The Dentist 2.

Dr. Feinstone escapes from the mental hospital where he has been held ever since his wife's adultery sent him on a deranged killing spree. Hoping to resume a normal life, he makes his way to a quiet Midwestern town and establishes himself in a new practice under an assumed name. Things are starting to look up for Dr. 'Caine' – that is, until the day he catches his new love in the arms of someone else. As before, the impact of romantic betrayal sends him over the edge into madness and murder, with his unfortunate patients once again bearing the brunt of his hostility.