Remineralising Enamel Caries Using Dual-Action Peptide GA-KR12

Abstract

Objectives: To investigate the antibiofilm and remineralising effects of the dual-action peptide GA-KR12 on artificial enamel caries. Methods: Enamel blocks underwent Streptococcus mutants biofilm challenge to create artificial caries. Then the blocks underwent biochemical cycling for three weeks. Enamel blocks were treated with sterilised deionised water as control or GA-KR12 twice daily during the cycling procedure. After the cycling procedure, the biofilm's architecture, viability, and growth kinetics on enamel blocks were determined, respectively, by scanning electron microscopy (SEM), confocal laser scanning microscopy, and quantitative (culture colony-forming units, CFUs). The mineral loss, calcium-to-phosphorus ratio, crystal characteristics and surface morphology of the enamel surface were determined, respectively, using micro-computed tomography, energy dispersive spectroscopy, X-ray diffraction and SEM. Results: SEM showed confluent growth of S. mutans in the control group but not in the GA-KR12-treated group. The dead-to-live ratios of the control group were lower than that of the GA-KR12-treated group (p<0.001), whereas the log CFUs of the control group were higher than that of the GA-KR12-treated group (p<0.001). The control group's lesion depth and mineral loss were higher than that of the GA-KR12-treated group (p<0.001). The calcium-to-phosphorus molar ratios of the control group were lower than that of the GA-KR12-treated group (p<0.001). The hydroxyapatite in the GA-KR12-treated group was better crystallised than that in the control group. The remineralised prismatic pattern on enamel blocks was observed in the GA-KR12-treated. Conclusions: The dual-action peptide GA-KR12 potentially is applicable for managing enamel caries because it inhibited the growth of S. mutans biofilm and promoted the remineralisation of artificial enamel caries.