Tuesday, August 21, 2018

Bioengineered Tooth Replacement Opens Doors to New Therapies

Tooth loss is a significant health issue currently affecting millions of people worldwide. While artificial dental implants are the existing standard tooth replacement therapy, they do not exhibit many properties of natural teeth and can be associated with complications leading to implant failure. Two articles published in the September 2018 issue of the Journal of Dental Research share recent advances in bioengineering teeth.

In the article “Bioengineered Tooth Buds Exhibit Features of Natural Tooth Buds” Pamela Yelick, Tufts University School of Dental Medicine, Boston, Mass., USA and co-authors explored new methods to create highly cellularized bioengineered tooth bud constructs that include features that resemble natural tooth buds such as the dental epithelial stem cell niche, enamel knot signaling centers, transient amplifying cells and mineralized dental tissue formation. The constructs were composed of postnatal dental cells encapsulated within a hydrogel material that were implanted subcutaneously into immunocompromised rats.

File:Loss of tooth characteristics.jpg
Credit; Itdent / Wikimedia Commons


This is the first report that describes the use of postnatal dental cells to create bioengineered tooth buds that exhibit evidence of these features of natural tooth development, pointing to future bioengineered tooth buds as a promising, clinically relevant tooth replacement therapy.

In the article “Bone Marrow Stromal Cells Promote Innervation of Bioengineered Teeth” Sabine Kuchler-Bopp, French National Institute of Health and Medical Research and Fédération de Médecine Translationnelle de Strasbourg, France, and co-authors developed a strategy where autologous mesenchymal cells coming from bone marrow can be used to supply nerves to bioengineered teeth without treatment that uses an immunosuppressor. The innervation of teeth is essential for their function and protection but does not occur spontaneously after injury. This new method provides innervation while avoiding multiple side effects associated with immunosuppressors.

“These exciting studies point to a promising future for bioengineered teeth,” said Journal of Dental ResearchEditor-in-Chief William V. Giannobile. “This cutting-edge research has the potential to advance tooth replacement therapy and the science base to bring such regenerative medicine treatments to improve clinical care.”




Contacts and sources:
Elise Bender
The International Association for Dental Research (IADR)
The IADR/AADR Journal of Dental Research (JDR)
 

Stone Tools Reveal Modern Human-Like Gripping Capabilities 500,000 Years Ago

Research carried out at the University of Kent demonstrates that a technique used to produce stone tools that were first found half a million years ago is likely to have needed a modern human-like hand

This research is the first to link a stone tool production technique known as 'platform preparation' to the biology of human hands. Demonstrating that without the ability to perform highly forceful precision grips, our ancestors would not have been able to produce advanced types of stone tool like spear points.

The technique involves preparing a striking area on a tool to remove specific stone flakes and shape the tool into a pre-conceived design.

Comparison between a Handaxe and a Clovis Point

Credit: Alastair Key and Metin Eren

Platform preparation is essential for making many different types of advanced prehistoric stone tool, with the earliest known occurrence observed at the 500,000-year-old site of Boxgrove in West Sussex (UK).

The study, led by Dr Alastair Key, of the University's School of Anthropology and Conservation, and funded by the British Academy, investigated how hands are used during the production of different types of early stone technology.

Using sensors attached to the hand of skilled flint knappers (stone tool producers), the researchers were able to identify that platform preparation behaviours required the hand to exert significantly more pressure through the fingers when compared to all other stone tool activities studied.

The research demonstrates that the Boxgrove hominins (early humans) would have needed significantly stronger grips compared to earlier populations who did not perform this behaviour. It further suggests that highly modified and shaped stone tools, such as the handaxes discovered at Boxgrove and stone spear points found in later prehistory, may not have been possible to produce until humans evolved the ability to perform particularly forceful grips.

This discovery is particularly important because human hand bones rarely survive in the fossil record.

Dr Key said: 'Hand bones from before 300,000 years ago are rare, particularly when compared to other human fossils such as teeth, so the fact we can study the manipulative capabilities of our early ancestors from the stone tools they produced is incredibly exciting'.






Contacts and sources:
Sandy FlemingUniversity of Kent

Citation: The findings Manual restrictions on Palaeolithic technological behaviours Key, A. and Dunmore, C.J. 2018 are published open access in PeerJ 6: e5399 and are freely available here.
https://peerj.com/articles/5399/