Doctor, I have lost faith in root canal treatment for teeth with a sinus tract. What do you recommend?

A sinus tract = a 20–25% decrease in the success rate. For this reason, greater care is needed in these cases, and I prefer CaOH2 medication for at least 3 weeks. Better irrigation and activation, a well-sealed temporary filling and, if possible, an apical plug with MTA will be beneficial. If healing does not occur, apical surgery may be considered.