Low temperature plasma jets could replace dentist's drill
21 January 2010
German scientists have used low temperature plasma jets to
clean tooth dentin of bacteria. The process could be a painless
replacement for the dentist's drill.
The study is published in the February issue of the Journal of
Medical Microbiology.
Firing low temperature plasma beams at dentin — the fibrous tooth
structure underneath the enamel coating — was found to reduce the amount
of dental bacteria by up to 10,000-fold. This could lead to the use of
cold plasma technology to remove infected tissue in tooth cavities
instead of drilling into the tooth.
Scientists at the Leibniz-Institute of Surface Modifications, Leipzig
and dentists from the Saarland University, Homburg, Germany, tested the
effectiveness of plasma against common oral pathogens including
Streptococcus mutans and Lactobacillus casei. These
bacteria form films on the surface of teeth and are capable of eroding
tooth enamel and the dentin below it to cause cavities. If left
untreated it can lead to pain, tooth loss and sometimes severe gum
infections.
In this study, the researchers infected dentin from extracted human
molars with four strains of bacteria and then exposed it to plasma jets
for 6, 12 or 18 seconds. The longer the dentin was exposed to the plasma
the greater the amount of bacteria that were eliminated.
Plasmas are known as the fourth state of matter after solids, liquids
and gases and have an increasing number of technical and medical
applications. Plasmas are produced when high-energy processes strip
atoms of one or more of their electrons. This forms high-temperature
reactive oxygen species that are capable of destroying microbes. These
hot plasmas are already used to disinfect surgical instruments. Cold
plasmas are already used in devices used for room sterilisation.
Dr Stefan Rupf from Saarland University who led the research said
that the recent development of cold plasmas that have temperatures of
around 40 degrees Celsius showed great promise for use in dentistry.
"The low temperature means they can kill the microbes while preserving
the tooth. The dental pulp at the centre of the tooth, underneath the
dentin, is linked to the blood supply and nerves and heat damage to it
must be avoided at all costs."
Dr Rupf said using plasma technology to disinfect tooth cavities
would be welcomed by patients as well as dentists. "Drilling is a very
uncomfortable and sometimes painful experience. Cold plasma, in
contrast, is a completely contact-free method that is highly effective.
Presently, there is huge progress being made in the field of plasma
medicine and a clinical treatment for dental cavities can be expected
within 3 to 5 years."