Universal cements: dual activated and chemically activated
The clinical success of indirect restoration procedures
depends among others on the cementation technique
used to create a stable bond between the restoration
and the different dental structures. Resin cements
have been widely used in the fixation of inlays, onlays,
crowns and pins due to their improved mechanical
properties, ease of use and esthetic qualities.
However, many new products have appeared in the
dental market, making the choice of materials a difficult
task for professionals.
Resin cements are composed of a matrix of Bis-
GMA or UEDMA, monomers with a low molecular
weight, such as TEGDMA, and functional hydrophilic
groups that promote adhesion to dentin, such as
HEMA and 4-META Resin-based cements may
contain the monomer MDP (10-methacryloyloxydecyl
dihydrogen phosphate), which also promotes adhesion.
Adhesive cementation is a critical phase that
involves the application of an adhesive system and a
cementation agent. Consequently, this slow, sensitive
and complex procedure requires multiple steps.
Universal cements, which involve a process of dual
polymerization, have recently been launched in the market. However, the use of a multimode adhesive
system is recommended. These adhesives can be
applied to enamel and/or dentin, offering the possibility
of using them as a conventional (complete conditioning
technique) or self-etching system. These
systems differ in relation to the availability of the
monomer MDP, which interacts chemically with the
hydroxyapatite of dental tissue.