what should I look for.

My two year old fell and hit her mouth two months ago, chipping one of her front teeth.  I took her to the dentist and he xray'd the tooth no nerve damage just a chip.

Well now two months later I noticed the tooth next to the chip one is turning grey.  The gum above it looks normal and healthy.  I called the dentist and told him what I saw and he said that unless it becomes absessed there is nothing to do and we don't want to pull it because it is holding the space for the perminent tooth to come in.

question is what do I look out for, how do I know if it turns into an absessed tooth.  

[Jerome Bogin, D.D.S.]

Look for a bubble or pimple above the tooth. This would indicate that the nerve has died and then treatment would be necessary. The discoloration of the tooth doesn't necessarily mean that the nerve will die.