Perhaps a regular cleaning by a dental hygienist would help. I wonder if there are foods that are good for teeth. I give my dog biscuits that are supposed to help clean his teeth. By the time my mother died at 88, her teeth were literally falling out right in front of me, and she had had excellent dental care throughout her life. Truth is, we're all going to fall apart somehow someday. Do what you can and let the rest go. IMHO