Hist 7
•Download as PPTX, PDF•
3 likes•242 views
- Enamel is composed of enamel rods (prisms), rod sheaths, and interrod regions. Enamel rods are bundles of hydroxyapatite crystals that run obliquely from the dentin-enamel junction to the enamel surface. They have a hexagonal cross-section and keyhole shape longitudinally. - Rod sheaths surround the organic matrix around 2/3 of enamel rods. Interrod regions are the spaces between rods. Enamel tufts and lamellae contain organic materials and arise from the dentin-enamel junction and enamel surface, respectively. - With age, enamel wears down from mastication, decreases in permeability, and darkens in color.
Report
Share
Report
Share
Recommended
Hist 5
Amelogensis is the process of enamel formation. It occurs in four main phases: morphogenic, secretory, maturation, and protective. In the morphogenic phase, inner enamel epithelial cells interact with dental papilla cells to determine tooth shape. In the secretory phase, ameloblasts secrete enamel matrix proteins and minerals to form enamel rods. During maturation, the enamel mineralizes further as proteins are removed. In the protective phase, ameloblasts become cuboidal cells that protect the enamel surface from the dental sac until eruption.
Epithelial cell rests of malassez
The root sheath breaks down and cementoblasts arise from the dental sac as dentin growth causes the physical breakdown of the epithelial diaphragm. Dental follicle cells then invade and form cementoblasts, which lay down cementum on the root surface. Remnants of the broken down root sheath remain as rests of Malassez.
Oral Histology "tooth development"
1. The document describes the morphological stages of tooth development from the dental lamina stage through the bell stage.
2. It explains the histological changes that occur in each stage, including the differentiation of cells in the enamel organ and dental papilla.
3. Root formation begins after enamel and dentin deposition reaches the cemento-enamel junction, guided by the epithelial root sheath of Hertwig.
Root formation and periodontal ligament
The document describes the development of the dental pulp and root formation. It discusses:
- How the dental pulp develops from mesenchymal cells that differentiate into odontoblasts and fibroblasts.
- How the dental papilla and follicle form during the bud and cap stages and their roles in tooth development.
- How odontoblasts and cementoblasts differentiate during the bell stage to lay down dentin and cementum.
- The development of blood vessels and nerves that enter the dental pulp.
- How root formation is directed by the Hertwig's epithelial root sheath and how this determines root morphology.
- The formation of acellular cementum on root surfaces by
Root formation
This document discusses root formation in teeth. It begins by explaining that the root starts developing after the crown is complete, as epithelial cells from the inner and outer enamel epithelium proliferate to form the Hertwig's root sheath in two layers. This sheath then bends to form an epithelial diaphragm. Next, it describes how the root grows in length as the root sheath elongates below the stationary diaphragm, inducing odontoblast differentiation and dentin deposition. Finally, it notes that the epithelial root sheath breaks down after root formation, with remnants residing in the periodontium as epithelial rests of Malassez.
Root Formation
The root of a tooth develops after the crown is completed through the formation of a cervical loop. As the cervical loop grows down into the dental sac, it forms Hertwig's root sheath, which shapes the root and induces dentin formation in the root area. For single-rooted teeth, the root sheath grows like a cuff or tube around the newly forming pulp, while for multi-rooted teeth, the epithelial diaphragm develops tongue-like extensions that divide the root into two or three portions when they contact each other in the furcation area.
Development of Teeth
This document discusses the development of teeth from initiation to eruption. It begins with an overview and introduces the key tissues involved - epithelium and ectomesenchyme. It then covers the molecular signaling pathways, formation of the primary epithelial band and dental lamina, and the sequential developmental stages from bud to bell stage. Defects at each stage like anodontia, fusion and macro/microdontia are also summarized. Finally, it discusses the processes of amelogenesis and root formation in detail.
Enamel pearl
An enamel pearl, or enameloma, is a small white mass of ectopic enamel attached to a root surface near the cementoenamel junction (CEJ). It can contain enamel, dentin, and pulp. Enamel pearls are caused by the persistence of Hertwig's epithelial root sheath during root development, allowing it to form enamel. They range in size from 0.3 to 4 mm and commonly form on the maxillary and mandibular molars. Enamel pearls promote plaque retention and provide a niche for bacteria, which can lead to periodontal problems if left untreated.
Recommended
Hist 5
Amelogensis is the process of enamel formation. It occurs in four main phases: morphogenic, secretory, maturation, and protective. In the morphogenic phase, inner enamel epithelial cells interact with dental papilla cells to determine tooth shape. In the secretory phase, ameloblasts secrete enamel matrix proteins and minerals to form enamel rods. During maturation, the enamel mineralizes further as proteins are removed. In the protective phase, ameloblasts become cuboidal cells that protect the enamel surface from the dental sac until eruption.
Epithelial cell rests of malassez
The root sheath breaks down and cementoblasts arise from the dental sac as dentin growth causes the physical breakdown of the epithelial diaphragm. Dental follicle cells then invade and form cementoblasts, which lay down cementum on the root surface. Remnants of the broken down root sheath remain as rests of Malassez.
Oral Histology "tooth development"
1. The document describes the morphological stages of tooth development from the dental lamina stage through the bell stage.
2. It explains the histological changes that occur in each stage, including the differentiation of cells in the enamel organ and dental papilla.
3. Root formation begins after enamel and dentin deposition reaches the cemento-enamel junction, guided by the epithelial root sheath of Hertwig.
Root formation and periodontal ligament
The document describes the development of the dental pulp and root formation. It discusses:
- How the dental pulp develops from mesenchymal cells that differentiate into odontoblasts and fibroblasts.
- How the dental papilla and follicle form during the bud and cap stages and their roles in tooth development.
- How odontoblasts and cementoblasts differentiate during the bell stage to lay down dentin and cementum.
- The development of blood vessels and nerves that enter the dental pulp.
- How root formation is directed by the Hertwig's epithelial root sheath and how this determines root morphology.
- The formation of acellular cementum on root surfaces by
Root formation
This document discusses root formation in teeth. It begins by explaining that the root starts developing after the crown is complete, as epithelial cells from the inner and outer enamel epithelium proliferate to form the Hertwig's root sheath in two layers. This sheath then bends to form an epithelial diaphragm. Next, it describes how the root grows in length as the root sheath elongates below the stationary diaphragm, inducing odontoblast differentiation and dentin deposition. Finally, it notes that the epithelial root sheath breaks down after root formation, with remnants residing in the periodontium as epithelial rests of Malassez.
Root Formation
The root of a tooth develops after the crown is completed through the formation of a cervical loop. As the cervical loop grows down into the dental sac, it forms Hertwig's root sheath, which shapes the root and induces dentin formation in the root area. For single-rooted teeth, the root sheath grows like a cuff or tube around the newly forming pulp, while for multi-rooted teeth, the epithelial diaphragm develops tongue-like extensions that divide the root into two or three portions when they contact each other in the furcation area.
Development of Teeth
This document discusses the development of teeth from initiation to eruption. It begins with an overview and introduces the key tissues involved - epithelium and ectomesenchyme. It then covers the molecular signaling pathways, formation of the primary epithelial band and dental lamina, and the sequential developmental stages from bud to bell stage. Defects at each stage like anodontia, fusion and macro/microdontia are also summarized. Finally, it discusses the processes of amelogenesis and root formation in detail.
Enamel pearl
An enamel pearl, or enameloma, is a small white mass of ectopic enamel attached to a root surface near the cementoenamel junction (CEJ). It can contain enamel, dentin, and pulp. Enamel pearls are caused by the persistence of Hertwig's epithelial root sheath during root development, allowing it to form enamel. They range in size from 0.3 to 4 mm and commonly form on the maxillary and mandibular molars. Enamel pearls promote plaque retention and provide a niche for bacteria, which can lead to periodontal problems if left untreated.
root formation tooth development
This document discusses root formation in teeth. It begins by outlining the objectives and subtopics to be covered, which include root sheath development, root formation, and the fate of the epithelial root sheath. During root formation, the epithelial root sheath forms and bends to create the epithelial diaphragm, which encloses the primary apical foramen. The root then grows in length as the root sheath induces nearby cells to form odontoblasts, which deposit dentin. For single-rooted teeth the sheath forms a tube, while for multi-rooted teeth extensions divide the root. After dentin formation, the epithelial root sheath breaks down and its remnants become epithelial rests of Malasse
Enamel
Enamel is the hardest substance in the body, composed primarily of hydroxyapatite crystals (96% inorganic). It is acellular and highly mineralized. Enamel is formed by ameloblasts and is composed of enamel rods oriented perpendicular to the dentin-enamel junction. The rods are composed of tightly packed hydroxyapatite crystals in a protein matrix that directs their growth. Enamel provides protection and strength to teeth.
Amelogenisis
The document describes the life cycle of ameloblasts and the process of amelogenesis. There are seven stages in the life cycle of ameloblasts: 1) morphogenic, 2) differentiation, 3) secretory, 4) transitional, 5) maturative, 6) protective, and 7) desmolytic. Amelogenesis involves two processes - formation of the enamel matrix through protein secretion and mineralization through hydroxyapatite deposition and maturation. Defects in amelogenesis can result from conditions like febrile diseases or tetracycline intake, producing malformed or discolored enamel. Enamel undergoes age-related changes like attrition, discoloration, and increased hardness due
Crown formation
The document summarizes the development of teeth from the formation of formative cells to the stages of tooth formation including crown formation. It discusses the four main stages of tooth development - the dental lamina, bud, cap and bell stages. It also describes the processes of dentinogenesis and amelogenesis, including the roles of odontoblasts and ameloblasts in forming dentin and enamel respectively through secretion, mineralization and maturation stages.
Enamel
Enamel is the hardest tissue in the body and is composed primarily of hydroxyapatite crystals. It is formed through the process of amelogenesis by ameloblasts, which transition between secretory and maturation stages as they lay down the enamel matrix and facilitate mineralization. The unique structure of enamel, including enamel rods and interrod enamel, provides hardness but requires the underlying dentin to compensate for enamel's brittleness. The complex life cycle of ameloblasts and specialized enamel proteins are required for this intricate mineralization process and formation of enamel's highly mineralized structure.
Develpoment of enamel / dental implant courses
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.
Tooth development .. hesham dameer
The document discusses the stages of tooth development from initiation to root formation. It describes the morphological stages as dental lamina, bud, cap, and bell stages. The histophysiological stages are initiation, proliferation, histodifferentiation, morphodifferentiation, and apposition. Key events include formation of the dental lamina and tooth buds, invagination of the enamel organ during the cap and bell stages, differentiation of ameloblasts and odontoblasts, and deposition of enamel and dentin. During the root stage, the cervical loop forms the root sheath to guide root formation.
Applied Histology of Pulp and Periradicular Tissues
The document discusses the structure and development of the dental pulp. It begins by describing the pulp as a soft tissue composed of mesenchymal cells and specialized odontoblasts. The close relationship between odontoblasts and dentin results in the pulp-dentin complex. The primary role of the pulp is to produce dentin, but it also functions as a sensory organ. The document then proceeds to discuss pulp embryology and development, pulp anatomy and histology, innervation and sensitivity, aging changes, and other related topics.
Pulp
The document discusses the development, cells, vessels, and nerves of dental pulp. It states that dental pulp develops from ectomesenchymal cells of the dental papilla and provides odontogenic, nutritive, sensory, and defensive functions. The principal cells of pulp are odontoblasts, fibroblasts, and undifferentiated mesenchymal cells. Odontoblasts secrete dentin and are located in the odontoblastic zone near the dentin, while fibroblasts and mesenchymal cells are located deeper in the cell rich zone and pulp core. Blood vessels and nerves enter the pulp through the apical foramen to provide nutrients and sensation.
PDL, PERIODONTAL LIGAMENT.
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.
Amelogenesis
Amelogenesis is the process of enamel formation. It occurs in two steps - organic matrix formation and mineralization. During the secretory stage, cells called ameloblasts secrete enamel matrix proteins that make up the organic portion of enamel. In the maturation stage, ameloblasts facilitate the removal of water and organic material from enamel while depositing minerals, resulting in fully mineralized enamel. Ameloblasts undergo morphological and functional changes throughout their lifespan to facilitate the different stages of enamel formation.
Development of tooth Part 2
This document summarizes the process of tooth development from the dental lamina through the various stages to clinical considerations. It begins with the dental lamina and vestibular lamina developing from the oral ectoderm. Tooth buds then develop from the dental lamina, going through the bud, cap and bell stages as the enamel organ, dental papilla and follicle form. Root development occurs after crown formation. The stages and common anomalies in tooth development are described to provide dentists with an understanding of this complex process.
Life cycle of ameloblast
Amelogenesis is the formation of enamel. During amelogenesis, the ameloblast (enamel-forming cells) undergo various stages i.e the life cycle of ameloblast.
For more content check out my blog: www.rkharitha.wordpress.com "a little about everything dental"
Root formation
The document discusses the process of root formation, including the roles of the root sheath and epithelial diaphragm. It notes that the root sheath forms from epithelial cells and encloses the primary apical foramen. As the root grows in length, the root sheath induces cells to form root dentin. The root sheath then breaks down, with remnants becoming epithelial rests of Malassez in the periodontal ligament. Abnormalities can occur if the root sheath is disrupted, preventing proper dentin formation.
Tooth development
For first year dental student, i got this from the internet.. Hope this can help u guys understand more about the tooth development.. Btw, good luck for minitest OB tomorrow.. No sacrifice, no victory!
Enamel
Enamel is the hardest tissue in the human body. It is highly mineralized, primarily made up of hydroxyapatite crystals. Enamel's principal component is calcium hydroxyapatite. Enamel has a low organic content but a very high mineral content, giving it excellent abrasion resistance to withstand forces from chewing. The basic structural unit of enamel is the enamel rod or prism, consisting of tightly packed hydroxyapatite crystallites that run from the enamel-dentin junction to the tooth surface.
Development of periodontium
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.
Tooth development 2
1. The document describes the stages of tooth development from the dental lamina stage through the late bell stage. It discusses the formation and roles of structures like the enamel organ, dental papilla, and dental sac.
2. Key stages include histodifferentiation, morphodifferentiation, and apposition. During these stages, structures like ameloblasts and odontoblasts differentiate and deposit enamel and dentin matrices.
3. The enamel organ is composed of the outer enamel epithelium, stellate reticulum, stratum intermedium, and inner enamel epithelium. These structures play roles in organizing tooth shape, transporting nutrients, and producing enamel.
Tooth development
This document provides an overview of tooth development from the primary epithelial band through the various developmental stages including bud, cap and bell stages. It discusses the formation of the vestibular lamina, dental lamina and fate of the dental lamina. Key processes like dentinogenesis, amelogenesis, Hertwig's root sheath formation and root development are summarized. Developmental disorders affecting tooth size, shape, number and structure are also outlined. The document concludes by reviewing agents that can affect tooth development such as vitamin deficiencies and medications.
TOOTH ENAMEL - HISTOPATHOLOGY FOR STUDENTS
Enamel is the highly mineralized protective covering on tooth crowns. It is composed primarily of hydroxyapatite crystals arranged in microscopic rods that extend from the dentin-enamel junction to the enamel surface. The document discusses the physical and chemical properties of enamel, as well as its microscopic structure including rods, striations, Hunter-Schreger bands, and perikymata surface features. It also describes the development of enamel, including the life cycle of ameloblasts and the various stages of amelogenesis. Clinical considerations related to enamel such as hypocalcified areas, age changes, and dental caries are briefly mentioned.
Enamel
Enamel is the hardest tissue in the human body that covers the anatomical crown of a tooth. It is made up of hydroxyapatite crystals arranged in enamel rods or prisms. Enamel provides protection to the underlying dentin and allows for chewing and grinding of food. It is formed by ameloblasts, which deposit an organic matrix that mineralizes into enamel. Enamel can demineralize from acid produced by bacteria, leading to dental caries if left untreated.
Enamel
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
More Related Content
What's hot
root formation tooth development
This document discusses root formation in teeth. It begins by outlining the objectives and subtopics to be covered, which include root sheath development, root formation, and the fate of the epithelial root sheath. During root formation, the epithelial root sheath forms and bends to create the epithelial diaphragm, which encloses the primary apical foramen. The root then grows in length as the root sheath induces nearby cells to form odontoblasts, which deposit dentin. For single-rooted teeth the sheath forms a tube, while for multi-rooted teeth extensions divide the root. After dentin formation, the epithelial root sheath breaks down and its remnants become epithelial rests of Malasse
Enamel
Enamel is the hardest substance in the body, composed primarily of hydroxyapatite crystals (96% inorganic). It is acellular and highly mineralized. Enamel is formed by ameloblasts and is composed of enamel rods oriented perpendicular to the dentin-enamel junction. The rods are composed of tightly packed hydroxyapatite crystals in a protein matrix that directs their growth. Enamel provides protection and strength to teeth.
Amelogenisis
The document describes the life cycle of ameloblasts and the process of amelogenesis. There are seven stages in the life cycle of ameloblasts: 1) morphogenic, 2) differentiation, 3) secretory, 4) transitional, 5) maturative, 6) protective, and 7) desmolytic. Amelogenesis involves two processes - formation of the enamel matrix through protein secretion and mineralization through hydroxyapatite deposition and maturation. Defects in amelogenesis can result from conditions like febrile diseases or tetracycline intake, producing malformed or discolored enamel. Enamel undergoes age-related changes like attrition, discoloration, and increased hardness due
Crown formation
The document summarizes the development of teeth from the formation of formative cells to the stages of tooth formation including crown formation. It discusses the four main stages of tooth development - the dental lamina, bud, cap and bell stages. It also describes the processes of dentinogenesis and amelogenesis, including the roles of odontoblasts and ameloblasts in forming dentin and enamel respectively through secretion, mineralization and maturation stages.
Enamel
Enamel is the hardest tissue in the body and is composed primarily of hydroxyapatite crystals. It is formed through the process of amelogenesis by ameloblasts, which transition between secretory and maturation stages as they lay down the enamel matrix and facilitate mineralization. The unique structure of enamel, including enamel rods and interrod enamel, provides hardness but requires the underlying dentin to compensate for enamel's brittleness. The complex life cycle of ameloblasts and specialized enamel proteins are required for this intricate mineralization process and formation of enamel's highly mineralized structure.
Develpoment of enamel / dental implant courses
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.
Tooth development .. hesham dameer
The document discusses the stages of tooth development from initiation to root formation. It describes the morphological stages as dental lamina, bud, cap, and bell stages. The histophysiological stages are initiation, proliferation, histodifferentiation, morphodifferentiation, and apposition. Key events include formation of the dental lamina and tooth buds, invagination of the enamel organ during the cap and bell stages, differentiation of ameloblasts and odontoblasts, and deposition of enamel and dentin. During the root stage, the cervical loop forms the root sheath to guide root formation.
Applied Histology of Pulp and Periradicular Tissues
The document discusses the structure and development of the dental pulp. It begins by describing the pulp as a soft tissue composed of mesenchymal cells and specialized odontoblasts. The close relationship between odontoblasts and dentin results in the pulp-dentin complex. The primary role of the pulp is to produce dentin, but it also functions as a sensory organ. The document then proceeds to discuss pulp embryology and development, pulp anatomy and histology, innervation and sensitivity, aging changes, and other related topics.
Pulp
The document discusses the development, cells, vessels, and nerves of dental pulp. It states that dental pulp develops from ectomesenchymal cells of the dental papilla and provides odontogenic, nutritive, sensory, and defensive functions. The principal cells of pulp are odontoblasts, fibroblasts, and undifferentiated mesenchymal cells. Odontoblasts secrete dentin and are located in the odontoblastic zone near the dentin, while fibroblasts and mesenchymal cells are located deeper in the cell rich zone and pulp core. Blood vessels and nerves enter the pulp through the apical foramen to provide nutrients and sensation.
PDL, PERIODONTAL LIGAMENT.
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.
Amelogenesis
Amelogenesis is the process of enamel formation. It occurs in two steps - organic matrix formation and mineralization. During the secretory stage, cells called ameloblasts secrete enamel matrix proteins that make up the organic portion of enamel. In the maturation stage, ameloblasts facilitate the removal of water and organic material from enamel while depositing minerals, resulting in fully mineralized enamel. Ameloblasts undergo morphological and functional changes throughout their lifespan to facilitate the different stages of enamel formation.
Development of tooth Part 2
This document summarizes the process of tooth development from the dental lamina through the various stages to clinical considerations. It begins with the dental lamina and vestibular lamina developing from the oral ectoderm. Tooth buds then develop from the dental lamina, going through the bud, cap and bell stages as the enamel organ, dental papilla and follicle form. Root development occurs after crown formation. The stages and common anomalies in tooth development are described to provide dentists with an understanding of this complex process.
Life cycle of ameloblast
Amelogenesis is the formation of enamel. During amelogenesis, the ameloblast (enamel-forming cells) undergo various stages i.e the life cycle of ameloblast.
For more content check out my blog: www.rkharitha.wordpress.com "a little about everything dental"
Root formation
The document discusses the process of root formation, including the roles of the root sheath and epithelial diaphragm. It notes that the root sheath forms from epithelial cells and encloses the primary apical foramen. As the root grows in length, the root sheath induces cells to form root dentin. The root sheath then breaks down, with remnants becoming epithelial rests of Malassez in the periodontal ligament. Abnormalities can occur if the root sheath is disrupted, preventing proper dentin formation.
Tooth development
For first year dental student, i got this from the internet.. Hope this can help u guys understand more about the tooth development.. Btw, good luck for minitest OB tomorrow.. No sacrifice, no victory!
Enamel
Enamel is the hardest tissue in the human body. It is highly mineralized, primarily made up of hydroxyapatite crystals. Enamel's principal component is calcium hydroxyapatite. Enamel has a low organic content but a very high mineral content, giving it excellent abrasion resistance to withstand forces from chewing. The basic structural unit of enamel is the enamel rod or prism, consisting of tightly packed hydroxyapatite crystallites that run from the enamel-dentin junction to the tooth surface.
Development of periodontium
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.
Tooth development 2
1. The document describes the stages of tooth development from the dental lamina stage through the late bell stage. It discusses the formation and roles of structures like the enamel organ, dental papilla, and dental sac.
2. Key stages include histodifferentiation, morphodifferentiation, and apposition. During these stages, structures like ameloblasts and odontoblasts differentiate and deposit enamel and dentin matrices.
3. The enamel organ is composed of the outer enamel epithelium, stellate reticulum, stratum intermedium, and inner enamel epithelium. These structures play roles in organizing tooth shape, transporting nutrients, and producing enamel.
Tooth development
This document provides an overview of tooth development from the primary epithelial band through the various developmental stages including bud, cap and bell stages. It discusses the formation of the vestibular lamina, dental lamina and fate of the dental lamina. Key processes like dentinogenesis, amelogenesis, Hertwig's root sheath formation and root development are summarized. Developmental disorders affecting tooth size, shape, number and structure are also outlined. The document concludes by reviewing agents that can affect tooth development such as vitamin deficiencies and medications.
What's hot (19)
Applied Histology of Pulp and Periradicular Tissues
Applied Histology of Pulp and Periradicular Tissues
Similar to Hist 7
TOOTH ENAMEL - HISTOPATHOLOGY FOR STUDENTS
Enamel is the highly mineralized protective covering on tooth crowns. It is composed primarily of hydroxyapatite crystals arranged in microscopic rods that extend from the dentin-enamel junction to the enamel surface. The document discusses the physical and chemical properties of enamel, as well as its microscopic structure including rods, striations, Hunter-Schreger bands, and perikymata surface features. It also describes the development of enamel, including the life cycle of ameloblasts and the various stages of amelogenesis. Clinical considerations related to enamel such as hypocalcified areas, age changes, and dental caries are briefly mentioned.
Enamel
Enamel is the hardest tissue in the human body that covers the anatomical crown of a tooth. It is made up of hydroxyapatite crystals arranged in enamel rods or prisms. Enamel provides protection to the underlying dentin and allows for chewing and grinding of food. It is formed by ameloblasts, which deposit an organic matrix that mineralizes into enamel. Enamel can demineralize from acid produced by bacteria, leading to dental caries if left untreated.
Enamel
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
Enamel & amelogenesis part 2
The document discusses the structural features of enamel. It begins by describing the basic structural unit of enamel, the enamel rod, as seen under light and electron microscopy. It notes key details about enamel rods like their number, direction, course, and diameter. It also discusses structures related to enamel's incremental growth like cross striations, striae of Retzius, perikymata, and the neonatal line. Finally, it mentions how these incremental lines represent the rhythmic formation of enamel and can indicate metabolic disturbances.
Enamel
Enamel is the hardest and most highly mineralized tissue in the human body. It is composed primarily of hydroxyapatite crystals arranged in prisms or rods called enamel rods. Enamel rods run from the dentinoenamel junction to the outer surface of the enamel in a wavy pattern. The microscopic structure of enamel, including enamel rods, interrod enamel, rod sheaths, cross-striations, Hunter-Schreger bands and enamel spindles provide strength and resilience to the enamel. Ameloblasts are specialized epithelial cells responsible for secreting and mineralizing the enamel matrix in a process called amelogenesis which occurs in several stages over the life of the tooth.
Enamel
Enamel is the hardest and most highly mineralized tissue in the human body. It forms a protective covering on the crown of teeth. Enamel is composed primarily of hydroxyapatite crystals arranged in prisms or rods. The basic structural unit of enamel is the enamel rod or prism, which are formed by ameloblasts during enamel development. Enamel rods extend from the dentinoenamel junction to the outer enamel surface in a wavy pattern.
Enamel
Enamel is the hardest substance in the human body. It is composed primarily of hydroxyapatite crystals arranged in rods (prisms) that run from the dentin-enamel junction to the outer enamel surface. The basic structural unit of enamel is the enamel rod, which is hexagonal or oval in cross-section. Between the rods is the interrod enamel. Enamel gains its strength through the interweaving of tightly packed hydroxyapatite crystals in parallel alignment within the rods.
HYPOCALCIFIED STRUTURES OF ENAMEL.pptx
This document provides an overview of enamel structure and composition. It begins with an introduction to enamel as the hardest tissue in the body, composed primarily of hydroxyapatite crystals. It then describes various hypocalcified structures found in enamel, such as rod sheath, incremental lines, enamel lamellae and tufts. Surface structures like perikymata and enamel cuticle are also discussed. In conclusion, it emphasizes that enamel is about 96% inorganic mineral and 4% organic material, with hydroxyapatite crystals forming its primary composition. Hypocalcified zones indicate areas of weakness where dental caries can develop.
Enamel.pptx
This document provides an overview of the microscopic structure and features of enamel. It discusses the composition of enamel and the cells responsible for its formation. The key structural units of enamel are described as enamel rods (prisms), interrod enamel, and rod sheaths. Specific anatomical features like Hunter's lines, striae of Retzius, enamel tufts, and enamel lamellae are defined. The orientation and arrangement of enamel rods throughout the tooth is also summarized.
Enamel seminar.pptx
The document discusses the structure and development of enamel. It begins by describing the physical and chemical properties of enamel, including its hardness, thickness, density and composition of hydroxyapatite crystals. It then details the microscopic structure of enamel, including enamel rods, rod sheaths, Hunter-Schreger bands and enamel lamellae. The development of enamel and formation of the enamel organ and its layers (outer enamel epithelium, stellate reticulum, stratum intermedium) are also summarized.
Enamel.pptx
This document provides an overview of enamel, including its physical and chemical properties, structure, development, and clinical aspects. Some key points:
1. Enamel is the hardest tissue in the body and covers the anatomical crown of teeth. It is composed primarily of hydroxyapatite crystals arranged in rods or prisms.
2. Enamel develops through a process called amelogenesis, where enamel matrix proteins are secreted by specialized cells called ameloblasts. The matrix then undergoes mineralization.
3. Enamel has a complex structure including rods, perikymata, and other features that contribute to its hardness and protection of the tooth. Its structure and composition can be altered by
Enamel - DCPS
Enamel is the hardest tissue in the human body and forms a protective covering on the tooth. It is composed primarily of inorganic hydroxyapatite crystals with a small amount of organic material. Enamel has a highly organized microscopic structure of enamel rods (prisms) that extend from the enamel-dentin junction to the enamel surface. The direction of the rods helps provide strength to the enamel. Between the rods is interprismatic enamel cementing the rods together. Disruptions during enamel formation and maturation can result in enamel abnormalities.
Enamel
This document provides information about the structure of enamel in teeth. It discusses striations of Retzius, enamel rods, tufts and lamellae. It explains how variations in organic material deposition during development lead to darker and lighter banding in enamel. It also describes structures like the neonatal line, gnarled enamel, Hunter-Schreger bands, cross-striations and enamel spindles. Electron micrographs show enamel features like rods, tufts and the dentinoenamel junction in detail.
Enamel
This document discusses the structure and properties of enamel. It begins by defining enamel as the outermost layer of tooth covering made of highly mineralized tissue. The structure of enamel is described including enamel rods, interrod substance, and rod sheaths. Physical properties like hardness, thickness and chemical composition consisting mainly of hydroxyapatite are covered. Incremental growth lines including cross striations, striae of Retzius and neonatal line are also summarized. Hypo-mineralized enamel structures such as enamel spindles, tufts and lamellae are defined. Finally, the surface structure of enamel including outer structureless enamel and perikymata grooves are described.
Enamel CONSERVATIVE DENTISTRY AND ENDODONTICS
This document provides an overview of the structure and properties of enamel. It discusses the physical and chemical composition of enamel, including its high mineral content and hydroxyapatite crystals. It describes the microscopic structure of enamel, including enamel rods, interrod enamel, and surface features like striations of Retzius. It also summarizes the life cycle of ameloblasts and the process of amelogenesis. Bleaching effects on enamel and developmental disturbances are briefly covered.
Enamel
The document discusses the structure and composition of dental hard tissues, focusing on enamel. It describes enamel as the outermost rigid tissue that covers the tooth crown. Enamel is composed primarily of hydroxyapatite crystals arranged in rods that run from the dentin-enamel junction toward the outer surface. The rods are arranged to provide strength and withstand forces during chewing. Enamel hardness allows it to function in mastication but renders it brittle, requiring the underlying dentin as support.
Enamel
1) Enamel is the hardest tissue in the body, covering the crowns of teeth. It consists mainly of inorganic hydroxyapatite crystals (96%) arranged in prisms, providing protection and resisting forces.
2) Enamel formation (amelogenesis) involves matrix formation by ameloblasts followed by mineralization. During life, the enamel surface is susceptible to acid dissolution from dietary and bacterial sources, causing caries.
3) Environmental factors like nutrition and fluoride exposure during tooth development can affect enamel quantity and quality, as can hereditary conditions like amelogenesis imperfecta.
enamel and dentin biology.ppt
- Teeth are composed of enamel, dentin, and cementum. Enamel covers the crown and is the hardest substance in the body. It is formed by ameloblasts and consists of enamel rods made of hydroxyapatite crystals. Dentin lies underneath enamel and is less mineralized. It is formed by odontoblasts and contains dentinal tubules that originally housed the odontoblasts. The dentinoenamel junction connects enamel and dentin. Throughout life, dentin continues forming as secondary and tertiary dentin in response to stimuli.
enamel.ppt
This document discusses the structure and properties of enamel. It begins with an overview of the layers of the tooth and describes enamel in more detail. Enamel is composed primarily of hydroxyapatite crystals arranged in prisms/rods. It covers the anatomical crown and is the hardest substance in the body. The document outlines various properties of enamel like thickness, hardness, permeability, and discusses its microscopic structure including rods, interrod substance and enamel lamellae. It also compares primary and permanent enamel and summarizes the processes of amelogenesis and age-related changes in enamel.
Enamel significance in operative dentistry /certified fixed orthodontic cour...
Enamel significance in operative dentistry /certified fixed orthodontic cour...Indian dental academy
Welcome to Indian Dental Academy
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.
Indian dental academy has a unique training program & curriculum that provides students with exceptional clinical skills and enabling them to return to their office with high level confidence and start treating patients
State of the art comprehensive training-Faculty of world wide repute &Very affordable.
Similar to Hist 7 (20)
Enamel significance in operative dentistry /certified fixed orthodontic cour...
Enamel significance in operative dentistry /certified fixed orthodontic cour...
More from Ahmed S.Ibrahim
Oral Hygiene
Our mouths are connected to the rest of our bodies, with the same blood and nerves, so oral health is important for overall health. Good oral hygiene through processes like cleaning helps prevent dental issues like cavities, gum disease, bad breath, and other problems. A study examined dental students' oral hygiene using the Silness and Loe plaque index to assess prevention of such conditions.
Oral Hygiene
To have a healthy body, you need a healthy mouth as the same blood and nerves connect the mouth to the rest of the body. Oral hygiene includes keeping the mouth clean and is necessary to prevent dental caries, gingivitis, periodontitis, bad breath and other dental problems. Maintaining good oral hygiene can prevent dental caries, gingivitis, periodontitis and halitosis.
Oral Hygiene
It is important to think of our mouths as connected to the rest of our bodies, as the same blood and nerves serve both. To have overall health, it is necessary to have a healthy mouth through good oral hygiene practices that keep the mouth clean and prevent dental issues like cavities, gum disease, and bad breath.
Periodontal ligament
The document provides information on the periodontal ligament. It discusses that the periodontal ligament is a specialized connective tissue located between the cementum and bone, attaching the tooth to the jaw. It has principal collagen fibers arranged in bundles that provide flexibility and strength. The periodontal ligament contains fibroblasts, osteoblasts, cementoblasts, osteoclasts and cementoclasts. It transmits occlusal forces to the bone, attaches teeth, absorbs shock, and remodels through constant turnover of old cells and fibers. It also provides nutrition, sensation and a soft tissue casing to protect nerves and blood vessels.
Hist 12 lab
The gingiva is covered by keratinized stratified squamous epithelium that shows projections called rete pegs into the underlying connective tissue. The epithelium has 4 layers - the stratum corneum, stratum granulosum, stratum spinosum, and stratum basale. In addition to epithelial cells, the gingiva contains melanocytes, Langerhans cells, and Merkel cells. The connective tissue underneath contains collagen fibers, predominantly type VII, elastin fibers made of elastin and fibrillin, and oxytalin fibers that resemble immature elastic fibers.
عرض اجنة
The document discusses the process of human development from fertilization through the first week. It explains that fertilization occurs when a sperm penetrates an ovum in the fallopian tube, forming a zygote with 46 chromosomes. The zygote then undergoes rapid cell division as it is transported down the fallopian tube by cilia motion. By the end of the first week, the embryo has divided into multiple identical cells or blastomeres.
Lec 11 polymer and polymerization part ii
The document discusses various materials used for denture bases, including cellulose and phenol-formaldehyde, but notes that acrylic resin (polymethyl methacrylate or PMMA) is now the preferred material. It outlines the ideal requirements for denture base materials and describes the different types of PMMA resins, including heat cure, cold cure, light cure, and microwave cured. The document provides details on the composition, mixing, and curing of heat cure PMMA resin and compares its properties to cold cure resin. It also briefly discusses light cure, microwave cured, and injection molded resins.
Lec 10 part i polymer and polymerization
Polymerization is the process of linking monomers together to form polymers. There are two main types of polymerization: condensation and addition. Addition polymerization is more common for dental resins and occurs in three stages - initiation, propagation, and termination. Factors like monomer type and structure, molecular weight, and cross-linking affect the properties of the resulting polymer. Thermoplastic polymers can be remelted and reshaped, while thermosetting polymers permanently harden during curing. Polymers have many applications in dentistry, including restorative materials, adhesives, impression materials, and prosthetics.
General anatomy fierst year 2016
This document provides an overview of human anatomy and key anatomical structures. It begins by defining anatomy and its subfields. It then introduces important anatomical terms for describing body structures, including anatomical planes (coronal, sagittal, axial), body cavities (thoracic, abdominal, pelvic), and directional/positional terms. The remaining sections describe the central nervous system including the brain parts (cerebrum, brainstem, cerebellum) and spinal cord. It also briefly introduces the peripheral nervous system and its divisions. The document concludes by discussing joints, including their classification into fibrous, cartilaginous, and synovial joints.
Hist 9
Cementum is a calcified tissue that covers the root of a tooth and anchors it to the alveolar bone via Sharpey's fibers. It is lighter in color than dentin, softer, and composed of 45-50% inorganic hydroxylapatite and 50-55% organic materials and water. Cementum is avascular and receives nutrients from the periodontal ligament. It is deposited continuously throughout life to maintain the tooth's attachment as the surface layers age. Cementum forms the cementoenamel junction with enamel and has a smooth junction with dentin. Cementum formation begins after root dentin formation, with cells from the dental sac differentiating into cementoblasts that lay down
Hist 6
Incremental lines in dentine include von Ebner lines which reflect daily variations in mineralization and appear as fine lines perpendicular to the dentin-tooth junction. Counter lines of Owens are hypocalcified lines that distinguish in cross sections as accentuated lines arising from disturbances in dentin matrix mineralization. Neonatal lines separate prenatal from postnatal dentin and result from incomplete calcification at birth due to metabolic changes, appearing in first molars and being useful in forensic dentistry to determine if a child died before or after birth.
Hist 4 pract
Dentin is the mineralized tissue found underneath enamel that surrounds the dental pulp. It is composed mainly of hydroxyapatite crystals (70%) along with collagen (20%) and water (10%). Dentin formation (dentinogenesis) occurs in two stages - first, odontoblast cells secrete an unmineralized dentin matrix called predentin, then mineralization of the matrix occurs from the inside out in either a globular or linear pattern. Odontoblasts undergo differentiation, formation, and quiescence stages as they secrete predentin, retreat into the pulp canal leaving behind dentinal tubules, and reduce activity over time.
Hist 3
The document discusses the morphological stages of early tooth development which include the dental lamina, bud stage, cap stage, and bell stage. It describes the key events and structures that develop during each stage, including the formation of the enamel organ, dental papilla, and dental sac. The bud stage involves proliferation of cells leading to condensation. The cap stage involves invagination of the enamel organ. The bell stage involves continued growth and differentiation of cells into ameloblasts and odontoblasts that will form the enamel and dentin. Transitory structures like the enamel knot, enamel cord, and enamel niche are also discussed.
Hist 2
1. The primitive oral cavity is lined by a 2-3 cell thick layered epithelium covering embryonic connective tissue formed from neural crest cells.
2. Tooth development involves three overlapping phases: initiation, morphogenesis, and histogenesis, during which dental tissues differentiate.
3. The first sign of tooth development is the formation of a continuous epithelial band around the primitive oral cavity, which divides into vestibular and dental lamina. The dental lamina then invaginates and forms 20 buds for the primary teeth.
Hist 1
Oral histology is the study of the microscopic anatomy of oral tissues. It describes the tissues of the teeth, periodontium, and oral mucosa. Histopathology studies diseased tissues obtained from biopsies or autopsies under light, scanning electron, or transmission electron microscopes. Tissues are sectioned and stained, often with hematoxylin and eosin, to distinguish cells and extracellular matrices microscopically. Specimens undergo fixation, dehydration, clearing, embedding in paraffin, sectioning, mounting, and staining for examination.
First trimester-in-oral-histology-projections-slides-dr.-nada
This document discusses the stages of tooth development from the dental lamina stage through the bell stage. It describes the epithelial and mesenchymal tissues involved in early tooth development including the dental lamina, dental bud, inner and outer enamel epithelium, dental papilla, and stellate reticulum. The document also examines the structure of mature tooth tissues such as enamel, dentin, cementum, and pulp, and highlights features such as the dentinoenamel junction, von Ebner's lines in dentin, and cellular components of the pulp like arterioles, venules, and nerves. Pointers indicate various anatomical structures on microscope slides.
Oral histology lab 3,4
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive functioning. Exercise causes chemical changes in the brain that may help boost feelings of calmness and well-being.
Ex 6a connective_tissues
The document describes and compares the different types of connective tissues in the body, including loose connective tissue, adipose tissue, dense connective tissue, cartilage types like hyaline cartilage and elastic cartilage, fibrocartilage, bone, and blood. Examples are given of where each tissue is located in the body.
Histo. lab1,2(2)
This document discusses the preparation of histological specimens and the development of teeth. It covers topics like fixing tissue samples in formalin, embedding samples in paraffin wax, sectioning samples using a microtome, and staining. It also discusses the different types of epithelia like simple squamous, stratified squamous, and transitional epithelium. Finally, it mentions the process of odontogenesis, or tooth development.
More from Ahmed S.Ibrahim (20)
First trimester-in-oral-histology-projections-slides-dr.-nada
First trimester-in-oral-histology-projections-slides-dr.-nada
Recently uploaded
The Electrocardiogram - Physiologic Principles
These lecture slides, by Dr Sidra Arshad, offer a quick overview of the physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar lead (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
6. Describe the flow of current around the heart during the cardiac cycle
7. Discuss the placement and polarity of the leads of electrocardiograph
8. Describe the normal electrocardiograms recorded from the limb leads and explain the physiological basis of the different records that are obtained
9. Define mean electrical vector (axis) of the heart and give the normal range
10. Define the mean QRS vector
11. Describe the axes of leads (hexagonal reference system)
12. Comprehend the vectorial analysis of the normal ECG
13. Determine the mean electrical axis of the ventricular QRS and appreciate the mean axis deviation
14. Explain the concepts of current of injury, J point, and their significance
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. Chapter 3, Cardiology Explained, https://www.ncbi.nlm.nih.gov/books/NBK2214/
7. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
Does Over-Masturbation Contribute to Chronic Prostatitis.pptx
In some case, your chronic prostatitis may be related to over-masturbation. Generally, natural medicine Diuretic and Anti-inflammatory Pill can help mee get a cure.
Hemodialysis: Chapter 5, Dialyzers Overview - Dr.Gawad
- Video recording of this lecture in English language: https://youtu.be/Pt1nA32sdHQ
- Video recording of this lecture in Arabic language: https://youtu.be/uFdc9F0rlP0
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
REGULATION FOR COMBINATION PRODUCTS AND MEDICAL DEVICES.pptx
It includes regulation of combination products and medical devices. FDA and industry liaisons.
pathology MCQS introduction to pathology general pathology
pathology MCQS introduction to pathology general pathology
Adhd Medication Shortage Uk - trinexpharmacy.com
The UK is currently facing a Adhd Medication Shortage Uk, which has left many patients and their families grappling with uncertainty and frustration. ADHD, or Attention Deficit Hyperactivity Disorder, is a chronic condition that requires consistent medication to manage effectively. This shortage has highlighted the critical role these medications play in the daily lives of those affected by ADHD. Contact : +1 (747) 209 – 3649 E-mail : sales@trinexpharmacy.com
Promoting Wellbeing - Applied Social Psychology - Psychology SuperNotes
A proprietary approach developed by bringing together the best of learning theories from Psychology, design principles from the world of visualization, and pedagogical methods from over a decade of training experience, that enables you to: Learn better, faster!
Histololgy of Female Reproductive System.pptx
Dive into an in-depth exploration of the histological structure of female reproductive system with this comprehensive lecture. Presented by Dr. Ayesha Irfan, Assistant Professor of Anatomy, this presentation covers the Gross anatomy and functional histology of the female reproductive organs. Ideal for students, educators, and anyone interested in medical science, this lecture provides clear explanations, detailed diagrams, and valuable insights into female reproductive system. Enhance your knowledge and understanding of this essential aspect of human biology.
Integrating Ayurveda into Parkinson’s Management: A Holistic Approach
Explore the benefits of combining Ayurveda with conventional Parkinson's treatments. Learn how a holistic approach can manage symptoms, enhance well-being, and balance body energies. Discover the steps to safely integrate Ayurvedic practices into your Parkinson’s care plan, including expert guidance on diet, herbal remedies, and lifestyle modifications.
Osteoporosis - Definition , Evaluation and Management .pdf
Osteoporosis is an increasing cause of morbidity among the elderly.
In this document , a brief outline of osteoporosis is given , including the risk factors of osteoporosis fractures , the indications for testing bone mineral density and the management of osteoporosis
Histopathology of Rheumatoid Arthritis: Visual treat
Histopathology of Rheumatoid Arthritis: Visual treat
8 Surprising Reasons To Meditate 40 Minutes A Day That Can Change Your Life.pptx
8 Surprising Reasons To Meditate 40 Minutes A Day That Can Change Your Life.pptxHolistified Wellness
We’re talking about Vedic Meditation, a form of meditation that has been around for at least 5,000 years. Back then, the people who lived in the Indus Valley, now known as India and Pakistan, practised meditation as a fundamental part of daily life. This knowledge that has given us yoga and Ayurveda, was known as Veda, hence the name Vedic. And though there are some written records, the practice has been passed down verbally from generation to generation.Recently uploaded (20)
Does Over-Masturbation Contribute to Chronic Prostatitis.pptx
Does Over-Masturbation Contribute to Chronic Prostatitis.pptx
Hemodialysis: Chapter 5, Dialyzers Overview - Dr.Gawad
Hemodialysis: Chapter 5, Dialyzers Overview - Dr.Gawad
REGULATION FOR COMBINATION PRODUCTS AND MEDICAL DEVICES.pptx
REGULATION FOR COMBINATION PRODUCTS AND MEDICAL DEVICES.pptx
pathology MCQS introduction to pathology general pathology
pathology MCQS introduction to pathology general pathology
Vestibulocochlear Nerve by Dr. Rabia Inam Gandapore.pptx
Vestibulocochlear Nerve by Dr. Rabia Inam Gandapore.pptx
Promoting Wellbeing - Applied Social Psychology - Psychology SuperNotes
Promoting Wellbeing - Applied Social Psychology - Psychology SuperNotes
Integrating Ayurveda into Parkinson’s Management: A Holistic Approach
Integrating Ayurveda into Parkinson’s Management: A Holistic Approach
Osteoporosis - Definition , Evaluation and Management .pdf
Osteoporosis - Definition , Evaluation and Management .pdf
Histopathology of Rheumatoid Arthritis: Visual treat
Histopathology of Rheumatoid Arthritis: Visual treat
Muscles of Mastication by Dr. Rabia Inam Gandapore.pptx
Muscles of Mastication by Dr. Rabia Inam Gandapore.pptx
8 Surprising Reasons To Meditate 40 Minutes A Day That Can Change Your Life.pptx
8 Surprising Reasons To Meditate 40 Minutes A Day That Can Change Your Life.pptx
Hist 7
- 10. Microscopical appearance of enamel: Under light microscope the basic structural unite of enamel appear composed of: • rods or prism. • Rod sheath. • Inter rod region.
- 11. Enamel Rode (E.R.):- • Consist of a highly packed hydroxy apatite crystals and highly organized in pattern. • Each E.R. run from dentino-enamel junction to enamel surface in oblique direction and a wavy course due to the movement of ameloblast cells during amelogenesis. • Diameter of E.R. is largest at the surface of enamel and smaller at the dentino-enamel junction in a ratio of about (2:1). • Shape of E.R. in cross section under light microscope, appear hexagonal, sometimes it appears round or oval in shape. Cross section of human enamel has a fish scale like appearance. • Longitudinal section of E.R. appear as a keyhole shape, each keyhole consisted of head and tail, the head represent rod and tail represent inter rod region. Head is at occlussal or incisal edge and the tail is located cervically. The direction of E.R. at the cusp and incisal edge has a vertical direction while cervically each E.R. has an inclination about 2º tilt it becomes horizontal cervically.
- 12. Rod sheath (R.S.):- It represent the organic matrix of enamel and it form an envelop surrounds 2/3 of head of E.R.. R.S. develops due to irregular arrangement of the crystals and it is firstly attack by dental caries. Inter-rod substance A region between 2 rods called cementing substance or tail region.
- 16. Enamel tufts, they are grass like structures arise at the dentino- enamel junction and reach into the enamel to about one fifth consist of a hypoclcified enamel rods and interpresmatic substance. Enamel lamellae: are thin leaf like structures arise from enamel surface toward dentino-enamel junction. They are filled with organic material and water. They result from failure of maturation process.
- 23. Age changes in enamel • With age, enamel become worn out because of masticatory attrition. • Age also causes a decrease in the permeability of enamel. • Discoloration: enamel become more darker with the age.