I had an abscess on my upper right middle tooth and the dentist started a root canal on it, since than my face has swelled up somewhat,nothing noticeable, but I notice it. Before I had this root canal I was on two different antibotics that didn't work, now they gave me antibotics again and they are not working. I am supposed to go back on Tuesday to finish this root canal, what now? Will they have to pull it? Should I be really worried because this infection or abscess won't clear up?