Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Shark teeth are not harder than human teeth

30.07.2012
Scientists at the University of Duisburg-Essen (UDE) and the Max-Planck-Institut für Eisenforschung (MPIE) in Düsseldorf have analyzed the structure of shark teeth and human teeth.
The results of this research project are surprising: Although shark teeth contain 100% of a fluoride (i.e. the mineral which is also present in low concentrations in toothpastes), they are not harder than our teeth.

It is not by coincidence that the material and nano scientists have analyzed shark teeth. "I had wanted to do this for a long time", underlined Matthias Epple, Professor for Inorganic Chemistry. "We have been investigating biomineralization at the UDE for several years. It is our main goal to determine the effect of inorganic minerals on biological systems, such as teeth, bones and seashells.

It is well-known that sharks have enamel which consists of the very hard mineral fluoroapatite. So far, no scientist has investigated this with high-end chemical and physical methods." This was now done by Epple and his colleague from the MPIE Professor Dierk Raabe, together with Dr Oleg Prymak and Joachim Enax. The main part of the work was carried out at UDE. The MPIE was the institute, where especially the mechanical measurements took place.

For this study the teeth of shortfin mako shark and tiger shark were literally "taken apart" – for these shark species have different habits of eating their prey. By scanning electron microscopy and X-ray diffraction, the scientists analyzed the order, the size and the nature of the fluoroapatite crystals and determined the hardness of the teeth locally in small areas with mechanical measurements.

Epple and his co-workers showed that the chemical and crystallographic composition of teeth is similar in different shark species, although mako sharks "tear" into the flesh of their prey while tiger sharks "cut" it. The interior consists of the more elastic dentin; the outer part is the highly mineralized enamel.

Thus one might suppose that shark teeth are harder than human teeth. "The human enamel consists of a little softer mineral, hydroxyapatite, which is incidentally also present in bones." By carrying out a comparative study with a human tooth, the scientists discovered something surprisingly new: It is just as robust as that of that fearful animal. "This is due to the special micro- and nanostructure of our teeth.

The crystals in human teeth have a special arrangement and they are "glued together" by proteins, which stops cracks from running through the whole tooth", said Epple, who is also a member of the Center for Nanointegration Duisburg-Essen (CENIDE). Incidentally nature has equipped all creatures similarly: If teeth were fully mineralized they would be in danger of cracking upon mechanical shock.

The scientists are now continuing their research on shark teeth, e.g. on sharks of different age. With their experiments they are trying to imitate these structures to lay the foundations for novel dental prostheses. "It would be great if – sometime in the future - one could repair teeth with a material, which is more natural than today`s provisional solutions."

Until then, humans will have to accept that sharks still have better teeth: They are replaced continuously and do not develop any cavities. "The reason might be the fluoroapatite and the revolving set of teeth which is always immersed in sea water", explained Matthias Epple. "And finally: Sharks do not eat sugar."

The research findings are published in the recent issue of the Journal of Structural Biology, 178 (2012). DOI http://dx.doi.org/10.1016/j.jsb.2012.03.012.

Further information: Prof. Dr. Matthias Epple, University of Duisburg-Essen, +49 0201/183-2413, matthias.epple@uni-due.de

Note for editorial staff: Prof. Epple will be out of office until August, 20th. The university press office can contact him. Please write to Ms. Ulrike Bohnsack, ulrike.bohnsack@uni-due.de

Ulrike Bohnsack | idw
Further information:
http://www.uni-due.de

More articles from Life Sciences:

nachricht Researchers develop eco-friendly, 4-in-1 catalyst
25.04.2017 | Brown University

nachricht Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017
25.04.2017 | Laser Zentrum Hannover e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

NASA's Fermi catches gamma-ray flashes from tropical storms

25.04.2017 | Physics and Astronomy

Researchers invent process to make sustainable rubber, plastics

25.04.2017 | Materials Sciences

Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017

25.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>