Inlays and Onlays

When is it time to get a dental inlay? Or am I better off with a dental onlay? What’s the difference between an inlay and an onlay anyway? Is one or the other better for me?

These are just some of the questions that start a conversation with your dentist when it comes to the topic of inlays and onlays.

Dental inlays and onlays are methods used to restore your tooth, particularly molars and premolars. These are considered when your tooth has had fairly extensive damage that a basic filling just wouldn’t cut it this time, while intact enough that you won’t be needing a dental crown.

First off, what’s a dental inlay?
So what is an inlay in dental terms? A dental inlay is sort of like a filling but is premolded (based on an impression of your tooth) and then fitted into the grooves of your tooth, well within the cusps.

So, when you’ll be going for an inlay procedure, you’ll be given some local anesthetic, and your dentist will then clear away the decayed area of your tooth and clean out a recess to receive your dental inlay.

This restorative method is used to repair your tooth as long as the cusps or the tooth are intact.

With an impression (or a 3D scan) of your tooth, your dentist has taken from you earlier, he sends it to a laboratory, which then crafts your new dental inlay (although some clinics can now create and fit inlays for you in one appointment).

With regards to dental inlay material, inlays today are made of a solid piece of ceramic, porcelain, or a gold alloy. They are fitted according to the shape and size of the cleaned-out cavity. The color is made to match the natural look of your tooth, and the new biting surfaces and grooves are also customized for you.

What is the difference between a dental inlay and onlay?
A dental onlay works just like an inlay, except that this method of tooth restoration also incorporates the cusp (or part of the cusp) by covering it, hence onlaying the missing cusps.

As far as a dental inlay vs onlay is concerned, an onlay is procedurally and functionally similar to a dental inlay.

What are inlays and onlays used for?
Inlays and onlays are restorative procedures used to preserve as much of your original tooth as possible while re-strengthening the inner portion of your tooth damaged by decay or injury.

Usually, when an old filling gets breached repeatedly, or when other direct restoration methods become quite challenging, an inlay is indicated. While small cavities can be easily addressed with direct composites, a larger cavity within a relatively salvageable tooth can call for a dental inlay.

Onlays are similarly indicated, just with the added objective of covering tooth cusps that might be needing restoration as well.

How long do inlays and onlays last?
Dental inlays and onlays are extremely durable, hence the demand of these types of restorative dental services.

Inlays and onlays use relatively tough, hard-wearing, damage-resistant materials that can last a lifetime (about 25 to 30 years) with proper care and maintenance.

They are superior to, say, more traditional metal fillings, in that they can help strengthen teeth, and by prolonging tooth life, as well as preventing more extensive treatments in the future.

Are onlays better than crowns?
With the intent of preserving and conserving as much of your original tooth as possible, your dentist will prefer an onlay or an inlay rather than a dental crown, if it can be managed.

Again, an onlay or inlay means your tooth might have mild to moderate damage (due to decay or trauma), but the cusps of your tooth are still mostly and relatively healthy and intact.

A crown will usually be recommended if the cusps have sustained a bit more extensive damage that it would be difficult to support an onlay.

An onlay can thus be considered as a “partial” crown– it covers more area than an inlay but doesn’t necessitate the need for a new dental crown.

Are veneers considered onlays?
Veneers, also referred to as a porcelain laminate or a porcelain veneer differs from an onlay, mostly due to its intent and indications.

While dental onlays are more restorative in its purpose and function, veneers are instead more cosmetic.

As they are wafer-thin structures designed to coat the front surfaces of teeth, veneers are usually requested by patients to give them a whiter, brighter smile (rather than actually building a tooth back up to full form).

Another difference is that onlays (and inlays) are used with posterior teeth– molars and premolars, while veneers are applied to the front of teeth (i.e. the surface that can be more easily seen).

What are composite inlays?
Composite inlays have been more popular (at least compared to the more expensive gold and porcelain inlays) in that they are considered to be stronger, while also able to look more like your natural teeth.

The material used for composite inlays are made of a special form of resin. The composite can be made to look a particular shade or opacity, it can be more easily repaired and modified if need be, and bonds well to existing material.


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