Which teams are undefeated in Super Bowl appearances?

Question

After NFL and AFL merge

Answer 1

San Francisco 49ers are 5-0
Baltimore Ravens are 1-0
Chicago Bears are 1-0
New York Jets are 1-0
Tamba Bay Buccaneers are 1-0

Answer 2

After the merger, only San Francisco (5-0), Tampa Bay (1-0), Baltimore (1-0), and Chicago (1-0) are undefeated. The NY Jets' appearance came before the merger.

Answer 3

49ers 5-0, Bears 1-0, Buccaneers 1-0, Ravens 1-0, Raiders 3-0 (did lose to Packers in SB II before merge), Colts 1-0 (lost to Jets in SB III before merge)