1. What is it About

You had an accident and lost two of your front tooth. You look pretty different now. You need to do something about them. You go to your dentist. He takes some sample tissue from your current teeth and you leave. When you return sometime later, he implants newly grown embryonic tissue into the place of your missing teeth. She advices you on your new diet and you leave. A few weeks later you come back for check-up. He shows you the small teeth growing in your jaw. It is identical to what you had before, since it is derived from your own genes. The cells know which tooth they have to become by getting signals from their surrounding environment. Eventually, your teeth are fully grown and are like the original you had before the accident.

You feel confident about your looks and wonder what people did in the past when they lost their teeth. The thought of false teeth makes you shiver.

2. Where is the Fun

• Being able to replace all your teeth at the age of 40 with brand new shiny teeth like when you were 20.
• Finally, after many years of smoking you managed to quit it for good. You are so happy now, though the shadow of the past is still there with your darker-than-normal teeth. Now you can get rid of that as well. All you need is to replace your teeth with new ones generated from your own body.

3. What are its Applications

Regenerative dentistry can open up a whole industry to regenerative biology as we start to master the creation of body parts. Teeth regeneration provides great benefits on its own, but the potential to regenerate other parts of the body such as liver, stomach, gallbladder or even heart is going to be the true prize.

4. How Developed is it

Organ replacement has been one of the hottest topics lately. The idea of replacing a damaged organ with a new one made out of your own flesh, or simply growing tissue for cosmetic applications will truly transform the way we live and think on many different aspects of life. The ethical issues associated with these are yet to be worked out. Of all organ regeneration techniques, teeth regeneration is most likely to occur first due to two reasons:

• People don’t die because of lack of teeth or failed teeth.
• It is much easier to experiment with different techniques while growing teeth than, say, growing liver.

In addition, it is reasonably easier to consider its ethical issues. If your dentist gets it wrong, you may simply end up with bad teeth which can be repaired or replaced with traditional methods such as crowns. However, a doctor needs to be extra careful when transplanting a liver made out of your tissue, since if it fails it can become life threatening. As a result much progress has been made already and no doubt this field will progress quickly in the future.

To make a tooth out of a human’s genes, there are three milestones:

• Source of cells from the patient that can form teeth should be easily obtainable.
• It should be possible to grow the teeth in the environment of an adult jaw.
• The shape and size of biological teeth must be controllable.

Progress has been made on all accounts. It is possible to use wisdom tooth (which may contain hidden stem cells) with a bio-degradable scaffold with the shape of a tooth to generate all the required cells, such as enamel, dentin and pulp tissue.

It is also possible to re-grow teeth. A team of University of Alberta researchers uses a completely different approach. They have created technology to reform human dental tissue using low-intensity pulsed ultrasound (LIPUS). Apparently, the tooth cells can get stimulated by ultrasound waves and can start to regenerate other type of cells required for a tooth.

The system-on-a-chip uses nanotechnology, is quite small and can fit comfortably inside a patient's mouth while packed in biocompatible materials. It can be easily mounted on an orthodontic or "braces" bracket or even a plastic removable crown. Originally they are targeting this device for those with mechanical injury from wearing orthodontic braces.

5. How Can it be Improved

The three milestones are yet to be reached. The most critical is perhaps sourcing suitable cells for the regeneration of tooth. The ideal scenario is to get the cells for your own teeth. It will be more convenient for a dentist, it makes more sense for the patient psychologically and it avoids the complexity of obtaining stem cells from bone marrows, not to mention all the ethical issues associated with it.

The other more practical issue is the environment that the tooth grows in. It is preferable to grow the teeth in the jaw, and with minimum inconvenience. Hence, faster development in a relaxed environment is more desirable. Not everyone may look forward to a liquid diet lasting for several month, only to get one teeth replaced with a brand new one!

6. What Does it Lead to

The implications of regenerative dentistry are huge. Initially, these technologies will be used by early adaptors and richer classes of the society. Considering that this has applications in cosmetic industry and modifications on teeth can have great effect on a person’s look, it is easy to see that the market for this will be huge. As with many other technologies, those who use it first will be initially resented, since others may not be able to afford it and will justify their lack of it by resentment. At this point, the society will consist of those who look unnaturally good looking and healthy for their age, while others look more traditional. It starts to differentiate the people between the haves and have-nots.

This will be similar to the growth of mobile phones. Initially the phones were used by businessmen for serious tasks. Later, when even students started to join in, they were ridiculed by the more conservative classes of the society that these devices did not suit the students and they effectively ruined the image of owning a mobile phone! Resentment has many side effects.

As the regenerative dentistry gets cheaper and more mainstream, the masses will join in and we will eventually end up with a society where everyone has some form of regenerated tooth one way or another. This conclusion is also applicable to regenerative organs, especially those organs that can have cosmetic effect.