Cementum

	WikiDoc Resources for Cementum
Articles
Most recent articles on Cementum Most cited articles on Cementum Review articles on Cementum Articles on Cementum in N Eng J Med, Lancet, BMJ
Media
Powerpoint slides on Cementum Images of Cementum Photos of Cementum Podcasts & MP3s on Cementum Videos on Cementum
Evidence Based Medicine
Cochrane Collaboration on Cementum Bandolier on Cementum TRIP on Cementum
Clinical Trials
Ongoing Trials on Cementum at Clinical Trials.gov Trial results on Cementum Clinical Trials on Cementum at Google
Guidelines / Policies / Govt
US National Guidelines Clearinghouse on Cementum NICE Guidance on Cementum NHS PRODIGY Guidance FDA on Cementum CDC on Cementum
Books
Books on Cementum
News
Cementum in the news Be alerted to news on Cementum News trends on Cementum
Commentary
Blogs on Cementum
Definitions
Definitions of Cementum
Patient Resources / Community
Patient resources on Cementum Discussion groups on Cementum Patient Handouts on Cementum Directions to Hospitals Treating Cementum Risk calculators and risk factors for Cementum
Healthcare Provider Resources
Symptoms of Cementum Causes & Risk Factors for Cementum Diagnostic studies for Cementum Treatment of Cementum
Continuing Medical Education (CME)
CME Programs on Cementum
International
Cementum en Espanol Cementum en Francais
Business
Cementum in the Marketplace Patents on Cementum
Experimental / Informatics
List of terms related to Cementum

Overview

The **cementum** is the surface layer of the tooth root *(B)*. Rather than being a passive entity like paint on a wall, cementum is a dynamic entity within the periodontium. It is attached to the alveolar bone *(C)* by the fibers of the periodontal ligament and to the soft tissue of the gingiva by the gingival fibers *(H)*.

Cementum is a specialized calcified substance covering the root of a tooth. Cementum is excreted by cells called cementoblasts within the root of the tooth and is thickest at the root apex. Its coloration is yellowish and it is softer than enamel and dentin due to being less mineralized.

The principle role of cementen within the tooth is to serve as a medium by which the periodontal ligaments can attach to the tooth for stability. Hence, its bottom surface is tangent to the periodontal ligaments running through the jaw (via collagen fibers), and the upper portion of the surface is firmly cemented to the dentin of the tooth. It also meets the enamel lower on the tooth at the cemento-enamel junction. Here the cementum is known as acellular cementum due to its lack of cellular components, and covers approximately 1/3-1/2 of the root. The more permeable form of cementen, cellular cementum, covers 1/3-1/2 of the root apex, where it binds to the dentin. There is also a third type of cementum, afibrillar cementum, which sometimes extends onto the enamel of the tooth.

The chemical makeup of cementum is similar to that of bone, but it lacks vascularization. Volumetrically, it is approximately 65% inorganic material (mainly hydroxyapatite), 23% organic material (mainly collagen type1]) and 12% water.