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

## TL;DR

This study compares how well silver diamine fluoride with potassium iodide and sodium fluoride varnish can help remineralize artificial tooth lesions in a lab setting.

## Contribution

The study introduces a novel combination of silver diamine fluoride with potassium iodide for remineralization and compares it to sodium fluoride varnish.

## Key findings

- SDF-KI significantly improved Vickers hardness compared to baseline levels.
- SDF-KI showed higher calcium uptake than F-varnish.
- SDF-KI promoted more fluoride-substituted apatite formation than F-varnish.

## Abstract

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.

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.

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.

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.