Effect of two biomimetic remineralizing systems on artificially demineralized enamel: Assessment of mineral recovery and orthodontic bracket bond strength.

OBJECTIVES: To evaluate the effect of two remineralizing systems (Regenerate™ and Orthocare™) on the mineral recovery of demineralized enamel and on the shear bond strength (SBS) of brackets.

METHODS: 180 bovine teeth were divided into four groups: 1)Intact enamel, 2)Demineralized enamel, 3)Demineralized enamel/Regenerate™, and 4)Demineralized enamel treated/Orthocare™. Groups 2 to 4 were demineralized. All samples were brushed three times daily; groups 1 and 2 without toothpaste, and groups 3 and 4 were treated with Regenerate™ or Orthocare™. Outcomes were assessed by SBS, adhesive remnant area, field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), Raman spectroscopy, surface microhardness, and micro-computed tomography (micro-CT). Parametric or non-parametric tests according to data distribution (α = 0.05).

RESULTS: Demineralized enamel showed significantly lower SBS, adhesive remnant, surface microhardness, mineral density, calcium and phosphorus content, and phosphate-related Raman parameters than intact enamel (p < 0.05). FE-SEM revealed increased porosity. Neither remineralizing system significantly restored SBS compared with untreated demineralized enamel. However, both treatments promoted partial enamel remineralization, improved calcium (Ca) and phosphorus (P) levels (p < 0.001), increasing surface microhardness and mineral density (p < 0.05). Raman showed greater recovery of phosphate (I960) and carbonate (I1070) peaks in the Regenerate™ group, indicating better mineralization and crystallinity recovery than Orthocare™.

CONCLUSIONS: Both agents partially remineralized enamel without fully restoring sound enamel properties. Regenerate™ demonstrated better mineral recovery than Orthocare™. However, the newly formed hydroxyapatite appeared immature, and bond strength was not significantly improved compared with demineralized enamel.

CLINICAL RELEVANCE: Remineralizing agents may improve demineralized enamel before orthodontic bonding without significantly affecting bracket bond strength.