When in question as to wether a tooth is a baby tooth or a permanent tooth, here are a couple of indicators to help distinguish the two:
First there are small protrusions located on the top of permanent teeth called mamelons. These are very noticable when the permanent teeth first erupt as with the permanent tooth located on the right, and they will wear off in time with use as with the permanent tooth on the left.
Secondly, baby teeth are very white in color. In permanent teeth, they look a bit more amber or yellowish in color. This is a perfectly normal occurance.