# Evaluation of Remineralization of White Spot Lesions with Quercetin Nanoparticles: An in vitro Study

## TL;DR

This study tested quercetin nanoparticles on tooth lesions and found they remineralize teeth as well as fluoride.

## Contribution

Quercetin nanoparticles were shown to have remineralization potential comparable to fluoride for white spot lesions.

## Key findings

- Quercetin nanoparticles (QNPs) showed similar remineralization effects to fluoride solutions.
- QNPs were more effective than quercetin microparticles in improving surface microhardness.
- QNPs and fluoride both significantly increased the Ca:P ratio compared to controls.

## Abstract

This study explored the synthesis of quercetin nanoparticles (QNPs) and evaluated the remineralization effect of QNPs on artificial white spot lesions on extracted human teeth.

QNPs were successfully synthesized, and their size was measured. Seventy-six extracted human molars were divided into 4 groups of n=19 to undergo a 10-day pH cycling protocol: 1000 ppm fluoride solution as aqueous NaF (group 1), 6.5% w/v quercetin microparticle solution (group 2), 4000 ppm QNP (group 3) and deionized water (group 4). Vickers microhardness tester, scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) and atomic force microscopy (AFM) were used to measure the surface microhardness (SMH), Ca:P ratio and surface roughness (Ra), respectively.

After remineralization, the SMH values were significantly different among all the experimental groups (p<0.001). The fluoride and QNP groups had significantly greater SMH values than the quercetin group. The AFM data showed a significant decrease, but the differences were not significant. The Ca:P values were significantly greater than those of the control in all 3 experimental groups, but the QNP and fluoride concentrations were significantly greater than those of quercetin. There were no significant differences between QNPs and fluoride according to any test.

It can be concluded from the results of this study that QNPs have similar remineralization potential to fluoride and are more effective than quercetin.

Key words:White Spot Lesion, Remineralization, Quercetin, Nanoparticles, Orthodontic Treatment.