S.T.
Hi J.,
I work as a certified/registered dental assistant. We usually see children at age 2-3 for there first visit. A few months ago I bought my daughter into the office where I work to have her teeth looked at. She has 10 teeth right now. We don't do much for them at this age. A full dental exam and count the teeth and let them get the feeling of being in the dental chair. We also polish the teeth. My daughter was wonderful except she didn't take well to the noise when we were polishing.
Make sure you brush his teeth morning and at night. Make sure that you do it. I don't know if your son is going through this "I do it" right now or not, but my daughter is. I let her do it and then mommy does it. No fluoride toothpaste right now unless he is really able to spit out.
Hope this helps and if you are concerned about what your dentist thinks talk to him/her about it. Do you have a dentist? Do you plan on taking him to your dentist or a pedodontist?