I had a severe toothache that was not going away. Dr. Harris took an X-ray and determined that a very old previous root canal (by a different doctor) had become infected. He went inside the tooth and cleaned out the old root canal and sanitized the inside of the tooth. I have had horrible pain at an endodontist before so I was very concerned but with Dr. Harris it was painless! What a relief. Recommend him wholeheartedly.