Structure and Junctions
- Cementum is composed of cementocytes, located in lacunae with canaliculi or canals.
- Cementum canals are oriented towards the periodontal ligament and contain cementocytic processes for nutrient diffusion.
- Cementoblasts can form subsequent layers of cementum if the tooth is injured.
- The cementum joins the enamel to form the cementoenamel junction (CEJ).
- The dentinocemental junction (DCJ) is formed by the apposition of cementum over the dentin.
- The attachment of cementum to the dentin is firm but not completely understood.
- The DCJ is a relatively smooth area in the permanent tooth.
- Cementum deposition helps in minor repair of any resorption to maintain attachment.
Types of Cementum
- Acellular extrinsic fiber cementum contains perpendicular collagen fibers and attaches the tooth to the alveolar bone.
- Cellular cementum is thick and contains both extrinsic and intrinsic collagen fibers.
- The first cementum formed during tooth development is acellular extrinsic fiber cementum.
- Main types of cementum include acellular afibrillar cementum, acellular extrinsic fiber cementum, cellular intrinsic fiber cementum, and mixed stratified cementum.
Composition
- Cementum is slightly softer than dentin.
- It consists of about 45-50% inorganic material (hydroxylapatite) and 50-55% organic matter and water.
- The organic portion is primarily composed of collagen and proteoglycans.
- Cementum receives nutrition from the surrounding periodontal ligament.
- Cementum is light yellow and has the highest fluoride content among mineralised tissues.
DNA Studies
- Cementum has five times the amount of mitochondrial DNA compared to dentin.
- DNA extraction and genetic analysis results from dental tissue are variable and unpredictable.
- The quantity of DNA available in dentin is affected by age and dental disease.
- The quantity of DNA available in cementum is not affected by age and dental disease.
Other Information
- Cementum has a dynamic tissue covering of the root.
- Its structure, function, and development have been studied.
- Acellular extrinsic fiber cementum has been analyzed using Raman analysis.
- Cementum is part of the periodontium.
- It has potential functions that are still being explored.
Cementum is a specialised calcified substance covering the root of a tooth. The cementum is the part of the periodontium that attaches the teeth to the alveolar bone by anchoring the periodontal ligament.
| Cementum | |
|---|---|
 The cementum is the surface layer of the tooth root, covering the dentin (which is labeled 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). | |
| Details | |
| Identifiers | |
| Latin | caementum |
| MeSH | D003739 |
| TA98 | A05.1.03.057 A03.1.03.007 |
| TA2 | 1612 |
| FMA | 55630 |
| Anatomical terminology | |
