How do you know if your root canal is infected? It's simple and probably frustrating for most. You can't know for sure until you get a cone beam ct scan. A lot of times random symptoms will pop up. Some that seem unrelated to your mouth like join pain, allergies, sinus infection, infection and inflammation in other areas in your body, jaw pain, etc. If you do have an infected root canal I recommend removing it and getting a ceramic implant. Here are some studies that show the danger of root cana