The Truth about All-Ceramic Inlays and Onlays
Dental inlays are fillings for tooth cavities that are made out of a solid substance. Inlays are fabricated outside of the mouth and then cemented into the tooth. Onlays are similar in design to inlays, but cover the portion of the tooth where a cusp would be. Crowns are onlays that cover all of the surfaces of the tooth. There are advantages and disadvantages to using all-ceramic inlays and onlays as opposed to traditional amalgam fillings or metal reinforced inlays and onlays.
All-ceramic inlays and onlays typically blend very naturally with the color and translucency of the rest of the tooth and other teeth, so the appearance of the smile is enhanced. In some cases, patients may achieve a healthier looking smile than could have been achieved by any other means, which can boost confidence. The ceramic that is used to fabricate inlays and onlays does not discolor over time, as some other materials may.
All-ceramic inlays and onlays are easy to clean and care for, as they blend seamlessly into the tooth. The application of all-ceramic inlays and onlays helps to protect the tooth against future decay and deterioration. Patients simply have to brush and floss the tooth which the ceramic inlay or onlay has been applied to in order to maintain the appearance and health of the tooth and the gums.
Fracture Risk Disadvantages
Ceramic is strong, but it is also brittle. Unfortunately, this means that inlays and onlays that are not reinforced with metal may be susceptible to breaks and fractures when pressure is applied to the tooth surface. Fractures can occur when patients eat foods that are very hard or if tooth grinding behaviors are present.
The marginal fit of ceramic inlays and onlays is inferior to that of gold inlays and onlays. While the marginal fit is deemed acceptable, the slight variation in fit may affect the bite alignment. When combined with the strength of ceramic, a variation in fit may cause wear on opposing teeth.
All-Ceramic Inlay and Onlay Application
Fitting all-ceramic inlays and onlays requires two visits to the dentist. During the first visit, the dentist examines the tooth that requires restoration and takes an impression using dental putty. The patient is typically fitted with a temporary inlay or onlay while the permanent one is being fabricated. When the patient returns, the temporary inlay or onlay is removed and the permanent restoration is cemented into place. The tooth is then given a final polish.