What percentage of bone loss is bad?

Bone loss happens irreversibly when periodontitis (periodontal disease) starts and continues as it progresses.

Any amount of bone loss is considered to mean that you have periodontal disease (even if it happened historically) but the condition can be considered stable or “in remission”. This happens if the condition is ‘switched off’ by keeping your gum inflammation levels low.

The actual amount of bone loss around your teeth is important. But the most relevant thing is the how quickly the bone loss is happening/ happened (so having comparative assessments including x-rays are essential) and the amount of bone loss in relation to your age.

That means 20% bone loss at the age of 80 is not so worrying as your teeth will probably out-live you assuming they are healthy and functioning well. The condition has been slow progressing.

On the other hand, 80% bone loss at the age of 20 (yes, aggressive forms of the condition can mean this is possible) would be much more worrying. Referral to a specialist Periodontist is definitely recommended in this scenario.