Since you are at work clove oil will numb the pain.

For future reference and others that are interested:
Garlic - you put a piece of it right on the tooth. It is a natural antibiotic and will cure the abscess. I've done it without the dentist. It burns but you leave it on as long as you can stand and then repeat.

I don't have health/dental insurance and have been using home remedies for years. It's safer too - no side effects.