Dr. Donald L. Theriault, a Board Certified Periodontist, is a native of Waterville Maine. He graduated from the University of Maine in Orono and Tufts University School of Dental Medicine. Following dental school, he joined the Air Force as a dentist. While in the service, he did a general practice residency in Nebraska and practiced in the Azore Islands, Japan and Florida. Dr. Theriault completed a two year residency in periodontology and implantology at the University of Pennsylvania and became Board Certified in 1994.

Dr Theriault is president of the Maine Society of Periodontology and a past president of the Greater Portland Dental Society. He is a member of the American Academy of Periodontology, American Dental Association and the Christian Medical and Dental Association.

Dr. Theriault has completed numerous dental mission trips to Honduras and Guatemala. He volunteers his time treating patients at The Root Cellar, an inner city mission in Portland and participates in the Maine Donated Dental Services program.

Dr Theriault and his wife, Doreen, live in Cape Elizabeth. He is active in his church and is still quite involved in the lives of his 3 grown children. He loves boating, electronics, cars, photography, hiking, hunting and fishing and has enjoyed some success as a "senior" track and field sprinter.