# Comparative Effects of At-Home and In-Office Bleaching on Discoloration Due to Treatment of White Spot Lesions With Silver Diamine Fluoride

## TL;DR

This study compares at-home and in-office bleaching to reduce dark staining caused by silver diamine fluoride on teeth with early enamel decay.

## Contribution

The study provides new evidence on the effectiveness of bleaching methods for SDF-induced discoloration in different lesion depths.

## Key findings

- In-office bleaching improved color change more than at-home bleaching in superficial lesions.
- Lesion depth did not significantly affect early-stage discoloration.
- Both bleaching methods partially restored tooth color but did not fully return it to normal.

## Abstract

Incipient enamel caries, known as white spot lesions (WSLs), can be prevented or halted with proper oral hygiene, diet control, and application of remineralizing agents such as silver diamine fluoride (SDF); however, dark staining is a major drawback of SDF. This study aimed to compare the effects of at-home and in-office bleaching on SDF-induced staining of WSLs.

In this in vitro study, 44 bovine central incisors were randomly assigned to 2 groups (n = 22) for artificial induction of superficial and deep WSLs. Next, both groups underwent remineralization by using 38% SDF for 1 min, rinsed, and stored in artificial saliva. After 1 week, each group was randomly divided into two subgroups (n = 11) to undergo at-home bleaching and in-office bleaching. The L⁣∗, a⁣∗, and b⁣∗ color parameters of all specimens were measured at 4 time points of baseline (sound enamel), after demineralization, after SDF remineralization, and after bleaching, and the color change (ΔE00) was calculated. Data were analyzed by one-way and two-way ANOVA and Sidak-adjusted post hoc test (α = 0.05).

Lesion depth did not significantly affect early-stage discoloration (p  > 0.05). However, a significant interaction was found between lesion depth and bleaching type at later stages (p  < 0.001). In-office bleaching significantly improved ΔE00 compared to at-home bleaching but only in superficial lesions (p  < 0.001).

Both at-home and in-office bleaching can lighten dark lesions caused by SDF after remineralization, although they may not fully restore tooth color to normal. In-office bleaching led to significantly greater color improvement than at-home bleaching in superficial lesions.