Many times I've heard people speak of practices in the dental office as an "OSHA violation". I've heard this phrase from dentists, sales people, even consultants. Frequently, the practice in question doesn't actually fall under OSHA, however. In order to be compliant, you need to know to what regulation you're trying to comply and from whom the regulation originates.
The CDC, FDA and OSHA are all agencies that concern dental offices. But sometimes it can get confusing over who governs what (and there is a small amount of overlap too). For the most part, you can simply keep track with the common axiom of "follow the money".
If you're concerned about an item you've purchased (i.e. something you've given money to someone else to procure) it's probably governed by the FDA. The FDA is responsible for the safety and efficacy of drugs and medical devices (within the context of a dental office).
If you're concerned about the welfare of someone you're giving money to for work (i.e. an employee) then you need to worry about OSHA. OSHA exists to help keep workers safe.
If the area of concern is over someone that gives you money to perform services (i.e. a patient) you need to be concerned with the guidelines of the CDC. The CDC is concerned with stopping the spread of disease and protecting the general public.
The various government agencies are there to protect you as well as your employees and the general public. It's important to get accurate information from the correct source so you can protect yourself and remain compliant.