Remineralising Artificial Dentine Caries With Fluoride Solution With Silver Nano-particles

Objectives: To investigate the effect of a novel fluoride solution with silver nano-particles (FAgNP) in remineralising artificial dentine caries.
Methods: Human dentine blocks were demineralised to simulate dentine caries and allocated into three groups. The blocks in the first group (Gp1) received a topical application of a FAgNP solution containing 11300 ppm fluoride and 600 ppm silver. The blocks in the second group (Gp2) received a topical application of a 38% silver diamine fluoride solution (positive control). The blocks in the third group (Gp3) received deionized water (negative control). The treated blocks were subjected to pH cycling for cariogenic challenge. The surface morphology and cross-sectional features were investigated by scanning electron microscopy (SEM). Crystal characteristics, lesion depth, collagen degradation and colour change (Delta E) of the dentine blocks were assessed by X-ray diffraction (XRD), micro-computed tomography (Micro-CT), spectrophotometry with a hydroxyproline assay and VITA spectrophotometer, respectively.
Results: SEM showed that dentine collagen was exposed in Gp3, but not in Gp1 and Gp2. The XRD analysis revealed that silver chloride and metallic silver were formed in Gp2. Lesion depths of Gp1, Gp2 and Gp3 were 121±14 µm, 114±7 µm and 339±20 µm, respectively (p<0.05; Gp3>Gp1, Gp2). The concentration of hydroxyproline liberated from collagen of Gp1, Gp2 and Gp3 were 130±25 µg/ml, 122±28 µg/ml, and 335±21µg/ml, respectively (p<0.05; Gp3>Gp1, Gp2). The difference in colour change between Gp2 and Gp3 (Delta E=0.2) was not clinically significant.
Conclusions: This laboratory study demonstrated FAgNP solution remineralised dentine and inhibited collagen degradation in artificial dentine carious lesion. Moreover, the solution did not evidently stain dentine carious lesion.