- These are the two leading toothpastes. If you use this one, Crest, stick around. We have something interesting to tell you. The six month results have just come in on a test comparing your toothpaste's ability to reduce cavities with this one, Colgate. You oughta know that one of these toothpastes reduced cavities better, significantly better than the other. The more effective toothpaste is your toothpaste, Crest. It's the blue one with fluoride, a well-known ingredient that helps reduce cavities. You probably didn't know it, but Colgate doesn't have fluoride. Maybe results showing that one toothpaste reduced cavities far better than another isn't earth shaking news. But if you're concerned about cavities, it's comforting to know you've made a good choice. Crest, the blue toothpaste with fluoride.