New York--Martin/Williams Advertising, Minneapolis, took the Grand CEBA for overall excellence last night at the fourth annual Creative Excellence in Business Advertising awards. Martin/Williams' advertisement, for a professional dental whitener made by Minneapolis-based 3M Worldwide, likened a white picket fence to the efficacy of the product. The ad was also awarded best single ad--spread or larger. Other winners included: Stein, Rogan & Partners, New York, best interactive ads, for client Sunnyvale, Calif.-based Infoseek Corp.; WestWayne, Atlanta, best ad campaign--three or more ads, for client American Cyanamid Co., Parsippany, N.J.; Carmichael Lynch, Minneapolis, best single ad--one page or less, for client Rapala-Normark Group, Minnetonka, Minn.; Fallon McElligott, Minneapolis, best insert--special supplements, for client Richmond, Va.-based Virginia Commonwealth University Advertising Center. The CEBA Awards were organized by The American Business Press, New York, and held at The Hudson Theater.