The short answer is: maybe. Dental disease can be a big problem for your dog, especially if it is advanced. Sometimes, bad teeth need soft food rather than hard food, because hard food can be painful or impossible to eat. Tiny dogs like Chihuahuas are particularly prone to dental problems and disease because their mouths are too small for all their teeth, and this causes all kinds of complications over time. Ideally, dental disease is addressed by your vet (get those dead/dying/broken teeth out of there! they aren't doing a darn thing except causing the world's longest headache and body-wide inflammation), but if it hasn't been yet or can't be, consider soft food for that doggo. And definitely talk to your vet.