DENTAL RESINS, MISCELLANEOUS DENTAL MATERIALS,
Section I. DENTAL RESINS FOR RESTORATIVE DENTISTRY
Because of its esthetic (term used for an artistically pleasing appearance)
properties, resin can be used for the reproduction of lost tooth structure. The dental
officer prepares the cavity in the tooth in the usual manner, inserts the plastic mixture
directly into the cavity, and allows it to polymerize at mouth temperature. These
materials are often referred to as direct-filling resins. Certain shortcomings in the
physical properties of resins restrict their use when esthetics, such as the restoration of
anterior teeth, are the principal concern. Although not as strong as amalgams, resins
are designed to meet the needs of a specific area of a tooth or mouth. The most
commonly used and most widely accepted is composite resin.
a. Clinical Use. Composite resins are the most commonly used material for all
permanent anterior restorations and are increasingly being used in posterior
restorations. These resins make excellent restorative materials because of their good
resistance to wear and their excellent esthetics. Silar, Adaptic, and Concise are some
of the trade names of composite resins.
b. Chemical Composition. Composite resins are composed of universal paste
with filler and catalyst paste. All composite resins use quartz (a hard rock-forming
mineral) as a filler.
c. Properties. Composite resins have excellent esthetic properties. In fact, the
universal paste will match 89 percent of all tooth shades. Tints are available for the
other 11 percent. Composite resins have good resistance to wear because of the filler.
They also have an acceptable compressive strength of 35,000 psi. Thermal expansion
is at a minimum. (The manufacturer claims that the thermal expansion is close to the
normal expansion of tooth structure.) Solubility and shrinkage are low. Refrigeration of