My son is 5 years 4M old. As soon as his teeth were out, they started decaying also. Due to tooth ache and decay we had to get 4-5 teeth extracted by the time he was less than 3. For more than a year he has given up feeding bottle, brushes his teeth both in morning and night and rinses his mouth after meal. Yet, decay continues, though at much lesser pace. kindly suggest what should we do.