Select Page
Zent Flex Toothbrush –  2019

Improper brushing is a significant health issue, but not brushing often enough isn’t the only form of improper brushing. Many people exert too much pressure while brushing, causing gum recession and wearing away of tooth enamel. Zent aims to fix this problem with the Flex toothbrush, which breaks away when too much force is applied. We helped Zent design and engineer the Flex.

The key to the Zent Flex is the flexible TPE joint that’s overmolded between the handle and head. The independent head bends out of the way when a certain amount of force is applied. Inside the joint are two spring steel snaps that provide a firm hold right up until the breaking point is reached, at which point they quickly give way. It’s sort of the slap bracelet of toothbrushes. This balance between firm support within the safe pressure range, and quick release when over-stressed was a tricky engineering challenge.

Early concepts explored several directions, including magnets and mechanical hinges. We developed several prototypes for testing mechanical approaches, and ultimately determined a spring steel hinge was the most promising and feasible. Our process then refined the design further, with 3d prints, and pre-production samples. We worked directly with suppliers for the custom spring components and plastic injection parts.  With clear communication, we achieved a design for the joint that breaks away at a force within the range of pressure recommended by studies from the Journal of Clinical Periodontology.

Design of the plastic parts also required careful consideration. An ultimately simple final product belies the complexity of the tooling design. For a feasible unit cost, it’s important that much of the assembly is automated. 


We also developed the brand and product logos for Zent and the Flex. We expressed cleanliness with simple and geometric letterforms. Given the dynamic nature of the toothbrush, the product logo is appropriately active and energetic, though still modern enough to live comfortably next to the brand mark



To convey the need and advantages of the Flex, we developed messaging and created the webstore for Zent. During an initial launch, visitors could pre-order toothbrushes. Once production-level product was available, the site was converted for customers to enjoy several purchasing plans.