Cleaning tartar off exposed roots

[Annie364]

I'm in a bit of a pickle after a new dentist visit. A new dentist has said I need an extra long cleaning session because he said it might be painful (he said I could need 2 sessions of 30 minutes instead of just 1 session), even though I can't see much tartar at all on my teeth and I've never had a problem with hygienist cleaning before. He said there’s a very little bit of tartar behind my lower front teeth, and some around the back molars (I don't have wisdom teeth). I can't see any tartar at all when I look in the mirror at the fronts of the teeth when I smile.
It was only afterwards I realised he might be planning to clean off tartar on an exposed root on an upper 1st molar which has erupted downwards due to a removed tooth beneath it, and also on another somewhat exposed root on an upper 2nd molar on the other side, both root canalled teeth.
Won't the exposed root after cleaning be more vulnerable to getting cavities than the current tartar-covered root, due to the lack of enamel on tooth roots making them rather soft, plus be extra sensitive compared to a tartar covered root?
And surely any gum would grow back very slowly if at all, and also because it's erupted downwards, I can't expect gum to grow all the way down to cover that root anyway, so it'll always be exposed and extra vulnerable to cavities ... is that right?
Because of all that, I'm really concerned about whether I should be getting this cleaning on the roots at all.
It's a bit hard to get a photo of the tooth in the mirror, but this is it. I don't know how far up the root the tartar goes under the gum. In the past I just thought that root was maybe just discoloured brown perhaps due to the infection in the tooth, rather than tartar-covered - is mine actually just discoloured?
Thanks so much for any help.

 

[Gordon]

Won't the exposed root after cleaning be more vulnerable to getting cavities than the current tartar-covered root, due to the lack of enamel on tooth roots making them rather soft, plus be extra sensitive compared to a tartar covered root?

No. The tartar is a home for a massive load of bacteria, so leaving it there will lead to further bone loss and probably decay underneath it.

 

[Annie364]

Thanks so much Gordon!
I'm a bit concerned beause I read that deep root cleaning can end up making your recession look worse which can be quite noticeable - even though you are healthier because the bacteria has been removed. For example if you have 10mm pockets and those are reduced to a healthy level of 3mm, then you will notice that your gums are 7mm “shorter” than they once were. Is that right?

 

[Gordon]

Not really. There's a difference between a pocket and recession. In a pocket the gum appears to be sitting normally round the tooth, but the alveolar bone has disappeared leaving a big gap or pocket around the tooth. In recession, the gum level has followed the bone level so there isn't a pocket as such.

If you leave somebody with 10mm pockets then it won't be a problem for long because the teeth won't be staying...