Dr. O'Brien is a 1980 graduate of Marlborough High School and a 1984 graduate of Saint Anselm College in Manchester, NH. He then attended Tufts University School of Dental Medicine and received his DMD degree in 1989. He joined the practice of the late Dr. James Naumes immediately after graduation and has been treating the residents of Marlborough and the surrounding communities for the last 33 years.