Demineralization Inhibitory Effects of Highly Concentrated Fluoride Dentifrice and Fluoride Gels/Solutions on Sound Dentin and Artificial Dentin Caries Lesions in vitro
Objectives: The aim of this in vitro study was to compare the
demineralization inhibitory effect of gels/solutions used in
combination with either standard or highly fluoridated dentifrices on sound dentin as well as on artificial dentin carieslike lesions. Methods: Bovine dentin specimens (n = 240)
with two different surfaces each (sound [ST] and artificial caries lesion [DT]) were prepared and randomly allocated to
twelve groups. Weekly interventions during pH-cycling (28
days, 6 × 120 min demineralization/day) were: the application of gels/solutions containing amine fluoride/sodium fluoride (12,500 ppm F [ppm]; pH = 4.4; AmF); NaF (12,500 ppm;
pH = 6.6; NaF1); NaF (12,500 ppm; pH = 6.3; NaF2); silver diamine fluoride (14,200 ppm; pH = 8.7; SDF); acidulated phosphate fluoride (12,500 ppm; pH = 3.8; APF), and no intervention (standard control; S). Furthermore, half of the specimens
in each group were brushed (10 s; twice per day) with dentifrice slurries containing either 1,450 ppm (e.g., AmF1450) or
5,000 ppm (e.g., AmF5000). Differences in integrated mineral
loss (ΔΔZ) and lesion depth (ΔLD) were calculated between
values before and after pH-cycling using transversal microradiography. Results: After pH-cycling Ss showed significantly increased ΔZDT and LDDT values, indicating further demineralization. In contrast, except for one, all groups including fluoride gels/solutions showed significantly decreased
ΔZDT values. Additional use of most fluoride gels/solutions
significantly enhanced mineral gain, mainly in the surface
area; however, acidic gels/solutions seemed to have negative effects on lesion depths. Significance: Under the present pH-cycling conditions the highly fluoridated dentifrice
significantly reduced caries progression and additional application of nearly all of the fluoride gels/solutions resulted
in remineralization. However, there was no difference in the
remineralizing capacity of fluoride gels/solutions when used
in combination with either standard or highly fluoridated
dentifrices
