cementum

noun

ce·​men·​tum si-ˈmen-təm 

: 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

However, the inner (dentine) layer of these building blocks twist to the right, while the outer (cementum) layer twists left. — New Atlas, 18 Aug. 2026

The team found that while the outer layer of the tusk, called the cementum, has a structure that spirals left, the inner part, dentine, spirals right. — Jackie Flynn Mogensen, Scientific American, 18 Aug. 2026

The dentine and cementum, in turn, are made up of microscopic collagen fibrils mineralized with nanoparticles of hydroxyapatite. — Jennifer Ouellette, ArsTechnica, 18 Aug. 2026

What’s more, tooth roots are covered in cementum, a material much softer than enamel and far more vulnerable to decay and wear. — Daryl Austin, Forbes.com, 14 Aug. 2025

Anything that damages the enamel or cementum can cause tooth sensitivity. — Mark Gurarie, Health, 21 June 2025

Biologists and forensic scientists count cementum rings (these microscopic structures encircle a tooth's root and vary in shade and thickness by season) in teeth for the same reason. — Paul Smaglik, Discover Magazine, 7 Aug. 2024

In the years sows are pregnant, their teeth will grow a thick cementum layer from gaining so much weight. — Katie Hill, Outdoor Life, 28 Sep. 2023

Word History

Etymology

New Latin, from Latin caementum

First Known Use

1842, in the meaning defined above

Rhymes for cementum

• momentum
• omentum
• tegmentum
• tomentum
• argumentum
• sacramentum
• testamentum
• centum
• mentum

Kids Definition

cementum

noun

ce·​men·​tum si-ˈment-əm 

: an outside bony layer that covers the part of the tooth normally within the gum

Medical Definition

cementum

noun

ce·​men·​tum si-ˈment-əm 

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

called also cement

compare dentin, enamel