If you are asking the question, odds are you are doing both, and that is what matters most.
The argument for flossing first is this: You are removing a large majority of plaque and food debris from in between the teeth and then brushing it away. This removal also always for the fluoride in your toothpaste to come into contact with your tooth surfaces more easily, giving you more of a benefit from your toothpaste and its cavity fighting power.
Others prefer to floss after brushing, doing their best to get a majority of plaque and food debris out before flossing. This method is also makes sense; one recommendation would be to either rinse with water or a mouthwash after flossing to rid your mouth of any bacteria that may be floating around after flossing.
In the end, it all comes down to this: the sequence of brushing and flossing makes no difference as long as you do a thorough job. Brushing and flossing is the best way to remove decay-causing plaque from your teeth and help maintain optimal oral health.
For more information, talk to your local Plymouth, MN dentist at your next dental appointment with Life Smiles.