My son's tooth cavity

 Hey! My son is a candy lover. His father gives him chocolate and candies every day. When I warn him about this, he started giving that when I am not around.. I am afraid of this because it will make my son's teeth worse. He brushes twice a day, but I know that it doesn't make any tremendous change while we have a tooth decay. His tooth color slightly started changing to brown. I discussed my son's case with the children's dentist in Ajax. I came to know about the dental sealants which protect our teeth from decay. Also, I understood that sealants act as a protective layer. Let me know about the procedures? How long will sealants last? My son has a fear to consult a dentist because he is very much afraid of the pain during dental procedures. Will it be painful? I will be thankful if anyone is able to clear all my doubts which I have mentioned above!