What age did you start brushing your lo's teeth? What brand of toothbrush and toothpaste did you use?

With my eldest, we started brushing his teeth when he turned 1. We used Sansfluo. He had 6 teeth already that time. Sad to say, he's just 3 years old now and his front teeth are destroyed. He loves to eat too much sweets and even if we brush his teeth, it didn't help. :(