Coast Dental Blog
Fast Facts - Acellular and Cellular Cementum
Fast Facts - Perio Edition Episode 17
[Andrew Johnston, RDH]
Welcome back, everyone. You are listening to another episode of Fast Facts- Perio Edition brought to you by A Tale of Two Hygienists in partnership with DentistRX. And now, please welcome your host, Katrina Sanders.
[Katrina Sanders, RDH]
This week, we are continuing the conversation around dental anatomy, and at this point in the episode, I want you guys to know that I did propose to our producers that I'd like to shrink us all down, put us into a tiny magic school bus and actually see this anatomy for ourselves, and they said, no... I'm kidding.
So with that, this week, we're going to continue the conversation. This time we're going to talk not only about cementum, but the types of cementum and how cementum really responds to physiologic features within the body.
So we have two different types of cementum. In hygiene school, we learned that acellular cementum is cementum without cells in it. Rather, it doesn't contain Cementocytes. This acellular cementum is actually formed before tooth eruption and it's kind of found on that coronal two thirds of the root. It's about .1 millimeters in thickness and it gets super thin as we move toward the CEJ.
Cellular cementum, on the other hand, is going to cover that apical third of the root and furcations and it's about .5 millimeters in thickness. So it's definitely going to comprise or provide the entire thickness or bulk of cementum.
Now, when we see tooth wear like attrition, for example, the body compensates by depositing more layers of cellular cementum. Cellular cementum at that apex forms in incremental layers or appositional growth, kind of like rings around a tree, if you can imagine that and so as these layers are continually deposited in that apical area, know that as well, the body is also depositing bone in that alveolar crest and in the socket.
That's done intentionally. We want to be able to maintain a vertical dimension of the face and we want to maintain length of the root. So instead of resorbing, cementum is deposited continuously. Now, it's important to know that cementum itself does not resorbed as readily as bone does because it's avascular and it's protective. This allows, for example, orthodontic movement to be possible without the resorption of roots. But as many of us have seen, we know that cementum and bone itself can be resorbed under certain circumstances, like inappropriate orthodontic movement and things like cysts, tumors, trauma, teeth that have been replanted, you know, periapical disease or periodontal disease.
Therefore, instead of resorption, followed by deposition of new cells, a new layer of cementum is formed on the most superficial or oldest layer of tissue.
Well you guys, that concludes this week. Thank you so much. Join us next week for more anatomy talk.
This has been another episode of Fast Facts - Perio Edition with Katrina Sanders, RDH. Please feel free to reach me on Instagram @thedentalwinegenist or on my website www.KatrinaSanders.com Cheers.
[Andrew Johnston, RDH]
Thank you for listening to another episode of Fast Facts - Perio Edition, brought to you in part by DentistRX makers of the InteliSonic line of power brushes. Find out more by visiting their website at www.dentistrx.com. We'll see you next week for another Fast Fact!