Archive for March, 2016

Tiny Silica Particles Could Maybe Repair Damaged Teeth

silica sand pile conveyor image

Researchers at the University of Birmingham have shown how the development of coated silica nanoparticles could be used in restorative treatment of sensitive teeth and preventing the onset of tooth decay.

The study, published in the Journal of Dentistry, shows how sub-micron silica particles can be prepared to deliver important compounds into damaged teeth through tubules in the dentine.

The tiny particles can be bound to compounds ranging from calcium tooth building materials to antimicrobials that prevent infection.

Professor Damien Walmsley, from the School of Dentistry at the University of Birmingham, explained, “The dentine of our teeth have numerous microscopic holes, which are the entrances to tubules that run through to the nerve. When your outer enamel is breached, the exposure of these tubules is really noticeable. If you drink something cold, you can feel the sensitivity in your teeth because these tubules run directly through to the nerve and the soft tissue of the tooth.”

“Our plan was to use target those same tubules with a multifunctional agent that can help repair and restore the tooth, while protecting it against further infection that could penetrate the pulp and cause irreversible damage.”

The aim of restorative agents is to increase the mineral content of both the enamel and dentine, with the particles acting like seeds for further growth that would close the tubules.

Previous attempts have used compounds of calcium fluoride, combinations of carbonate-hydroxypatite nanocrystals and bioactive glass, but all have seen limited success as they are liable to aggregate on delivery to the tubules. This prevents them from being able to enter the opening which is only 1 to 4 microns in width.

However, the Birmingham team turned to sub-micron silica particles that had been prepared with a surface coating to reduce the chance of aggregation.

When observed using high definition SEM (Scanning Electron Microsopy), the researchers saw promising signs that suggested that the aggregation obstacle had been overcome.

Professor Zoe Pikramenou, from the School of Chemistry at the University of Birmingham, said, “These silica particles are available in a range of sizes, from nanometer to sub-micron, without altering their porous nature. It is this that makes them an ideal container for calcium based compounds to restore the teeth, and antibacterial compounds to protect them. All we needed to do was find the right way of coating them to get them to their target.  We have found that different coatings does change the way that they interact with the tooth surface.”

“We tested a number of different options to see which would allow for the highest level particle penetration into the tubules, and identified a hydrophobic surface coating that provides real hope for the development of an effective agent.”

Our next steps are to optimize the coatings and then see how effective the particles are blocking the communication with the inside of the tooth.  The ultimate aim is to provide relief from the pain of sensitivity.


Henry Sapiecha

DIY Dentistry: How This College Kid Fixed His Teeth Using a 3D Printer

Braces. The word triggers in me flashbacks of rolling balls of wax onto the wires to prevent the inside of my mouth from being torn open, or choosing which color rubber-bands I wanted to display each month (orange and black in October. Red and green in December. Red, white, and blue in July). I was one of the lucky adolescent ducks who got to don headgear while I slept.

Ah, memories.

The orthodontist’s office becomes a kind of second home during this coming-of-age period of a teenager’s life. Most teenagers, that is.

Amos Dudley, a 3D artist and New Jersey Institute of Technology student, has figured out how to create his own set of clear Invisalign braces after failing to wear his retainer, consequently causing his teeth to shift back into chaos. But being the broke (albeit, enterprising) college kid that he was, Amos decided to take matters into his own hands.

Kids, don’t try this at home.

First, Amos took a mold of his teeth, using alginate powder, and placed it into a yogurt container (oh college) filled with Permastone. He then scanned the casing, generating digital models for several sets of aligners—which he then 3D-printed.

As he documented on his blog: “Creating the animation was…fairly trivial—I separated the visible crowns of the teeth from the gumline, and then made a manifold model from each of the shells. I didn’t bother adjusting the geometry of the gums—they are soft. Then it was just a matter of animating them into their correct positions. I measured the total distance of travel, and divided it by the maximum recommended distance a tooth can travel per aligner.”

Next, using a vacuum form machine, Amos created plastic aligners that fit his 3D-printed models, utilizing the same plastic (and therefore safe) retainer material orthodontists use.

Fun fact numero uno: 3D-printing the actual aligners wouldn’t work.

Fun fact numero dos: apparently you can buy retainer plastic on eBay. “The sale of dental supplies really isn’t tightly controlled,” Amos told Gizmodo. “Who wants them other than dentists?”

The result?

teeth before dental work image

teeth after dental work image

Amos admits that the aligners are more comfortable than braces. “I’ve been wearing them all day and all night for 16 weeks, only taking them out to eat. I’m planning on fabricating a bunch of retainers for the current position, which I can use—till I die—at night.”

Of course, because this process involves your face, actual dental professionals advise against this sort of Martha-Stewart-do-it-yourself-teeth-straightening business. Lots of other people have tried and failed (miserably) to fix their pearly whites. (Don’t Google this if you want to keep your lunch down).

Associate professor of orthodontics at the University of Minnesota School of Dentistry Brent Larson said: “I’m impressed with the way Amos was able to use the scanning and printing technology that he had available to engineer and produce his own aligners but a little frightened that he would actually use them to treat himself without a professional assessment of the health and function of the teeth.”

You don’t need to tell me twice. One of the most scarring movie scenes I’ve ever watched is from Castaway (you know, the Tom-Hanks-Wilson-volleyball-love-story), where Hanks’ character knocks out a rotting tooth using a giant rock and an ice skate blade. While Amos’ denture venture is incredibly impressive, I’m happy leaving my teeth to the professionals.


Henry Sapiecha