Culbreath was arrested for marijuana possession in January, and became expendable after the Steelers cut Scott, also an offensive tackle, last week. Culbreath was taken in the seventh round out of South Carolina State, but never played for Detroit. He spent last season on injured reserve.
The Lions terminated the contract Monday of defensive back Aaron Berry after a Pennsylvania assault arrest, his second bust of the summer.
Running back Mikel Leshoure was arrested for marijuana possession in May. He'll miss the season's first two games.
Also in May, defensive tackle Nick Fairley was arrested in Alabama on drunken driving charges. It was his second arrest in two months.