Poor Diet Can Lead To Dental Problems
A poor diet can lead to teeth and gum disease. When a cat eats in the wild, it will tend to catch small rodents and birds and eat them whole, that includes the skeleton. This naturally cleans their teeth and tends to keep them strong. Now compare that with a good quality wet food. There is generally nothing in a wet food that allows the cat to crunch. There are some home made recipes that include bone that has been ground up, which does help to keep teeth clean and healthy.
Here are some videos on how to look after and treat your cats teeth.
As always prevention is better than cure however if your cats teeth have deteriorated it is always best to get an expert opinion form a vet.