But aleC, isn't that a bit unfair? Eating carbohydrates is a choice, subject to free will. We eat it despite knowing it's bad for teeth. That's like a well designed tractor that tolerates a wide range of oils and diesels as fuels and even runs if you mix in some sugar, but we insist on feeding it pure molasses.
Nothing can be designed for every use and abuse. Design is always making choices of what to design for. Thus every design has an envelop inside of which it should perform well. That implies you can take any design outside of its envelop. If you do, don't blame the design.
God created man for a state of paradise, where no agriculturally grown and industrially processed food was a design criterion. Presumably, our teeth are well designed to such stone-age diet. It was a choice (or long chain of choices, starting with eating that damned forbidden fruit) that took our teeth outside their design envelop.