Abstract
GC everX Posterior Presentation
Prof. Pekka Vallittu, University of Turku, Institute of Dentistry
and Turku Clinical Biomaterials Centre – TCBC, Turku, Finland,
E-mail: Pekka.Vallittu@utu.fi
Replacement of damaged dental tissues is utilizing modern
adhesive techniques, which have turned especially restorative and
prosthetic dentistry to a new era. Fiber-reinforced composites
(FRCs) have been utilized in a variety of technical and everyday
applications since 1950s. Interestingly, begin of the use of FRCs in
dental and medical fields has been slow, although there have been
urgent
needs
for
cost-effective
mechanically
and
esthetic-
cosmetically high quality materials. At the moment, the dental
profession has one new exceptionally widely useable group of
material – FRCs – to be used clinically.
The biggest demand for the industry in dental materials field has
been finding material solutions to replace amalgam in large molar
restorations to be used by direct techniques. Present composites
made of particular fillers and resin matrix have not been able to
solve problems related to fracture propagation through composite
and isotropic polymerization contraction. Due to this, bulk
fractures can occur. On the other hand, particulate fillers keep the
composite isotropic in terms of many properties, including
polymerization shrinkage. Shrinkage causes gaps between the
restoration and the tooth, and predispose to secondary caries.
everX Posterior is a short fiber-reinforced composite, which is used
to replace tissue largely damaged teeth, especially of dentine.
Glass fibers of everX Posterior material simulate collagen fibers of
dentine, and provide high toughness (5.1 MPa /m1/2) of the
restoration-tooth system. The value of toughness exceeds the
value of dentine, which is a collagen fiber-reinforced natural
material. Length of the glass fibers has been optimized to provide
high strength and toughness and to have good adaptation to the
dimensions of posterior teeth. At the same fibers of everX
Posterior also control and minimize polymerization shrinkage of
the composite resin. everX Posterior is used as bilayered filling
material, i.e. the outermost part of the filling, which simulates
enamel,
is
made
of
high
quality
hybrid
composite
resin.
Attachment of overlaying particulate composite to everX Posterior
is ensured by fibers, which simulates attachment of enamel to
dentine via collagen fiber decussation. This results in high load
bearing capacity for the restored tooth.