Nestle and Colgate-Palmolive have joined forces to challenge Wrigley, the world’s No. 1 chewing gum maker, for leadership of the fast-growing market for dental chewing gum.Nestle, the world’s biggest consumer food company, and Colgate-Palmolive, the world’s No. 1 maker of toothpaste, have signed an agreement to develop and market on a worldwide basis a new range of “portable oral care” products that “taste good, clean teeth and freshen breath.”The first ...