Tag Archives: tooth enamel

Brighten and whiten your teeth (more safely) with nanoparticles?

This is for anyone who’s ever suspected that the all the tooth brightening and whitening might not be such a good idea after all. A July 18, 2018 news item on Nanowerk announces work on what scientists hope will be a safer way to whiten teeth (Note: A link has been removed),

In the age of Instagram and Snapchat, everyone wants to have perfect pearly whites. To get a brighter smile, consumers can opt for over the counter teeth-whitening treatments or a trip to the dentist to have their teeth bleached professionally. But both types of treatments can harm teeth.

According to an article published in ACS Biomaterials Science & Engineering (“Blue-Light -Activated Nano-TiO2@PDA for Highly Effective and Nondestructive Tooth Whitening”), researchers have now developed a new, less destructive method.

A July 18, 2018 American Chemical Society (ACS) news release (also on EurekAlert), which originated the news item expands on the theme,

Teeth can become discolored on their outer surfaces when people consume colored foods and drinks, such as coffee, tea or red wine. As a result, many people turn to non-invasive whitening treatments that bleach the teeth. Currently, the most common bleaching agent is hydrogen peroxide, which steals electrons from the pigment molecules that cause teeth discoloration, and this process can be sped up by exposing teeth to blue light. But high concentrations of hydrogen peroxide can break down a tooth’s enamel, causing sensitivity or cell death. So, Xiaolei Wang, Lan Liao and colleagues wanted to see if a different blue-light-activated compound could be a safer, but still effective, alternative.

The team modified titanium dioxide nanoparticles with polydopamine (nano-TiO2@PDA) so that they could be activated with blue light. In a proof-of-concept experiment, the nano-TiO2@PDA particles were evenly coated on the surface of a tooth and irradiated with blue light. After four hours of treatment, the whitening level was similar to that obtained with hydrogen-peroxide-based agents. The group notes that no significant enamel damage was found on the surface of the tooth, and the treatment was significantly less cytotoxic than hydrogen peroxide. In addition, the nano-TiO2@PDA therapy showed antibacterial activity against certain bacteria.

Here’s a link to and a citation for the paper,

Blue-Light -Activated Nano-TiO2@PDA for Highly Effective and Nondestructive Tooth Whitening by Feng Zhang, Chongxue Wu, Ziyu Zhou, Jiaolong Wang, Weiwei Bao, Lina Dong, Zihao Zhang, Jing Ye, Lan Liao, and Xiaolei Wang. ACS Biomater. Sci. Eng., Article ASAP DOI: 10.1021/acsbiomaterials.8b00548 Publication Date (Web): June 19, 2018

Copyright © 2018 American Chemical Society

This paper is behind a paywall.

Of course, there’s always the question of what happens as we pour more and more engineered titanium dioxide nanoparticles into our bodies and ultimately into the environment.

Nanoscale elements that govern the behaviour of our teeth

Are we going to be adopting atomically correct dental hygiene practices in the future? It’s certainly a possibility given the latest Australian research announced in a Sept. 7, 2016 news item on Nanowerk (Note: A link has been removed),

With one in two Australian children reported to have tooth decay in their permanent teeth by age 12, researchers from the University of Sydney believe they have identified some nanoscale elements that govern the behaviour of our teeth.

Material and structures engineers worked with dentists and bioengineers to map the exact composition and structure of tooth enamel at the atomic scale.

Using a relatively new microscopy technique called atom probe tomography, their work produced the first-ever three-dimensional maps showing the positions of atoms critical in the decay process.

The new knowledge on atom composition at the nanolevel has the potential to aid oral health hygiene and caries prevention, and has been published today in the journal Science Advances(“Atomic-scale compositional mapping reveals Mg-rich amorphous calcium phosphate in human dental enamel”).

A Sept. 8, 2016 University of Sydney press release, which originated the news item, expands on the theme (Note: A link has been removed),

Professor Julie Cairney, Material and Structures Engineer in the Faculty of Engineering and Information Technologies, said:

“The dental professionals have known that certain trace ions are important in the tough structure of tooth enamel but until now it had been impossible to map the ions in detail.

“The structure of human tooth enamel is extremely intricate and while we have known that magnesium, carbonate and fluoride ions influence enamel properties scientists have never been able to capture its structure at a high enough resolution or definition.”

“What we have found are the magnesium-rich regions between the hydroxyapatite nanorods that make up the enamel.”

“This means we have the first direct evidence of the existence of a proposed amorphous magnesium-rich calcium phosphate phase that plays an essential role in governing the behaviour of teeth. “

Co-lead researcher on the study, Dr Alexandre La Fontaine from the University’s Australian Centre for Microscopy and Microanalysis, said:

“We were also able to see nanoscale ‘clumps’ of organic material, which indicates that proteins and peptides are heterogeneously distributed within the enamel rather than present along all the nanorod interfaces, which was what was previously suggested.

“The mapping has the potential for new treatments designed around protecting against the dissolution of this specific amorphous phase.

“The new understanding of how enamel forms will also help in tooth remineralisation research.”

Here’s a link to and a citation for the paper,

Atomic-scale compositional mapping reveals Mg-rich amorphous calcium phosphate in human dental enamel by Alexandre La Fontaine, Alexander Zavgorodniy, Howgwei Liu, Rongkun Zheng, Michael Swain, and Julie Cairney. Science Advances  07 Sep 2016: Vol. 2, no. 9, e1601145 DOI: 10.1126/sciadv.1601145

This paper is open access.