Use Miswaak. In that also preferrably Zaitoon ki Miswaak. It is the best solution for all teeth problems. Use it like 4-5 times daily. The teeth will start to turn white, breath will become odourless, cavities will be removed. U can eat freely whatever you like and will experience no problems insha Allah. Thats guaranteed, not because I am recommending but because its a Sunnat of Our Beloved Prophet (SAW). Its supposed to be the BEST.
One of the negative effects of using tooth brush is that it makes your gums weak. Also you may feel fresh breath, but the odour causing bacterias are not fully removed. After a few minutes, this odour can be felt again.
Start using Miswaak with toothbrush. When you are comfortable with Miswaak, then just stop using toothbrush and use only Miswaak.
I am using only Miswaak for 4 years now, Alhamdulillah no mouth related problems till now.
The biggest advantage of using Miswaak, apart from these little temporary ones, person is able to recite Kalimah when dying.