Smell or bad odour from your cap may have various reasons , like food lodgement between the gums and your cap, infection in your gums , infected tooth There are various reasons of food lodgement To know the exact reason , we need to assess you clinically and we will need some X-rays , for which you will need to visit a dentist .

Hi! I understand the trouble you are currently facing. Please share a picture of the same tooth.

Hello May be it is infected,or thr s space Visit to clinic to check it

Smell due to infection and improper cap fitted over there .

Hi Stinky smell is most likely coz of food lodgement in and around ur cap.

Hi kindly visit a dentist and check if the broken tooth is root canal treated and then capped. The smell may be a sign of infection, poor oral hygiene maybe even food lodgement at that region.