Here's the breakdown:
When to use a comma:
* If D.D.S. follows a name: You'd use a comma if D.D.S. is part of a person's full name, like this: "Dr. John Smith, D.D.S."
* If D.D.S. is part of a title following a name: You'd use a comma if the title appears after the name, like this: "John Smith, D.D.S., spoke at the conference."
When to omit a comma:
* If D.D.S. is a standalone abbreviation: You wouldn't use a comma if D.D.S. is used independently, like this: "The patient is being treated by a D.D.S."
Example:
* Correct: "Dr. Emily Carter, D.D.S., will be performing the surgery."
* Correct: "The new dentist, a D.D.S., is very skilled."
* Incorrect: "The new dentist, D.D.S., is very skilled."
Ultimately, whether you need a comma depends on how you're using the abbreviation D.D.S. in your sentence.