Depending where you live there are dental clinics, either through city hospitals or county health clinics.
They are usually staffed by first year dental students. They cannot refuse treatment for financial reasons. You can pay based on a sliding scale based on income. Or apply for charitycare.
CapitalOne or CareCredit offers no interest(for one year) credit cards for specifically medical/dental.
Last go to a dental school, they often offer reduced fees.
Good luck
If you are running a fever- GO IMMEDIATELY!