To repair damage involving
over 1/3 of the tooth's biting surface, rather than using a simple
filling, or a crown,
a dentist will often use an inlay, or an onlay.
Inlays and onlays,
can be porcelain, gold, or resin reinforced ceramic cast sections
that are bonded to the damaged area of a tooth. An inlay
is similar to a filling and lies inside the cusp tips of a tooth;
an onlay is a more extensive reconstruction that covers one or
more cusps of a tooth.
Inlays and onlays
are both traditionally made of gold; however, porcelain is now
becoming the material of choice because of its strength and potential
to match the natural color of your tooth.
Inlays and onlays
are placed in two dental visits. At the first visit, the
old filling, or decay, is removed, and the tooth is prepared for
the inlay / onlay. The dentist will then make an impression
of the tooth, and send this impression to a dental laboratory.
This impression will be used by the laboratory to construct a
porcelain or gold inlay / onlay that will fit excatly into your
tooth. At this time the dentist will place a temporary sealing
on your tooth and schedule a second appointment.
At the second visit,
the temporary is removed. Your dentist will then ensure
that the inlay / onlay is bonded into the tooth with a strong
bonding resin, and polished smooth.
Considerations:
Typically fillings can reduce the strength of the tooth by
up to 50%. Inlays and onlays, however, because they are
bonded directly into the tooth with special reins, can actually
increase the strength of the tooth by up to 75%; as a result,
they can last from 10-30 years, and in some cases, provide a good
alternative to a crown.