sounds a little cheesy and long
You don't need to say "dentist shadowing"... just shadowing is fine, your not gonna shadow the assistant are you? Its already implied that its the dentist your wanting to shadow.
Remove "active practice environment" because... if the office is in business, they are active believe me.
and what does "to gain exposure to experience" mean?..... why not just say "to gain knowledge about the typical working day of a dentist".... or something along those lines. Keep it short and simple.