Monthly Archives: November 2019

New way to grow new teeth for patients


A group of histologists and dentists from School of Biomedicine, Far Eastern Federal University (FEFU), teamed up with Russian and Japanese colleagues and found cells that are probably responsible for the formation of human dental tissue. Researchers propose to apply the study outcome within the development of bioengineering techniques in dentistry aimed at growing new dental tissue for patients. A related article is published in the International Journal of Applied and Fundamental Research.

FEFU scientists used human prenatal tissues to study the early stage of development of the embryonic oral cavity during the period when the teeth were set up – from the 5th to the 6th week. They have recognized several types of cells that are involved in the formation of one of the teeth rudiments — the enamel (dental) organ. Among them, chromophobe cells with elongated spindle-shaped form have been identified which are also responsible for the development of human teeth in the first weeks of embryo formation. The data obtained can provide a fundamental basis for the development of bioengineering therapies in dentistry and gastroenterology.

Numerous attempts to grow teeth from only the stem cells involved in the development of enamel, dentin and pulp, i.e. ameloblasts and odontoblasts, were not successful: there was no enamel on the samples, teeth were covered only by defective dentin. The absence of an easily accessible source of cells for growing dental tissue seriously restricts the development of a bioengineering approach to dental treatment. To develop technologies of tissue engineering and regenerative medicine — promising methods of treatment in dentistry — the cells identified by us may become the clue to the new level of quality dental treatment. Natural implants that are completely identical to human teeth will no doubt be better than titanium ones, and their lifespan can be longer than that of artificial ones, which are guaranteed for 10-15 years. Although for a successful experiment, we still have a lack of knowledge about intercellular signaling interactions during the teeth development.‘ said Ivan Reva, Senior Researcher of the Laboratory for Cell and Molecular Neurobiology, School of Biomedicine, FEFU.

The scientist noted that large chromophobe cells reside not only the place where the teeth of the embryo form, but also exist at the border where the multilayers squamous epithelium of the oral cavity passes into the cylindrical epithelium of the developing digestive tube. This means that the new bio-engineering approach is relevant not only for growing new dental tissue but also for growing organs for subsequent transplantation and likely will be applied in gastroenterology.

Source: https://www.eurekalert.org/

How To Print Crowns And Bridges, Surgical Guides For Dental Implant

Back at CES this year, we talked with 3D-printer maker Formlabs about its early experimentation in using its printers to make dentures faster and more affordably than existing alternatives. A few months later, the company is going deep on the concept. They’re releasing a 3D printer meant specifically for dental use, opening up a whole new wing called “Formlabs Dental” and acquiring their main resin supplier in order to better make materials for the dental industry.

Unfamiliar with Formlabs? The main thing to know is that their printers use Stereolithography (SLA) rather than the Fused Deposition Modeling (or FDM) that most people probably think of when it comes to 3D printing; in other words, they use carefully aimed UV lasers to precisely harden an otherwise goopy resin into whatever you want to print, whereas FDM printers heat up a solid material until it’s malleable and then push it through a hot glue gun-style nozzle to build a model layer by layer. SLA tends to offer higher accuracy and resolution, whereas FDM tends to be cheaper and offer a wider variety of colors and material properties.

Formlabs calls its new dentistry-centric printer the “Form 3b” — which, as the name suggests, is a slight variation on the Form 3 printer the company introduced earlier this year. The base package costs about a thousand bucks more per unit over the non-dental Form 3, but comes with software meant to tie into a dental team’s existing workflow, along with a year of Formlab’s “Dental Service Plan,” which includes training, support and the ability to request a new printer if something needs repairing (rather than waiting for yours to get shipped back and forth). The company also says the 3b has been optimized to work with its dental resins, but doesn’t say much about how.

Speaking of resins: Formlabs is acquiring Spectra, which has been its primary supplier of resins since Formlabs started back in 2012. While the company isn’t disclosing any of the terms of the deal, it does say it has put over a million dollars into building an FDA-registered clean room to make medical-grade resins. Formlabs says that anyone who already buys materials and resin from Spectra can continue to do so.

The company’s new “Formlabs Dental” division, meanwhile, will focus on figuring out new dental materials and ways to better tie in to existing dentist office workflows. Right now, the company says, the Form 3b can be used to print crowns and bridges, clear retainers, surgical guides to help during dental implant procedures, custom mouth guards (or “occlusal splints”) and dentures.

Source: https://formlabs.com/
AND
https://techcrunch.com/

Bone Tissue Just Needs A Little Bit Of Encouragement To Regenerate

Regrowing bones is no easy task, but the world’s lightest solid might make it easier to achieve. Researchers have figured out a way to use hybrid aerogels, strong but ultralight materials, to prompt new bone tissue to grow and replace lost or damaged tissue. Although bone cancer is a relatively rare disease (it accounts for less than 1% of all cancers), people who suffer from it often end up losing a lot of bone tissue and in extreme cases, undergo amputation. The cancerous tissue has to be cut out, taking with it a large chunk of nearby healthy tissue to make sure that the cancer does not spread. This effectively removes the cancer, but also leaves the patient with a lot less bone than they started out with.

A recent study has used hybrid aerogels to restore the lost tissue by prompting bone regeneration. Aerogels are basically a combination of solid and gas. Think Jell-O, but one where the water has been slowly dried out and replaced completely by air. This slow and careful removing of liquid is what allows the gel to retain its shape instead of shriveling into a hard lump. The pairing of solid and gas makes aerogels extremely light and very porous. These two qualities make them exceptionally suitable to use as scaffolds, which can be used as physical roadmaps for the developing bone to follow as it grows.

A section of bone with osteosarcoma, a type of bone cancer. This is one of the cases where lost tissue could be restored by prompting bone regeneration.

Currently, the most common methods of bone regeneration either graft new bone on to the repair site or slowly pull two bits of bone further and further apart to allow new bone to grow in the gap. If you think that these methods sound painful, complicated, and expensive, you are right.

It turns out that bone tissue just needs a little bit of encouragement to regenerate. Most of the time, simple mechanical pressure will do the trick. The fiddly bit is getting the new bone tissue to grow in the right direction and for the right amount of time. Stop it too early and the bone will be too weak to actually serve a purpose. Let it grow too much and it will end up as painful projections. This balanced growth can be achieved by using a scaffold, which is where hybrid aerogels come in. A scaffold is a structure that is placed at the site of bone repair, where it guides the growing tissue along its destined path. A good scaffold is strong but not too stiff, lasts just long enough for fresh tissue to develop, and has a lot of pores for the growing bone to snake through. This last bit is what makes a scaffold very similar to real bone. Hybrid aerogels happen to be a magic material that hits all these notes.

There are a lot of different kinds of scaffolds to choose from, ranging from ceramic and metals to cellulose hydrogels. So what makes hybrid aerogels any better than other scaffolds? For one, they are half made of proteins (that’s the “hybrid” bit), which are eventually broken down by the body. The other half, silica, slowly melts away as orthosilicic acid, which is known to hasten wound healing. Their pore size can be controlled during the manufacturing process, making it easy to adapt them to different uses. They are also being tested as drug delivery systems, meaning that the material could be spiked with medicines or growth factors before using it as a scaffold.

Earlier this year, three research labs based out of Iran, Germany, and Austria got together and decided to fuse a very strong protein with a very light and porous aerogel. The very strong protein is silk fibroin, the stuff found in silkworm cocoons and used to make fancy fabrics. It makes the aerogel strong and just stiff enough to use for bone growth. With the raw materials ready, the scientists started with Phase I: make the hybrid aerogel. Throw a source of silica, silk fibroin, some acid and a touch of detergent into a pot. Bake for an hour and voilà! You have yourself a silica-silk fibroin hybrid aerogel.

 Hybrid aerogels are strong but ultralight materials. Here, the flower is protected from the fire by the insulating properties of the aerogel
The researchers made the perfect hybrid aerogel – hydrophilic (water-loving), not too stiff, and adequately biodegradable.

Having made the material, they now moved to Phase II: check if the hybrid aerogels are in any way harmful to human cells. In fact, the cells seemed to really like the material. When the hybrid aerogel was placed in a dish containing bone cells, they readily grew on its surface, depositing the proteins and minerals required for bone growth along the way.

On to Phase III: implant the hybrid aerogel in mice and check if it stimulates bone regeneration. The researchers made small bone injuries in two groups of mice and implanted the hybrid aerogel in one of them. After 25 days, they saw that the mice with the implants showed faster and better healing than the mice without implants. The aerogel was not just allowing new bone to grow, but also making it grow faster than normal.

This ability of the hybrid aerogel to speed up bone regeneration places it on the forefront of new therapeutic technologies. Imagine having bone fractures healing in a span of days, as opposed to weeks. Or being able to tell a bone cancer patient that, “Yes, you have to cut out a section of their leg but it can be easily grown back, no worries.” Hybrid aerogels are possibly the biomaterial that could make such conversations a reality.

Source: https://massivesci.com/

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