ce·​men·​tum | \ si-ˈmen-təm How to pronounce cementum (audio) \

Definition of cementum

: a specialized bony layer of connective tissue covering the dentin of the part of a tooth normally within the gum — see tooth illustration

Examples of cementum in a Sentence

Recent Examples on the Web An annulus, or dark ring, is formed each winter between the cementum formed in spring and summer growth periods. Alan Clemons, Outdoor Life, 18 Mar. 2021 From the moment a tooth emerges from the gum, cementum starts to form annual layers, similar to a tree's rings. Jack Guy, CNN, 25 Mar. 2020 The researchers are also working with high-resolution CT scans to develop a non-destructive method of studying cementum. Jack Guy, CNN, 25 Mar. 2020 In a similar vein, a substance called cementum protects your teeth’s roots, which contain the pulpy center that holds blood vessels and nerves. Korin Miller, SELF, 18 Apr. 2018 Instead, the tooth bases were caked in cementum, a bony material that affixed the teeth to the jaw, and Caldwell says that the teeth appeared to have been dislodged during fossilization. Michael Greshko, National Geographic, 2 Nov. 2016

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'cementum.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of cementum

1842, in the meaning defined above

History and Etymology for cementum

New Latin, from Latin caementum

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Time Traveler for cementum

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The first known use of cementum was in 1842

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Cite this Entry

“Cementum.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/cementum. Accessed 29 Jun. 2022.

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More Definitions for cementum


ce·​men·​tum | \ si-ˈmen-təm How to pronounce cementum (audio) \

Kids Definition of cementum

: a thin bony layer covering the part of a tooth inside the gum


ce·​men·​tum | \ si-ˈment-əm How to pronounce cementum (audio) \

Medical Definition of cementum

: a specialized external bony layer covering the dentin of the part of a tooth normally within the gum

called also cement

— compare dentin, enamel

More from Merriam-Webster on cementum

Britannica.com: Encyclopedia article about cementum


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