My son has got 4 teeth now. When do you need to start brushing their teeth?

What I do to encourage my 2 years old son to start to brush his teeth since he turned 1: 1. Give him a real toothbrush and non fluoride toothpaste 2. Sing a brush teeth song during brushing teeth 3. I will brush together with him every morning and night 4. I get a step stool for him so he can access the tap water himself 5. Prepare a cup for him to rinse mouth, sometimes he will swollow the tap water but it's part of learning process 6. Do it daily! If you are not consistent kid will hard to pick up the habit and make it a routine