Comparison of hydroxyapatite and fluoride oral care gels for remineralization of initial caries: a pH-cycling study

Abstract

The present in vitro study investigated if simulated daily use of hydroxyapatite-based gel (15% HAP) remineralizes early caries lesions as effective as weekly use of high fluoride (12,500 ppm) concentration gel, comparing them with artificial saliva alone. MATERIALS AND METHODS: Three tooth blocks were produced from each of 20 bovine teeth. Caries-like lesion was created on each block by 4-day demineralization in acidified gel. The blocks were randomized into three remineralization groups (20 blocks/ group); Hydroxyapatite-based gel (Karex gelée, 15% HAP, fluoride-free), fluoride-based gel (Elmex gelée, 12,500 ppm F −), and artificial saliva (AS). Remineralization was conducted using pH-cycling model for 28 days with storage in AS. The pH cycling model consisted of 2 h demineralization once daily for all groups, and 3 min HAP gel application once daily, 3 min fluoride gel application once weekly, or remain in AS only respectively. Baseline and post-test mineral loss were quantified using microradiography. RESULTS: Paired t-tests (baseline vs. post-Test) indicated significant (p < 0.0001) remineralization in all groups. When compared against each other using Games-Howell's multiple comparison test, no significant difference in remineralization was observed between the two gels, but both gels exhibited significantly (p < 0.001) higher percentage mineral gain (HAP:39 ± 7%; fluoride:41 ± 11%) than AS alone (6 ± 2%). CONCLUSION: Hydroxyapatite-based gel (15% HAP) was as effective as fluoride-based gel (12,500 ppm F −) in remineralizing initial caries lesion.

Whitening Effects of a Novel Oral Care Gel with Biomimetic Hydroxyapatite: A 4-Week Observational Pilot Study

“…Particulate hydroxyapatite, Ca 5 (PO 4 ) 3 (OH), is a multifunctional biomimetic active ingredient used in preventive oral health care [ 1 , 2 , 3 , 4 , 5 , 6 ], and has a wide range of applications in this field. Specifically, it has been shown to remineralize both enamel and dentin, prevent caries [ 2 , 5 , 7 , 8 , 9 , 10 , 11 , 12 ], reduce bacterial colonization on teeth and dental surfaces [ 1 , 13 ], improve periodontal health [ 1 , 4 , 13 , 14 , 15 ], and improve symptoms associated with dentin hypersensitivity [ 3 , 16 , 17 ]. An important advantage of hydroxyapatite compared to other active ingredients in preventive oral health care is its high biocompatibility as it has no side effects when used in daily oral care [ 6 , 18 , 19 , 20 , 21 ].…”

“…Hydroxyapatite, the active ingredient, can be used, for example, in toothpastes [ 2 , 3 , 4 , 8 ] and mouthwashes [ 1 , 24 ]. Additionally, hydroxyapatite is commercially available at higher concentrations in gels to enhance the effects of daily tooth brushing [ 9 , 11 , 29 , 33 ]. Recent in vitro studies show that a newly developed hydroxyapatite gel has significant whitening [ 29 ] and enamel remineralizing effects [ 9 ] as well as erosion protective properties [ 33 ].…”

“…Additionally, hydroxyapatite is commercially available at higher concentrations in gels to enhance the effects of daily tooth brushing [ 9 , 11 , 29 , 33 ]. Recent in vitro studies show that a newly developed hydroxyapatite gel has significant whitening [ 29 ] and enamel remineralizing effects [ 9 ] as well as erosion protective properties [ 33 ]. Amaechi et al, for example, showed that this hydroxyapatite-gel is as effective as a highly concentrated fluoride gel with 12,500 ppm fluoride regarding remineralization of early caries lesions [ 9 ].…”

“…Recent in vitro studies show that a newly developed hydroxyapatite gel has significant whitening [ 29 ] and enamel remineralizing effects [ 9 ] as well as erosion protective properties [ 33 ]. Amaechi et al, for example, showed that this hydroxyapatite-gel is as effective as a highly concentrated fluoride gel with 12,500 ppm fluoride regarding remineralization of early caries lesions [ 9 ]. The hydroxyapatite gel can be used daily, whereas the application of highly concentrated fluoride gels is limited to once a week [ 9 ].…”

“…Amaechi et al, for example, showed that this hydroxyapatite-gel is as effective as a highly concentrated fluoride gel with 12,500 ppm fluoride regarding remineralization of early caries lesions [ 9 ]. The hydroxyapatite gel can be used daily, whereas the application of highly concentrated fluoride gels is limited to once a week [ 9 ].…”