Efficacy of the dual-action GA-KR12 peptide for remineralising initial enamel caries: an in vitro study.

Abstract

To investigate the antibiofilm and remineralising effects of the dual-action peptide GA-KR12 on artificial enamel caries. Enamel blocks with artificial caries were treated with sterilised deionised water as control or GA-KR12. The blocks underwent biochemical cycling with Streptococcus mutans for 3weeks. The architecture, viability, and growth kinetics of the biofilm 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, surface morphology, and crystal characteristics of the enamel surface were determined, respectively, using micro-computed tomography, energy dispersive spectroscopy, SEM, and X-ray diffraction (XRD). 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 and GA-KR12-treated groups were 0.42 ± 0.05 and 0.81 ± 0.08, respectively (p < 0.001). The log CFUs of the control and GA-KR12-treated groups were 8.15 ± 0.32 and 6.70 ± 0.49, respectively (p < 0.001). The mineral losses of the control and GA-KR12-treated groups were 1.39 ± 0.09gcm-3 and 1.19 ± 0.05gcm-3, respectively (p < 0.001). The calcium-to-phosphorus molar ratios of the control and GA-KR12-treated groups were 1.47 ± 0.03 and 1.57 ± 0.02, respectively (p < 0.001). A uniformly remineralised prismatic pattern on enamel blocks was observed in the GA-KR12-treated but not in the control group. The hydroxyapatite in the GA-KR12-treated group was better crystallised than that in the control group. The dual-action peptide GA-KR12 inhibited the growth of S. mutans biofilm and promoted the remineralisation of enamel caries. GA-KR12 potentially is applicable for managing enamel caries.