(80a) Near-Infrared Light Curable Composites for Advanced Dental Applications

Light-curable dental polymers (resins) are commonly used
in restorative surgery, prosthodontics and surgical procedures. Despite the
fact of wide application, there are clinical problems due to limitations of
blue light penetration: application is restricted to defects exposed to the
light source; layered filling of defect is required (see figure) [1].

In the present work, we therefore investigate a new way
to avoid problems inherent to conventional light-curing dental resins. We will
discuss the innovative approach dealing with deep tissue penetrating near
infrared light (NIR) and upconversion (UC) phosphors. The necessary light to
homogeneously harden a restorative resin inside a tooth can thus be generated
?on spot? inside the polymer and thereby avoids the absorbance loss problem of
current dental treatments (see figure).

We will focus on a novel technique for the
polymerization of light-curing resins: blending the resins with UC phosphor
particles and curing the material with blue UC emission upon NIR excitation. The
prepared composites could restore the cavities up to 7-10 mm deep in one step,
even positioned behind thin enamel or dentin obstacles. Potential substitution of commonly used light-curing polymers, providing
additional advantages to be discussed.

Reference: [1] R.G. Craig, in Restoraive
Dental Materials, Mosby, St. Louis, 2002.