Comparing tooth loss for populations comprising subjects with periodontal disease has been limited by broad and different definitions of disease severity. Numeric scores for periodontal disease severity and risk were used to enhance the precision of comparing tooth loss for two populations. Both populations received routine dental care, but only one received comprehensive periodontal treatment. The analysis provides evidence that adding periodontal treatment to routine dental care is associated with less tooth loss and more patients who do not lose any teeth. Furthermore, it may be possible to nearly eliminate tooth loss associated with periodontal disease.