Fillings, Inlays & Onlays

An inlay is a dental restoration that covers a fairly small part of the biting surface of a back tooth. It is cemented into place and cannot be taken off.

Inlays are made of two types of materials:
1. Porcelain: most like a natural tooth in color
2. Gold Alloy: strongest and most conservative in its preparation

Inlays restore a tooth to its natural size, shape and if using porcelain, color. They improve the strength, function and appearance of a broken down tooth that may otherwise be lost.

In having an inlay, some inherent risks exist both to the tooth and to the inlay itself. The risks to the tooth are:
– Preparation for an inlay weakens tooth structure and permanently alters the tooth underneath the inlay.
– Preparing for and placing an inlay can irritate the tooth and cause post-operative sensitivity which may last for up to 3 months.
– The tooth underneath the inlay may need root canal treatment less than 1% of the time during the lifetime of the tooth
– If the cement seal at the edge of the inlay is lost, decay may form at the juncture of the inlay and tooth

The risks to the inlay are:
‐ Porcelain may chip and metal may wear over time
‐ If the tooth needs a root canal after the inlay is permanently cemented, the procedure may fracture the inlay and the inlay may need to be replaced

Alternatives to placing an inlay are to either place a crown or a direct restoration such as composite or amalgam filling. Crowns are less conservative in their preparation and therefore weaken remaining tooth structure more than inlays. Composite and amalgam restorations remove decay and may restore teeth to their original form but are limited because they do not improve the long term function and aesthetics of broken down teeth as well as inlays

Excessive bite forces may lead to the inlay chipping or breaking

– Porcelain on an inlay may have a good color match with adjacent natural teeth when the inlay is placed but less of a match as your natural teeth age.
– An inlay may chip or break if used for abnormal activities (e.g. biting fishing line, sewing thread or finger nails, opening bottles)

An onlay is a dental restoration that covers a large part of the biting surface of a back tooth. It is cemented into place and cannot be taken off.

Onlays are made of two types of materials:
1. Porcelain: most like a natural tooth in color
2. Gold Alloy: strongest and most conservative in its preparation

Onlays restore a tooth to its natural size, shape and if using porcelain, color. They improve the strength, function and appearance of a broken down tooth that may otherwise be lost.

In having an onlay, some inherent risks exist both to the tooth and to the onlay itself. The risks to the tooth are:
– Preparation for an onlay weakens tooth structure and permanently alters the tooth underneath the onlay
– Preparing for and placing an onlay can irritate the tooth and cause “post-operative” sensitivity which may last for up to 3 months
– The tooth underneath the onlay may need root canal treatment less than 1% of the time during the lifetime of the tooth
-If the cement seal at the edge of the onlay is lost, decay may form at the juncture of the onlay and tooth The risks to the onlay are:
-Porcelain may chip and metal may wear over time
-If the tooth needs a root canal after the onlay is permanently cemented, the procedure may fracture the onlay and the onlay may need to be replaced

Alternatives to placing an onlay are to either place a crown or a direct restoration such as composite or amalgam filling. Crowns are less conservative in their preparation and therefore weaken remaining tooth structure more than onlays. Composite and amalgam restorations remove decay and may restore teeth to their original form but are limited because they:
Do not improve the strength of broken down teeth
Do not improve the long term function and aesthetics of broken down teeth as well as onlays

Excessive bite forces may lead to the onlay chipping or breaking

Porcelain on an onlay may have a good color match with adjacent natural teeth when the onlay is placed but less of a match as your natural teeth age. An onlay may chip or break if used for abnormal activities (e.g. biting fishing line, sewing thread or finger nails, opening bottles)