Sat urday 31 Aug ust 2019 The Guardian •
National^15
Scientists
fi nd way to
‘grow back’
damaged
tooth enamel
Nicola Davis
Scientists say they have fi nally cracked
the problem of repairing tooth enamel.
The substance is the hardest tissue in
the human body – but while it is tough,
it cannot self-repair.
Scientists have revealed a method
by which its complex structure can be
reproduced and the enamel essentially
“grown” back. The team behind the
research say the materials are cheap
and can be prepared on a large scale.
“After intensive discussion with
dentists, we believe that this new
method can be widely used in future,”
said Dr Zhaoming Liu , co-author, from
Zhejiang University in China.
Tooth decay is extremely common:
according to 2016 fi gures about 2.4 bil-
lion people worldwide live with caries
in permanent teeth , while 486 million
children have tooth decay in their milk
teeth. Materials such as resin, metal
alloys, amalgam and ceramics are used
to repair damaged tooth enamel, but
they are not ideal.
“The resin-based material still can-
not adhere well on enamel, and they
will get loose after around fi ve years,”
said Liu.
Scientists have found it diffi cult to
reproduce the complex structure of
natural tooth enamel. The research-
ers behind the latest study, published
in the journal Science Advances , say
they got around this problem by devel-
oping a way to produce tiny clusters of
calcium phosphate – the main compo-
nent of enamel – with a diameter of
just 1.5 nanometres – far smaller than
those previously employed.
The team applied the tiny clusters
to human enamel which had been
exposed to acid, fi nding that within
48 hours the clusters had given rise to
a crystalline layer, about 2.7 microme-
tres thick, with the complex, fi sh-scale
like structure of the underlying natu-
ral enamel.
Dr Sherif Elsharkawy, an expert in
prosthodontics at Kings College Lon-
don who was not involved in the work,
praised the research.
“The method is simple, but needs to
be validated clinically,” he said, adding
that the layers would have to be thicker
to be used in cavities. He believes it
could be several years before the
method can be used by dentists.Pussyfooting around Larry the Downing Street cat
turned tail and made his escape yesterday despite
the best eff orts of a group of young animal lovers. The
children had been visiting No 10 for a question and answer
session with the prime minister, Boris Johnson.PHOTOGRAPH:
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