My son, now 11 had several cavities when he was younger. If you have a good pediatric dentist, there should be no reason to use nitrous, but it does depend on the child's tolerance for sitting still too. A good pediatric dentist will make it a positive experience, play movies/music and give NO trauma to the experience. My son LOVES to go to the dentist, despite having several cavities filled, teeth removed and now, orthodontics. He has developed really terrific dental habits including flossing, mouthwash and brushing as a result of a great dentist and the consequences of cavities. He takes pride in his teeth now. I recommend getting the mouth rinse that turns the teeth blue or green to show where they arent reaching with the toothbrush. It makes it a game and they like brushing/flossing better. Also recommend buying "Flossies" or a generic brand of flosser. It may not be the most environmental means, because you throw them away with each use, but it teaches them how to floss and makes it a little easier. They can graduate to normal floss later. And, I recommend "Tooth Tunes" or some character electric toothbrush. If you arent TOTALLY confident in your pediatric dentist, then change it. Dont know where you live, but Dr. Andrea Mattia in Old Tappan, NJ is the BEST! Hope this was helpful!