Remineralization of molar incisor hypomineralization (MIH) with a hydroxyapatite toothpaste: an in-situ study

Abstract

Aim This randomized, double-blind, crossover, in-situ study, compared the efficacy of toothpastes based on microcrystalline hydroxyapatite (HAP; fluoride-free) or fluoride, in remineralizing molar incisor hypomineralization (MIH). Methods Two lesion-bearing enamel blocks were produced from each of thirty extracted permanent molars diagnosed with MIH. Sixty produced blocks were randomly assigned to two groups (30/group): 20% HAP or 1450 ppm fluoride toothpaste. Each group was subdivided into, etched (n = 20), with lesion surface treated with 32% phosphoric acid-etchant for 5 s, and unetched (n = 10). Blocks were cemented into intra-oral appliances (2 blocks/appliance) worn full-time by 15 subjects. Subjects used the toothpastes in a two-phase crossover manner, lasting 14 days per phase, after one-week washout period. Baseline and post-treatment mineral density (MD) was quantified using microcomputed tomography. Results Overall, both groups showed statistically significant (paired t-test; p < 0.001) net-gain when MD was compared pre-treatment and post-treatment. HAP: pre-treatment (1.716 ± 0.315) and post-treatment (1.901 ± 0.354), Fluoride: pre-treatment (1.962 ± 0.363) and post-treatment (2.072 ± 0.353). Independent t-test demonstrated a practically significantly (≥10%) higher percentage remineralization with HAP toothpaste (26.02 ± 20.68) compared with fluoride toothpaste (14.64 ± 9.60). Higher percentage remineralization was observed in etched than unetched samples. Conclusion The tested toothpaste based on hydroxyapatite can remineralize MIH lesions. Pre-treating the tooth surface with acid-etchant enhanced remineralization.

Remineralization Strategies for Teeth with Molar Incisor Hypomineralization (MIH): A Literature Review

“…In the field of toothpaste, a direct comparison of the MIH-remineralization efficacy and sensitivity relief between fluoride-free hydroxyapatite toothpastes and fluoride toothpastes has been published (see summaries of results in Table 3 and Table 4 ) [ 18 , 25 ]. Amaechi et al [ 22 ] have shown in an in situ study that a hydroxyapatite toothpaste showed a practically significantly higher percentage of remineralization compared with toothpaste with 1450 ppm fluoride [ 25 ]. The mineral density measurements in this study were performed with microcomputed tomography [ 25 ] ( Table 3 ).…”

“…Amaechi et al [ 22 ] have shown in an in situ study that a hydroxyapatite toothpaste showed a practically significantly higher percentage of remineralization compared with toothpaste with 1450 ppm fluoride [ 25 ]. The mineral density measurements in this study were performed with microcomputed tomography [ 25 ] ( Table 3 ). Ehlers et al have shown in a randomized controlled trial with MIH patients that the group that used hydroxyapatite toothpaste tended to be less sensitive compared with the group using toothpaste with 1400 ppm fluoride [ 18 ] ( Table 4 ).…”

“…Calcium phosphates like casein phosphopeptide amorphous calcium phosphate (CPP-ACP; ACP: Ca x (PO 4 ) Y · n H 2 O) and hydroxyapatite (HAP; Ca 5 (PO 4 ) 3 (OH)) have gained increased attention in recent years as biomimetic/bionic ingredients, that can be used for the remineralization of enamel and dentin and for caries prevention [ 24 , 25 , 26 , 27 , 28 , 29 , 30 ] as well as for biofilm control [ 31 , 32 ], periodontal health [ 33 ] and whitening [ 34 ]. Hydroxyapatite particles have been shown to form mineral-mineral bridges with the natural enamel surface [ 35 ].…”

“…Since MIH teeth have a reduced hydroxyapatite content and density compared to healthy teeth [ 10 ], the use of remineralizing oral care formulations with calcium phosphates is reasonable [ 25 , 28 ]. Additionally, calcium phosphates (e.g., hydroxyapatite) have been shown to be beneficial for pain relief of MIH-associated tooth sensitivity [ 18 , 20 , 36 ].…”

Overview on Adjunct Ingredients Used in Hydroxyapatite-Based Oral Care Products

“…The biomimetic active ingredient hydroxyapatite is used in various fields of oral care [ 7 , 14 , 15 , 16 , 18 , 103 ]. It remineralizes early caries lesions [ 104 , 105 , 106 , 107 ], reduces the initial bacterial attachment to enamel similar to 0.2% chlorhexidine [ 19 ], and acts as buffer and a calcium and phosphate reservoir in biofilms [ 108 ].…”