Do It Yourself Dentistry

The lore of do-it-yourself home dentistry used to involve a pair of pliers from Dad's handy old tool box. Or...better yet...string wrapped around a tooth on one end, and to a door knob on the other. Swing the door closed, and voila, you saved your self a trip to the dentist. 

The recent economic woes in the U.S. have led to an increased accounts of DIYers perfoming their own dentistry at home. A recent survey of dentists points to an increase in this type of behavior. So, perhaps it is not a surprise that the most popular technique involves Super Glue.

As amusing as it sounds, patients use many dangerous methods to save themselves a trip the to the dentist, from emery boards to power tools (i.e. dremel tools). I have been told by a patient that Super Glue worked better than Krazy Glue. Obviously he's had some experience in differentiating between the two in their effectiveness.

It is true that cyanocrylate, the generic name for Super Glue and Krazy Glue, which contains acrylic resins methyl-2-cyanocacrylate or 2-octal cyanoacrylate, is used by physicians for wound repair. In fact, cyancrylate bonds very well to surfaces that are moist and non-porous. Sounds perfect for that dental crown that keeps coming out, right?

Unfortunately, that notion is wrong and here’s why. The crown is a non-porous surface and can be moistened, but the tooth, despite being very moist, is also very porous. Therefore, the adhesion between the two is negligible and will not last. But the real danger is forcing the cyanocrylate down into the tubules of the tooth and killing the tooth. This will ultimately lead to the need for a root canal or even the loss of the tooth due to resorbtion.

What most people may not know is that a dental crown does not stay in place via adhesion. It remains in place for years merely by mechanical retention. Mechanical retention is best explained like this: Imagine placing an identical glass over another identical glass. Pick up the upper glass and the one below comes with it, and the two "stick" together as you lift the top glass.

Now try that with two identical bowls stacked face down on top of each other. It’s impossible to pick the bottom bowl by lifting the one placed on top. This is an illustration of the effects (and success) of mechanical retention.

So if that crown keeps falling off, it's not due to a lack of adhesion - it's due to the shape of the prepared tooth lacking in retentive features. Dentists typically don't actually use glues, we use cements to prevent saliva from seeping between the crown and tooth, which prevents tooth decay. In this light, I hope you see the futility of using a product like Super Glue in your mouth. It's not at all about stickiness - it's about the shape of the tooth and the tightness of the fit - that keeps the crown from falling off.

And because the human body has a high moisture content, cyanoacrylate adhesives will bond very effectively to the skin and other body parts. Getting glue on your fingers can bond the crown to your finger. It can be removed but it certainly can complicate the process. Your best choice is to see your dentist as soon as possible.