Aug 30 2022

Microbots To Clean Teeth

In my upcoming book, which I will now shamelessly plug – The Skeptics Guide to the Future (release date Sept 27th, but you can pre-order now) my co-authors and I spend a lot of time extrapolating cutting edge technology into the near and medium-term future. What are the technologies that are on the cusp of disrupting current technology and changing our lives? One of them is the technology to build ever-smaller and more capable machines – the technology of the very small. We can dream of having mature nanotechnology, robots at the nanoscale that can manipulate matter at the molecular level, but this is likely still centuries in the future. Between now and then there is a lot of territory, however.

In the meantime we can imagine what the most likely early applications will be. What is the low-hanging fruit? For medical purposes there are some likely early applications, even for robots that are not quite at the nanoscale, perhaps at the micro or even centimeter scale. Tiny robots can be useful as surgical aids. They can be injected through the skin (no incision necessary) where they can make precise interventions, such as removing tumors or suturing blood vessels. This could take microsurgery (which is already a thing) to the next level.

When such robots can be more autonomous or easy to control remotely, another possible early application is to have them crawl along the inside of the large and even medium-sized blood vessels, clearing up plaque and removing clots.  Or they can move along the inside of the intestines, removing polyps and scanning for cancers. In recent decades we have been transitioning from having to open up major body cavities in order to do surgery, to being able to do the same procedures through small holes using cameras and specially designed instruments. This has made many surgeries significantly less invasive, with dramatically reduced trauma and recovery time. Micro surgical robots have the potential to take this to the next level over the coming decades.

Another probable early application of medical microbots is oral health, the importance of which should not be underestimated. Good oral health is critical to overall health. One of the challenges to optimal oral health is that teeth cleaning is a tedious daily routine, and many people (especially the elderly) may lack the manual dexterity to do it well. Even without this issue, it is challenging to do a very thorough job of cleaning teeth, and depending on the arrangement of teeth it may be difficult to impossible to reach every surface of all teeth.

The oral cavity is also a very dirty place, with lots of bacteria. Mostly this is friendly bacteria, but not without consequences. The big one in terms of dental health is that bacteria eat sugars from the food we eat that get stuck in tiny pits and fissures in our teeth, and they release acid which causes damage to the tooth enamel. This can deepen the pit, causing more food to get trapped, and resulting in a vicious cycle until you have a cavity. Frequently brushing this food and bacteria away limits this process, but again if any part of the teeth are routinely missed or difficult to get to, the problem persists.

Imagine having tiny robots crawling along every bit of your teeth, completely removing plaque, bacterial biofilm, and bits of food. This approach has the potential to be more thorough than any other cleaning method. Recently researchers published –  Surface Topography-Adaptive Robotic Superstructures for Biofilm Removal and Pathogen Detection on Human Teeth. This is really a proof-of-concept, and not ready for direct application, but it does show the potential of this approach. The researchers use a magnetically controlled swarm of tiny robots composed of “iron oxide nanoparticles with catalytic and magnetic properties.” This allows them to conform to the topology of each tooth, to get into every crevice (essentially flossing), and also to adjust their stiffness. This means they can become just stiff enough to remove biofilm, without damaging the gums or removing enamel.

They studied their system on isolated (ex vivo) teeth and showed good results. The system can also retrieve bacteria and viruses for diagnostic purposes. This is just a first step in developing this technology (again, proof-of-concept). The next step is developing a system of delivery for live humans, such as a mouth-fitting device. This could work like fluoride applications do now, where you put on the plastic cup that fits around your teeth and holds the fluoride. Instead of brushing, it may be possible to just place such a cup on your teeth for a few minutes, perhaps while doing other morning activities. Because they are magnetic it could be easy to remove all the nanoparticles when the process is done.

Perhaps this would not have to be done every day. At first I imagine this kind of procedure would be done in the dentist’s office, as part of your biannual cleaning. This would just make the cleaning procedure easier and better. But as the tech advances and becomes cheaper, home versions will emerge. You could then do a dental-level cleaning at home, every month or so. You would still brush daily, but would back this up with intermittent deep microbot cleaning. As the process gets ever cheaper and easier, however, it may eventually replace daily brushing.

As we do in the book, we can just keep going, imagining how the technology will continue to mature. Perhaps these dental microbots will get smaller, until they are truly nanobots. Eventually they could do more than just cleaning. They can whiten teeth to a desired level, replace enamel, fix all micropits and cracks, and even repair chips. Perhaps at some point these dental nanobots will live on your teeth, providing constant cleaning and repair services – perfect, no-maintenance teeth.

But also, we have to remember that other technologies are advancing at the same time as the one technology you are considering. We may also be able to bioengineer oral bacteria that will not release acid, or cause bad breath. Our “nanobots” may be living bacteria. These technologies may also complement each other – engineered bacteria for daily health, with occasional deep robotic cleaning. We may also be able to simply regrow new teeth on demand, so easily that making individual teeth last for decades may be unnecessary. The fix for all bad or damaged teeth may simply be replacement. We may be able to replace them with bioengineered superteeth, resistant to damage or cavities.

Meanwhile we are stuck using a 500 year old technology (the first bristle toothbrush was invented in 1498). Seems like we are due for an upgrade.

No responses yet