Anyone who regularly rides a bike knows the importance of a puncture repair kit. A pinhole leak in your tyre's inner tube can quickly render a bike unrideable, but with a small sheet of adhesive rubber tape, the leak is sealed, so all you need to do is inflate your tyre and you're good to go. Yes, more intensive repairs will be needed in the not too distant future, but as a stopgap measure, this DIY repair is perfectly adequate. The trouble is that some people think this principle applies to anything that might need a temporary repair—even their own teeth. While there are ways to patch your own cavity or cover a chip or crack on a tooth, that doesn't mean you should do so.

Dental Cement

In order to perform dental work on your own teeth, you will need a DIY kit, which usually contains a type of dental cement. This is the first flaw in the plan. Sure, some shops and pharmacies will sell these kits, or they can be ordered online. But in the time it takes you to source the kit, a dentist could have easily corrected a chip or filled a cavity. Attempting to repair your own dental problem will generally prolong the problem.

No Substitute for Training

If you still happen to obtain a DIY tooth repair kit, it's best to leave it in its packaging. Yes, this packaging comes with instructions, but of course these instructions are no substitute for the seven years of training that your dentist has received. There's a real risk that you will make your dental problems significantly worse. But what's the harm?

The Utmost of Precision 

The application of any dental cement (or DIY kit equivalent) is hazardous. Although the material itself will be safe, it must be applied with the utmost of precision. It's all too easy to apply too much. The material will harden, and it can be impossible to remove without removing some of the tooth's structure (particularly when the tooth has deteriorated). What could have been a simple cavity now requires an extensive restoration. There's also the fact that the dental cement in a DIY kit will not be a precise colour match for your tooth, making your efforts look obvious and clearly amateur. 

Under no circumstances should you attempt to fix your own dental problems. You must schedule an appointment with your dentist, who will be able to quickly and calmly address the problem. Taking matters into your own hands is a good way to ensure that you'll need extensive (and expensive) dental work, so this must be avoided.