Patchy results often come from unequal gel application; usage well-fitted trays and avoid overfilling to prevent streaks
https://codydjku752.trexgame.net/for-how-long-does-teeth-whitening-last-a-practical-timeline
Irregular results often come from irregular gel application; use well-fitted trays and avoid overfilling to avoid streaks, gum inflammation, and lost product.