can I use Acyclovir for a tooth infection?

No you should get a definite diagnoses of what is causing your infection. Most often oral infections is caused by bacteria therefore you need an antibacterial antibiotic (ie penicillin). Acyclovir is anti-viral. The mechanism of action of antiviral is completely different than antibacterial.

Also , depending on the virus and indication, there are different dosage regimens  to treat viral infections so I do not recommend taking the acyclovir. You could me taking too little to elicit any therapeutic effect or too much which can be toxic.

   hey use hyrodgen peroxide it kills infections in the mouth it works............