The Cat With the Golden Tooth, Sandra Waugh VDM

Sandra Waugh VDM, MS, - Windsor Veterinary & Dental Service, Windsor, VT

April was a happy cat until she broke her upper canine (fang) tooth. Then she spent more time curled in her box and would not come out to greet her human friends. She no longer rubbed her face against our hands.

Cat owners often think that broken teeth do not bother their pet, because the signs of tooth pain can be very subtle. April’s change in behavior was a clear sign that something was bothering her, and the broken tooth was the most likely cause.

When a tooth is formed, it has three layers. To make this easier to visualize, think of a garden hose. If you cut across the hose, you will have the outer layer, often a shiny colored plastic, which wraps around the entire tube. Then comes a thicker rubber layer, which is the bulk of the hose. Then there is the central core, which is empty to allow water to flow.

A tooth is like a garden hose that is pinched at both ends. In the tooth, the outer layer is made of enamel, the hardest substance in the body. This is the shiny white tooth we are familiar with seeing. Once formed, enamel becomes inert and cannot repair itself. Under the enamel is dentin, which is much softer and is yellow in color. Dentin grows throughout the life of the tooth, and forms the bulk of the tooth. At first the dentin is a thin layer just under the enamel. As the tooth ages, the dentin thickens towards the center of the tube. Dentin is constructed as small tubules which radiate from the enamel into the center of the tube. The core of the tooth is not empty, but is occupied by the pulp which contains blood vessels, nerves, and supporting tissues, which nourish the dentin and provide sensitivity to the tooth. At the top of the tooth this space is called the pulp chamber and in the root is called the root canal, but it is really all one chamber.

If a tooth is broken, the pulp is exposed to the mouth, and bacteria easily invade into the chamber. The pulp usually cannot survive this, and dies. This allows bacteria to occupy the entire length of the tube, and they happily take up residence inside the dentin tubules. The bacteria can then exit the end of the root into the surrounding bone, causing infection there as well. The body can fight the infection that is in the bone, but can no longer reach the inside of the tooth, so the bone is constantly being re-infected as time goes on. This can be quite painful (ask anyone who has needed a root canal procedure!) Dead teeth are often discolored, as seen in the photograph.

April really wanted something special, so instead of extracting the tooth, a root canal procedure was performed. This involved cleaning out the inside of the tooth (pulp chamber and root canal) with files and disinfectant, and then filling the inside with an inert material that would seal the inside of the tooth. The top of the tooth is then sealed.

The top of the tooth was then prepared for a metal crown. This involved removing the enamel and some dentin to make a platform for the crown to rest upon, and to allow the crown to be similar in diameter to the original tooth. The canine teeth come together quite tightly when the cat closes the mouth, so the crown must fit into this space. Impressions were made with alginate and VPS and a stone model of the mouth was poured. All of this was sent away to a dental laboratory, which then fabricated the crown. Then we all waited (impatiently) for the crown to return to us. Especially April.

Some gold alloy was used when the crown was made to give it that nice warm, golden glow.

The day after the root canal procdure, April was like her “old self”. She gave her favorite humans a big greeting, with lots of squawks and rubbing of face on hands, dancing around and insisting on being petted. And when the gold crown went on, she was totally pleased.

Now April is the envy of all the other cats, and we have taken to calling her “Goldy”.

Why is the crown so short? Crowns in cats and dogs on the canine teeth are never made to the length of the original tooth. A metal crown that long would be very vulnerable to sideways pressure, and that could result in the tooth underneath fracturing at the base of the crown.

Why does the crown look fat? Because the original tooth was so small, the least amount of enamel and dentin were removed. The width of the metal was slightly more than the width of enamel and dentin that was removed. This makes the crown look a bit “fat”. The important thing is that April can close her mouth completely and in total comfort.

April is a 12 year old female spayed Domestic Shorthair cat residing at Windsor Veterinary & Dental Services. All photographs and radiographs are the property of and produced at Windsor Veterinary & Dental Services.