I posted before that my son was diagnosed just after he turned one year old.  At that point, our Onc said no to toothbrushes and to use mouth toothettes instead with the Cholorhexidine rinse because brushing would put him at too much risk for infection while on treatment.  We also went in monthly to our dentist for him to paint on a flouride treamtent with a q-tip to protect his teeth.  After doing this for 3.5 years, he had his first real exam and has no cavitities or concerns.  So far, so good.  He does have a little discolouration, but I'm finding its fading and the dentist said it may fade even more when he gets his first cleaning.  Also, these are all his baby teeth still.

We have had no troubles with his teeth (so far.  dx 9/11/07 ALL) except the dentist noted that Eli is getting plaque buildup which apprently is unusual for children. Eli's dentist prescribed a high flouride mouthwash for Eli to use.  Of course, he doesn't.  I guess it's hard to tell what would have happened without the chemo.  I have one son that has more cavities than Eli and brushes better.

Good luck