Here's part of an article on that topic from usatoday:
Quote....
Since then, there have been nine other cases in which interim senators, appointed to fill the vacancies of senators who resigned or died in office, did not seek election to their posts. Three ceded their seats to their replacements within 48 hours of the election. In the six other cases, it was a matter of weeks before the new senators were sworn in. Party affiliation doesn't appear to be the factor: Humphrey, a Democrat appointed to take the place of her late husband, Sen. (and LBJ's Vice President) Hubert Humphrey, stepped aside immediately when Republican Rudy Boschwitz was elected in Minnesota and Nicholas Brady, a Republican, let New Jersey Democrat Frank Lautenberg get a head start on his seniority. But appointed Sen. Kaneaster Hodges Jr. of Arkansas made fellow Democrat David Pryor wait to take office until the official beginning of his term.
Here's the list:
1962: Edward Kennedy, D-Mass., elected Nov. 6; sworn in Nov. 7
1964: Ross Bass, D-Tenn, elected Nov. 3; sworn in Nov. 4
1972: Bennett Johnston, D-La., elected Nov. 7; sworn in Nov. 14
1975: John Durkin, D-NH., elected Sept. 16; sworn in Sept. 18
1977: David Pryor, D-Ark., elected Nov. 7; sworn in Jan. 3, 1979
1978: Rudy Boschwitz, R-Minn., elected Nov. 7; sworn in Nov. 8
1982: Frank Lautenberg, D-N.J., elected Nov. 2; sworn in Dec. 27
1992: Kent Conrad, D-N.D., elected Dec. 4; sworn in Dec. 14
1993: Fred Thompson, R-Tenn., elected Nov. 8; sworn in Dec. 2
2003: Norm Coleman, R-Minn., elected Nov. 5; sworn in Jan. 3, 2003