Wearing a crown under the fistula may be a tooth with chronic periapical inflammation caused by the need to establish the pulp cavity channel, root canal treatment, and apical surgery, as follows.
1. Establishment of pulpal access: the crown can be removed before entering the pulpal cavity, or without removing the crown directly into the pulpal cavity.
2. Root canal treatment: Remove the inflamed pulp tissue, establish apical access, drain the inflammatory exudate from the apical part of the root canal, perform root canal rinsing and disinfection, and use root filling materials to fill the root canal tightly.
3. apical surgery: apical surgery, from the mouth of the fistula to the root of the apical part of the scraping fistula, remove the granulation tissue in the fistula, and cauterize the mouth of the fistula.
It is recommended to go to a regular medical institution to receive professional treatment.