  Analysis was carried out using QLF V.2.00 software (Inspektor Research Systems, Netherlands). 

Results:  Over the 12 week experimental period, only the toothpaste group was shown to have a significant effect on ΔF (p=0.000, 95% CI 13.9, 20.8) demonstrating a linear increase in mineral content.  Some remineralisation was seen in the other test groups but neither saliva (p=0.470, 95% CI -4.7, 2.1) nor CPP (p=0.320, 95% CI -1.7, 5.1) had significant effects on final ΔF of the samples.  QLF (ΔF) and TMR (ΔZ) showed good agreement with a correlation coefficient of r = -0.56. 

Conclusions:  The full remineralising potential of casein phosphopeptide has yet to be realised and refinements in the in vitro model are required.  Toothpaste was found to be an effective remineralising agent in vitro.