The Effect of Silver Diamine Fluoride Combined with Potassium Iodide and Sodium Fluoride on the Remineralisation of Hydroxyapatite

Purpose: To compare remineralisation efficacy between silver diamine fluoride (SDF) combined with potassium iodide (KI) and sodium fluoride (NaF) varnish using hydroxyapatite (HAP) artificial white spot lesions (AWSLs) demineralisation model.
Materials and Methods: A total of 25 HAP disks was randomly divided into five groups (n = 5): baseline, AWSLs, deionized water (DW), SDF-KI or F-varnish. After AWSLs were developed, the specimen was treated with either deionized water, SDF-KI or F-varnish. These specimens were then subjected to pH-cycling for 7 days. The remineralisation potential was assessed by measuring changes in Vickers hardness (VHN). Morphological and compositional analyses were conducted using scanning electron microscopy (SEM), energy dispersive x-ray (EDX), x-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). Ion-selective electrodes (ISE) were utilised to measure calcium and fluoride release.
Results: SDF-KI treatment demonstrated statistically significant remineralisation potential in restoring VHN values vs baseline levels (p 0.001). SEM, EDX, and XRD analyses confirmed the mineral deposits to indicate remineralisation. The uptake of calcium was higher in SDF-KI than in F-varnish (p = 0.011). The fluorapatite (FAP) and fluoride-substituted apatite formation were validated by FTIR and XRD analyses.
Conclusion: SDF-KI and F-varnish applications are both effective in promoting remineralisation on HAP disks. The application of SDF-KI affected the physicochemical and mechanical properties of demineralised HAP. The SDF-KI showed more formation of fluoride-substituted apatite and is effective in the hardening of demineralised HAP. Keywords: demineralisation, potassium iodide, remineralisation, silver diamine fluoride, sodium fluoride