Archive for the ‘MATERIALS’ Category

Smart Braces Take The Bite Out Of Conventional Orthodontia

One could say that donning a mouthful of braces isn’t the most pleasant of experiences. Researchers at King Abdullah University of Science & Technology (KAUST) are looking to revamp the process with smart, 3D-printed braces running on nontoxic batteries and light.

The new system centers around one lithium-ion (Li-ion) battery and two near-infrared light-emitting diodes (LEDs) on each tooth. This tech is situated on a 3D-printed, semitransparent dental strip that is flexible enough to remove in order to recharge.

The Li-ion batteries supply the power to the LEDs, turning them on and off. The rate of light therapy depends on specific programming by the dentist, determined by the individual needs of each tooth. Phototherapy has provided considerable benefits in orthodontic treatment, reducing cost, time, and promoting bone regeneration.

“We started embedding flexible LEDs inside 3D-printed braces, but they needed a reliable power supply,” says Muhammad Hussain, leader of the research, along with Ph.D. student Arwa Kutbee.

“After the incidents with the Samsung Galaxy 7 batteries exploding, we realized that traditional batteries in their current form and encapsulation don’t serve our purpose. So we redesigned the state-of-the-art lithium-ion battery technology into a flexible battery, followed by biosafe encapsulation within the braces to make a smart dental brace,” Hussain adds.

The battery redesign, mentioned by Hussain, was accomplished through dry-etching. This technique thinned the battery and increased flexibility by removing the silicon that is usually situated on its back. The final dimensions leveled at 2.25 mm x 1.7 mm.

Materials made of soft, biocompatible polymers surrounded the power supply to halt leakage. The outer coating was vital for the device to remain safe for human use.

The KAUST team sees these initial findings as a preliminary step that serves as a proof-of-concept prototype. Clinical trials are next on the to-do list.

The full details of the research can be found in an article published in the journal Flexible Electronics.

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Henry Sapiecha

Tiny Silica Particles Could Maybe Repair Damaged Teeth

silica sand pile conveyor image www.perfectwhiteteeth.net

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.

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Henry Sapiecha