# Impact of light activation on tooth whitening using three different light sources

## TL;DR

This study compares the effectiveness of three light sources in tooth whitening, finding that plasma arc-based light provides the best long-term results.

## Contribution

The study introduces a comparative analysis of three light sources for dental bleaching and highlights the importance of light type on long-term outcomes.

## Key findings

- Plasma arc-based light showed the most significant whitening effect at both 1-month and 6-month follow-ups.
- LED and Blue-phase N lights also improved tooth shade but less effectively than plasma arc-based light.
- No light activation resulted in minimal or no whitening over time.

## Abstract

Tooth discolorations, whether caused by external factors, internal factors, or the individual's own acceptance of the discoloration,
are often intricate in nature. The white colour of adult teeth fades as a result of alterations in the enamel and dentin. Dental
aesthetics heavily relies on tooth shade. Vital teeth whitening is a much sought-after cosmetic dental procedure aimed at enhancing one's
smile. Hence, our objective was to assess the effectiveness of three distinct light sources employed in dental whitening treatments. A
total of 20 patients were chosen who did not have any tooth decay or sensitivity in the dentin for our trial. The VITA shade guide was
used for pre-operative shade choosing. The group has been broken into four groups, namely Group A, Group B, Group C and Group D. The
McInnes solution was used to treat the tooth surface in Group A. No light activation was done. In Group B, after the application of
McInnes solution, it was activated with an LED light. Following the application of McInnes solution, Group C was subsequently activated
using Blue-phase N. In Group D, the McInnes solution was applied and subsequently activated using plasma arc-based light, specifically
red-blue light. All the assessed groups demonstrated some level of whitening effect, but the group that used plasma arc-based light
showed a more pronounced change in shade rank compared to the other groups. The mean difference in shade rank between the pre-operative
and 1-month post-operative stages was 2.20 for Group A, 3.40 for Group B, 5.80 for Group C, and 9.60 for Group D (p=0.026). Similarly,
the mean difference in shade rank between the pre-operative and 6-month post-operative stages was 0.00 for Group A, 2.60 for Group B,
3.60 for Group C, and 9.60 for Group D (p=0.011). The Kruskal-Wallis test revealed significant differences among the groups at both the
1-month and 6-month post-operative stages. It was discovered that the type of illumination used in dental bleaching greatly affects the
outcome, with some lights producing better long-term results than others. The data also show that specific light sources may boost the
efficacy of tooth bleaching operations, warranting a personalised strategy depending on the light's performance over time.