If you're honestly in a desperate situation to finish your classes ASAP for some uncontrollable reason, maybe a W would be better than a D.
If a W is not possible, I would try to focus on the science GPA IF AND ONLY IF they are at risk being lower than a C.
If the class is a prereq class for dental school, you're going to have to retake it anyway.
Also.... some schools don't see a D as passing so... you might want to reconsider retaking the class is you don't withdraw from it.