When a dentist is measuring how far gums have receded and looking for infection below the gum line they use a probe which they insert below the gum line and record how far it goes before hitting healthy tissue (or at least that is my understanding). They record the depth measurement of a tooth and then move onto the next using the same probe and without washing it in between.

It seems to me that this would be a great way to spread infection from one gum to the next. I asked my hygienist why this isn't considered unsafe. She started to explain to me why it wasn't dangerous and then caught herself and said "I don't know".

So am I right to be concerned? Might they be unwittingly spreading infection throughout the mouth by this seemingly unsanitary exam practice?

1 Answer 1



This line of reasoning expects infectious bacteria to be immobile on their own and "gums" to be isolated from one another in a regularly closed and healthily salivated mouth. If your practitioner would have put the probe into her own mouth before examining yours, then that would be a great way to spread whatever.

Your own mouth is an ecosystem where one, local, inflamed, infection can easily spread to any other place within your mouth, no probes needed. The bacteria can move on their own and your saliva provides a very convenient way of transportation. Everything that might spread is already there.

  • 1
    Can it spread so easily below the gum line?
    – Ruminator
    Commented Sep 14, 2017 at 0:56

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