Bell, 6-foot-5 and 311 pounds, started 30 games in four seasons in Buffalo. The deal was announced Wednesday.
A seventh-round pick in 2008, Bell replaced Peters after he was traded to Philadelphia. Peters, who went to his fifth Pro Bowl in January, ruptured his right Achilles tendon last week and had surgery on Tuesday. It's uncertain whether he'll return in 2012.
Bell was limited to just six games last year because of a shoulder injury. The 27-year-old Bell didn't play organized football until he went to Northwestern State on a basketball scholarship. He joined the football team as a defensive end after redshirting as a freshman and switched to the offensive line a year later.
Bell's first name previously was spelled Demetrius.