Q. Why there is pain at the apex during instrumentaion at second visit of removing pulp/pation was not complaining of pain at first visit/there is widening of peri ligament?do think that there is a need to priscribe antibiotic in case of having pain interappointment another thing!i heared that some doctors put cresole or eugenol on a paper point and insert on canal some will leave it for next vist and some will just leave it fot few second what is your opinion? if i put calcium hydroxide inside the canal (in case that patient is having pain while instrumentaion)does this reduce pain and infection without the need to give anti boitic and how long we leave it one week or two if two does this cuase calcification thank you for answering god bless you