as u are complaining of pain and not able to eat on that side i suspect there is a fracture of the tooth inside so better take an xray and decide of getting extracted if fractured or retain it doing a cap. for pain u can take amoxicillin and dolonex dt combination drugs for 3 days but not anything more than that

Hello I think you have not done cap as told by the dentist so this has happened

It is mandatory to crown/cap rct treated tooth esp back teeth which are used for chewing. Since your tooth is broken filling might come out. Also food must be getting stuck in there causing secondary infection in root canal and pain. It might cause u pain and swelling in future.

It seems from your description that probably you did not go for cap on the tooth after the root canal treatment was over and that is why a portion of the tooth has chipped off. Unwanted sequel can occur when the recommended treatment protocol is not followed. We do not recommend one sided chewing for any patient because that disturbs the balance of the dentition and can weaken the structures of the unused side. Unfortunately there is no alternative to a visit to the dentist for the correction of the structural damage, otherwise the risk of further damage always stands and can aggravate the symptoms further. Regards.