Biomimetic Hydroxyapatite Remineralizes Teeth With Molar Incisor Hypomineralization (MIH)

Objectives: Molar incisor hypomineralization (MIH) has a global prevalence of approximately 14.2%. MIH-affected enamel has a lower mineral content compared to healthy enamel. Therefore, effective remineralization strategies, particularly patient-applied home care procedures are needed. Different remineralization agents can be used such as calcium phosphates and fluoride. Toothpastes with biomimetic hydroxyapatite have shown promising results on remineralization of enamel and dentin, and on the reduction of MIH-related tooth sensitivity. Therefore, the aim of the present in situ study was to investigate the MIH-remineralization efficacy of a toothpaste based on hydroxyapatite. As a comparator, toothpaste with 1450 ppm fluoride was used.
Methods: Intra-oral appliances with MIH-affected enamel blocks were worn by 15 subjects (2 samples/subject; n=30/toothpaste group) while using the toothpastes. The toothpastes were used in a two-phase crossover design with each phase lasting 14 days. Each group had 20 etched (lesion surface treated with 32% phosphoric acid-etchant for 5 seconds) and 10 unetched enamel blocks. The mineral density of the lesions at baseline and after the study phase was measured with microcomputed tomography.
Results: Both the hydroxyapatite and the fluoride group showed significant (paired t-test; p<.001) net mineral gain relative to baseline. Independent t-test demonstrated a practically significantly (≥10%) higher percentage remineralization with hydroxyapatite toothpaste (26.02±20.68) compared with fluoride toothpaste (14.64±9.60). Higher percentage remineralization was observed in etched than unetched samples.
Conclusions: In conclusion, MIH-affected teeth can be effectively remineralized with the tested hydroxyapatite toothpaste. Pre-treating the tooth surface with acid-etchant enhanced remineralization.