all round for perfect colour match
ingenious solution to the problem of colour matching teeth
has been discovered by colour chemist Professor Stephen
Burkinshaw and dentistry consultant Dr Brian Nattress.
Say cheese - Dr Nattress (left) and Professor
Burkinshaw demonstrate their digital imaging system
can sometimes reveal an embarrassing display of teeth,
as dental fixtures such as crowns or bridges show up as
clearly false amongst our humbly off-white natural teeth.
dentists use just sixteen shades of white to find a match
for a patients teeth, and they pick the colour by
eye. The result is rarely satisfactory and when Dr Nattress
approached Professor Burkinshaw to find a solution, they
carried out an experiment to see if colour chemists could
pick better matches than dentists.
Burkinshaw recalls: Everyone got it wrong, which
just proved that the only way to do an exact colour match
was using some form of instrumentation.
instrumental methods had been tried, mostly using spectrophotometers
or colorimiters, which have been used for decades to match
colours in textiles and paints.
instruments use a tiny point of light to take a reading
of the colour, explains Professor Burkinshaw. Thats
fine for a homogenous colour, but teeth are far too complex.
We looked at it from a different angle, trying to mimc
the way you see other peoples teeth, as that would
be the ultimate judge of a correct match. The answer was
researchers teamed up with Olympus, and using a standard
digital camera, specially calibrated and with controlled
lighting, they set up a system to take a picture of the
patients mouth. This can then be sent by internet
to the dental laboratory, where software prints out a
colour recipe for the technician. The whole
thing is colour corrected at source, to ensure perfect
Nattress said: Clinical trials just completed at
the Universitys dental institute, have shown the
digital photography is a massive improvement on matches
by trained dentists. The system is now being marketed
on our behalf by the Swiss company, Metalor.
technology has potential applications in many other areas,
and the researchers have set up a company DentPark
Ltd through Leeds Innovations to further exploit
the potential of their research.