Life

Ask the Dentist: Why is a tooth sometimes more painful after having a filling?

Lucy Stock, dentist at Gentle Dental Care in Belfast, says that due to the nature of tooth decay, pain can sometimes be felt after a filling

If we leave decay in a tooth it will enlarge and eventually reach the nerve, causing it to die – the way to stop this is to remove the decay by drilling it out
If we leave decay in a tooth it will enlarge and eventually reach the nerve, causing it to die – the way to stop this is to remove the decay by drilling it out

SO YOU’VE gone into the dentist and all appears well with your teeth – they look OK to you and you aren’t having any pain. However, the X-rays show decay in the teeth and the dentist recommends a filling. Afterwards the tooth is annoyingly painful.

So what's going on? Has the dentist caused the pain? This seems logical; however, this is a typical scenario that is commonly misinterpreted.

Imagine the tooth as three Russian dolls where the outer doll represents the hard outer layer of enamel, the next inner doll is the softer dentine and the small solid doll is the pulp chamber that contains the tooth nerve and blood vessels.

A sugary diet leads to tooth softening and damaged enamel and dentine. If we leave decay in dentine it will enlarge and eventually reach the nerve, causing it to die. So the way to stop this is to remove the decay by drilling it out. I have never seen any evidence of the “natural ways” that are spoken about on the internet that purport that patients can reverse dentine decay but would be really interested to see any X-rays that people have of this happening.

Due to the process of removing decay a tooth nerve can be annoyed as we are working close to it. Fortunately the tooth has the ability to repair itself somewhat and in many cases sensitivity after a filling will settle down with time.

Helpfully there are now special regenerative creams that help teeth heal, reducing pain after a filling and keeping the tooth alive. But if the decay is too deep then it can be past the point that a tooth can repair itself and the nerve will die, forming a painful well of pus – an abscess. Also, if a filling is a tiny fraction too big – we are talking nanometers – this can also give pain, which is why a filling needs smoothed down.

It’s important to understand that the dentist is trying to fix the tooth and not make it worse but by the nature of what we do and how deep decay goes sometimes a tooth will become painful after a filling however without treatment the tooth is on an unexciting path to extraction.