Teeth can become brittle over the years, destroying existing restorations or requiring strengthening measures. A crown is long-lasting, covering the tooth to protect it. It will give you the confidence to eat what you want without fear that your filling will break, fall out or that your tooth will be compromised.
Onlays are a more conservative option with less drilling that gives the same amount of protection. It’s tooth-coloured, so you will never know it’s there.