Can a filling cause a root canal? told i had cavity no pain before during filling i said something felt wrong told to wait came back with pain xray looked fine at 6 month cleaning tooth still hurting new xray still fine nerve test said need root cana?

The filling in cavity was probably deep and close to the nerve .As time went on the nerve became infected from the deep cavity and pain resulted. The nerve is dying and a root canal is necessary in order to save the tooth, make sure you have a crown placed after root canal is finished.

The deep decay in the tooth resulted in the need for root canal therapy, not the filling. No pain does not mean no problem... think high blood pressure, diabetes, and even cancer. If the tooth tests non-vital, you need root canal therapy or extraction.

That's why you go for 6 month check-ups. Small cavities easy to fix with little risk. Large old untreated cavities pose risk to tooth vitality even if there is no pain. A filling is a surgical procedure, further stressing the tooth. The larger the filling, the greater the risk. Stop looking for someone to blame (other than yourself) and go see an Endodontist. your computer can't fix your tooth.