After playing 4 years at Tennessee State University, Dent was drafted in the eighth round by the Bears, with 203rd overall pick in the 1983 NFL Draft. At 6'5, 265 lbs., Dent was a great pass rusher who beat offensive tackles with his speed. He was part of the core of great players who made the Bears' defenses of the 1980's legendary. Between 1984 and 1985, Dent recorded 34.5 sacks.

In the 1985 season, Dent and the Bears had one of the most spectacular seasons in NFL history, finishing the season with a 15-1 record and shutting out both their opponents in the playoffs. Dent was a major factor in Chicago's success, leading the NFL with 17 sacks, while recovering 2 fumbles and intercepting 2 passes (1 of which was returned for a touchdown). In the 1985 playoffs, Dent was phenomenal, performing in what was quite possibly the most impressive defensive postseason performance in history. In the wild-card game against the New York Giants, Dent had one of the most dominant playoff performances in history. In the game, he recorded 7 tackles, 3.5 sacks, and 2 forced fumbles. In the NFC Championship Game, Dent, along with teamate Wilber Marshall, provided one of the most memorable playoff moments in history. It was late in the 4th quarter and it had just started to snow. Quarterback Dieter Brock dropped back to pass, but Dent got there and sacked him, knocking the ball loose. Marshall picked up the loose ball and returned it for a touchdown, a moment that was said to be a perfect end to the Bears' season (at home) and others say that the snow was "Papa Bear" George Halas giving his thumbs-up to the team. And of course, when The Bears went on to crush the New England Patriots 46-10 in Super Bowl XX, Dent was selected the game's MVP, as he shared 2 sacks, forced 2 fumbles, and blocked a pass.