My dentist gave me amoxicillin before the root canal for infection. then my endodontist prescribed clindamycin after the root canal procedure. which one should i take?

Infection: The different antibiotics can help focus on different antibiotics. I'm not sure what your question is but if you have specific questions you should call your doctor.

Probably beneficial: Both antibiotics are beneficial for dental infections. If the infection was somewhat non-responsive to amoxicillin, switching the antibiotic to Clindamycin may be quite effective.

Clindamycin: Clindamycin is usually more effective but has more side affects, especially within the GI tract. Probiotics are helpful with GI side affects if taken between doses of antibiotics.

Not a big deal: Both antibiotic are similar in action, gen dentist starts you on Amoxicillin to cover you until you see the specialist, who may decide even not to give you anything else if not necessary or he may elect to give you a stronger one, depending on the extent of the infection and the outcome of the treatment. If you want more explanation talk to the endodontist.