Plaque as a reservoir for active ingredients

The role of mechanical control of biofilm in the salivary pH after sucrose exposure in children with early childhood caries

This quasi-experimental study sought to investigate if the mechanical control of biofilm (3-times-a-day) modifies the saliva’s ability to buffer the oral environment after 20% sucrose rinse (SR_20%) in children with early childhood caries (ECC). Here, SR_20% reduced the saliva’s pH in both groups and the mechanical control of biofilm had a greater effect on this parameter after SR_20% in CF children. The mechanical control of biofilm evidenced a higher buffering capacity in CF children before SR_20%, which was not observed after SR_20%. Otherwise, the absence of mechanical control of biofilm showed that buffering capacity was comparable in the two groups before SR_20%, whereas after SR_20% the saliva’s buffering capacity of CF children was higher than ECC children. When biofilm was mechanically controlled, carbonic anhydrase VI activity did not change after SR_20% whereas the absence of mechanical control of biofilm reduced this enzyme activity after SR_20%. In conclusion, the mechanical control of biofilm did not change saliva’s ability to buffer the oral environment after SR_20% in children with ECC. On the other hand, CF children appeared to regulate more effectively the saliva’s pH than ECC children while the absence of mechanical control of biofilm mediated their pH-modifying ability after SR_20%.

Changes in the salivary electrolytic dynamic after sucrose exposure in children with Early Childhood Caries

This study sought to explore if the effect of 20% sucrose rinse (SR) on the salivary electrolytic concentration of calcium (Ca2+), phosphate (Pi) and fluoride (F-) in children with Early Childhood Caries (ECC) is different from healthy children. Here, fifty-eight  preschoolers aged 3 to 5 years were divided into 2 groups: caries-free (CF) and with ECC. Changes in saliva flow rate, pH and buffering capacity (BC), as well as in concentrations of Ca2+, Pi, and F-, and the degree of saturation in relation to hydroxyapatite (DSS HAp) and fluorapatite (DSS FAp) were evaluated. The pre-rinse [Ca2+] was higher in the ECC group in the CF group. A significant increase in [Ca2+] was demonstrated after SR in the CF group (p = 0.05). The [Pi] was reduced by 18% after SR in the ECC group (p = 0.007). The [F-] reduced in both groups after SR (p < 0.000). There was a moderate positive correlation between [Ca2+] and the DSS HAp and DSS FAp. Multivariate analysis showed that children with a higher [Ca2+] in pre-rinse saliva are more likely to have ECC. In conclusion, the effect of a 20% sucrose rinse on the electrolytic concentration of Ca2+, Pi and F- was different when children with ECC were compared with CF children.

Effect of NaF, AmF, KF gels and NaF toothpaste combined with a saliva substitute on dentin lesions in vitro

OBJECTIVE

The aim of the present in vitro study was to evaluate the remineralizing effects of NaF, AmF, KF gels and NaF toothpaste in combination with a potentially demineralizing saliva substitute (Glandosane; pH = 5.1) being widely used in Germany.

METHODS

In each of 120 dentin specimens, three artificial lesions were created. One lesion was covered for analysis of pre-demineralization (ΔZ_B). Treatments during pH cycling (3 × 1 h demineralization/day [pH = 5.0] and 3 × 3 h Glandosane/day; 12 h 100%humidity) were as follows: no treatment (NT), application (5 min,2×/day) of 12.500 ppm F^- [pH = 6.04] (NaF-gel₁), 12.500 ppm F^- [pH = 7.34] (NaF-gel₂), 12.500 ppm F^- [pH = 5.82] (AmF-gel), 1450 ppm F^- [pH = 7.35] (KF-gel), and 5000 ppm F^- [pH = 8.14]; (NaF-TP) for 7 days (E1). Subsequently, from each specimen, one lesion was covered, while the remaining lesion was cycled for another 7 days (E2). Differences in integrated mineral loss (ΔΔZ_E1/ΔΔZ_E2) were calculated between values before and after pH cycling.

RESULTS

Mean (95%CI) ΔZ_B was 3851 (3762;3939) vol% × μm. Except for NaF-gel₂ and NaF-TP, specimens of all other groups further demineralized. Only NaF-gel₂ induced a significant gain in mineral content (p ≤ 0.004; paired t test). Significant differences in the change of mineral loss were found between NT and all fluoride groups for both ΔΔZ_E1 and for ΔΔZ_E2 (p < 0.05, Bonferroni post hoc test). However, only NaF-gel₂ and NaF-TP induced remineralization.

CONCLUSION

Under the in vitro conditions chosen, all fluoride agents could significantly hamper the adverse effects of a demineralizing saliva substitute.

CLINICAL SIGNIFICANCE

In combination with a demineralizing saliva substitute, slight mineral gain was only observed for neutral NaF-gel₂ and 5000 ppm F^- toothpaste.