No dentist likes to think someone might be embezzling practice funds, but even conservative studies indicate that it actually happens in about one out of every six practices.
Make sure your practice has sound accounting systems. This will help prevent embezzlement, and you should have these systems anyway because they're essential to the financial health of the practice. With the right systems in place and periodic analysis of your numbers by experts (another component of good financial management of your practice), there's a good chance that any wrongdoing will be detected. And the mere presence of these preventive measures could keep someone from being tempted in the first place.
Don't be paranoid ... or naive. Embezzlement happens. It would be counterproductive to regard your team members suspiciously, but it would be equally unwise to assume that "it can't happen here." Implement the safeguards and let the accounting experts be vigilant on your behalf.
