IADR Abstract Archives
Remineralization Characteristics of Superficial and Advanced Enamel Artificial Caries
Objectives: The aim of this in vitro study was to evaluate the role of high-fluoride dentifrice on remineralization characteristics of superficial and advanced enamel artificial caries lesions.
Methods: Bovine enamel specimens with either one lowly [L] or highly [H] pre-demineralized (pH 4.95; 21 days) artificial caries lesions were prepared. Specimens with a mean ΔZbaseline,L (95% CI) of 5,120 (4,995; 5,245) vol%×µm for L lesions and a mean ΔZbaseline,H of 8,187 (8,036; 8,339) vol%×µm for H lesions were selected and randomly allocated to twelve groups (n=20). Treatments during pH-cycling (28 days and 6x60 min demineralization/day) were: brushing 2x/day with: fluoride-free (0 ppm F- [L0/H0]); 1,100 ppm F- [L1100/H1100]; 2,800 ppm F- [L2800/H2800]; 5,000 ppm F- [L5000/H5000); 5,000 ppm F- + glycerin [L5000+glycerin/H5000+glycerin]; and 5,000 ppm F- + TCP [L5000+TCP/H5000+TCP] containing dentifrices. Dentifrice slurries were prepared with deionized water (1:3wt/wt). After cycling specimens presenting lesion surface loss were discarded and for the remaining 202 specimens new transversal microradiography (TMR) analyses (ΔZpH-cycle/LDpH-cycle) were performed. Changes in mineral loss (ΔΔZ=ΔZbaseline-ΔZpH-cycle) and lesion depth (ΔLD=LDbaseline-LDpH-cycle) were calculated.
Results: Significant differences for ΔΔZ could be found between L0, L1100 and L5000 as well as H0, H1100 and H2800/H5000 (p≤0.049; Bonferroni post-hoc test). The correlation between ΔΔZ and F- was moderate for lowly and strong for highly demineralized specimens (rL=0.591; pL<0.001; rH=0.746; pH<0.001), indicating a fluoride dose-response for L and H. In general H led to a significant higher ΔΔZ compared with L, except for 0ppm F- (p≤0.003; two-tailed-t-test). After pH-cycling a second lesion front could only be observed in specimens of H5000 and H5000+TCP.
Conclusions: For both baseline substrate conditions a dose-response could be revealed. Furthermore, remineralization characteristics of enamel directly depended on baseline mineral loss.
Methods: Bovine enamel specimens with either one lowly [L] or highly [H] pre-demineralized (pH 4.95; 21 days) artificial caries lesions were prepared. Specimens with a mean ΔZbaseline,L (95% CI) of 5,120 (4,995; 5,245) vol%×µm for L lesions and a mean ΔZbaseline,H of 8,187 (8,036; 8,339) vol%×µm for H lesions were selected and randomly allocated to twelve groups (n=20). Treatments during pH-cycling (28 days and 6x60 min demineralization/day) were: brushing 2x/day with: fluoride-free (0 ppm F- [L0/H0]); 1,100 ppm F- [L1100/H1100]; 2,800 ppm F- [L2800/H2800]; 5,000 ppm F- [L5000/H5000); 5,000 ppm F- + glycerin [L5000+glycerin/H5000+glycerin]; and 5,000 ppm F- + TCP [L5000+TCP/H5000+TCP] containing dentifrices. Dentifrice slurries were prepared with deionized water (1:3wt/wt). After cycling specimens presenting lesion surface loss were discarded and for the remaining 202 specimens new transversal microradiography (TMR) analyses (ΔZpH-cycle/LDpH-cycle) were performed. Changes in mineral loss (ΔΔZ=ΔZbaseline-ΔZpH-cycle) and lesion depth (ΔLD=LDbaseline-LDpH-cycle) were calculated.
Results: Significant differences for ΔΔZ could be found between L0, L1100 and L5000 as well as H0, H1100 and H2800/H5000 (p≤0.049; Bonferroni post-hoc test). The correlation between ΔΔZ and F- was moderate for lowly and strong for highly demineralized specimens (rL=0.591; pL<0.001; rH=0.746; pH<0.001), indicating a fluoride dose-response for L and H. In general H led to a significant higher ΔΔZ compared with L, except for 0ppm F- (p≤0.003; two-tailed-t-test). After pH-cycling a second lesion front could only be observed in specimens of H5000 and H5000+TCP.
Conclusions: For both baseline substrate conditions a dose-response could be revealed. Furthermore, remineralization characteristics of enamel directly depended on baseline mineral loss.