Composite inlays and onlays

This is an alternative to gold or all ceramic inlays and onlays. They still perform the same function, namely that of treating a damaged or decayed tooth and are considered a stronger and more appealing option than a normal filling.

It is easy to become confused by composite (white) fillings and composite inlays and onlays so here is a way of distinguishing between the two.

Direct composite (white) filling

The composite white filling (also known as a direct white filling) is similar to your standard type of filling, for example the amalgam filling. Except that it is white in colour instead of the usual silver grey colour.

This is completed in one visit and all within the dentist’s surgery.

Direct white fillings are discussed in more detail in a separate section.

Indirect composite inlay

The composite inlay is similar in appearance to the composite filling except that it is larger and covers more of the surface of the tooth.

This is completed in two visits and the composite inlay itself is produced in a dental laboratory.

We hope this explains the difference between the two.

What are composite inlays and onlays?

A composite inlay/onlay is similar to other types of indirect fillings apart from the material used to treat a cavity or damaged tooth. This material is a composite resin which is white in appearance and enables the inlay/onlay to match the rest of your teeth.

Composite resin is an acceptable choice of material for an inlay or onlay, for people who tend to grind their teeth or have malocclusion (misaligned jaw which causes problems with their bite).

Composite inlays and onlays are a good choice for people with tooth decay which is too far advanced for a filling but not serious enough for a crown.

Advantages of composite inlays and onlays

A major advantage is their natural looking appearance. They have a white (or slightly off white) colour which allows them to blend in with the rest of your teeth.

Plus they provide a watertight seal between the tooth and the indirect filling which prevents the risk of bacteria entering that gap and causing an infection.

They do cause any friction with neighbouring teeth and are easy to polish and care for in general.

Disadvantages of composite inlays and onlays

There are a couple of disadvantages which you need to be aware of. Firstly, composite resin or ceramic are not as tough and long lasting as other materials, e.g. gold which means that they are likely to fracture.

Plus composite inlays/onlays have a tendency towards staining, often causes by food colouring/additives, which occurs after a few years.

There is a risk of the inlay/onlay becoming loose and falling off the tooth or being washed away although this is rather small.

How are composite inlays and onlays fitted?

These are fitted in two stages. The first stage involves the preparation of the tooth for the inlay/onlay. The tooth is cleaned and any decay removed. The dentist then takes an impression of the tooth via a mould and dental putty.

He or she will ask you to bite into the mould which will leave an imprint (impression). This is sent to a dental laboratory for the production of the onlay/onlay.

The dentist will place a temporary inlay/onlay onto your tooth as a short term measure which will be removed once your new inlay/onlay is ready.

The second stage is the placing of the inlay or onlay. The dentist will clean your teeth before cementing the inlay or onlay in place. This may require some reshaping to fit the surface of the tooth. Your teeth are given a final polish.