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.
The document discusses the development of teeth from the dental lamina stage through the various bell stages. It describes how the enamel organ, dental papilla, and dental sac form and their roles in tooth development. The stages of tooth development including bud, cap, and bell stages are summarized. Clinical conditions related to abnormalities in tooth development like dentinogenesis imperfecta, Hutchinson's incisor, and fusion are also mentioned.
This document provides information on the development, structure, and properties of enamel. It discusses how enamel is the hardest tissue in the body, composed primarily of hydroxyapatite crystals. Enamel develops in stages, with ameloblasts first secreting an organic matrix that then undergoes mineralization. Mature enamel has a rod and interrod structure arranged perpendicular to the tooth surface. The document also covers clinical considerations regarding enamel, such as developmental abnormalities, fluorosis, and implications for cavity preparation.
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
PHYSICAL PROPERTIES
CHEMICAL PROPERTIES
STRUCTURE OF ENAMEL
DEVELOPMENT OF ENAMEL
EPITHELIAL ENAMEL ORGAN
AMELOGENESIS
LIFE CYCLE OF AMELOBLASTS
AGE CHANGES IN ENAMEL
DEFECTS OF AMELOGENESIS
CLINICAL IMPLICATIONS
The presentation discusses about tooth enamel in detail including its formation, characteristics, structure and histological features along with its clinical considerations. It is well supported with diagrams for better understanding of the text.
Suggestions and feedback will be well appreciated.
This document provides information on cementum, including its definition, physical characteristics, chemical composition, formation (cementogenesis), classification, functions, anomalies, and clinical considerations. Cementum is the mineralized tissue covering tooth roots. It is softer than dentin and lacks enamel's luster. Cementum formation involves acellular and cellular stages. Cementum attaches the periodontal ligament fibers to the tooth root and allows for tooth repair. Abnormalities include hypercementosis, ankylosis, and cementomas. Cementum is an important part of the periodontium that aids in tooth attachment and repair.
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.
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.
The document discusses the development of teeth from the dental lamina stage through the various bell stages. It describes how the enamel organ, dental papilla, and dental sac form and their roles in tooth development. The stages of tooth development including bud, cap, and bell stages are summarized. Clinical conditions related to abnormalities in tooth development like dentinogenesis imperfecta, Hutchinson's incisor, and fusion are also mentioned.
This document provides information on the development, structure, and properties of enamel. It discusses how enamel is the hardest tissue in the body, composed primarily of hydroxyapatite crystals. Enamel develops in stages, with ameloblasts first secreting an organic matrix that then undergoes mineralization. Mature enamel has a rod and interrod structure arranged perpendicular to the tooth surface. The document also covers clinical considerations regarding enamel, such as developmental abnormalities, fluorosis, and implications for cavity preparation.
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
PHYSICAL PROPERTIES
CHEMICAL PROPERTIES
STRUCTURE OF ENAMEL
DEVELOPMENT OF ENAMEL
EPITHELIAL ENAMEL ORGAN
AMELOGENESIS
LIFE CYCLE OF AMELOBLASTS
AGE CHANGES IN ENAMEL
DEFECTS OF AMELOGENESIS
CLINICAL IMPLICATIONS
The presentation discusses about tooth enamel in detail including its formation, characteristics, structure and histological features along with its clinical considerations. It is well supported with diagrams for better understanding of the text.
Suggestions and feedback will be well appreciated.
This document provides information on cementum, including its definition, physical characteristics, chemical composition, formation (cementogenesis), classification, functions, anomalies, and clinical considerations. Cementum is the mineralized tissue covering tooth roots. It is softer than dentin and lacks enamel's luster. Cementum formation involves acellular and cellular stages. Cementum attaches the periodontal ligament fibers to the tooth root and allows for tooth repair. Abnormalities include hypercementosis, ankylosis, and cementomas. Cementum is an important part of the periodontium that aids in tooth attachment and repair.
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.
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.
Dentinogenesis is the formation of dentin by odontoblast cells that differentiate from dental papilla cells. Odontoblasts first form an uncalcified predentin matrix that then undergoes mineralization. There are two types of primary dentin formed - mantle dentin near the enamel and circumpulpal dentin forming the bulk of the tooth. Dentin has a microscopic structure consisting of dentinal tubules containing odontoblast processes, surrounded by highly mineralized peritubular dentin and less mineralized intertubular dentin.
Differences between primary and permanent dentitionAkshMinhas
A longitudinal radiological study of children (N = 549) who participated in a comprehensive preventive maintenance program showed that caries related events in the approximal surfaces of permanent teeth differed from those in deciduous teeth. Changes in the approximal surfaces of the younger permanent teeth were more pronounced than of the older primary teeth and differed significantly from 1 year to 2.5 years. These findings can be explained by posteruptive maturation of tooth enamel.
The document discusses the anatomy and features of dental pulp. It describes the pulp as a soft connective tissue occupying the pulp cavity at the center of teeth. The pulp is divided into coronal and radicular pulp. The coronal pulp is in the pulp chamber while the radicular pulp occupies the root canals. The document outlines the cell types found in pulp, including odontoblasts, fibroblasts, and immune cells. It also discusses the structural organization and development of pulp.
Cementum is the calcified tissue covering the roots of teeth. It has both acellular and cellular varieties. Acellular cementum lacks cementocytes and is laid down slowly with closely spaced incremental lines. Cellular cementum contains cementocytes within lacunae and canaliculi and is deposited more rapidly with wider spaced lines. Cementum is produced by cementoblasts, which are derived from the dental follicle or Hertwig's epithelial root sheath. Cementoblasts secrete cementum, while cementocytes are embedded within it and cementoclasts resorb it. Cementum provides anchorage for periodontal ligament fibers and adapts the tooth for function.
The document provides an overview of the pulp-dentin complex, including dentin and pulp. It discusses the physical and chemical properties of dentin, its structure including dentinal tubules and types of dentin. Dentinogenesis and age-related changes are also covered. The morphology, development, zones and cell types in pulp are summarized. The document establishes that dentin and pulp are embryologically, histologically and functionally the same tissue and should be considered as a complex.
Enamel is formed through the process of amelogenesis, which involves the life cycle of ameloblasts. Ameloblasts undergo morphological and physiological changes during the secretory, transitional, and maturative stages of amelogenesis. During the secretory stage, ameloblasts develop Tomes' processes which extend into the enamel matrix and help establish the rod and interrod structure of enamel. As enamel matures, ameloblasts transition to having microvilli and modulate between ruffled and smooth shapes to both remove organic material from the enamel and introduce inorganic minerals to fully mineralize the enamel.
This document provides details on the structure and composition of enamel. It notes that enamel is the hardest tissue in the body, covering the anatomical crown. It is made up primarily of hydroxyapatite crystals arranged in enamel prisms/rods from the dentin-enamel junction to the surface. The direction of the prisms changes in a sinusoidal pattern. Between the prisms is interprismatic enamel. Near the surface is aprismatic enamel which is more highly mineralized. Throughout life, the crown is covered by an organic layer or integument.
This document provides an overview of dentin, including:
- Its history, development, physical and chemical properties, structure, types, and innervation
- Dentinogenesis is the process by which dentin is formed through the secretion and mineralization of an organic matrix by odontoblasts.
- Dentin's main components are hydroxyapatite crystals, collagen fibers, non-collagenous proteins, and water. Its tubular structure and composition provide mechanical strength and sensitivity.
- Different types of dentin include primary, secondary, and tertiary dentin, which vary in their location, thickness, mineralization, and quality.
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.
This document provides an overview of cementum, the calcified tissue that forms the outer covering of tooth roots. It discusses the development, composition, histology, classification, and functions of cementum. Cementum begins forming at the cementoenamel junction and extends to the root apex. It is made up of inorganic hydroxyapatite and organic collagen fibers. Cementum provides a medium for periodontal ligament attachment and protects underlying dentin, helping to maintain tooth integrity under forces. It is capable of continuous deposition to repair damage or resorption on root surfaces.
The oral cavity is lined by oral mucosa, which is continuous with the skin and pharyngeal mucosa. The oral mucosa consists of three types - masticatory, lining, and specialized mucosa. Masticatory mucosa covers areas involved in chewing and is keratinized, while lining mucosa covers other soft tissue areas and is non-keratinized. Specialized mucosa covers the dorsal tongue and contains papillae involved in taste. The oral mucosa provides protection, sensation, secretion, permeability and thermal regulation functions.
This document provides information on enamel, the hardest tissue in the human body that covers the crowns of teeth. It discusses the physical and chemical properties of enamel, including its structure of enamel rods/prisms arranged in patterns. The development of enamel is described, with ameloblasts differentiating from epithelium and going through stages of formation, maturation, and protection before eruption. The summary concludes with key points about enamel's structure providing protection and resistance for teeth.
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 describes various anatomical structures found on teeth. It discusses structures such as cusps, tubercles, cingulum, ridges, inclined planes, fossae, grooves, and pits. Cusps are pointed projections found on posterior teeth that form the biting surfaces. Tubercles are small enamel extensions that can form due to trauma or disease. Ridges are convex elevations along tooth surfaces like marginal ridges along the edges. Fossae are irregular depressions found on tooth crowns. Grooves mark divisions between developmental lobes and pits are found at groove junctions.
The document summarizes the structure and composition of dentin. It discusses the different types of dentin - primary, secondary, tertiary - and their locations and functions. It also describes odontoblasts, the cells responsible for dentin formation, and dentinal tubules, the structures that span the thickness of dentin.
This document provides an overview of gingival anatomy and histology. It discusses the 3 parts of the gingiva - marginal, attached, and interdental gingiva. Microscopically, it describes the stratified squamous epithelium and underlying connective tissue. The epithelium consists of basal, spinous, granular, and corneal layers. The connective tissue contains collagen fibers, fibroblasts, and ground substance. Gingival fibers attach the gingiva to the tooth cementum. Blood supply and innervation is also summarized.
Cementum is the calcified tissue that covers the root surface of teeth. It is less calcified and harder than dentin. Cementum is classified based on the presence or absence of cells and fibers. Cellular cementum contains cementocytes within lacunae and forms later in life, while acellular cementum lacks cells and forms earlier. Cementum is deposited throughout life to maintain tooth structure and plays an important role in tooth attachment through Sharpey's fibers inserting into the cementum. Cementum can undergo resorption and repair in response to environmental changes and maintains tooth integrity under forces.
This document provides information on dentin, including its composition, formation, and types. Some key points:
- Dentin makes up the bulk of the tooth and is composed of 65% inorganic material (mainly hydroxyapatite) and 35% organic material (collagen and proteoglycans).
- Odontoblasts are cells responsible for dentin formation. Their processes extend into dentinal tubules that permeate the dentin.
- Dentin formation begins with predentin, which mineralizes to become circumpulpal dentin. Mantle dentin forms the outer layer near the enamel.
- Dentinal tubules contain peritubular dentin and connect the
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.
- 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.
Dentinogenesis is the formation of dentin by odontoblast cells that differentiate from dental papilla cells. Odontoblasts first form an uncalcified predentin matrix that then undergoes mineralization. There are two types of primary dentin formed - mantle dentin near the enamel and circumpulpal dentin forming the bulk of the tooth. Dentin has a microscopic structure consisting of dentinal tubules containing odontoblast processes, surrounded by highly mineralized peritubular dentin and less mineralized intertubular dentin.
Differences between primary and permanent dentitionAkshMinhas
A longitudinal radiological study of children (N = 549) who participated in a comprehensive preventive maintenance program showed that caries related events in the approximal surfaces of permanent teeth differed from those in deciduous teeth. Changes in the approximal surfaces of the younger permanent teeth were more pronounced than of the older primary teeth and differed significantly from 1 year to 2.5 years. These findings can be explained by posteruptive maturation of tooth enamel.
The document discusses the anatomy and features of dental pulp. It describes the pulp as a soft connective tissue occupying the pulp cavity at the center of teeth. The pulp is divided into coronal and radicular pulp. The coronal pulp is in the pulp chamber while the radicular pulp occupies the root canals. The document outlines the cell types found in pulp, including odontoblasts, fibroblasts, and immune cells. It also discusses the structural organization and development of pulp.
Cementum is the calcified tissue covering the roots of teeth. It has both acellular and cellular varieties. Acellular cementum lacks cementocytes and is laid down slowly with closely spaced incremental lines. Cellular cementum contains cementocytes within lacunae and canaliculi and is deposited more rapidly with wider spaced lines. Cementum is produced by cementoblasts, which are derived from the dental follicle or Hertwig's epithelial root sheath. Cementoblasts secrete cementum, while cementocytes are embedded within it and cementoclasts resorb it. Cementum provides anchorage for periodontal ligament fibers and adapts the tooth for function.
The document provides an overview of the pulp-dentin complex, including dentin and pulp. It discusses the physical and chemical properties of dentin, its structure including dentinal tubules and types of dentin. Dentinogenesis and age-related changes are also covered. The morphology, development, zones and cell types in pulp are summarized. The document establishes that dentin and pulp are embryologically, histologically and functionally the same tissue and should be considered as a complex.
Enamel is formed through the process of amelogenesis, which involves the life cycle of ameloblasts. Ameloblasts undergo morphological and physiological changes during the secretory, transitional, and maturative stages of amelogenesis. During the secretory stage, ameloblasts develop Tomes' processes which extend into the enamel matrix and help establish the rod and interrod structure of enamel. As enamel matures, ameloblasts transition to having microvilli and modulate between ruffled and smooth shapes to both remove organic material from the enamel and introduce inorganic minerals to fully mineralize the enamel.
This document provides details on the structure and composition of enamel. It notes that enamel is the hardest tissue in the body, covering the anatomical crown. It is made up primarily of hydroxyapatite crystals arranged in enamel prisms/rods from the dentin-enamel junction to the surface. The direction of the prisms changes in a sinusoidal pattern. Between the prisms is interprismatic enamel. Near the surface is aprismatic enamel which is more highly mineralized. Throughout life, the crown is covered by an organic layer or integument.
This document provides an overview of dentin, including:
- Its history, development, physical and chemical properties, structure, types, and innervation
- Dentinogenesis is the process by which dentin is formed through the secretion and mineralization of an organic matrix by odontoblasts.
- Dentin's main components are hydroxyapatite crystals, collagen fibers, non-collagenous proteins, and water. Its tubular structure and composition provide mechanical strength and sensitivity.
- Different types of dentin include primary, secondary, and tertiary dentin, which vary in their location, thickness, mineralization, and quality.
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.
This document provides an overview of cementum, the calcified tissue that forms the outer covering of tooth roots. It discusses the development, composition, histology, classification, and functions of cementum. Cementum begins forming at the cementoenamel junction and extends to the root apex. It is made up of inorganic hydroxyapatite and organic collagen fibers. Cementum provides a medium for periodontal ligament attachment and protects underlying dentin, helping to maintain tooth integrity under forces. It is capable of continuous deposition to repair damage or resorption on root surfaces.
The oral cavity is lined by oral mucosa, which is continuous with the skin and pharyngeal mucosa. The oral mucosa consists of three types - masticatory, lining, and specialized mucosa. Masticatory mucosa covers areas involved in chewing and is keratinized, while lining mucosa covers other soft tissue areas and is non-keratinized. Specialized mucosa covers the dorsal tongue and contains papillae involved in taste. The oral mucosa provides protection, sensation, secretion, permeability and thermal regulation functions.
This document provides information on enamel, the hardest tissue in the human body that covers the crowns of teeth. It discusses the physical and chemical properties of enamel, including its structure of enamel rods/prisms arranged in patterns. The development of enamel is described, with ameloblasts differentiating from epithelium and going through stages of formation, maturation, and protection before eruption. The summary concludes with key points about enamel's structure providing protection and resistance for teeth.
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 describes various anatomical structures found on teeth. It discusses structures such as cusps, tubercles, cingulum, ridges, inclined planes, fossae, grooves, and pits. Cusps are pointed projections found on posterior teeth that form the biting surfaces. Tubercles are small enamel extensions that can form due to trauma or disease. Ridges are convex elevations along tooth surfaces like marginal ridges along the edges. Fossae are irregular depressions found on tooth crowns. Grooves mark divisions between developmental lobes and pits are found at groove junctions.
The document summarizes the structure and composition of dentin. It discusses the different types of dentin - primary, secondary, tertiary - and their locations and functions. It also describes odontoblasts, the cells responsible for dentin formation, and dentinal tubules, the structures that span the thickness of dentin.
This document provides an overview of gingival anatomy and histology. It discusses the 3 parts of the gingiva - marginal, attached, and interdental gingiva. Microscopically, it describes the stratified squamous epithelium and underlying connective tissue. The epithelium consists of basal, spinous, granular, and corneal layers. The connective tissue contains collagen fibers, fibroblasts, and ground substance. Gingival fibers attach the gingiva to the tooth cementum. Blood supply and innervation is also summarized.
Cementum is the calcified tissue that covers the root surface of teeth. It is less calcified and harder than dentin. Cementum is classified based on the presence or absence of cells and fibers. Cellular cementum contains cementocytes within lacunae and forms later in life, while acellular cementum lacks cells and forms earlier. Cementum is deposited throughout life to maintain tooth structure and plays an important role in tooth attachment through Sharpey's fibers inserting into the cementum. Cementum can undergo resorption and repair in response to environmental changes and maintains tooth integrity under forces.
This document provides information on dentin, including its composition, formation, and types. Some key points:
- Dentin makes up the bulk of the tooth and is composed of 65% inorganic material (mainly hydroxyapatite) and 35% organic material (collagen and proteoglycans).
- Odontoblasts are cells responsible for dentin formation. Their processes extend into dentinal tubules that permeate the dentin.
- Dentin formation begins with predentin, which mineralizes to become circumpulpal dentin. Mantle dentin forms the outer layer near the enamel.
- Dentinal tubules contain peritubular dentin and connect the
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.
- 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.
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.
This document summarizes the structure and formation of enamel. It begins by describing enamel as the hardest substance in the body, composed primarily of hydroxyapatite crystals. It then discusses the composition, structure, and organization of enamel rods and crystals. Hunter-Schreger bands and incremental lines are described as well. The lifecycle of ameloblasts and stages of amelogenesis - morphogenic, organizing, formative, maturative, and protective - are summarized.
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 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.
The periodontium consists of cementum, the periodontal ligament (PDL), alveolar bone, and gingiva surrounding the tooth. The PDL is a specialized connective tissue between cementum and alveolar bone that functions to support the teeth, absorb chewing forces, provide sensory feedback, and enable nutrient transport. It contains collagen fiber bundles arranged to withstand forces. Cementum is a hard, avascular tissue covering roots that provides attachment for collagen fibers. The alveolar bone forms the tooth sockets and contains the PDL. Molecular factors regulate tissue development and regeneration.
The enamel is the outermost covering of the tooth crown. It is the hardest tissue in the body, composed mainly of inorganic hydroxyapatite crystals and water. Histologically, enamel is made up of enamel rods that extend from the dentin into the enamel in a pattern that provides strength. The rods are arranged into Hunter-Schreger bands that further reinforce the enamel. Properties of enamel allow it to function in mastication but also make it susceptible to conditions like dental caries if not properly cared for and maintained. Clinical applications include fluoride to strengthen enamel, acid etching to promote bonding in restorations, and bleaching to change the appearance of enamel.
This document provides an introduction to dental anatomy and physiology. It discusses the structures of teeth such as enamel, dentin, cementum and dental pulp. It describes the primary and secondary dentitions. Teeth are classified as incisors, canines, premolars and molars. Tooth anatomy includes the crown, root and pulp chamber. The four main dental tissues and periodontal tissues are also introduced. Factors in the oral cavity such as plaque, saliva, pH and their roles in demineralization and remineralization are overviewed.
Enamel significance in operative dentistry /certified fixed orthodontic cour...Indian dental academy
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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 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.
This document provides information about a seminar on enamel, dentin, and pulp presented by Dr. Ashish Kalhan. It discusses the key structures and properties of enamel, dentin, and pulp.
Enamel is the outermost covering of the tooth. It is the hardest tissue in the body and provides protection. It is made up of enamel rods arranged in a prism-like pattern. Dentin lies underneath the enamel and makes up the bulk of the tooth. It contains dentinal tubules that house odontoblast processes. The innermost living tissue is the pulp, which contains blood vessels, nerves, and odontoblasts.
The document discusses the physical and chemical properties of enamel
The periodontal ligament connects the tooth to the alveolar bone and is made of specialized connective tissue. It develops as cells from the dental follicle migrate into the newly formed root cementum. The principal fibers of the ligament develop with tooth eruption, first entering the alveolar bone and later organizing into bundles. Microscopically, the ligament contains fibroblasts, progenitor cells, and extracellular fibers and ground substance. The fibroblasts are responsible for collagen synthesis and turnover and have a higher rate of protein production compared to gingiva or bone fibroblasts.
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.
The document discusses the alveolar bone, including its definition, components, development, structure, clinical applications, and appearance on x-rays. It notes that the alveolar bone contains the tooth sockets and supports the teeth. The alveolar bone proper surrounds the tooth root and is perforated by Volkmann's canals. The supporting alveolar bone consists of cortical plates and spongy bone between the plates and alveolar bone proper. The alveolar bone undergoes remodeling and modeling during tooth movement and in response to functional forces.
1. Tooth development begins around the 6th week of gestation with the formation of the primary epithelial band, which divides into the dental lamina and vestibular lamina.
2. Teeth develop through a series of stages from bud to bell shaped to advanced bell stage when mineralization begins and root formation commences.
3. The dental lamina gives rise to the tooth buds and plays a role in shaping tooth development through later stages. The enamel organ and dental papilla are structures that form within the developing tooth bud.
Enamel presentation. prepared by mohammed yahiaMaher Aziz
This document discusses the structure and formation of enamel. It begins by defining enamel and outlining its formation through the stages of odontogenesis and amelogenesis. Key details are provided on the histological layers involved in enamel formation, as well as the life cycle of ameloblasts. The physical and chemical properties of enamel are then examined, including its hardness, permeability and solubility. The document concludes by describing various histological features of enamel such as enamel rods, striations of Retzius, and the dentino-enamel junction.
It is a presentation in detail about the strongest structure of the oral cavity "ENAMEL". It is a simple topic but people find it difficult to learn about it. I hope my presentation is a simple method to learn about it. I would like to thank my professors for assign me this project and i learn't a lot from it and still learning my basics daily.
Similar to Enamel CONSERVATIVE DENTISTRY AND ENDODONTICS (20)
This document provides an overview of temporomandibular joint disorders (TMD). It begins with definitions of TMD and discusses the history of terminology used to describe TMD. The anatomy of the temporomandibular joint and surrounding structures is described. Several etiological theories for TMD are discussed, including biomechanical, hormonal, traumatic, occlusal, and joint hypermobility theories. Signs and symptoms, diagnosis, classifications, and various treatment approaches for TMD are also outlined. The document contains detailed information on TMD intended for healthcare professionals.
1. The document discusses various treatment approaches for temporomandibular disorders (TMDs) including definitive treatments that address etiological factors and supportive treatments aimed at managing symptoms.
2. Definitive treatments include occlusal appliance therapy using stabilization, anterior positioning, anterior/posterior bite planes, and pivoting/soft appliances to modify occlusion. Other definitive treatments are selective tooth grinding and restorative/orthodontic procedures.
3. Supportive treatments involve physical therapies like heat/coolant therapy, ultrasound, TENS, acupuncture and manual techniques as well as pharmacological therapies.
This document provides an overview of biocompatibility testing for dental materials. It defines biocompatibility and outlines the historical background and requirements for biocompatible materials. The document discusses various in vitro and animal biocompatibility tests, including cytotoxicity, cell function, and mutagenesis assays. It notes that in vitro tests provide initial screening but cannot fully predict in vivo response, while animal tests are more comprehensive but also have limitations. The goal of biocompatibility testing is to systematically evaluate materials before clinical use to protect patients.
The document discusses the anatomy and histology of the root apex. It describes the development of root structures including the apical constriction, cementodentinal junction, and apical foramen. Variations in root apex morphology are discussed including accessory canals, resorption, and calcifications. The clinical significance of understanding root apex anatomy for procedures like working length determination, apical resection, and apexification are summarized.
This document provides an overview of the blood supply of the head and neck region. It begins with an introduction to circulation and the functional parts including arteries, arterioles, capillaries, and veins. It then details the major arteries supplying the head and neck, including the common carotid artery, external carotid artery, and its branches like the lingual artery and facial artery. It also discusses the internal carotid artery and its branches. Finally, it briefly mentions the venous drainage and pulp vasculature before concluding.
This document discusses diagnosis and treatment planning for removable partial dentures. It begins by defining key terms like diagnosis, treatment planning, and removable partial denture. It emphasizes the importance of a thorough patient interview and medical/dental history to accurately diagnose issues and develop a treatment plan. The document outlines factors to consider in the patient interview and examining the patient's mouth, teeth and bone. It discusses how various medical conditions and medications can impact treatment and the need to consult physicians in some cases.
This document provides an overview of splinting of traumatized teeth. It discusses the history, definitions, rationale, principles, indications, objectives, and classifications of splinting. Various splint types are described in detail, including wire ligatures, arch bars, composite and wire, orthodontic wire and brackets, fibre, titanium trauma splints, and more. Flexible splints that allow physiological movement are preferred to rigid splints. The optimal duration of splinting depends on the specific injury but is typically 4-6 weeks. Longer immobilization can lead to bone loss from periodontal issues.
This document provides an overview of dental amalgam. It begins with a brief introduction, then discusses the history of amalgam use dating back to ancient China. The document outlines various classifications of amalgam and lists indications and contraindications for its use. Advantages include ease of use and strength, while disadvantages include esthetics and weakness of tooth structure. The document discusses the composition of amalgam, including the roles of individual components like silver, tin and copper. It also summarizes the amalgamation reaction and properties of amalgam like strength, creep and corrosion resistance.
The document discusses various aspects of wound healing, including definitions of regeneration, repair, and primary and secondary intention healing. It describes the process of regeneration as proliferation of parenchymal cells to restore original tissues, while repair involves proliferation of connective tissue elements and fibrosis. Primary intention healing occurs when a clean, surgically incised wound is approximated by sutures, resulting in re-epithelialization within 48 hours and scar formation over 4 weeks. Secondary intention healing applies to wounds with tissue defects that are left open to heal more slowly through granulation tissue formation and contraction over weeks.
This document provides information on bone structure and function. It begins with definitions of bone and its functions, which include providing shape and support, protecting organs, and storing minerals. It describes the various types of bone based on development and microscopic appearance. It discusses the anatomy of long bones and bone structure including lamellae, osteons, Haversian canals, and Volkmann's canals. It provides information on cells involved in bone remodeling including osteoblasts, osteoprogenitor cells, and osteoclasts. It covers regulators of bone formation including hormones, proteins, and vitamins. It also discusses alveolar bone development, classification, and changes that occur after tooth extraction.
Executive Directors Chat Leveraging AI for Diversity, Equity, and InclusionTechSoup
Let’s explore the intersection of technology and equity in the final session of our DEI series. Discover how AI tools, like ChatGPT, can be used to support and enhance your nonprofit's DEI initiatives. Participants will gain insights into practical AI applications and get tips for leveraging technology to advance their DEI goals.
हिंदी वर्णमाला पीपीटी, hindi alphabet PPT presentation, hindi varnamala PPT, Hindi Varnamala pdf, हिंदी स्वर, हिंदी व्यंजन, sikhiye hindi varnmala, dr. mulla adam ali, hindi language and literature, hindi alphabet with drawing, hindi alphabet pdf, hindi varnamala for childrens, hindi language, hindi varnamala practice for kids, https://www.drmullaadamali.com
A review of the growth of the Israel Genealogy Research Association Database Collection for the last 12 months. Our collection is now passed the 3 million mark and still growing. See which archives have contributed the most. See the different types of records we have, and which years have had records added. You can also see what we have for the future.
This slide is special for master students (MIBS & MIFB) in UUM. Also useful for readers who are interested in the topic of contemporary Islamic banking.
How to Build a Module in Odoo 17 Using the Scaffold MethodCeline George
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Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
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Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
Thinking of getting a dog? Be aware that breeds like Pit Bulls, Rottweilers, and German Shepherds can be loyal and dangerous. Proper training and socialization are crucial to preventing aggressive behaviors. Ensure safety by understanding their needs and always supervising interactions. Stay safe, and enjoy your furry friends!
Assessment and Planning in Educational technology.pptxKavitha Krishnan
In an education system, it is understood that assessment is only for the students, but on the other hand, the Assessment of teachers is also an important aspect of the education system that ensures teachers are providing high-quality instruction to students. The assessment process can be used to provide feedback and support for professional development, to inform decisions about teacher retention or promotion, or to evaluate teacher effectiveness for accountability purposes.
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
2. • Introduction
• Functions of enamel
• Physical and chemical properties
• Surface structures of enamel
• Life cycle of ameloblasts and Amelogenesis
• Enamel adhesion
• Effect of bleaching on enamel
• Developmental disturbances of enamel
• Age changes and clinical considerations
• References
CONTENTS
3. INTRODUCTION
• Enamel is a protective covering of variable thickness over the entire surface of the
crown.
• Enamel is the hardest calcified tissue in the human body.
• The shape and contour of the cusps receive their final modeling in the enamel.
• The cells that are responsible for the formation of enamel (Ameloblasts) are lost as
the tooth erupts into the oral cavity, and hence can’t renew itself.
• To compensate this enamel undergoes complex structural organization and high
degree of mineralization.
4. FUNCTIONS OF ENAMEL
• Transfers occlusal load to the biomechanical unit.
• It prevents premature wearing of dentine.
• Prevents hypersensitivity of dentine.
• Protects pulp dentine complex from thermal, chemical and electrical substances.
• Provides aesthetics.
• Helps in maintain contacts, contours and vertical dimension.
5. PHYSICAL PROPERTIES
• Hardest calcified tissue- high content of mineral salts and crystalline arrangement.
• Modulus of elasticity and hardness- more at the surface than at the DEJ.
• Maximum thickness: 2-2.5mm
• Semi-permeable membrane.
• Specific gravity – 2.8
• Translucency- degree of calcification and homogenesity.
• Color : ranges from light yellow to bluish gray.
• Incisal areas may have a bluish tinge where the thin edge consists of only a double layer of
enamel and cervical areas show yellowish tinge because of thinness of the enamel.
Kumar GS. Orban's oral histology & embryology. Elsevier Health Sciences; 2014 Feb 10.
7. INORGANIC MATERIAL
• The inorganic material of enamel is hydroxyapatite.
• The crystals are hexagonal in cross section.
• The shape of the single crystal is rod with an equilateral
hexagon base.
• The crystals are arranged to form enamel rods or prisms.
• The core of the crystal are rich in Mg and carbonate.
• Water is present in the crystals and in between the crystals.
Kumar GS. Orban's oral histology & embryology. Elsevier Health Sciences; 2014 Feb 10.
8. ENAMEL RODS
• Prisms- cylindrical in longitudinal section. (rods)
• Diameter averages 4 micro meters.
• DEJ to the surface of the tooth- tortuous.
• Length of most of the rods> thickness of enamel—oblique and wavy
course.
• Diameter of rods from DEJ to surface= 1:2 increase
DIRECTION OF RODS:
• Oriented at right angles to dentine.
• Wavy course from DEJ to enamel surface.
Kumar GS. Orban's oral histology & embryology. Elsevier Health Sciences; 2014 Feb 10.
9. • Cross section—fish scale appearance.
• ARCADE outlines—near DEJ.
• KEYHOLE or PADDLE shaped prism— Longitudinal Sections
• Head is directed towards occlusal aspects and tail towards the
cervical aspect of the tooth.
• When enamel is cut longitudinally section passes through heads
of one row of rods and tails of the adjacent row.
• This produces an appearance rods separated from interrod
substance.
• 5 um breadth, 9 um length– rod measurement.
• Hydroxyapatite crystals– parallel to long axis of prisms, deviation-
40 degrees.
ULTRASTRUCTURE
Kumar GS. Orban's oral histology & embryology. Elsevier Health Sciences; 2014 Feb 10.
10. ROD SHEATH
• The boundary between the rod and interrod substance is delimited by a narrow
space containing organic material.
• It is a thin peripheral layer.
• Darker than the rod.
• Relatively acid resistant.
• Less calcified and contains more organic matter
than the rod itself.
INTERPRISMATIC SUBSTANCE:
• Cementing rods together.
• Less calcified than the rod and more calcified than the rod sheath.
Kumar GS. Orban's oral histology & embryology. Elsevier Health Sciences; 2014 Feb 10.
11. STRIATIONS
• Each enamel rod is built up of segments separated by dark lines that gives its
striated appearance.
• Become more visible by the action of acids.
• These rods are segmented because the enamel matrix is formed in a rhythmic
manner.
• In humans these segments seem to be uniform length of about 4 microns.
Kumar GS. Orban's oral histology & embryology. Elsevier Health Sciences; 2014 Feb 10.
12. HUNTER SCHREGER BANDS
• The change in the direction of the rods is responsible for appearance of
the Hunter Schreger bands.
• Alternating dark and light bands of varying widths seen in longitudinal
sections under oblique reflected light.
• They originate at DEJ and ends at some distance from outer enamel
surface.
• The prisms which are cut longitudinally produce dark bands called
PARAZONES.
• The prisms cut transversely produce light bands called DIAZONES.
• The angle between these two is 40 degrees.
Kumar GS. Orban's oral histology & embryology. Elsevier Health Sciences; 2014 Feb 10.
13. INCREMENTAL LINES OF RETZIUS AND
PERIKYMATA
• Appears as brownish bands in ground sections.
• They illustrate the incremental pattern of the enamel, that is, the
successive apposition of layers of enamel during formation of the
crown.
• In longitudinal sections– surround tip of dentin.
• In transverse sections— concentric circles.
• Perikymata are the transverse wave like grooves, believed to be the
external manifestation of the striae of Retzius.
• They are continuous around a tooth and usually lie parallel to each
other and to CEJ.
Kumar GS. Orban's oral histology & embryology. Elsevier Health Sciences; 2014 Feb 10.
14. PRISMLESS ENAMEL OTHER SURFACE
STRUCTURES
• Structureless enamel– 30um
• All deciduous and 70% permanent
teeth.
• Cervical areas of teeth.
• Hydroxyapetite crystals are parelllel
to one another and perpendicular
to striae of Retzius.
• More mineralized than enamel
beneath.
• Pits- 1-1.5um- ends of ameloblasts.
• Enamel caps-small elevations-10-
15um- enamel mineralization on non-
mineralizable debris.
• Enamel brochs-Larger elevations.
Kumar GS. Orban's oral histology & embryology. Elsevier Health Sciences; 2014 Feb 10.
15. ENAMEL CUTICLE NEONATAL LINE
• A delicate membrane called Nasmyth’s
membrane.
• Primary enamel cuticle.
• Covers entire crown of newly erupted tooth.
• Secreted by ameloblasts when enamel
formation is completed.
• Basal lamina found beneath epithelia.
• Soon disappears due to masticatory forces.
• Erupted enamel- pellicle- precipitate of
salivary proteins.
• Accentuated incremental
line of Retzius.
Kumar GS. Orban's oral histology & embryology. Elsevier Health Sciences; 2014 Feb 10.
16. ENAMEL LAMELLAE ENAMEL TUFTS
• Thin leaf like structures that extend from enamel
surface towards DEJ.
• Sometimes penetrates dentine.
• More organic less mineral content.
• Seen in transverse ground sections.
Kumar GS. Orban's oral histology & embryology. Elsevier Health Sciences; 2014 Feb 10.
• Arise at DEJ and reach into enamel to
about 1/5 to 1/3 of its thickness.
• Ground sections– grass like.
• Seen in transverse sections.
17. ENAMEL SPINDLES
• Odontoblastic processes that pass across the DEJ into
enamel.
• Since many are thickened at their end they have been
termed as spindles.
• Direction of odontoblastic process and spindles
corresponds to the original direction of ameloblasts.
• Before hard substances were formed.
• Direction- at right angles to dentin.
• Ground sections– dark in transmitted light.
Kumar GS. Orban's oral histology & embryology. Elsevier Health Sciences; 2014 Feb 10.
18. GNARLED ENAMEL DEJ
• Over the cusps of teeth the rods
appear twisted around each other in a
seemingly complex arrangement and
this optical appearance known as
gnarled enamel.
GNARLED ENAMEL
Kumar GS. Orban's oral histology & embryology. Elsevier Health Sciences; 2014 Feb 10.
19. LIFE CYCLE OF AMELOBLASTS
MORPHOGENIC STAGE
ORGANISING STAGE
FORMATIVE STAGE
MATURATIVE STAGE
PROTECTIVE STAGE
DESMOLYTIC STAGE
POST
SECRETORY
PRE
SECRETORY
SSECRETORY
Kumar GS. Orban's oral histology & embryology. Elsevier Health Sciences; 2014 Feb 10.
20. MORPHOGENIC STAGE
• Before ameloblasts are fully differentiated and produce
enamel, they interact with adjacent mesenchymal cells,
determining the shape of the DEJ.
• Cells are short and columnar, with large oval nuclei that
almost fill the cell body.
• During ameloblasts differentiation, terminal bars appear
concomitantly with migration of mitochondria to the
basal region of the cell.
Kumar GS. Orban's oral histology & embryology. Elsevier Health Sciences; 2014 Feb 10.
21. ORGANISING STAGE
• Characterized by change in the appearance of the cells of IEE.
• They become longer and the nucleus free zones at the distal ends of
the cells become almost as long as the proximal parts containing the
nuclei.
• Reversal of functional polarity takes place.
• Clear cell free zone between the IEE and dental papilla disappears.
• Thus epithelial cells come into close contact with the connective tissue
cells of the pulp., which differentiate into odontoblasts.
• During terminal phase of organizing stage dentine formation begins.
• First appearance of the dentine is the critical phase of the life cycle of
IEE.
Kumar GS. Orban's oral histology & embryology. Elsevier Health Sciences; 2014 Feb 10.
22. FORMATIVE STAGE
• Ameloblasts enter into formative stage after the first layer of
dentine is formed.
• Cells retain the same length and arrangement.
• Changes in the organization and number of cytoplasmic
organelles are related to initiation of SECRETION of enamel
matrix.
• Earliest change is development of blunt cell processes on
the ameloblast surface and penetrate the basal lamina and
enter predentine.
Kumar GS. Orban's oral histology & embryology. Elsevier Health Sciences; 2014 Feb 10.
23. MATURATIVE STAGE
• Full mineralization of enamel forms after most if the
thickness of the enamel matrix has been formed in the
occlusal parts of the crown and incisal areas.
• Ameloblasts are slightly reduced in length and closely attach
to enamel matrix.
• Ameloblasts display microvilli at their distal proximities and
cytoplasmic vacuoles containing material resembling
enamel matrix are present.
• These structures indicate absorptive function of these cells.
Kumar GS. Orban's oral histology & embryology. Elsevier Health Sciences; 2014 Feb 10.
24. PROTECTIVE STAGE
• The enamel has completely developed, and has fully
calcified, the Ameloblasts cease to be arranged in a well-
defined layer.
• Cells then form a stratified epithelial covering of enamel,
the so-called reduced enamel epithelium.
• The function of REE is that of protecting the mature
enamel by separating it from the connective tissue until
tooth erupts.
• If connective tissue comes in contact with the enamel,
anomalies may develop.
Kumar GS. Orban's oral histology & embryology. Elsevier Health Sciences; 2014 Feb 10.
25. DESMOLYTIC STAGE
• The reduced enamel epithelium proliferates and
seems to induce atrophy of the connective tissues
separating it from oral epithelium.
• Epithelial cells elaborate enzymes that are able to
destroy connective tissue fibers by desmolysis.
• Premature degeneration of the reduced enamel
epithelium may prevent the eruption of a tooth.
Kumar GS. Orban's oral histology & embryology. Elsevier Health Sciences; 2014 Feb 10.
26. AMELOGENESIS
Amelogenesis or enamel formation is a two step process.
Organic matrix formation
Mineralization
• Amelogenin a component of enamel matrix proteins, undergo extracellular
degradation by proteolytic enzymes and break into smaller low molecular weight
fragments.
• These are suggested to have specific function in regulating crystal growth.
Kumar GS. Orban's oral histology & embryology. Elsevier Health Sciences; 2014 Feb 10.
27. TOMES PROCESS
• The surfaces of the ameloblasts facing the developing enamel are not
smooth.
• There is an interdigitation of the cells and enamel rods that they
produce.
• This is a result of the fact that the long axes of the ameloblasts are not
parallel to the long axes of the rods.
• The projections of the ameloblasts into the enamel matrix have been
named as Tome’s processes.
• The junctional complexes which form at the distal end are called distal
terminal bars.
• These terminal bars separate the Tome’s processes from the cell
proper.
Kumar GS. Orban's oral histology & embryology. Elsevier Health Sciences; 2014 Feb 10.
28. ENAMEL ADHESION
• Acid etching transforms the smooth enamel into an irregular surface and increases its
surface free energy.
• The formation of resin microtags within the enamel surface is the fundamental mechanism
of resin-enamel adhesion. (micromechanical)
TYPE- 1 TYPE- II TYPE- III
Roberson T, Heymann HO, Swift Jr EJ. Sturdevant's art and science of operative dentistry. Elsevier Health Sciences; 2006 Apr 13.
Anusavice KJ, Shen C, Rawls HR, editors. Phillips' science of dental materials. Elsevier Health Sciences; 2012 Sep 27.
29. 50% conc monocalcium phosphate monohydrate rinsed off.
<27% conc dicalciumphosphate monohydrate cannot be rinsed, adhesion
interference
Barkmeier WW, et al: Effects of 15 vs 60 second enamel acid conditioning on adhesion and morphology, Oper Dent 11:111-116, 1986.
• An etching time of 60 seconds permanent enamel using 30% to 40% phosphoric acid.
• For primary enamel– 45-60 seconds
• Severe fluorosed teeth– 75-90 sec (fluorosis index=4)
30. RETENTIVE FEATURES PLACED IN ENAMEL
• Partial bevel- for cast metal restorations
• Short bevel- for cast metal restorations
• Skirt preperations: Skirts are thin extensions
of the facial or lingual proximal margins of
the cast metal onlay that extend from the
primary flare to a termination just past the
transitional line angle of the tooth.
• Bevelling the composite restorations.
Roberson T, Heymann HO, Swift Jr EJ. Sturdevant's art and science of operative dentistry. Elsevier Health Sciences; 2006 Apr 13.
Marzouk MA, Simonton AL, Gross RD. Operative dentistry. Modern theory and practice, 1st ed. St Louise-Tokyo, Ishiyahu EuroAmerica Inc.
1985.
31. EFFECT OF BLEACHING ON ENAMEL
• In office extracoronal bleaching- gel with 25% to 38% H2O2.
• The light source can be a laser (e.g., argon, CO2), halogen, plasma
arc, or light-emitting diodes (LED).
• For professional at home bleaching- 3% to 7.5% H2O2 or 10 to 22%
carbamide peroxide, especially those with 10% carbamide peroxide.
• Several investigators reported alteration of enamel surfaces
associated with bleaching treatments, including shallow depression,
increased porosity, and slight erosion.
• Associated with products using acidic pre rinse or gels of low pH.
Ingle JI, Bakland LK, Baumgartner JC, editors. Ingle's endodontics 6. Pmph usa; 2008.
32. 75 volunteers were distributed according to the bleaching technique (n=25):
(a) at-home: 10%HP (Opalescence GO) for 15 days of continuous use (1 hour per day);
(b) in-office: 40%HP (Opalescence Boost) in three clinical sessions (40 minutes each session);
(c) combined: one initial session with 40%HP, and the rest with 10%HP for 15 days of
continuous use.
Clinical evaluations and Ca and P concentration collections were obtained before, during
bleaching treatment, and 15 days after conclusion of treatment.
RESULTS:
• The in-office technique presented the lowest tooth sensitivity.
• All techniques resulted in lower Ca and P concentrations in enamel at each time point,
compared with the baseline concentrations.
• Calcium concentrations did not differ significantly among the treatments (P= 0.9360).
• Phosphorus concentration at the 8th day was higher for the in-office technique group (P<
0.05).
Dourado AP, Carlos NR, Amaral FL, França FM, Turssi CP, Basting RT. At-home, in-office and combined dental bleaching techniques
using hydrogen peroxide: Randomized clinical trial evaluation of effectiveness, clinical parameters and enamel mineral content.
American journal of dentistry. 2019 Jun;32(3):124-32.
34. DEVELOPMENTAL DISTURBANCES OF ENAMEL
AMELOGENESIS IMPERFECTA:
• A developmental disturbance in the structure of the enamel.
• Etiology : a genetic autosomal defective gene linked to the locus DXS85 at
Xp22.
• This is identified as a general location of human gene for amelogenin., a
principle protein in developing enamel.
• Hypoplastic : characterized by deficiency in the quality of enamel. Clinically
manifested as pits or grooves on the enamel surface.
• Hypocalcified : characterized by enamel that is insufficiently mineralized,
appearing clinically as soft and discolored, easy to remove.
• Hypomaturative : associated with abnormalities during the maturation of
enamel formation, giving the enamel an opaque and chalky appearance.Shafer WG, Hine MK, Levy BM, Rajendran R, Sivapathasundharam B. A textbook of oral pathology. Philadelphia: Saunders; 1983 Sep 20.
35. ENVIRONMENTAL ENAMEL HYPOPLASIA
• May be defined as incomplete or defective formation of the organic enamel matrix.
• A number of factors, each capable of producing injury to ameloblasts may give rise to
this condition.
• Rickets during the time of tooth formation is most common known cause of enamel
hypoplasia.
• Deficiencies of vitamin A and C also been named as causes for enamel hypoplasia.
• Vit – D deficiency causes pitting type of enamel defects.
NUTRITIONAL DEFICIENCIES
Shafer WG, Hine MK, Levy BM, Rajendran R, Sivapathasundharam B. A textbook of oral pathology. Philadelphia: Saunders; 1983 Sep 20.
36. CONGENITAL SYPHILLIS
• This hypoplasia involves maxillary and mandibular central incisors and first
molars.
• Characteristic shape of upper central incisor is “SCREW-DRIVER” shaped
incisors. (Hutchinson’s teeth).
• The incisal edge is usually notched.
• Molars are referred as mulberry molars.
Shafer WG, Hine MK, Levy BM, Rajendran R, Sivapathasundharam B. A textbook of oral pathology. Philadelphia: Saunders; 1983 Sep 20.
measles, chickenpox and scarlet fever
Pitting type – CI, LI, CUSPIDS, MOLARS
37. FLUOROSIS
• Mottled enamel
• 0.9 to 1.0 ppm.
• Chronic ingestion of fluoride in
drinking water leads to dental fluorosis.
• Appears as a hypocalcified lesions on
the surface of enamel.
Shafer WG, Hine MK, Levy BM, Rajendran R, Sivapathasundharam B. A textbook of oral pathology. Philadelphia: Saunders; 1983 Sep 20.
Peter S. Essentials of preventive and community dentistry. Arya (Medi) Publishing House; 2009.
38. AGE CHANGES AND CLINICAL CONSIDERATIONS
MICROSCOPIC CHANGES:
• Loss of Perikymata - generalized loss of rod ends
- more on buccal and lingual
- height of contour
- anterior teeth than posterior
• Localized increase in elements such as nitrogen and fluorine – darker color.
• Increase in the size of the crystal reduces permeability.
• Increase in the organic content of enamel.
Kumar GS. Orban's oral histology & embryology. Elsevier Health Sciences; 2014 Feb 10.
39. MACROSCOPIC CHANGES
ATTRITION:
It is a mechanical wear of the incisal or occlusal tooth structure
as a result of functional or parafunctional movements of the
mandible.
ABRASION:
It is defined as an abnormal tooth structure loss resulting from
direct frictional forces between the teeth and external objects
or from frictional forces between contacting teeth in the
presence of an abrasive medium.
Kumar GS. Orban's oral histology & embryology. Elsevier Health Sciences; 2014 Feb 10.
Roberson T, Heymann HO, Swift Jr EJ. Sturdevant's art and science of operative dentistry. Elsevier Health Sciences; 2006 Apr 13.
40. EROSION
• Progressive loss of dental tissue by chemical processes not involving bacteria.
• EXTRINSIC : Contact with acidic media, food.
• INTRINSIC : gastric acids regurgitated into esophagus and mouth.
Kumar GS. Orban's oral histology & embryology. Elsevier Health Sciences; 2014 Feb 10.
Roberson T, Heymann HO, Swift Jr EJ. Sturdevant's art and science of operative dentistry. Elsevier Health Sciences; 2006 Apr 13.
41. REFERENCES
• Kumar GS. Orban's oral histology & embryology. Elsevier Health Sciences; 2014 Feb 10.
• Ten Cate AR, Nanci A. Ten Cate's oral histology: development, structure, and function.
Elsevier; 2013.
• Shafer WG, Hine MK, Levy BM, Rajendran R, Sivapathasundharam B. A textbook of oral
pathology. Philadelphia: Saunders; 1983 Sep 20.
• Roberson T, Heymann HO, Swift Jr EJ. Sturdevant's art and science of operative
dentistry. Elsevier Health Sciences; 2006 Apr 13.
• Anusavice KJ, Shen C, Rawls HR, editors. Phillips' science of dental materials. Elsevier
Health Sciences; 2012 Sep 27.
• Phillips RW. Skinner's science of dental materials. Philadelphia: Saunders; 1973.
42. • Barkmeier WW, et al: Effects of 15 vs 60 second enamel acid conditioning on adhesion
and morphology, Oper Dent 11:111-116, 1986.
• Marzouk MA, Simonton AL, Gross RD. Operative dentistry. Modern theory and
practice, 1st ed. St Louise-Tokyo, Ishiyahu EuroAmerica Inc. 1985.
• Ingle JI, Bakland LK, Baumgartner JC, editors. Ingle's endodontics 6. Pmph usa; 2008.
• Peter S. Essentials of preventive and community dentistry. Arya (Medi) Publishing
House; 2009.
Editor's Notes
2- 2.5, knife edge.
Density
Non- electric condutive
Low and high mol wt
mg and carbonate
Parallel to prisms and make prisms
Surrounded by organic substance.
5 million- LI
12 million- molars
Seen in enamel which is insufficiently calcified.
Light microscope-Diurnal rhythms in enamel formation
Functional adaptation
Variation in mineralization.
30 perikymata per mm- cej
10 per mm- occlusal or incisal
Surface structures- perikymata, prismless enamel, pits, enamel caps, brochs
Hypocalcified structures-rod sheath,
in lines of retzius,
lamella,
tufts,
crack,
spindles,
neonatal line
Function of cuticle- to protect the surface of newly formed enamel by the resorptive activity of the surrounding vascular tissue prior to it eruption.
A- poorly calcified rod segments
B- degenerated cells
C- erupted teeth cracks filled with organic matter.
Functional adaptation, imperfections
MOF- MPD
Picket fence arrangement of tomes process.
Resin tags- 6um in diameter and 10 to 20 um in length.