Dental Asia March/April 2019

User Report
CENTION N:
REDEFINING DENTAL RESTORATIONS
Written by Prof. Dr Mohan Bhuvaneswaran, Chennai/India
A user report on a
self-curing resin-based
filling material from
Ivoclar Vivadent.
Direct restoratives play a
major role in our day-to-day
clinical practice. Most of our
clinical work revolves around
restoring tooth structure
that has been lost due to carious or
non-carious processes.
Restoring the tooth back to its original
shape, function and aesthetic properties
is the aim of every conservative dentist. A
wide range of direct restorative materials
has been developed to achieve this. The
beginnings of restorative dentistry reach
back into ancient times when precious
metal such as gold was used to replace
lost tooth structure. Later, silver amalgam
was developed and became a versatile
filling material. Bulk-fill composites are
the protagonists of the latest standard
of filling materials today.
Objective: minimally invasive
preparation
Current approaches in restorative
dentistry aim to preserve the biological
tissues, dentin and enamel for example,
and to use minimally invasive preparation
techniques. The idea of “extension for
prevention” has become obsolete. Nor is
it any longer necessary to remove tooth
structure just to accommodate the filling
material. Adhesive restorative materials
have promoted these advances and yet,
silver amalgam is still in use, even after
150 years since it was launched. Another
popular choice of filling materials is glass
ionomer, which was first introduced in the
1970s by Wilson and Kent.
Declining popularity of amalgam
Silver amalgam is indicated for the
restoration of Class I and II cavities in
load bearing situations and in areas
where aesthetics is not a concern. If
a silver amalgam filling is placed, the
width at the isthmus of the cavity should
measure 25% of the maximum intercuspal
distance. In wider cavities, the clinician
has to look for possible alternatives.
Dental amalgam is a technique-resistant,
cost-effective material that can be placed
without requiring any major equipment. In
spite of its simple application procedure,
the clinical performance of amalgam is
exceptional. Approximately 90% of all
amalgam fillings were still fully functional
after 10 years in situ in a report by
Anusavice. The report attributes these
findings to the capability of amalgam to
minimise micro leakage, even if it does not
adhere to the tooth structure.
Nonetheless, the popularity of amalgam
has been decreasing in recent years
due to aesthetic concerns and the
comparatively large loss of tooth
structure. The environmental pollution
caused by mercury is also a concern.
The latter is gaining in importance as the
use of mercury has generally become
a controversy, fuelling the debate in
the media about the biocompatibility of
amalgam. The decisions of the Minamata
Convention regarding the use of mercury
have been taken seriously. Gradual
phasing out of amalgam is widely
supported and has become inevitable.
Popularity of glass ionomers (GI)
in spite of its drawbacks
Available in a powder-liquid mixture,
glass ionomer has gained significantly in
popularity due to its chemical adhesion to
the tooth structure, its biocompatibility
and its anti-cariogenic properties.
Glass ionomer results in an excellent
marginal seal because it chemically bonds
to the tooth structure. Ion release and
caries inhibiting effects are additional
beneficial properties of glass ionomers.
Although it is white in colour, it is never
been seen as an aesthetic filling material. In
stress-bearing areas, glass ionomer
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DENTAL ASIA MARCH / APRIL 2019