What Are Dental Inlays and Onlays? 

Dental inlays and onlays – the middle ground between fillings and crowns

When it comes to fixing a tooth that’s seen better days, you’ve probably heard of fillings and crowns, but what if you need something in between? That’s where dental inlays and onlays come in – they’re the perfect option if a tooth is too damaged for a standard filling but not quite damaged enough for a full crown. 

We find that lots of patients have never heard of them until their dentist suggests one, so let’s clear things up and look at exactly what they are, how they work, and why they might be the perfect answer for perfecting your smile.

What is a dental inlay or onlay?

Think of dental inlays and onlays as custom-made pieces for your teeth that are missing. They’re designed to restore a tooth that’s too damaged for a simple filling but doesn’t need a full crown.

• Dental inlays fit neatly inside the grooves of your tooth, like a filling but crafted in a dental lab for a precise fit.
• Dental onlays do everything an inlay does but also covers one or more of the chewing cusps (the raised bits on your tooth). That’s why you might hear people call them onlays for teeth as they literally sit on the tooth.

The great thing about dental inlays and onlays is that they’re made from tooth-coloured materials, so they blend in beautifully to create a natural looking smile. 

When are inlays and onlays used?

• If you have decay or damage too large for a regular filling
• If you don’t need a full crown to cover the entire tooth
• If you have a large old filling needs replacing
• If you’d like a stronger, longer-lasting solution than a simple filling

Basically, if your tooth is structurally compromised but still has plenty of healthy tissue left, an inlay or onlay can rebuild it without removing more tooth than necessary.

Is an onlay a crown?

In short, no, an onlay is not a crown, but they’re related. 

A crown covers the whole tooth all the way down to the gum line, like a cap, whereas an onlay, on the other hand, covers only the biting surface and the cusps. Think of it as a partial crown, big enough to reinforce the tooth but smaller than a full cap.

So if your dentist says you need an onlay, you’re not quite in crown territory yet, which is often great news because it means more of your natural tooth can stay intact.

Are onlays better than crowns?

It depends on your situation, because if your tooth is heavily damaged or has had root canal treatment, a crown is usually the better option for full coverage and protection.

But if you still have plenty of healthy tooth structure, an onlay is less invasive, preserves more of your natural enamel, and still gives you excellent strength.

So, are onlays better than crowns? They can be, if your tooth only needs partial coverage as they strike the perfect balance between durability and conservation of your tooth.

Are onlays better than fillings?

Again, it all comes down to how much of the tooth is damaged because fillings are great for small cavities or chips. But when a filling gets too big, it can actually weaken your tooth over time, acting a bit like a wedge that can crack the surrounding enamel.

Onlays (and inlays) are custom-made to fit perfectly and bond strongly to the tooth which reinforces the tooth’s structure and can last much longer than a large filling.

So, are onlays better than fillings? In many cases, yes, especially if you want a strong, durable, and natural-looking result for bigger repairs.

The benefits of dental inlays and onlays

They save more of your tooth – Unlike crowns that cover the whole tooth, inlays and onlays only replace the part that’s actually damaged. That means more of your healthy enamel stays exactly where it belongs.

Super strong and long-lasting – Made from super strong materials, they’re much tougher than big fillings so they can handle all the chewing and crunching for many years.

A natural look that blends in – No metal in sight, just a smooth, tooth-coloured finish that matches your smile perfectly. Most people won’t even spot you’ve had dental work done.

Custom-made for a perfect fit – Because inlays and onlays are crafted precisely to your tooth’s shape, they fit like a glove and seal out bacteria and decay far better than an overstuffed filling.

They strengthen weak teeth – If your tooth has been weakened by decay or an old filling, an inlay or onlay reinforces it and helps prevent cracks or further damage down the line.

Less invasive than a crown – Crowns are fantastic when needed, but if you don’t have to cover the whole tooth, why do it? Onlays and inlays let you keep as much of your natural tooth structure as possible.

What’s involved in getting an inlay or onlay?

1. Prepping the tooth
   First, your dentist will gently remove any decay or old filling material and clean the area. They’ll shape the space so your new inlay or onlay fits perfectly.
   
2. Taking impressions
   Next, we’ll take an impression or a digital scan of your tooth, which is like creating a blueprint so the lab can craft your custom restoration to match your tooth exactly.
   
3. Placing a temporary
   While your inlay or onlay is being made (usually about 1–2 weeks), you’ll get a temporary filling or cover which will protect your tooth and keep things comfortable in the meantime.
   
4. Fitting the final restoration
   Once your inlay or onlay is ready, you’ll come back for a second appointment where your dentist will remove the temporary, check the fit and colour, and bond your new restoration securely in place. We’ll also make sure your bite feels just right.
   
5. Back to normal
   That’s it! You’ll leave with a tooth that looks natural, feels smooth, and is strong enough to handle all your favourite foods again.

At Smile Stories, we’re here to help you weigh up your options and pick the treatment that keeps your smile strong, healthy, and looking fantastic.

Got questions or think you might need an inlay or onlay? Book a consultation with us today, we’ll walk you through everything and make sure you feel confident about your dental care.