Dental and other oral diseases are very common in cats. Specific diseases include gingivitis-periodontitis, tooth fractures, resorptive lesions, and stomatitis.
Gingivitis-periodontitis is inflammation of the gums and other support structures of the teeth. It is due in part to accumulation of plaque and tartar. Gingivitis can be partially prevented by removing plaque. This can be done most effectively by brushing a cat's teeth. Cornell University has a good video describing how to brush a cat's teeth. It is better to start when they are kittens. If you start when cats are older, it is best to have an examination done first to make sure that there aren't any painful teeth in the mouth.
Plaque Reducing Foods and Treats
There are foods and treats that are intended to help decrease plaque formation. I don't usually recommend any of these because when they are tested scientifically, they are compared to other dry foods. Also, no long term studies have been done on the traumatic effect these hard foods have on the relatively delicate teeth of cats.
Until the dental treats and foods are compared to canned foods without any carbohydrates, and shown to be beneficial long term, I am going to withhold judgment on their value.
Abscesses are pockets of infection. When they involve teeth, they can be due to advanced periodontitis or they can be due to broken teeth. These are very painful and may not be detectable without radiographs of the teeth.
Even though cats won't tell us that their mouths hurt, abscess are always painful and should always be treated.
Tooth resorption in cats results in FORLs (Feline Odontoclastic Resorptive Lesions - AKA Feline Oral Reorptive Lesions).
These are very common and easily missed on physical examination.
These resorptive lesions are very painful holes that form in teeth.
Stomatitis means inflammation of the mouth and when we talk about it in cats, we are referring to a syndrome that causes extensive chronic inflammatory disease. We don't know what causes it but it is usually only effectively treated by extracting most or all of the teeth. There are other things that can help but they usually just serve to delay treatment and delaying treatment can worsen the prognosis.
Dr. Niemiec is a local San Diego board certified veterinary dental specialist. This is his video on feline stomatitis.