Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Open wide and say 'zap'

20.08.2009
Optics Express paper describes new way to clinically assess condition of tooth enamel using lasers

A group of researchers in Australia and Taiwan has developed a new way to analyze the health of human teeth using lasers. As described in the latest issue of Optics Express, the Optical Society's (OSA) open-access journal, by measuring how the surface of a tooth responds to laser-generated ultrasound, they can evaluate the mineral content of tooth enamel -- the semi-translucent outer layer of a tooth that protects the underlying dentin.

This is the first time anyone has been able to non-destructively measure the elasticity of human teeth, creating a method that can be used to assess oral health and predict emerging dental problems, such as tooth decay and cavities.

"The ultimate goal is to come up with a quick, efficient, cost-effective, and non-destructive way to evaluate the mineralization of human dental enamel," says David Hsiao-Chuan Wang, a graduate student at the University of Sydney in Australia and first author on the paper in Optics Express. Wang and his advisor Simon Fleming, a physics professor at the University of Sydney's Institute of Photonics and Optical Science, collaborated on the study with dental researchers at the University of Sydney and ultrasonic evaluation researchers at National Cheng Kung University in Tainan City, Taiwan.

Stronger than bone, enamel is the hardest and the most mineralized substance of the human body -- one of the reasons why human teeth can survive for centuries after a person has died. It envelops teeth in a protective layer that shields the underlying dentin from decay.

Throughout a person's lifetime, enamel constantly undergoes a cycle of mineral loss and restoration, in which healthy teeth maintain a high mineral content. If the balance between mineral loss and gain is lost, however, teeth can develop areas of softened enamel -- known as carious lesions -- which are precursors to cavities and permanently damaged teeth.

Enamel demineralization is caused by bad oral hygiene. Not brushing, for instance, can lead to the build-up of dental plaques, and bacteria in these plaques will absorb sugars and other carbohydrates a person chews and produce acids that will dissolve the minerals in tooth enamel.

Quantifying the mineral content of tooth enamel can help dentists determine the location and the severity of developing dental lesions. Existing methods for evaluating enamel are limited, however. Dentists can visually assess the teeth, but dental lesions can be hard to spot in certain parts of the mouth because they are obscured by dental plaque, saliva, or the structure of a tooth itself. Dentists can use sharp instruments to probe the enamel, but this can be destructive to the teeth and gums. X-ray scans can reveal dental lesions, but they give no information on the level of mineralization.

For research purposes, "nano-indentation" is commonly used for gaining information on the elasticity of tooth enamel -- a measure of its mineral content -- but nano-indentation destroys the measured regions of the enamel in the process and is only used to look at extracted teeth.

What Wang, Fleming, and their colleagues wanted to do was to develop a clinical method that would give as much information as nano-indentation and could be used to assess tooth enamel in actual patients while being completely non-destructive. So they developed a way to measure the elasticity of tooth enamel by adapting laser ultrasonic surface wave velocity dispersion, a method similar to what industrial engineers use to evaluate the integrity of thin films and metals.

The method uses short duration laser pulses to excite ultrasonic waves that propagate along the surface and penetrate only a small distance into a tooth. The velocity of these waves is influenced by the elastic properties of the enamel on a tooth, and by detecting the ultrasonic waves with fiber optics at various points, they can determine the enamel's elasticity, which is directly related to its mineralization.

In their Optics Express article, Wang, Fleming, and their colleagues showed that they could use this technique on extracted human teeth. They have not yet tested the technique on a living person's teeth, and it will likely take several years before any eventual device is ready for use in the dentist's office.

This work was funded by the Australian Government and Bio-Dental Technology Pty. Ltd.

Paper: "Laser Ultrasonic Surface Wave Dispersion Technique for Non-destructive Evaluation of Human Dental Enamel," Hsiao-Chuan Wang et al., Optics Express.

About OSA

Uniting more than 106,000 professionals from 134 countries, the Optical Society (OSA) brings together the global optics community through its programs and initiatives. Since 1916 OSA has worked to advance the common interests of the field, providing educational resources to the scientists, engineers and business leaders who work in the field by promoting the science of light and the advanced technologies made possible by optics and photonics. OSA publications, events, technical groups and programs foster optics knowledge and scientific collaboration among all those with an interest in optics and photonics.

Colleen Morrison | EurekAlert!
Further information:
http://www.osa.org

More articles from Physics and Astronomy:

nachricht A single photon reveals quantum entanglement of 16 million atoms
16.10.2017 | Université de Genève

nachricht On the generation of solar spicules and Alfvenic waves
16.10.2017 | Instituto de Astrofísica de Canarias (IAC)

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

Im Focus: New nanomaterial can extract hydrogen fuel from seawater

Hybrid material converts more sunlight and can weather seawater's harsh conditions

It's possible to produce hydrogen to power fuel cells by extracting the gas from seawater, but the electricity required to do it makes the process costly. UCF...

Im Focus: Small collisions make big impact on Mercury's thin atmosphere

Mercury, our smallest planetary neighbor, has very little to call an atmosphere, but it does have a strange weather pattern: morning micro-meteor showers.

Recent modeling along with previously published results from NASA's MESSENGER spacecraft -- short for Mercury Surface, Space Environment, Geochemistry and...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

Conference Week RRR2017 on Renewable Resources from Wet and Rewetted Peatlands

28.09.2017 | Event News

 
Latest News

A single photon reveals quantum entanglement of 16 million atoms

16.10.2017 | Physics and Astronomy

The melting ice makes the sea around Greenland less saline

16.10.2017 | Earth Sciences

On the generation of solar spicules and Alfvenic waves

16.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>