Patient guide
Composite filling or ceramic inlay: which does your tooth need?
How dentists decide between a direct composite filling and an inlay or onlay, how long each lasts, and which can be done in one visit.
By Dr. Kang Jun-guMedically reviewed by Dr. Kang Jun-guPublished Updated 4 min read
Quick answer
Small to medium cavities are usually best treated with a composite (resin) filling done in one visit. Larger cavities, or teeth with cusps at risk of breaking, often do better with a ceramic inlay or onlay, which is stronger and can be milled in the clinic the same day. The size of the cavity, not the price, should decide.
Composite filling
- Tooth-coloured resin placed and shaped directly
- Best for small to medium cavities and front teeth
- Done in one visit
- Keeps the most natural tooth
Ceramic inlay or onlay
- Made outside the mouth and bonded in
- Better for large cavities or weak cusps
- Stronger and more wear-resistant
- Can be designed and milled the same day
How the decision is made
The dentist looks at how much healthy tooth is left around the cavity. If walls are thin, a filling can crack the tooth over time, and an inlay or onlay protects it better.
Questions people also ask
How long do composite fillings last?
Typically many years with good care. Large composites in back teeth wear faster than ceramic.
Does a same-day inlay fit as well as a lab-made one?
Digitally milled inlays fit very precisely. For simple back-tooth inlays, results are comparable to lab-made ones.
Need this looked at in Seoul?
Check-ups, scaling and whitening, with fees shown before we start.
Dr. Kang is a board-certified Integrated Dentistry specialist trained at Yonsei, Harvard and Columbia. He treats every patient at the Gongdeok clinic himself.
About Dr. KangHow we write these guides: each guide is written from questions our patients ask, reviewed by Dr. Kang, and updated when guidance changes. It is general information, not a diagnosis. For advice about your own teeth, please book a check-up.
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