Making the world better, one answer at a time. Pigs have rounded teeth that are adapted to their diet of plant material and soft meats. Pigs are not carnivores so they don't need sharp teeth.he artificial sweeteners in diet soda is proven not to promote tooth decay.   The acid in diet coke causes tooth decay, regardless, although the acidity in diet coke is less than apple juice/apple cider. Although both will stain your teeth.