IADR Abstract Archives
Comparative Study of the Caries Remineralizing Effect of Hydroxyapatite-Containing Toothpaste Formulations: a pH Cycling Study
Objectives: This in vitro study compared the efficacy of natural Hydroxyapatite (natHAP) in Happy™ tooth powder and Happy™ toothpaste (Natural Tooth Health LLC), with other marketed synthetic HAP and fluoride in remineralizing initial caries.
Methods: Initial caries lesions were produced on 105 bovine enamel blocks by 5-day demineralization in a Microbial Caries Model using Todd Hewitt’s broth growth media inoculated with Streptococcus mutans and Lactobacilli acidophilus and fed 3 times daily with 10% sucrose treatment (6 min/episode). The 105 caries-bearing blocks were stratified among 7 treatment groups (15/group); natHAP tooth powder, natHAP-low toothpaste, natHAP-high toothpaste, natHAP-UG toothpaste, synthetic nanosize HAP (nanoHAP), Fluoride toothpaste (NaF), and Artificial saliva (AS). The groups were subjected to remineralization for 28 days using a pH-cycling model with daily regimen of three 2-minute toothpaste slurry treatments, one 5-min acidic challenge, and artificial saliva storage for the rest of the day. Surface microhardness (SMH) of each block was measured after demineralization (SMHD) and after remineralization (SMHR). Paired t-test was used for intra-group comparison (SMHD vs SMHR) while Tukey’s multiple comparison tests were used for inter-group comparisons of the mean percentage remineralization (%Rem).
Results: Paired t-test indicated statistically significant (p<0.001) remineralization in all groups. Inter-group comparison showed no statistically significant difference among the groups in their achieved %Rem, except that the %Rem achieved with AS (9.1±6.28%) was significantly lower than those of natHAP-high (30.61±21.92%) and Fluoride (28.43±15.78%) toothpastes. No statistically significant differences in %Rem among the natHAP formulations or between the natural and synthetic HAP formulations. The natHAP formulations exhibited dose-dependent efficacy, with natHAP-high inducing the highest %Rem.
Conclusions: Within the limit of this study, toothpaste based on either natural or synthetic HAP have comparable efficacy to standard fluoride toothpaste in remineralizing initial caries. Natural and synthetic hydroxyapatite were equally effective in remineralizing initial caries.
Methods: Initial caries lesions were produced on 105 bovine enamel blocks by 5-day demineralization in a Microbial Caries Model using Todd Hewitt’s broth growth media inoculated with Streptococcus mutans and Lactobacilli acidophilus and fed 3 times daily with 10% sucrose treatment (6 min/episode). The 105 caries-bearing blocks were stratified among 7 treatment groups (15/group); natHAP tooth powder, natHAP-low toothpaste, natHAP-high toothpaste, natHAP-UG toothpaste, synthetic nanosize HAP (nanoHAP), Fluoride toothpaste (NaF), and Artificial saliva (AS). The groups were subjected to remineralization for 28 days using a pH-cycling model with daily regimen of three 2-minute toothpaste slurry treatments, one 5-min acidic challenge, and artificial saliva storage for the rest of the day. Surface microhardness (SMH) of each block was measured after demineralization (SMHD) and after remineralization (SMHR). Paired t-test was used for intra-group comparison (SMHD vs SMHR) while Tukey’s multiple comparison tests were used for inter-group comparisons of the mean percentage remineralization (%Rem).
Results: Paired t-test indicated statistically significant (p<0.001) remineralization in all groups. Inter-group comparison showed no statistically significant difference among the groups in their achieved %Rem, except that the %Rem achieved with AS (9.1±6.28%) was significantly lower than those of natHAP-high (30.61±21.92%) and Fluoride (28.43±15.78%) toothpastes. No statistically significant differences in %Rem among the natHAP formulations or between the natural and synthetic HAP formulations. The natHAP formulations exhibited dose-dependent efficacy, with natHAP-high inducing the highest %Rem.
Conclusions: Within the limit of this study, toothpaste based on either natural or synthetic HAP have comparable efficacy to standard fluoride toothpaste in remineralizing initial caries. Natural and synthetic hydroxyapatite were equally effective in remineralizing initial caries.