Patchy outcomes typically come from irregular gel application; use well-fitted trays and avoid overfilling to avoid streaks
https://archeristf570.wpsuo.com/why-professional-whitening-is-safer-for-your-enamel-2
Irregular results often originate from uneven gel application; usage well-fitted trays and prevent overfilling to avoid streaks, gum inflammation, and squandered item.