The document discusses dental cementum, which covers the root surface of teeth. It begins with definitions of cementum and its history of discovery. Cementum has physical properties like being pale yellow and softer than dentin. Chemically, it is composed of hydroxyapatite crystals and type I collagen. Cementum formation (cementogenesis) involves cementoblasts depositing an organic matrix that then undergoes mineralization. Cementum is laid down in two stages - the prefunctional stage during root development and the functional stage after the tooth reaches occlusion.
Cementum is the mineralized tissue covering the roots of teeth that provides attachment for collagen fibers linking the tooth to surrounding bone. It begins at the cementoenamel junction and continues along the root to the apex. Cementum is avascular and less hard than dentin. It contains both inorganic minerals and organic materials including collagen. Cementoblast cells synthesize cementum by laying down an organic matrix that subsequently mineralizes. Cementum thickness varies along the root and increases with age. It provides for functional adaptation and resistance to resorption during orthodontic tooth movement.
The periodontal ligament (PDL) is a soft connective tissue located between the cementum on the root of a tooth and the alveolar bone. It consists of collagen fibers, cells like fibroblasts and cementoblasts, blood vessels, and nerves. The principal fibers of the PDL are arranged in groups to help support the tooth, resist movement, and absorb forces during chewing. The PDL transmits occlusal forces to the bone, attaches the tooth, and maintains the gingiva.
1. The junctional epithelium is a specialized non-keratinized stratified squamous epithelium that attaches to the tooth surface and forms a collar around the cervical portion.
2. It develops from the reduced enamel epithelium during tooth eruption. The reduced enamel epithelium fuses with the oral epithelium and transforms into the junctional epithelium.
3. The junctional epithelium attaches firmly to the tooth surface through hemidesmosomes of the basal cells (called DAT cells) and an internal basal lamina. This structure is called the epithelial attachment apparatus.
The document discusses aging changes that occur in the periodontium. Key points:
- With aging, the gingival epithelium thickens due to acanthosis. Connective tissue ridges become more prevalent in young individuals while papillae predominate in old individuals.
- The periodontal ligament has greater elastic fibers, decreased vascularity and cellular elements, and altered collagen with aging. Alveolar bone shows increased osteoporosis and irregular surfaces facing the ligament.
- Subgingival plaque in older adults contains more enteric rods and pseudomonads, and increased pathogens like P. gingivalis. Periodontitis is associated with increased risk of conditions like diabetes, coronary
This document provides an overview of cementum, including:
- Its physical characteristics, composition, classification, and formation process (cementogenesis).
- The cells involved in cementum formation and maintenance, including cementoblasts and cementocytes.
- Its locations and junctions with other tissues like enamel and dentin.
- The functions of cementum in anchoring teeth, adaptation, and repair.
- Some developmental anomalies and abnormalities that can affect cementum.
This document provides an overview of the periodontal ligament (PDL), including its development, cells, extracellular components, fiber groups, and structures. The PDL is a specialized connective tissue that attaches teeth to alveolar bone. It contains fibroblasts that secrete collagen fibers, along with blood vessels, nerves, and progenitor cells. The principal fiber groups resist various forces on teeth. The PDL allows teeth to withstand chewing forces through its extracellular matrix and continual remodeling by synthetic and resorptive cells.
The document discusses the dentogingival junction and junctional epithelium. It begins with an introduction and overview of the three zones of gingival epithelium. It then covers the historical aspects and development of the junctional epithelium. The structure of the junctional epithelium is described including its anatomical features, epithelial attachment apparatus involving hemidesmosomes, and dynamic aspects like rapid turnover. The permeability and various functions of the junctional epithelium are also summarized.
This document provides an overview of the temporomandibular joint (TMJ). It discusses the anatomy of the TMJ, including the articular disc that divides it into upper and lower compartments. The histology of the TMJ bones, articular disc, capsular ligament, and synovial fluid are described. The innervation and blood supply of the TMJ are also covered. Common disorders like ankylosis and dislocation are reviewed. Age-related changes to the TMJ are outlined, as well as its development beginning in the 10th week of gestation.
Cementum is the mineralized tissue covering the roots of teeth that provides attachment for collagen fibers linking the tooth to surrounding bone. It begins at the cementoenamel junction and continues along the root to the apex. Cementum is avascular and less hard than dentin. It contains both inorganic minerals and organic materials including collagen. Cementoblast cells synthesize cementum by laying down an organic matrix that subsequently mineralizes. Cementum thickness varies along the root and increases with age. It provides for functional adaptation and resistance to resorption during orthodontic tooth movement.
The periodontal ligament (PDL) is a soft connective tissue located between the cementum on the root of a tooth and the alveolar bone. It consists of collagen fibers, cells like fibroblasts and cementoblasts, blood vessels, and nerves. The principal fibers of the PDL are arranged in groups to help support the tooth, resist movement, and absorb forces during chewing. The PDL transmits occlusal forces to the bone, attaches the tooth, and maintains the gingiva.
1. The junctional epithelium is a specialized non-keratinized stratified squamous epithelium that attaches to the tooth surface and forms a collar around the cervical portion.
2. It develops from the reduced enamel epithelium during tooth eruption. The reduced enamel epithelium fuses with the oral epithelium and transforms into the junctional epithelium.
3. The junctional epithelium attaches firmly to the tooth surface through hemidesmosomes of the basal cells (called DAT cells) and an internal basal lamina. This structure is called the epithelial attachment apparatus.
The document discusses aging changes that occur in the periodontium. Key points:
- With aging, the gingival epithelium thickens due to acanthosis. Connective tissue ridges become more prevalent in young individuals while papillae predominate in old individuals.
- The periodontal ligament has greater elastic fibers, decreased vascularity and cellular elements, and altered collagen with aging. Alveolar bone shows increased osteoporosis and irregular surfaces facing the ligament.
- Subgingival plaque in older adults contains more enteric rods and pseudomonads, and increased pathogens like P. gingivalis. Periodontitis is associated with increased risk of conditions like diabetes, coronary
This document provides an overview of cementum, including:
- Its physical characteristics, composition, classification, and formation process (cementogenesis).
- The cells involved in cementum formation and maintenance, including cementoblasts and cementocytes.
- Its locations and junctions with other tissues like enamel and dentin.
- The functions of cementum in anchoring teeth, adaptation, and repair.
- Some developmental anomalies and abnormalities that can affect cementum.
This document provides an overview of the periodontal ligament (PDL), including its development, cells, extracellular components, fiber groups, and structures. The PDL is a specialized connective tissue that attaches teeth to alveolar bone. It contains fibroblasts that secrete collagen fibers, along with blood vessels, nerves, and progenitor cells. The principal fiber groups resist various forces on teeth. The PDL allows teeth to withstand chewing forces through its extracellular matrix and continual remodeling by synthetic and resorptive cells.
The document discusses the dentogingival junction and junctional epithelium. It begins with an introduction and overview of the three zones of gingival epithelium. It then covers the historical aspects and development of the junctional epithelium. The structure of the junctional epithelium is described including its anatomical features, epithelial attachment apparatus involving hemidesmosomes, and dynamic aspects like rapid turnover. The permeability and various functions of the junctional epithelium are also summarized.
This document provides an overview of the temporomandibular joint (TMJ). It discusses the anatomy of the TMJ, including the articular disc that divides it into upper and lower compartments. The histology of the TMJ bones, articular disc, capsular ligament, and synovial fluid are described. The innervation and blood supply of the TMJ are also covered. Common disorders like ankylosis and dislocation are reviewed. Age-related changes to the TMJ are outlined, as well as its development beginning in the 10th week of gestation.
The document discusses the structure and development of dentin. It describes dentin as the layer beneath enamel that provides shape and structure to teeth. Dentin forms in stages that mirror tooth development from the lamina bud stage through late bell stage. Key features of dentin include dentinal tubules that contain odontoblastic processes and layers like peritubular dentin, intertubular dentin, and predentin near the pulp. Dentin is laid down in primary, secondary, and tertiary forms throughout life.
Definition of periodontal pocket, classification, Histopathology of periodontal pocket, microflora involved, pathogenesis, periodontal pocket as a healing lesion, microtopography of root surface, treatment of periodontal pocket
The dentogingival junction is the region where the tooth is attached to the gingiva. It initially forms with the emergence of the tooth into the oral cavity, with the enamel covered by epithelium. Over time, the junction shifts apically as the epithelium separates from the enamel surface in a process called passive eruption. The junctional epithelium, which is more permeable, eventually attaches at the cementoenamel junction. In unhealthy conditions, the junction and sulcus can shift further onto the root surface, forming a pathological periodontal pocket.
The document discusses the junctional epithelium (JE), which is a non-keratinized stratified squamous epithelium that adheres to the tooth surface at the base of the gingival crevice. It outlines the history of terminology used to describe the JE from 1915 to 1971. It describes the boundaries, length, shape, and cell layers of the JE. Finally, it notes some key functions of the JE, including acting as a barrier, allowing gingival crevicular fluid flow, providing attachment to the tooth, and secreting antimicrobial peptides.
Here are the key types of dentin and their histological features:
- Primary dentin (mantle, circumpulpal) - forms bulk of tooth, contains dentinal tubules
- Mantle dentin - thin layer near pulp, large collagen fibers perpendicular to DEJ
- Circumpulpal dentin - below mantle dentin, smaller collagen fibers parallel to DEJ
- Predentin - unmineralized matrix secreted by odontoblasts
- Secondary dentin - forms with age/stimulation within pulp chamber
- Regular secondary dentin - mild stimulus, uniform deposition on pulp chamber walls
- Irregular/reparative dentin - severe stimulus, localized deposition near exposed dentin
The document summarizes the development of teeth from the initial formation of the primary epithelial band and dental lamina through the bud, cap and bell stages. It describes how the enamel organ and surrounding dental papilla and sac develop during these stages. Key stages of root formation controlled by Hertwig's epithelial root sheath are also outlined. The timeline of human tooth development from 6 weeks gestation through adulthood is provided. Molecular insights regarding signaling pathways such as FGF, SHH and BMPs controlling tooth morphogenesis and patterning are discussed.
Cementum is a hard, avascular connective tissue that covers the roots of teeth. It provides attachment for the periodontal ligament fibers and protects the underlying dentin. There are two types of cementum - acellular and cellular. Acellular cementum is laid down early in development and provides the main attachment for teeth. Cellular cementum is laid down later and is found mainly in the apical regions. Cementum is continuously deposited over the life of the tooth to maintain its length and acts to repair resorption of the root surface.
The periodontal ligament is a dense connective tissue that occupies the space between the root of a tooth and the alveolar bone. It contains collagen fibers, cells, blood vessels, and nerves. The fibers are arranged in different groups to support the tooth and allow movement during mastication while protecting the underlying bone. The periodontal ligament provides nutrition to cementum and bone, senses pressure, and facilitates tooth movement during orthodontic treatment by stimulating bone remodeling through fiber tension and compression. It also protects the tooth and bone by distributing forces and containing mechanoreceptors.
Blood supply,nerve supply and lymphatic drainage of the periodontium finalDr. Neha Pritam
The document discusses the blood supply, nerve supply, and lymphatic drainage of the periodontium. It states that the periodontium receives its blood supply from branches of the internal maxillary artery and its lymphatic drainage involves drainage to local lymph nodes. It also describes the rich nerve supply to the periodontium derived from the trigeminal nerve and its branches. Changes in microcirculation and lymphangiogenesis occur in the periodontium during periodontal disease.
Guided tissue regeneration (GTR) involves placing barriers over defects to separate gingival tissues and allow regeneration of periodontal ligament and bone. Animal and human studies show that excluding epithelium and allowing repopulation of defects by periodontal ligament cells leads to new attachment. Both resorbable and non-resorbable membrane barriers have been used for GTR with the goal of preventing epithelial migration and promoting regeneration. GTR has been shown to be predictable for treating intra-bony defects and grade II furcations.
The periodontal ligament is a specialized connective tissue that connects the cementum of teeth to the alveolar bone. It develops from the dental follicle during root formation and tooth eruption. The periodontal ligament is composed of collagen fibers, fibroblasts, blood vessels and nerves. The principal collagen fibers are arranged in bundles and attach to the cementum and bone. The periodontal ligament helps maintain homeostasis between the teeth and surrounding tissues and allows for tooth mobility.
This document provides an overview of gingival epithelium, including its microscopic features, structural characteristics, defense mechanisms, and renewal process. It defines gingiva as the part of oral mucosa that covers the alveolar process and surrounds tooth necks. Gingiva consists of three types: marginal, attached, and interdental gingiva. The gingival epithelium contains keratinocytes and melanocytes. Keratinocytes form the bulk of the epithelium and undergo continuous renewal, while melanocytes transfer melanin to keratinocytes. The degree of keratinization varies between oral mucosal sites.
The periodontium develops from neural crest cells that migrate into the developing dental arches. The dental lamina forms and invaginates into the underlying mesenchyme, forming the tooth bud. The bud develops through the cap and bell stages as the enamel organ and dental papilla form. The dental follicle gives rise to the periodontal ligament, cementum and alveolar bone. Cementoblasts deposit cementum on the root surface. Periodontal ligament fibers develop from the dental follicle and insert into the cementum and bone. The gingiva develops as the tooth erupts, with the reduced enamel epithelium transforming into junctional epithelium and sulcular epithelium.
The periodontal ligament is a connective tissue that connects the tooth to the alveolar bone. It contains collagen fibers, fibroblasts, cementoblasts, osteoblasts and other cells. The principal collagen fibers of the periodontal ligament originate on the cementum and insert into the alveolar bone in different orientations to provide structural support to the tooth and resist various forces. The periodontal ligament is essential for functions such as tooth eruption and maintains the space between the tooth and bone.
A presentation on the topic of microscopic section of gingiva. This topic is mostly looked on by periodontists. A very important chapter in the speciality in dentistry of periodontology and implantology department. Basic understanding of microscopic features and clinical features of gingiva is an important topic for post graduate as well as undergraduate students in the dental field.
The document discusses the periodontal ligament (PDL), which is the soft connective tissue that surrounds tooth roots and attaches cementum to alveolar bone. It defines PDL and describes its extent, average width, development from the dental follicle, orientation of collagen fibers, cellular elements including fibroblasts, cementoblasts, osteoblasts, and epithelial rests of Mallassez. The document also covers the biochemical composition and ground substance of PDL, as well as its blood supply, nerve supply, age-related changes, and role in healing after periodontal surgery.
The document discusses the alveolar bone, including its definition, composition, structure, cells, blood supply, and changes associated with orthodontic forces. It notes that alveolar bone surrounds and supports the teeth sockets. It is composed primarily of inorganic minerals and collagen. Microscopically, it contains osteons arranged in concentric lamellae around Haversian canals. Osteoblasts build bone while osteoclasts resorb it, maintaining a constant state of remodeling. The alveolar bone has a rich blood supply from the superior and inferior alveolar arteries and drains via lymph vessels. Orthodontic forces induce changes in the bone's morphology and turnover.
Cementum is the mineralized connective tissue covering tooth roots. It has several functions including anchoring collagen fibers from the periodontal ligament to provide attachment between the tooth and bone. Cementum can be classified based on its location, cellularity, fiber content, and other characteristics. It plays roles in adaptation, repair, and maintaining the periodontium. The cemento-enamel junction describes the interface between cementum and enamel at the cervical portion of the tooth root.
This document discusses the development of the periodontium, which includes the cementum, periodontal ligament, alveolar bone, and gingiva. It describes how the tooth germ develops from the enamel organ and dental papilla through stages of growth. Root formation is induced by Hertwig's epithelial root sheath, which regulates the development of cementum, periodontal ligament, and alveolar bone through cellular differentiation and protein signaling. The periodontium develops through reciprocal interactions between the enamel organ and dental follicle mesenchyme.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.
Cementum is a hard, mineralized tissue found on the anatomical roots of teeth. It has several subtypes based on cellularity and collagen fiber organization. Cementum is composed of hydroxyapatite crystals and collagen fibers. It is formed by cementoblasts and cementocytes. Cementum provides attachment of periodontal ligament fibers to the tooth and continues growing throughout life. The main types are acellular and cellular cementum. Acellular cementum forms earlier and is less cellular while cellular cementum forms later and more rapidly to adapt to functional forces. Cementum plays an important role in tooth attachment and is involved in pathological processes like root resorption.
The document discusses the structure and development of dentin. It describes dentin as the layer beneath enamel that provides shape and structure to teeth. Dentin forms in stages that mirror tooth development from the lamina bud stage through late bell stage. Key features of dentin include dentinal tubules that contain odontoblastic processes and layers like peritubular dentin, intertubular dentin, and predentin near the pulp. Dentin is laid down in primary, secondary, and tertiary forms throughout life.
Definition of periodontal pocket, classification, Histopathology of periodontal pocket, microflora involved, pathogenesis, periodontal pocket as a healing lesion, microtopography of root surface, treatment of periodontal pocket
The dentogingival junction is the region where the tooth is attached to the gingiva. It initially forms with the emergence of the tooth into the oral cavity, with the enamel covered by epithelium. Over time, the junction shifts apically as the epithelium separates from the enamel surface in a process called passive eruption. The junctional epithelium, which is more permeable, eventually attaches at the cementoenamel junction. In unhealthy conditions, the junction and sulcus can shift further onto the root surface, forming a pathological periodontal pocket.
The document discusses the junctional epithelium (JE), which is a non-keratinized stratified squamous epithelium that adheres to the tooth surface at the base of the gingival crevice. It outlines the history of terminology used to describe the JE from 1915 to 1971. It describes the boundaries, length, shape, and cell layers of the JE. Finally, it notes some key functions of the JE, including acting as a barrier, allowing gingival crevicular fluid flow, providing attachment to the tooth, and secreting antimicrobial peptides.
Here are the key types of dentin and their histological features:
- Primary dentin (mantle, circumpulpal) - forms bulk of tooth, contains dentinal tubules
- Mantle dentin - thin layer near pulp, large collagen fibers perpendicular to DEJ
- Circumpulpal dentin - below mantle dentin, smaller collagen fibers parallel to DEJ
- Predentin - unmineralized matrix secreted by odontoblasts
- Secondary dentin - forms with age/stimulation within pulp chamber
- Regular secondary dentin - mild stimulus, uniform deposition on pulp chamber walls
- Irregular/reparative dentin - severe stimulus, localized deposition near exposed dentin
The document summarizes the development of teeth from the initial formation of the primary epithelial band and dental lamina through the bud, cap and bell stages. It describes how the enamel organ and surrounding dental papilla and sac develop during these stages. Key stages of root formation controlled by Hertwig's epithelial root sheath are also outlined. The timeline of human tooth development from 6 weeks gestation through adulthood is provided. Molecular insights regarding signaling pathways such as FGF, SHH and BMPs controlling tooth morphogenesis and patterning are discussed.
Cementum is a hard, avascular connective tissue that covers the roots of teeth. It provides attachment for the periodontal ligament fibers and protects the underlying dentin. There are two types of cementum - acellular and cellular. Acellular cementum is laid down early in development and provides the main attachment for teeth. Cellular cementum is laid down later and is found mainly in the apical regions. Cementum is continuously deposited over the life of the tooth to maintain its length and acts to repair resorption of the root surface.
The periodontal ligament is a dense connective tissue that occupies the space between the root of a tooth and the alveolar bone. It contains collagen fibers, cells, blood vessels, and nerves. The fibers are arranged in different groups to support the tooth and allow movement during mastication while protecting the underlying bone. The periodontal ligament provides nutrition to cementum and bone, senses pressure, and facilitates tooth movement during orthodontic treatment by stimulating bone remodeling through fiber tension and compression. It also protects the tooth and bone by distributing forces and containing mechanoreceptors.
Blood supply,nerve supply and lymphatic drainage of the periodontium finalDr. Neha Pritam
The document discusses the blood supply, nerve supply, and lymphatic drainage of the periodontium. It states that the periodontium receives its blood supply from branches of the internal maxillary artery and its lymphatic drainage involves drainage to local lymph nodes. It also describes the rich nerve supply to the periodontium derived from the trigeminal nerve and its branches. Changes in microcirculation and lymphangiogenesis occur in the periodontium during periodontal disease.
Guided tissue regeneration (GTR) involves placing barriers over defects to separate gingival tissues and allow regeneration of periodontal ligament and bone. Animal and human studies show that excluding epithelium and allowing repopulation of defects by periodontal ligament cells leads to new attachment. Both resorbable and non-resorbable membrane barriers have been used for GTR with the goal of preventing epithelial migration and promoting regeneration. GTR has been shown to be predictable for treating intra-bony defects and grade II furcations.
The periodontal ligament is a specialized connective tissue that connects the cementum of teeth to the alveolar bone. It develops from the dental follicle during root formation and tooth eruption. The periodontal ligament is composed of collagen fibers, fibroblasts, blood vessels and nerves. The principal collagen fibers are arranged in bundles and attach to the cementum and bone. The periodontal ligament helps maintain homeostasis between the teeth and surrounding tissues and allows for tooth mobility.
This document provides an overview of gingival epithelium, including its microscopic features, structural characteristics, defense mechanisms, and renewal process. It defines gingiva as the part of oral mucosa that covers the alveolar process and surrounds tooth necks. Gingiva consists of three types: marginal, attached, and interdental gingiva. The gingival epithelium contains keratinocytes and melanocytes. Keratinocytes form the bulk of the epithelium and undergo continuous renewal, while melanocytes transfer melanin to keratinocytes. The degree of keratinization varies between oral mucosal sites.
The periodontium develops from neural crest cells that migrate into the developing dental arches. The dental lamina forms and invaginates into the underlying mesenchyme, forming the tooth bud. The bud develops through the cap and bell stages as the enamel organ and dental papilla form. The dental follicle gives rise to the periodontal ligament, cementum and alveolar bone. Cementoblasts deposit cementum on the root surface. Periodontal ligament fibers develop from the dental follicle and insert into the cementum and bone. The gingiva develops as the tooth erupts, with the reduced enamel epithelium transforming into junctional epithelium and sulcular epithelium.
The periodontal ligament is a connective tissue that connects the tooth to the alveolar bone. It contains collagen fibers, fibroblasts, cementoblasts, osteoblasts and other cells. The principal collagen fibers of the periodontal ligament originate on the cementum and insert into the alveolar bone in different orientations to provide structural support to the tooth and resist various forces. The periodontal ligament is essential for functions such as tooth eruption and maintains the space between the tooth and bone.
A presentation on the topic of microscopic section of gingiva. This topic is mostly looked on by periodontists. A very important chapter in the speciality in dentistry of periodontology and implantology department. Basic understanding of microscopic features and clinical features of gingiva is an important topic for post graduate as well as undergraduate students in the dental field.
The document discusses the periodontal ligament (PDL), which is the soft connective tissue that surrounds tooth roots and attaches cementum to alveolar bone. It defines PDL and describes its extent, average width, development from the dental follicle, orientation of collagen fibers, cellular elements including fibroblasts, cementoblasts, osteoblasts, and epithelial rests of Mallassez. The document also covers the biochemical composition and ground substance of PDL, as well as its blood supply, nerve supply, age-related changes, and role in healing after periodontal surgery.
The document discusses the alveolar bone, including its definition, composition, structure, cells, blood supply, and changes associated with orthodontic forces. It notes that alveolar bone surrounds and supports the teeth sockets. It is composed primarily of inorganic minerals and collagen. Microscopically, it contains osteons arranged in concentric lamellae around Haversian canals. Osteoblasts build bone while osteoclasts resorb it, maintaining a constant state of remodeling. The alveolar bone has a rich blood supply from the superior and inferior alveolar arteries and drains via lymph vessels. Orthodontic forces induce changes in the bone's morphology and turnover.
Cementum is the mineralized connective tissue covering tooth roots. It has several functions including anchoring collagen fibers from the periodontal ligament to provide attachment between the tooth and bone. Cementum can be classified based on its location, cellularity, fiber content, and other characteristics. It plays roles in adaptation, repair, and maintaining the periodontium. The cemento-enamel junction describes the interface between cementum and enamel at the cervical portion of the tooth root.
This document discusses the development of the periodontium, which includes the cementum, periodontal ligament, alveolar bone, and gingiva. It describes how the tooth germ develops from the enamel organ and dental papilla through stages of growth. Root formation is induced by Hertwig's epithelial root sheath, which regulates the development of cementum, periodontal ligament, and alveolar bone through cellular differentiation and protein signaling. The periodontium develops through reciprocal interactions between the enamel organ and dental follicle mesenchyme.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.
Cementum is a hard, mineralized tissue found on the anatomical roots of teeth. It has several subtypes based on cellularity and collagen fiber organization. Cementum is composed of hydroxyapatite crystals and collagen fibers. It is formed by cementoblasts and cementocytes. Cementum provides attachment of periodontal ligament fibers to the tooth and continues growing throughout life. The main types are acellular and cellular cementum. Acellular cementum forms earlier and is less cellular while cellular cementum forms later and more rapidly to adapt to functional forces. Cementum plays an important role in tooth attachment and is involved in pathological processes like root resorption.
Final - Cementum - Basics and Applied Aspects (Dr. Sabitha Sudarsan)1.pptxPrasanthThalur
This document provides an overview of cementum, a specialized connective tissue that covers tooth roots. It discusses the development, physical characteristics, composition, and microscopic structure of cementum. There are two main types - acellular cementum which covers the cervical third of roots and lacks cells, containing mineralized Sharpey's fibers, and cellular cementum which forms after tooth eruption and contains cementocytes in lacunae. The document outlines the roles of cementoblasts, cementocytes, and various proteins involved in cementogenesis.
cementum in health and disease final ppt.pptxPrasanthThalur
Cementum is the mineralized tissue covering tooth roots. It is avascular and non-innervated. There are two types - acellular and cellular cementum. Acellular cementum is deposited earlier and covers cervical root surfaces. Cellular cementum is deposited later and is found apically. Cementum functions to anchor teeth via Sharpey's fibers inserting into it from the periodontal ligament. Cementum deposition continues throughout life, maintaining proper tooth position and compensating for wear. Age-related changes include increased thickness with no change at the cementodentinal junction.
The document discusses dental cementum, which covers the root surfaces of teeth. It begins by defining cementum and describing its development, characteristics, and histology. Cementum begins forming at the cementoenamel junction and extends to the root apex. It is composed of cementoblasts, cementocytes, and cementoclasts. The document classifies cementum based on location, cellularity, collagen fiber composition, and the classification system of Schroeder. Cementum plays an important role in attaching the tooth to the surrounding alveolar bone.
The document discusses the junctional epithelium (JE), providing definitions, historical concepts, and details on its structure and function. Some key points:
- JE is the non-keratinized stratified squamous epithelium that forms a collar around the cervical portion of the tooth below the cementoenamel junction.
- There has been debate around its attachment to the tooth surface, but transmission electron microscopy showed it is attached via hemidesmosomes to the internal basal lamina on the tooth surface.
- JE develops as the tooth erupts, with the reduced enamel epithelium transforming into JE over 1-2 years in a coronal to apical direction via cell changes.
- It plays a
Enamel defects can be caused by disturbances during enamel development and mineralization. The document discusses the history of understanding enamel defects and the life cycle of ameloblasts, which produce enamel. It describes how factors like infections, nutritional deficiencies, and other illnesses during tooth development can disrupt ameloblast activity and cause hypoplasia, hypomineralization, or hypomaturation. The severity and duration of the disturbance determines if it results in enamel absence, improper calcification, or other defects. Maternal health, nutrition and illnesses can also affect enamel development in utero and after birth.
The junctional epithelium is a non-keratinized stratified squamous epithelium that forms an attachment to the tooth surface. It develops from the reduced enamel epithelium during tooth eruption. The junctional epithelium acts as a barrier against oral pathogens and allows for host defense mechanisms to reach the gingival sulcus. It has a rapid turnover rate of 4-6 days and can quickly regenerate after injury. The attachment to enamel is mediated by hemidesmosomes in the epithelial cells that are connected to the internal basal lamina on the tooth surface. Disruption of this attachment can initiate periodontal pocket formation and disease.
This document discusses the development of the periodontium, which includes the cementum, periodontal ligament, alveolar bone, and gingiva that support teeth. It first describes the development of cementum, which forms on tooth roots through the process of cementogenesis by cementoblasts. It then discusses the development of the periodontal ligament from the dental follicle prior to tooth eruption, and the development of alveolar bone and gingiva from the dental follicle. The document provides details on the structure, composition and functions of cementum and the periodontal ligament.
Cementum is the mineralized tissue covering tooth roots. It consists of inorganic minerals like hydroxyapatite and organic materials like collagen. Cementum forms through cementogenesis, led by cementoblasts. There are two stages of cementogenesis - matrix formation where cementoblasts lay down an unmineralized matrix, and mineralization where crystals are deposited. Cementum can be classified as acellular or cellular based on the presence of cementocytes, and primary or secondary based on formation time. Cementum functions to attach teeth to bone and allows for adaptation.
This document provides an overview of dentin, including its:
- History and discovery
- Physical and mechanical properties
- Chemical composition
- Formation through dentinogenesis and the life cycle of odontoblasts
- Classification based on development, location, and mineralization pattern
- Histology including primary, secondary, tertiary, and other types of dentin
- Age-related changes and clinical significance
The summary covers the key aspects and classifications of dentin discussed in the document in 3 sentences.
this ppt includes information regarding a dental tissue know as the cementum.
It is a hard tissue covering the roots of the teeth.
this ppt includes, the composition, formation, types, cells and functions the cementum plays in maintaining the integrity of the tooth .
Hertwig's epithelial root sheath is broken up and separated from the root, allowing differentiation of cementoblasts and formation of cementum. This marks the transition from root formation to development of the periodontium, including the periodontal ligament, cementum, and alveolar bone. Mesenchymal cells in the dental follicle and perifollicular region develop into fibroblasts that synthesize collagen fibers and other proteins to form the principal fiber groups of the periodontal ligament. Homeostasis of the periodontium is maintained by regulators that prevent mineralization and allow proliferation and remodeling of tissues in response to forces.
A Small effort to make this theory topic a little practical!!
The knowledge of this basic structure is actually the first building block towards dentistry.
Proper knowledge leads to correct diagnosis and henceforth desired treatment.
This document provides an overview of cementum, the mineralized tissue that coats tooth roots. It discusses the definitions, development, classification, physical and chemical characteristics, proteins, and functions of cementum. It also addresses cementum resorption and repair, age-related changes, anomalies, and its role in periodontal disease. The document is a lecture on cementum presented by Dr. Sidra Rahman and contains sections on introduction, history, definitions, development, classification, characteristics, proteins, and more.
The periodontal ligament is a complex connective tissue that surrounds the tooth root and connects it to the alveolar bone. It is composed of collagen fibers, cells like fibroblasts and cementoblasts, blood vessels and nerves. The PDL develops from the dental follicle during root formation and ranges in width from 0.15-0.38mm. It contains principal fibers that extend obliquely from cementum to bone and adapt to functional changes in teeth. The PDL maintains homeostasis between the hard tissues of cementum and bone through regulatory molecules and cells.
Cementum also commonly known as root cementum , is a highly mineralized tissue covering the entire root surface.
Cementum is also often referred to as a bone-like tissue. Cementum contains two types of fibers, mainly extrinsic (Sharpey's) fibers and intrinsic fibers. Fibroblasts and cementoblasts are the fiber secreting cells.
The document discusses the historical evidence for bacteria playing a primary role in the etiology of periodontal disease. Early investigations from 1880-1930 suggested a variety of microorganisms could be involved, including amebae, spirochetes, fusiforms, and streptococci. While therapies targeting these organisms showed some success, their precise roles remained unclear due to limitations of detection techniques. Subsequently, stronger evidence accumulated from studies of acute infections, correlations of plaque/disease, antibiotic treatment trials, host immune responses, animal models, and more advanced microbiology approaches. Overall a bacterial etiology of periodontal disease became firmly established, though the field continues refining understanding of specific pathogen identities and disease associations.
The document discusses the endocrinology of sex hormones and their effects on the periodontium. It covers the main sex steroid hormones - androgens like testosterone, estrogens like estradiol, and progestins like progesterone. It describes their mechanisms of action, roles in various physiological conditions like puberty, menstruation, pregnancy, and menopause. Fluctuations in sex hormone levels during these conditions can impact the periodontal tissues by altering the subgingival microbiota and increasing vascular permeability and inflammation. The periodontium is identified as a target tissue for sex hormones.
This document discusses several controversies in periodontics. It addresses debates around the classification of periodontal diseases, factors involved in periodontal pathogenesis like invasiveness of bacteria and the role of the periodontal epithelium. It also examines controversies in diagnosing periodontal diseases and determining an accurate prognosis. Additionally, it looks at debates around treatments like gingival curettage, tooth mobility and splinting, one stage full-mouth disinfection versus quadrant SRP, and whether results are comparable between non-surgical and surgical periodontal therapy. The document acknowledges that while knowledge has improved, some controversies remain due to limitations in present diagnostic methods and incomplete understanding of periodontal pathology.
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1. Inducible nitric oxide synthase (iNOS) is involved in inflammatory processes by synthesizing nitric oxide (NO) in response to stimuli like cytokines.
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The document discusses the influence of epigenetics on oral health. It defines epigenetics as heritable changes in gene expression that do not involve changes to the underlying DNA sequence. The key epigenetic mechanisms discussed are DNA methylation, histone modification, and regulation by non-coding RNA. Environmental stressors can induce epigenetic changes that influence oral diseases. Epigenetics provides a link between the genome and environment and helps explain phenotypic changes in oral health.
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B-cells play a central role in the humoral immune response by differentiating into antibody-secreting plasma cells upon activation. They can be activated through T-cell dependent or independent pathways to produce high or low affinity antibodies, respectively. In periodontal diseases, B-cells are involved in the host immune response against the bacterial biofilm and help control infection through antibody production. Their fate in periodontal diseases includes differentiation into plasma cells or memory B-cells to provide long-lasting immunity. B-cells also participate in periodontal bone resorption through antibody-mediated mechanisms.
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4. INTRODUCTION
Cementum is an avascular mineralized tissue covering the entire root
surface. Due to its intermediary position, forming the interface between
root dentin and periodontal ligament, cementum is a component of the
tooth itself, but belongs functionally to the dental attachment apparatus,
that is, the periodontium.
Gonçalves PF, Sallum EA, Sallum AW et al. Dental cementum reviewed: Development,
structure, composition, regeneration and potential functions. Braz J Oral Sci. January/March
2005 ;4: 651-658
5. Dental cementum is unique in various aspects: it does not undergo
continuous remodeling like bone, but continues to grow in thickness
throughout life.
Gonçalves PF, Sallum EA, Sallum AW et al. Dental cementum reviewed: Development,
structure, composition, regeneration and potential functions. Braz J Oral Sci. January/March
2005 ;4: 651-658
6. Unlike dentin and enamel, where there are clear differences in the
proteins present in these tissues and the factors regulating their
functions when compared with bone, cementum has not demonstrated
to express specific proteins, appearing to contain factors in common
with bone and to be developmentally controlled by similar factors.
Gonçalves PF, Sallum EA, Sallum AW et al. Dental cementum reviewed: Development,
structure, composition, regeneration and potential functions. Braz J Oral Sci. January/March
2005 ;4: 651-658
7. DEFINITION
Cementum is the calcified, avascular mesenchymal tissue that forms
the outer covering of the anatomic root.
8. HISTORY
According to Denton, cementum was first demonstrated microscopically
by
Fraenkel and Raschkow (1835)
Retzius (1836)
Yamamoto T, Hasegawa T, Yamamoto T et al. Histology of human cementum: Its structure,
function, and development. Japanese Dental Science Review 2016 ;52: 63-74
9. PROPERTIES
Physical properties:-
• Pale yellow with dull surface.
• Softer than dentine.
• Permeability varies with age and the type of cementum, the cellular
varieties being more permeable.
• Readily removed by abrasion owing to relative softness and thinness
cervically.
Tencate R. Periodontium. In : Textbook of Oral Histology. 8. Elsevier; 2015: 205-232.
10. Chemical properties:-
• Wet weight basis- 65% inorganic material, 23% organic material, 12%
water.
• By volume- 45% inorganic material, 33% organic material, 22%
water.
• The degree of mineralization varies in different part of the tissues.
• The principal component is hydroxyapatite crystals, approx. 55 nm
wide and 8 nm thick..
• The collagen is virtually all Type-I collagen.
Tencate R. Periodontium. In : Textbook of Oral Histology. 8. Elsevier; 2015: 205-232.
11. COMPOSITION
Since cementum is not a uniform, mineralized
connective tissue, differences in the proportional
composition of the chemical constituents exist
between the various cementum varieties.
Biochemical studies have shown that “cementum” has
a chemical composition similar to bone.
Bosshardt DD, Selvig KA. Dental cementum: The dynamic tissue covering of the root.
Periodontol 2000, 1997; 13: 41-75
12. To about equal parts per volume, cementum is
composed of water, organic matrix and minerals.
About 50% of the dry mass is inorganic, and consists
of hydroxyapatite crystals.
The remaining organic matrix contains largely
collagens, glycoproteins, and proteoglycans.
Bosshardt DD, Selvig KA. Dental cementum: The dynamic tissue covering of the root.
Periodontol 2000, 1997; 13: 41-75
13. 1.ORGANIC MATRIX
Collagens:
a) The organic matrix of cementum consists primarily of collagens.
b) The two typical fibril-forming collagens Type I (90%) and Type III
(5%) are found in cementum.
c) Type- XII, a fibril-associated collagen with interrupted triple helices,
binds to Type- I collagen and also to noncollagenous matrix proteins.
d) Trace amounts of Type V, VI, XIV, are also found.
Bosshardt DD, Selvig KA. Dental cementum: The dynamic tissue covering of the root.
Periodontol 2000, 1997; 13: 41-75
14. • Plays structural as well as morphogenic roles.
• Provides scaffolding for mineral crystals.
Type-I
collagen
• Coats type-I collagen fibrils.
• Less cross-linked collagen
• High concentration during development and
repair/ regeneration.
Type-III
collagen
Bosshardt DD, Selvig KA. Dental cementum: The dynamic tissue covering of the root.
Periodontol 2000, 1997; 13: 41-75
15. The procollagen molecules are secreted and aggregate extracellularly
to form cross-striated collagen fibrils with the typical 67 nm banding
pattern.
This striking banding pattern stands out in electron micrographs and is
partly obscured when the collagenous matrix is mineralized.
Frequently observed in membrane bound compartments within the
cementoblasts cytoplasm.
These serve to position newly produced fibril segments to already
existing fibril bundles.
Bosshardt DD, Selvig KA. Dental cementum: The dynamic tissue covering of the root.
Periodontol 2000, 1997; 13: 41-75
16. Non-collagenous proteins:
1.Cementum is rich in glycoconjugates :-
glycolipids
glycoproteins
proteoglycans.
2. Non-collagenous proteins found in cementum are :-
bone sialoprotein
Dentin matrix protein-1
Dentin sialoprotein
fibronectin
Bosshardt DD, Selvig KA. Dental cementum: The dynamic tissue covering of the root.
Periodontol 2000, 1997; 13: 41-75
21. Bone Sialoprotein and Osteopontin :-
1. Phosphorylated and sulfated glycoprotein.
2. Binds tightly to the collagenous matrices and hydroxyapatite.
3. Participates in the mineralization process
4. Reveals cell attachment properties through the tripeptide sequence
(Arg-Gly-Asp)
5. Acellular afibrillar cementum and acellular extrinsic fiber cementum.
Bosshardt DD, Selvig KA. Dental cementum: The dynamic tissue covering of the root.
Periodontol 2000, 1997; 13: 41-75
22. 2. INORGANIC MATRIX
Bosshardt DD, Selvig KA. Dental cementum: The dynamic tissue covering of the root.
Periodontol 2000, 1997; 13: 41-75
Cementum is less mineralized than root dentin.
Acellular extrinsic fibre cementum appears more mineralized than
cellular intrinsic fibre cementum and cellular mixed stratified
cementum.
Chemical and physio-chemical studies indicate that the mineral
component is the same as in the other calcified tissues, ie.
Hydroxyapatite (Ca10(PO4)6(OH)2) with small amounts of
amorphous calcium phosphates.
23. Transmission electron microscopy and electron diffraction analyses
have confirmed that the mineral crystals are arranged with their
crystallographic c-axis parallel to the long axis of the collagen fibril
with which they are associated.
Contains 0.5%-0.9% magnesium ions, and almost equal amount of
calcium ions.
Up to 0.9% ash weight fluoride content.
0.1-0.3% Sulphur.
Trace elements- Cu, Zn, Na.
Bosshardt DD, Selvig KA. Dental cementum: The dynamic tissue covering of the root.
Periodontol 2000, 1997; 13: 41-75
24. CEMENTOGENESIS
1.Cementoblasts:-
• Studies have shown a possibility that acellular and cellular
cementum have different developmental origin.
• Derived from dental follicle which is of ectomesenchymal origin.
or
• Recent ultrastructural and immunohistochemical studies have shown
that the cementoblasts originate from the epithelial cells of HERS
when they undergo an epithelial-mesenchymal transformation.
• HERS is actively involved in the formation of both types of
cementum.
26. Gottlieb indicated that HERS was removed from the root surface prior
to cementum deposition.
Insitu hybridization and immunolocalization data reveals amelogenin
mRNA and enamel proteins were restricted to the crown enamel and
were absent from root surface
Western blot tests showed cementum protein extracts did not cross
react with amelogenin antibodies.
Cementum is a dental follicle derived connective tissue that forms
subsequent to HERS disintegration.
Gonçalves PF, Sallum EA, Sallum AW et al. Dental cementum reviewed: Development,
structure, composition, regeneration and potential functions. Braz J Oral Sci. January/March
2005 ;4: 651-658
27. The differentiation of cementoblasts from cementoprogenitor cells and
the formation of the dentinocemental junction are temporally and
spatially closely related to dentin formation.
The initiation of cementogenesis is, therefore, restricted to a narrow
band (200-300 µm) encircling the forming root at its most apical
portion.
This circular band extends coronally from the advancing root edge
and shifts in the apical direction while the root elongates.
Bosshardt DD, Selvig KA. Dental cementum: The dynamic tissue covering of the root.
Periodontol 2000, 1997; 13: 41-75
28. 2.CEMENTOCYTES:-
Cementocytes are similar in morphology
to osteocytes.
Numerous cell processes radiate outward
from the central cell body. The cell body
resides in the lacuna, while the
cytoplasmic extensions reside in the
canaliculi.
In living cementocytes, the canaliculi
containing the cell processes are oriented
towards the PDL, i.e., toward the source
of nutrition.
29. Since all cementum is avascular, the buried (deeper) cementocytes of
cellular cementum are totally dependent upon the diffusion of
nutrients from the vessels within the PDL.
Cementocytes in deeper layers are characterized by a reduction in
cytoplasmic organelles & by a concomitant increase in inactive
nuclear chromatin (heterochromatin), indicating degeneration/
marginal activity of cells.
At a depth of 60µm/ more, cementocytes show definite signs of
degeneration such as cytoplasmic clumping & vesiculation.
The lacunae in the deeper layers appear to be empty at the light
microscopic level, suggesting complete degeneration of cells.
31. Formed during root
development. Extends over a
period of 3.75-7.75 years(root
formation). Primary distribution
of the main cementum is
determined for each root.
Commences when the tooth is
about to reach the occlusal
level. Adaptive and reparative
processes carried out by
biological responsiveness of
cementum.
Pre-functional stage
Functional stage
32. Diekwisch in 2001 described cementogenesis as :-
Deposition of dentin along the inner aspect of
HERS.
Hertwigs epithelial root sheath disintegrates
Dental follicle cells penetrate the epithelial
layer.
Invades the root surface.
Gonçalves PF, Sallum EA, Sallum AW et al. Dental cementum reviewed: Development,
structure, composition, regeneration and potential functions. Braz J Oral Sci. January/March
2005 ;4: 651-658
33. Newly formed dentin comes in contact with
the cells of the dental follicle.
Differentiation of cementoblasts along the
external surface of root
Protein secretion by cementoblasts
Mainly collagen and proteoglycans which
forms the organic matrix of cementum
Matrix maturation and mineralization.
34. Initial cementum formation. The
first increment of cementum forms
against the root dentin surface.
Epithelial cell rests of Malassez
(remnants of the root sheath) can be
seen within the follicular tissue.
Cell rests of Malassez
Periodontal ligament
dentin
cementum
35.
36. • HERS disintegrates into small clusters or strands of epithelial
cells.
• Undergo epithelial/ mesenchymal transformation into
fibroblasts and cementoblasts, deposit acellular and cellular
cementum respectively.
• Becomes incorporated into cellular cementum.
• Trapped between cementum and dentin during formation of
the apical part of the root.
Gonçalves PF, Sallum EA, Sallum AW et al. Dental cementum reviewed: Development,
structure, composition, regeneration and potential functions. Braz J Oral Sci. January/March
2005 ;4: 651-658
37. • The only incontrovertible fact is, they retain
epithelial phenotype and survive in PDL as epithelial
rests of Malassez.
Gonçalves PF, Sallum EA, Sallum AW et al. Dental cementum reviewed: Development,
structure, composition, regeneration and potential functions. Braz J Oral Sci. January/March
2005 ;4: 651-658
38. 4.CEMENTO-DENTINAL JUNCTION
The terminal apical area of
cementum where it joins the
internal root dentin is called
cementodentinal junction or
CDJ.
Width of CDJ is 2 to 3µm and
remains relatively stable.
Scalloped in deciduous teeth &
smooth in the permanent teeth.
39. Cementoprogenitor cells differentiate along the newly deposited and
not yet mineralized matrix of the radicular mantle dentin into
cementoblasts.
At the beginning of their maturation on the root surface, they extend
numerous tiny cytoplasmic processes into the loosely arranged and
not yet mineralized dentinal matrix.
This enables the cementoblasts to position the initially secreted
collagen fibrils of the cementum matrix among those of the dentinal
matrix.
Bosshardt DD, Selvig KA. Dental cementum: The dynamic tissue covering of the root.
Periodontol 2000, 1997; 13: 41-75
40. This leads eventually to an intimate
interdigitation of the two different fibril
populations.
The mineralization of the outermost layer of
the dentin matrix, (mantle dentin) appears to
be delayed.
Mineralization front in dentin reach the future
dentinocemental junction, not before the
implantation of the cementum matrix is
established and the dentinal matrix is
completely covered with the collagen fibrils of
cementum.
Bosshardt DD, Selvig KA. Dental cementum: The dynamic tissue covering of the root.
Periodontol 2000, 1997; 13: 41-75
41. 5. MINERALIZATION
Begins in the depth of the precementum.
Fine hydroxyapatite crystals are deposited
1. Between the collagen fibrils.
2. Within the collagen fibrils.
According to Zander and Hurzeler, the mean linear rate of cementum
deposition on single rooted tooth is about 3μm per year.
The width of precementum layer is 3-5 μm.
Bosshardt DD, Selvig KA. Dental cementum: The dynamic tissue covering of the root.
Periodontol 2000, 1997; 13: 41-75
42. Sharpey’s fibres
Sharpey’s fibres are collagen fibres embedded into cementum on one
side and into the alveolar bone on another.
Numerous but smaller at their attachment into cementum than bone.
Mineralization is at right angle to the long axis of the fibres- in
function, the fibres are subjected to tensional forces.
In primary acellular cementum- fully mineralized.
In cellular cementum- mineralized partially at periphery.
43.
44.
45. CLASSIFICATION
1. Based on time of formation (B.Gottlieb JP, 1942)
Primary cementum Secondary cementum
• Formed before eruption and
prior to teeth reaching functional
occlusion.
• Devoid of cells
• Contains randomly oriented
collagen fibrils embedded in a
granular matrix.
• Subsequent to occlusal contact.
• Contains cells
• Coarse collagen fibrils oriented
parallel to root surface and
Sharpey’s fibers perpendicular
to root surface.
Tencate R. Periodontium. In : Textbook of Oral Histology. 8. Elsevier; 2015: 205-232.
46. 2.Based on presence or absence of cells (B.Gottlieb, 1942)
47. 3. Based on location of tooth :-
Coronal cementum Radicular cementum
4. Based on origin of fibers (Selvig,1965) :-
Intrinsic fibers Extrinsic fibres
48. 5. Based on location, structure, function, rate of formation,
biochemical composition and degree of mineralization
cementum can be classified as(Schroeder,1992):
Acellular Afibrillar Cementum
Acellular Extrinsic Fiber Cementum.
Cellular Mixed Stratified Cementum.
Cellular Intrinsic Fiber Cementum.
Intermediate cementum
49. Consist of mineralized matrix.
This matrix appears similar to interfibrillar
matrix of acellular extrinsic fibre cementum.
Contains neither collagen fibrils nor
embedded cells.
It has no function in tooth attachment.( lack
of collagen fibrils).
1. Acellular Afibrillar Cementum
50. Light microscopy Electron microscopy
•Stands out by basophilia.
•More or less uniform appearance.
•Less homogeneous appearance.
•Multifarious appearance- a
variable number of layers with
varying electron density and
different texture, can either be
granular or reticular.
51. Its formation commences at the end of enamel maturation and
continues for an unknown period of time.
Found as isolated patches or as the most cervical part of AEFC on
enamel just coronal to CEJ.
3 theories of formation have been proposed :-
1. Connective tissue cells produce AAC, if this is true connective tissue
cells must replace REE.
2. AAC is an epithelial product, deposited by inner enamel epithelial
cells which are about to become HERS.
3. AAC is a mere precipitate derived from tissue fluid or serum.
Yamamoto T, Hasegawa T, Yamamoto T et al. Histology of human cementum: Its structure,
function, and development. Japanese Dental Science Review 2016 ;52: 63-74
53. Covers upto 60-90% of the root length in single rooted tooth and
cervical half to one-third in multirooted tooth.
With age, thickness increases upto 50-200 µm.
Its formation commences shortly after crown formation is completed
and always before cellular intrinsic fibre cementum starts to form on
more apical root portions.
Produced by cementoblasts which commence their differentiation in
closest proximity to advancing root edge.
Contains collagen fibres and noncollagenous proteins as organic
matrices, both fully mineralized.
Yamamoto T, Hasegawa T, Yamamoto T et al. Histology of human cementum: Its structure,
function, and development. Japanese Dental Science Review 2016 ;52: 63-74
54. Collagen fibres :-
Belong to extrinsic fibres group.
Densely packed and arranged nearly perpendicular to root surfaces.
Diameter- approx. 3-6 µm.
Shows branching and anatomising.
These fibres are implanted into the dentinal matrix.
The extrinsic fibres remain short until the tooth is about to reach the
occlusal level.
AEFC functions in anchorage to the surrounding bone.
Yamamoto T, Hasegawa T, Yamamoto T et al. Histology of human cementum: Its structure,
function, and development. Japanese Dental Science Review 2016 ;52: 63-74
55. INCREMENTAL LINES OF SALTER
•Also known as resting line, formed
during intermediate AEFC formation.
•Highly mineralized.
•These lines represent the periodic
deposition of the cementum layers in
frequent association with an abrupt
change in the direction of sharpey’s
fibres.
Yamamoto T, Hasegawa T, Yamamoto T et al. Histology of human cementum: Its structure,
function, and development. Japanese Dental Science Review 2016 ;52: 63-74
56. 3. CELLULAR MIXED STRATIFIED CEMENTUM
Yamamoto T, Hasegawa T, Yamamoto T et al. Histology of human cementum: Its structure,
function, and development. Japanese Dental Science Review 2016 ;52: 63-74
• CMSC covers interradicular and apical
portion regions of root.
•Thickness 400-600µm incisors, 500µm in
canines, between 300-1000µm in
premolars, 700-1500µm in molars.
57. The intrinsic fibre
predominant over
Sharpey’s fibres.
Harbours both
intrinsic and
extrinsic fibres
within calcified
matrix.
This matrix
consists of viable
cementocytes.
Increases in
thickness
throughout life.
Co-product of
fibroblasts and
cementoblasts.
Newmann, Takei, Klokkevold et al. Anatomy Of The Periodontium. In: Carranza’s Clinical
Periodontology. 11:Elsevier; 2011: 12-51
58. After the formation
of CIFC when the
periodontal ligament
becomes organized,
cementum may form
around some of the
periodontal ligament
fiber bundles.
These get
incorporated into
cementum(CIFC)
and become
partially
mineralized.
In human teeth,
incorporation of
periodontal ligament
fibers into CEFC
occurs only rarely,
essentially in the
AEFC component of
CMSC.
Newmann, Takei, Klokkevold et al. Anatomy Of The Periodontium. In: Carranza’s Clinical
Periodontology. 11:Elsevier; 2011: 12-51
59. Yamamoto T, Hasegawa T, Yamamoto T et al. Histology of human cementum: Its structure,
function, and development. Japanese Dental Science Review 2016 ;52: 63-74
61. After atleast half the root formation, a more rapidly formed and less
mineralized cementum is deposited on the unmineralized dentin
surface near the advancing root edge.
Doesn’t encase any Sharpey’s fibres, has organic matrix consisting of
intrinsic fibres which are synthesized by cementoblasts.
Lacunae with cementocytes.
Fastest growing cementum- may repair any resorptive defect in
reasonable time.
Has no immediate role in tooth attachment Adaptive tissue
that brings and maintains tooth in proper position.
Newmann, Takei, Klokkevold et al. Anatomy Of The Periodontium. In: Carranza’s Clinical
Periodontology. 11:Elsevier; 2011: 12-51
62. INTERMEDIATE CEMENTUM
Also known as Hyaline layer of Hopewell-Smith.
Ill-defined zone extending from pre-CEJ to the apical third of the root.
Appears to contain cellular remnants of HERS.
Contains enamel like protein (amelogenin)- helps in attachment of
cementum to dentin.
63. CEMENTOENAMEL JUNCTION
Cementoenamel junction is the anatomical boundary between enamel
on tooth crown and cementum which covers the root of the tooth-
Franchischone and Consolaro, 2008.
It is the place where gingival fibres are attached to a tooth in a healthy
state- reference benchmark- to assess periodontal destruction-
Berendregt et al, 2009.
Choquet, in 1899- 1st person to describe CEJ.
Roa I, Del Sol M, Cuevas J. Morphology of the cement-enamel junction (CEJ), clinical
correlations. Int. J. Morphol 2013; 31(3): 894-898
64. TYPES OF CEMENTOENAMEL JUNCTION
1.Cementum over
enamel
2.Butt joint 3.Gap junction 4.Enamel over
cementum
Roa I, Del Sol M, Cuevas J. Morphology of the cement-enamel junction (CEJ), clinical
correlations. Int. J. Morphol 2013; 31(3): 894-898
65.
66. CLINICAL APPLICATION
In contact with the oral environment,
becomes susceptible to the
morphological changes induced by
physical agents
Esberard et al in 2007 Chemical agents such as bleaching agent
may induce detectable changes in CEJ.
Gasic et al in 2012 No changes in morphology of CEJ to
chemical agents.
Komabayashi et al in 2008 No difference between tooth surfaces,
bleaching agent will penetrate more or
less easily to the dentinal tubules and
hence affect dental pulp.
Fonseca & Fonseca in 1992 and
Satheesh et al in 2011
Type 1 & 3 are more susceptible to
caries, structural integrity causing more
adhesion of biofilms.
Roa I, Del Sol M, Cuevas J. Morphology of the cement-enamel junction (CEJ), clinical
correlations. Int. J. Morphol 2013; 31(3): 894-898
67. Palamara et al in 2006, Hur et
al in 2011
CEJ is the area where highest
number of non-carious cervical
lesions occur.
Cuniberti de Rossi & Rossi in
2009
Classes 2 & 4 are the most
susceptible to abfraction.
Roa I, Del Sol M, Cuevas J. Morphology of the cement-enamel junction (CEJ), clinical
correlations. Int. J. Morphol 2013; 31(3): 894-898
68. Continuous deposition of cementum throughout life
At a linear rate.
More at apical region than cervically.
Non-functioning teeth have thicker cementum than functioning teeth.
Increase in width of cementum by 5-10 times (Berglundh, 1991).
There is tendency for cementum to reduce root surface concavities. Thus thicker
layers of cementum may form in root surface grooves and in the furcations of
multirooted teeth.
AGE CHANGES
Bosshardt DD, Selvig KA. Dental cementum: The dynamic tissue covering of the root.
Periodontol 2000, 1997; 13: 41-75
71. Cementum resorption is not necessarily continuous & may alternate
with periods of repair & deposition of new cementum. The newly
formed cementum is demarcated from the root by a deeply staining
irregular line, termed reversal line, which delineates the border of
previous resorption.
Reversal lines contain a few collagen fibrils & highly accumulated
proteoglycans with mucopolysaccharides (GAGs). (Yamamoto et al,
2000).
When the resorptive activity of the odontoclasts has ceased and the
stimulus for new odontoclasts recruitment disappears, repair occurs.
Bosshardt DD, Selvig KA. Dental cementum: The dynamic tissue covering of the root.
Periodontol 2000, 1997; 13: 41-75
72. REPAIR
Morphological studies have shown that two different repair matrices
become attached to the resorbed root surface.
Following the detachment of odontoclasts from the root surface,
cementogenic cells repopulate the Howship’s lacunae.
Attach the initial repair matrix to a thin decalcified layer of residual
and exposed collagen fibrils.
These cells and their respective repair tissues reveal remarkable
homologies to the initial genesis of the two major cementum varieties
(i.e., AEFC & CIFC) on growing roots.
Bosshardt DD, Selvig KA. Dental cementum: The dynamic tissue covering of the root.
Periodontol 2000, 1997; 13: 41-75
73. The interdigitation of the newly formed collagen fibrils with the
residual dentinal matrix fibrils occurs before the new attachment site
becomes obscured by electron-dense material.
Eventually, a basophilic and electron-dense reversal line forms at the
fibrillar junction.
Subsequently deposited repair matrix usually resembles CIFC forms
on nonresorbed roots.
Bosshardt DD, Selvig KA. Dental cementum: The dynamic tissue covering of the root.
Periodontol 2000, 1997; 13: 41-75
74. The strong resemblance of the initial formation of the two repair
matrices with the initiation of AEFC and CIFC on the forming root
indicates that repair cementogenesis recapitulates the events occurring
during root development,
A notion that is in line with the views of Aukhil(1992) and MacNeil &
Somerman (1993) but in contrast with the concept hold by Pitaru et
al. (1994).
Bosshardt DD, Selvig KA. Dental cementum: The dynamic tissue covering of the root.
Periodontol 2000, 1997; 13: 41-75
75. PERIODONTAL PATHOLOGY
Concrescence
Form of fusion which occurs after root
formation.
United by cementum
Thought to arise as a result of traumatic injury
or crowding of teeth with resorption of
interdental bone.
May occur before or after tooth eruption
Diagnosed radiographically
Extraction of one may result in the extraction
of the other.
76. CERVICAL ENAMEL PROJECTION
• Represent dipping of enamel from CEJ toward the bifurcation
• More in mandibular molars – buccal surface
• Correlated positively to localized loss of periodontal attachment
with furcation involvement
77. HYPERCEMENTOSIS
Abnormal thickening of the cementum
May effect all teeth of the dentition, be confined to a single tooth, or
even affect only parts of one tooth.
Cemental hypertrophy Cemental hyperplasia
If overgrowth improves functional
qualities of cementum.
if overgrowth occurs in non-
functional teeth.
Newmann, Takei, Klokkevold et al. Anatomy Of The Periodontium. In: Carranza’s Clinical
Periodontology. 11:Elsevier; 2011: 12-51
78. Types of hypercementosis :-
1. Generalized
e.g.. Paget’s disease.
2. Localized
e.g.. Low grade periapical irritation.
Newmann, Takei, Klokkevold et al. Anatomy Of The Periodontium. In: Carranza’s Clinical
Periodontology. 11:Elsevier; 2011: 12-51
79. CEMENTAL TEARS
Detachment of a fragment of cementum from root surface, owing to
an acute injury or from intermittent episodes of sustained pressure.
Tears have been observed within unexposed cementum as well as in
cementum exposed within the pocket.
The cemental tears can remain partially attached or be completely
detached from the root surface.
Caused due to excessive occlusal loading (parafunctional habits) or
due to trauma.
80.
81. CEMENTICLES
Cementicles are round ovoid bodies that are found on the surface of
the cementum or in the periodontal ligament.
Cementicles may
Lie free in the periodontal ligament adjacent to the cementum
surface - Free cementicles
Attached to the cementum surface - Attached or sessile cementicles.
Or incorporated into the cementum layer - Embedded cementicles.
82. They may develop from:-
Calcified epithelial Cell Rest of Malassez.
Small spicules of cementum or alveolar bone that are traumatically
placed in PDL.
Calcified Sharpey’s fibers.
Calcified thrombosed vessel in PDL.
84. CONCLUSION
The periodontal
tissues form a
functional unit
designed to
maintain tooth
support and
protection.
In particular,
cementum, by
virtue of its
structural and
dynamic
qualities,
provides tooth
attachment and
maintainence of
occlusal
relationship.
The dynamic
features of
cementum are
particularly
highlighted by
its repair
potential.
Bosshardt DD, Selvig KA. Dental cementum: The dynamic tissue covering of the root.
Periodontol 2000, 1997; 13: 41-75
85. REFERENCE
Bosshardt DD, Selvig KA. Dental cementum: The dynamic tissue
covering of the root. Periodontol 2000, 1997; 13: 41-75
Gonçalves PF, Sallum EA, Sallum AW et al. Dental cementum
reviewed: Development, structure, composition, regeneration and
potential functions. Braz J Oral Sci. January/March 2005 ;4: 651-
658.
86. Yamamoto T, Hasegawa T, Yamamoto T et al. Histology of human
cementum: Its structure, function, and development. Japanese Dental
Science Review 2016 ;52: 63-74
Berkovitz BK, Holland GR, Moxham BJ. Cementum. In: Oral
anatomy, histology and embryology. 4. Mosby; 2009. 168-179
Roa I, Del Sol M, Cuevas J. Morphology of the cement-enamel
junction (CEJ), clinical correlations. Int. J. Morphol 2013; 31(3): 894-
898.
87. Tencate R. Periodontium. In : Textbook of Oral Histology. 8.
Elsevier; 2015: 205-232.
Newmann, Takei, Klokkevold et al. Anatomy Of The Periodontium.
In: Carranza’s Clinical Periodontology. 11:Elsevier; 2011: 12-51
Editor's Notes
Oral anatomy, histology and embryology, chap 11, cementum pg 168-179
Transition between aefc and cifc, both appears as a translucent structureless layer. Cementocytes are present in cifc