What Is the Difference Between a Crown, Inlay and an Onlay

Inlays and Onlays, along with fillings and crowns are all kinds of restorative work by dentists to repair single damaged teeth, where a mouldable, hard-setting material is applied to a tooth and allowed to set in place.

Usually, a dentist will remove any damaged or decayed tooth material beforehand, by drilling.

There are many causes for the kind of damage that require this kind of repair, natural tooth decay, poor oral hygiene, symptoms of medical problems such as osteoporosis, bulimia or acid reflux, as well as accidental scrapings and other traumas.

Fillings & Materials

The most basic form of tooth repair, and most commonly known, is the filling, where an eroded or decayed tooth is restored to its original size and shape using a hard setting filling material.

Often, some damaged tooth will need to be removed beforehand but this is not always the case. Either way, fillings are finished in a single visit.

Many different materials can be used, with a range of appearances and prices, including gold, porcelain, silver amalgam, plastic, composite resin and glass ionomer.

Which of these you would like can be discussed with your dentist at the Dorset Dental Implant Clinic.

Inlays and Onlays

More complex repairs require inlays or onlays.

Whether a repair is an inlay or an onlay depends on the extent of the damage to the tooth that it is treating- specifically, whether or not the injury or decay affects the cusp.

The cusp is the pointed part of the tooth – the ‘occlusal or incisal eminence’.

Different types of teeth have different amounts of cusps; incisors, front teeth have one point, whereas molars, back teeth usually have 4.

The Repair Process

Inlays repair damage that does not affect the cusp of the tooth, whereas onlays are a reformation of the cusp(s) of the tooth or teeth.

For a dentist to complete an inlay or an onlay, more than one session will be needed.

1. In the first session, the dentist will remove any damaged tooth material and prepare the remaining cavity for the repair to be applied.
2. Then the dentist will take a mould of the cavity and send it to the laboratory when a custom-fitted inlay or onlay will be manufactured to the exact specification of your tooth.

In the second session, the filling will be applied.

Crowns and Implants

In more serious cases, where a whole tooth needs to be replaced, a crown or an implant will be used.

A crown is used when the whole visible part of the tooth needs to be repaired but the root of the tooth within the gum is healthy enough to be left intact.

The process is similar to inlays and onlays, although the crown is likely to be a little more costly.

The most major restoration that can be done for a single tooth is the implant; an entirely new artificial tooth is inserted with a titanium screw into the jawbone.