You can probably do better stuff. Like honestly go see if you can watch in a dental lab what they do. That would be nice, and you might even be able to practice some stuff you will actually be doing 1st year in dental school - waxing, making impressions, etc.
If you want to shadow a specialist, go shadow an OMFS for like 20 hours or so, and then call it quits. Doubt orthos, endos would let you shadow.