A periodontist is a dentist who specializes in the prevention, diagnosis, and treatment of periodontal disease, and in the placement of dental implants.Periodontists are also experts in the treatment of oral inflammation.hey can also treat patients with severe gum problems using a range of surgical procedures. In addition, periodontists are specially trained in the placement, maintenance, and repair of dental implants. During the first visit, the periodontist usually reviews the patient’s complete medical and dental histories.