The dental practice is many things. Quiet is not one of them.
Despite the inherent difficulty of finding a quiet location within the practice where you can make your video, it is possible. The best things to consider for a quiet video are very simple: time and location. Maybe your office closes one day a week. Grab a camera that day. Or perhaps you have a business office away from your operatories. Go there!
For a few more tips on how you can achieve the best audio for your video, watch this.