What Is A Porcelain Onlay & How Much Does It Cost?

Article written by Dr Nissit Patel BDS MClinDent (Pros)

I am often asked about various different dental treatments and one of them involves porcelain onlays. Most of my patients know about porcelain veneers but in general, porcelain onlays are not well known. I will attempt to explain the treatment in simple detail, with explanation on the procedure, what to expect, why they are beneficial and the fee scales involved.

A porcelain onlay is a ceramic replacement for a badly damaged tooth which will replace most of the biting surface of the tooth including the chewing cusps. This may have been from tooth decay, trauma, from a root canal treatment or from a lost filling. In general terms, if the percentage of the biting surface of the tooth that needs replacement outweighs the natural remaining tooth, we will often advise a porcelain onlay as the restoration of choice versus a direct filling.

This is a question that is often asked when deciding between a dental crown and a porcelain onlay. A crown replaces the entire top surface of the tooth and in that respect does some have advantages over onlays in that we can alter the shape of the tooth, determine the thickness of material and provide more resistance and retention form in most cases. However, with crowns we do need to cut the tooth down by 1-2mm all the way around to accommodate the material being used. Therefore, if there is still plenty of healthy tooth present, this could be quite destructive. Porcelain onlays replace the damaged part of the tooth and the biting surfaces so that the process is generally less invasive and preserves tooth structure.

Here are the key steps to a porcelain onlay procedure:

1. Thorough planning. Sometimes we will use a diagnostic wax up which the laboratory will make for us as a guide to the final design of the onlay.

2. A small imprint is made of the teeth using putty. This will help us make a temporary onlay.

3. Preparation. The tooth in questions will be prepared with a minimally invasive approach. This usually done under local anaesthetic.

4. Digital scans will be taken.

5. The temporary onlay will be made and cemented with a soft cement called 'tempbond'

6. The scans are sent to the laboratory for digital design and manufacture. The material of choice is called E Max by Ivoclar.

7. The temporary onlay is removed and the porcelain onlay is evaluated for fitting, bite, contacts and aesthetics.

8. The onlay is cemented with an adhesive cement and polished.

9. For a few days, we advise a soft diet and no extremes of heat and cold.

10. We will then review the tooth usually at the next check up.

Here is a great example of a classic onlay. A back molar tooth has lost a large filling which meant the cusps were also lost which are vital to function.

This is a really good question and can only be answered with we don't know! Essentially, longevity will depend on a number of factors including the overall quality of the treatment, the skill of the laboratory, how well you clean and maintain the tooth, how heavy the bite is, diet and whether you grind your teeth at night. If you do suffer from bruxism ( grinding at night), using a night guard is essential to protect your teeth.

The cost of a porcelain onlay in the UK will vary between dental practices. Our fees for an E Max onlay is £800 or £640 if you join our membership plan. This is well worth it while by the way!

If you would like to enquiry about porcelain onlay treatment or any other dental treatment, please get in touch or feel free to arrange a free video consultation with Dr Nissit Patel.