Podcast
Questions and Answers
Cementum is a calcified, avascular connective tissue that covers the dentin of the root.
Cementum is a calcified, avascular connective tissue that covers the dentin of the root.
True
Cementum is the most well-understood mineralized tissue in the body.
Cementum is the most well-understood mineralized tissue in the body.
False
Cementoblasts are known to be a unique cell type, distinct from osteoblasts.
Cementoblasts are known to be a unique cell type, distinct from osteoblasts.
False
Cementum thickness remains consistent throughout the root.
Cementum thickness remains consistent throughout the root.
Signup and view all the answers
The primary function of cementum is to provide attachment for collagen fibers of the periodontal ligament.
The primary function of cementum is to provide attachment for collagen fibers of the periodontal ligament.
Signup and view all the answers
What is the name of the epithelial cell sheath that plays a crucial role in cementogenesis?
What is the name of the epithelial cell sheath that plays a crucial role in cementogenesis?
Signup and view all the answers
Cementum mineralization is characterized by a random precipitation of ions into an organic matrix.
Cementum mineralization is characterized by a random precipitation of ions into an organic matrix.
Signup and view all the answers
Which of the following proteins are involved in promoting cementum mineralization?
Which of the following proteins are involved in promoting cementum mineralization?
Signup and view all the answers
Keratan sulfates-lumican and fibromodulin, major proteoglycans, are exclusively found in the mineralized cementum.
Keratan sulfates-lumican and fibromodulin, major proteoglycans, are exclusively found in the mineralized cementum.
Signup and view all the answers
Insulin-like growth factor (IGF) is involved in monitoring cementum mineralization only during the development phase.
Insulin-like growth factor (IGF) is involved in monitoring cementum mineralization only during the development phase.
Signup and view all the answers
Cementum is more readily resorbed compared to bone.
Cementum is more readily resorbed compared to bone.
Signup and view all the answers
Which factor(s) contribute to the slower resorption rate of cementum compared to bone ?
Which factor(s) contribute to the slower resorption rate of cementum compared to bone ?
Signup and view all the answers
Cementum, like bone, possesses a lamellar appearance and contains marrow spaces.
Cementum, like bone, possesses a lamellar appearance and contains marrow spaces.
Signup and view all the answers
Cementum formation commences before root formation during tooth development.
Cementum formation commences before root formation during tooth development.
Signup and view all the answers
Cementum contains the highest concentration of fluoride among all mineralized tissues.
Cementum contains the highest concentration of fluoride among all mineralized tissues.
Signup and view all the answers
Study Notes
Cementogenesis and Cementum
- Cementum is a thin, calcified, avascular connective tissue covering the root dentin.
- It's the least understood mineralized tissue in the body.
- Cementoblasts are the cells responsible for cementogenesis. Their origin is uncertain; they might be a specialized subset of osteoblasts or a unique cell type.
- Cementum cells (cementoblasts) possess receptors for parathyroid hormone (PTH) and parathyroid hormone-related protein (PTHrP), responding similarly to factors regulating osteoblast activity.
- Cementum thickness varies, thickest at the root apex and interradicular areas of multi-rooted teeth, and thinner towards the cervix.
- Cementum firmly adheres to the dentin and the periodontal ligament (P.D.L.) fibers.
- A primary function is attaching to collagen fibers of the P.D.L., maintaining proper tooth position and integrity, responding to factors promoting tooth repair and regeneration.
Cementogenesis - Matrix Formation
- Cementum formation (cementogenesis) has two major stages: matrix formation and maturation.
- Matrix formation involves the production of collagen type I and ground substance.
Cementogenesis - Maturation
- Maturation involves the deposition of hydroxyapatite crystals in the organic matrix, solidifying the cementum tissue.
Cementogenesis - Hertwig's Epithelial Root Sheath (HERS)
- Cementogenesis begins after the Hertwig epithelial root sheath (HERS) fragments.
- HERS is an epithelial collar derived from the enamel organ's apical portion.
- HERS's disintegration triggers cementoblast activation and cementogenesis.
Cementogenesis - Mineralization
- Cementum mineralization follows matrix formation, not random ion precipitation.
- Key proteins (e.g., osteocalcin, osteonectin) act as nucleators for mineralization, while other proteins (e.g., bone sialoprotein, alkaline phosphatase) promote apatite crystal growth.
Cementum Properties and Clinical Considerations
- Cementum resists resorption compared to bone, which aids in orthodontic tooth movement.
- Cementum resorption can occur from trauma, or excessive occlusal forces. The body can respond to resorption by forming new cementum to repair the previous outline/shape of the root; this is termed anatomic repair
- In cases of deeper resorption, the root outline may not recover, resulting in a "bay-like" recess. The periodontal ligament space is regained by bone formation (functional repair).
Types of Cementum
- Acellular: lacks cementocytes; found primarily on the coronal portion of the root.
- Cellular: contains cementocytes; predominant in the apical portion of the root.
- Intermediate: a transitional type, characterized by entrapped epithelial cells and often found in premolars and molars.
Cementum Structure
- Cementum has a specific structure, involving cementocytes and cementoid layer.
Cementum - Chemical Composition
- Cementum has a 45-50% inorganic component (hydroxyapatite crystals) and a 50-55% organic component (collagen, polysaccharides, trace elements).
- It has the highest fluoride concentration among mineralized tissues.
Cemento-Enamel Junction
- The cemento-enamel junction (CEJ) varies across different teeth: sharp and well-defined in permanent teeth; scalloped in deciduous teeth.
Incremental Lines of Salter
- These lines are hypermineralized areas in cementum with less collagen and more ground substance. They are parallel to the surface in acellular cementum and appear as annuli in cellular cementum.
Functions of Cementum
- Serves as a medium for collagen fiber (Sharpey's fibers) attachment to the periodontal ligament (PDL).
- Continuous cementum formation maintains the PDL attachment apparatus integrity.
- Cementum deposition compensates for tooth wear (attrition).
- It’s essential for root repair in case of fractures or resorption.
Hypercementosis
- Hypercementosis is an abnormal thickening of cementum.
- It can be diffuse or localized.
- If hypertrophy is functional, it's termed cementum hypertrophy.
- If not functionally significant, it's hyperplasia.
Clinical Considerations, Summary
- Cementum's resistance to resorption is crucial for orthodontic tooth movement.
- Cemental resorption may follow trauma or excessive occlusal force. -There are distinct types - acellular, cellular, intermiedate, and afibrillar-
- There is both an anatomic and functional repair mechanism in response to root resorption.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Explore the intricacies of cementogenesis and the role of cementum in dental health. Understand the cellular components involved in cementum formation and its structural significance in teeth. This quiz encompasses key concepts related to cementum's properties and functions.
