I was on 10 day regimen of penicillin for a tooth abscess. the dentist filled my tooth then pain seriously worsened. now im taking clindamycin and starting fourth day..still in severe pain.?

Root canal?: Did you get a filling or root canal? Sounds like you need a root canal perhaps. If a root canal was done sometimes after a root canal if the tooth was badly infected it takes few days for pain to go away. If you get swelling must see dentist right away. Sorry you are hurting...

Abcess: If you had an abcessed tooth, then a filling is not the right treatment. The abcessed tooth would require a root canal treatment. If you had a root canal treatment , then possibly the new antibiotic needs to work. Sometimes adding a steroid can help. You may consult with an emdodontist, or root canal specialist, for a second opinion. Also make sure another tooth nearby isn't the culprit.

Not a cure: Antibiotics can be bacteriocidal or bacteriostatic: that is kill the bugs or knock them down. It sounds to me as you had a tooth infection which was draining through the tooth itself. By permanently filling the tooth, an avenue for pus and inflammatory products cannot escape and pain will dramatically increase. Diagnosis and treatment plan all important. Root canal, antibiotics and temp filling.

Reevaluation: What you describe is an unusual situation. Your tooth situation needs to be reevaluated by your dentist or another dentist. Take this step today to prevent potential complications.