Biomedical Engineering Reference
In-Depth Information
hydroxyapatite, with the formation of an intermediate layer of
polyacrylates, particularly rich in calcium and phosphate ions;
-
direct bonds to calcium ions of the apatite [WIL 88].
Although GICs are considered “self-adhesive” to dental tissues, the
dental surface is not without effect on the adhesion performance. The
dental tissues are always covered by the smear layer (drilling residue)
that impedes contact with GIC. Hence, conditioning is required to
remove it (Figures 11.4 and 11.5). A number of acids or products have
been proposed to prepare the dental surface.
Figure 11.4.
Dentin surface without conditioning
An application of polyacrylic acid (10-20%) seems to be the most
reliable solution compared to phosphoric or citric acid (too
demineralizing). An interesting alternative is the use of
ethylenediaminetetraacetic acid (EDTA).
Figure 11.5.
Dentin after polyacrylic acid conditioning (20%)
