IADR Abstract Archives
Effects of Nano-hydroxyapatite Toothpaste on Enamel Surface Hardness
Objectives: To investigate the effect of 2.5%nano-hydroxyapatite toothpaste(NaHA) on surface microhardness(SMH) of demineralized enamel compared to fluoride(F) and non-fluoride(NC) toothpaste.
Methods: Thirty flat ground buccal enamel surfaces were randomly divided into 3 groups regarding to surface treatment; NC group(negative control) which samples were treated with non-fluoride toothpaste and two experimental groups; F group with fluoride toothpaste and NaHA group with nano-hydroxyapatite toothpaste treated. Measurement of Knoop SMH of enamel was performed using digital microhardness tester (6 indentations, 0.49N load for 20s at each measurement) at the beginning and recorded as baseline. Then SMH measurements were repeated after demineralization with 1.0% citric acid for 3 minutes and after 14 days of surface treatments (2 minutes, twice-a-day),consecutively. SMH data were statistically analyzed by One-Way ANOVA with post hoc comparisons and Two-Way repeated measures ANOVA (p<0.05).
Results: In all groups, demineralization process significantly decreased the means SMH of enamel specimens(170.5±50.1 to 171.6±60.9) compared to baseline(235.2±48.0 to 260.4±73.8). After surface treatment, the means SMH of F and NaHA groups(275.5±19.8 and 317.7±21.2, respectively) were significantly higher than its demineralized and baseline SMH. Moreover, nano-hydroxyapatite toothpaste treated demineralized enamel exhibited the significant improvement of SMH compared with the treatment with fluoride toothpaste.
Conclusions: Enamel surface treatment with fluoride or nano-hydroxyapatite toothpaste could be able to reverse the surface hardness of demineralized enamel.
Methods: Thirty flat ground buccal enamel surfaces were randomly divided into 3 groups regarding to surface treatment; NC group(negative control) which samples were treated with non-fluoride toothpaste and two experimental groups; F group with fluoride toothpaste and NaHA group with nano-hydroxyapatite toothpaste treated. Measurement of Knoop SMH of enamel was performed using digital microhardness tester (6 indentations, 0.49N load for 20s at each measurement) at the beginning and recorded as baseline. Then SMH measurements were repeated after demineralization with 1.0% citric acid for 3 minutes and after 14 days of surface treatments (2 minutes, twice-a-day),consecutively. SMH data were statistically analyzed by One-Way ANOVA with post hoc comparisons and Two-Way repeated measures ANOVA (p<0.05).
Results: In all groups, demineralization process significantly decreased the means SMH of enamel specimens(170.5±50.1 to 171.6±60.9) compared to baseline(235.2±48.0 to 260.4±73.8). After surface treatment, the means SMH of F and NaHA groups(275.5±19.8 and 317.7±21.2, respectively) were significantly higher than its demineralized and baseline SMH. Moreover, nano-hydroxyapatite toothpaste treated demineralized enamel exhibited the significant improvement of SMH compared with the treatment with fluoride toothpaste.
Conclusions: Enamel surface treatment with fluoride or nano-hydroxyapatite toothpaste could be able to reverse the surface hardness of demineralized enamel.