GLASSIONOMER CEMENT FOR PERMANENT DENTAL RESTORATIONS: A 48-MONTHS,
MULTI-CENTRE, PROSPECTIVE CLINICAL TRIAL
Figure 1 A mesio-occlusal class II composite
restoration is shown in an upper right first molar.
The restoration margins present chippings and
the restoration itself is not functional
Figure 2 The situation is shown after
positioning of the rubber dam, cleaning the
cavity and positioning of a curved partial matrix
execution of retentive walls, bevels, notches, or
unnecessary removal of healthy tooth tissue
Figure 3 The restoration after application of
high-viscosity GIC. The removal of the matrix
was performed after 3 min. from mixing time to
ensure the initial hardening of the material
Figure 4 The completed restoration after
rubber dam removal, occlusal check, finishing
and application of the resin coating. The
coating confers the “glossy” appearance to
the restoration. Good marginal adaptation and
overall acceptable aesthetics of the restoration
can be recognized
due to a poor level of marginal sealing and a
relatively low resistance to wear (12). Glassionomer
cements for dental restorations also acquired
the label of cheap materials, not of high quality,
especially useful for rapid restoration, and more
focussed on social assistance, becoming the
material of choice for Atraumatic Restorative
Dentistry (ART) (14-16). Recently, the introduction
of nanotechnology in dentistry allowed for
significant structural changes in many dental
materials, from impression materials (17) to resin
composites (18,19), and in particular also for
glassionomer cements (17,19). In particular, the
limits of hardness and resistance to stress of GICs
have been significantly improved, and modern
GICs can also give an aspect of natural translucency
and coloration to restorations, representing a valid
aesthetic solution (20, 21).
Moreover, manufacturers improved fluoride
release from modern GICs in order to increase
their role in the treatment and prevention of caries.
As a consequence, recent studies identified high
concentrations of fluoride and other ions in the
dentine adjacent to GICs restorations (2,3). It was
also demonstrated that, by ion release, GICs can
strongly remineralise the demineralized dentine
when a layer of material is placed directly on the
affected dentinal surface (22).
Considering the evolution of GICs and their role
as bioactive materials, the aim of this study was
to evaluate the durability and possible issues of
a novel GIC system based on a high-viscosity
glassionomer cement coated with a light-curable
resin based on nanotechnology, when used for
long-term teeth restorations.
Methodology
Patients visited at the Dental Clinic of the IRCCS
Galeazzi Orthopedic Institute (Milan, Italy) from
2007 to 2010 who required dental restorations
11