I had a cleaning recently that went really well. No current fillings, but I had a root canal which was removed about 2 years ago. From the time that my root canal was completed, I had terrible headaches. This went on the entire time that the tooth was in my mouth… about 2-3 years. It had an abscess and started to lift and was painful. I changed dentists and they wanted to save the tooth, but I refused due to the pain. Two weeks after the removal, my headaches started going away. Based on the chart, it was #18.