When Colgate was developing its new low-waste Keep toothbrush, which has a reusable aluminum handle and replaceable heads (a starter pack costs $9.99; additional heads are $4.99 for two), the company ...

Katherine Martinko is an expert in sustainable living. She holds a degree in English Literature and History from the University of Toronto. Haley Mast is a freelance writer, fact-checker, and small ...

Earlier this year, Colgate released a connected toothbrush, an artificially intelligent mouth cleaner that would be sold at Apple Stores for $100 a pop. It looks like most electric toothbrushes: thick ...