This case involves a failure to diagnose periodontal disease over an extended period of time. The defendant is a retired dentist who had previously provided dental care to the plaintiff for over 2 decades in New Hampshire. The patient stopped treatment with the defendant when defendant retired, and was then seen by a new dentist that the defendant recommended. The new dentist was surprised by the poor condition of the patient’s teeth and indicated evidence of periodontal decay dating back nearly 15 years. As a result, the plaintiff had to have a number of invasive treatments, including a root canal and the removal of several teeth.