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
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.
This document provides an overview of dentin, including its composition, formation process (dentinogenesis), physical properties, histology, types, innervation, and age-related changes. It discusses the differences between primary and permanent dentin, infected vs affected dentin, the smear layer, and dentin bonding systems. The document concludes with a brief discussion of the role of dentin in forensic odontology. Key points include that dentin is a mineralized tissue containing dentinal tubules that contain odontoblast processes, and its formation involves both collagen matrix formation and subsequent mineralization.
Dentin with emphasis on applied physiology and pathology Nadeem Aashiq
This document provides an overview of the structure and properties of dentin. It discusses the composition, physical properties, and microscopic structure of dentin. Key points include that dentin is composed of organic and inorganic materials, including collagen, water and hydroxyapatite crystals. It describes the arrangement of dentinal tubules and peritubular dentin. Primary, secondary and tertiary dentin formation is explained. The roles of odontoblasts and dentinal fluid are also summarized. The document considers age-related changes in dentin like dead tracts and sclerosis.
The document discusses the properties and development of dentin. It begins by introducing dentin and its role in tooth structure. Then it covers the physical and chemical properties of dentin, including its composition, hardness, thickness and density. The stages of dentin development and mineralization are described. Histologically, the key features of dentin are dentinal tubules, peritubular dentin, intertubular dentin and predentin. Structural lines like the dentinoenamel junction and Tome's granular layer are also outlined. Finally, the document notes different types of dentin like mantle dentin.
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.
Garima Singh presented on the topic of dentin. Key points included:
- Dentin is the tissue found underneath enamel and makes up the bulk of teeth. It contains dentinal tubules that contain odontoblast processes and connect the pulp chamber.
- Dentin is made up of 70% inorganic material (mainly hydroxyapatite), 20% organic material (mainly type I collagen), and 10% water. It undergoes dentinogenesis through collagen matrix formation and mineralization.
- There are different types of dentin, including primary, secondary, and tertiary dentin which are formed at different stages. Characteristics like tubule orientation and mineralization differ between primary and permanent dentin
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
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.
This document provides an overview of dentin, including its composition, formation process (dentinogenesis), physical properties, histology, types, innervation, and age-related changes. It discusses the differences between primary and permanent dentin, infected vs affected dentin, the smear layer, and dentin bonding systems. The document concludes with a brief discussion of the role of dentin in forensic odontology. Key points include that dentin is a mineralized tissue containing dentinal tubules that contain odontoblast processes, and its formation involves both collagen matrix formation and subsequent mineralization.
Dentin with emphasis on applied physiology and pathology Nadeem Aashiq
This document provides an overview of the structure and properties of dentin. It discusses the composition, physical properties, and microscopic structure of dentin. Key points include that dentin is composed of organic and inorganic materials, including collagen, water and hydroxyapatite crystals. It describes the arrangement of dentinal tubules and peritubular dentin. Primary, secondary and tertiary dentin formation is explained. The roles of odontoblasts and dentinal fluid are also summarized. The document considers age-related changes in dentin like dead tracts and sclerosis.
The document discusses the properties and development of dentin. It begins by introducing dentin and its role in tooth structure. Then it covers the physical and chemical properties of dentin, including its composition, hardness, thickness and density. The stages of dentin development and mineralization are described. Histologically, the key features of dentin are dentinal tubules, peritubular dentin, intertubular dentin and predentin. Structural lines like the dentinoenamel junction and Tome's granular layer are also outlined. Finally, the document notes different types of dentin like mantle dentin.
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.
Garima Singh presented on the topic of dentin. Key points included:
- Dentin is the tissue found underneath enamel and makes up the bulk of teeth. It contains dentinal tubules that contain odontoblast processes and connect the pulp chamber.
- Dentin is made up of 70% inorganic material (mainly hydroxyapatite), 20% organic material (mainly type I collagen), and 10% water. It undergoes dentinogenesis through collagen matrix formation and mineralization.
- There are different types of dentin, including primary, secondary, and tertiary dentin which are formed at different stages. Characteristics like tubule orientation and mineralization differ between primary and permanent dentin
middle layer of tooth the dentin which has yellowish in colorRenu710209
dentin is the resilient structure of tooth which gives yellowish color and protect the underlying dentalpulp and innervated structures from external stimuli
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.
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.
This document discusses dentinogenesis, the formation of dentin by odontoblasts. It describes the different types of dentin formed at various stages - mantle dentin, primary dentin, secondary dentin, and tertiary dentin. It also discusses the regional distribution and structure of different zones of dentin, including mantle dentin, circumpulpal dentin, secondary dentin, tertiary dentin, predentin, interglobular dentin, and the granular layer of Tomes. Additionally, it compares intratubular and intertubular dentin, and provides notes on sclerotic dentin, dead tracts, incremental lines of Von Ebner and Andersen, lines of primary
Dentin forms the bulk of the tooth and contains dentinal tubules that run from the outer dentin to the pulp cavity. Dentinal tubules are hollow tubes that carry odontoblastic processes and nerves. They decrease in diameter and become more spaced out from the pulp cavity to the outer dentin. There are different types of dentin including primary dentin which surrounds the pulp and secondary dentin which is laid down after root formation. Tertiary dentin is formed in response to injury or trauma and can be reactionary or reparative depending on the stimulus. The dentin surrounding each tubule, called peritubular dentin, is more mineralized than the intertubular dentin
The document discusses the formation and types of dentin. It begins by explaining that dentinogenesis is initiated by odontoblasts and forms the bulk of each tooth crown and root. There are several types of dentin that form at different stages: mantle dentin forms first along the enamel layer, primary dentin makes up most of the tooth, and secondary and tertiary dentins are deposited throughout life. Tertiary dentin specifically forms in response to stimuli like decay. Dentin contains tubules that house odontoblast processes and provide sensitivity; it is made up of both organic and inorganic components including collagen and hydroxyapatite.
Dentin is the mineralized hard tissue that forms the bulk of the tooth beneath enamel and cementum. It is sensitive and continues to form throughout life at the expense of the pulp. Dentinogenesis begins when the dental papilla differentiates into odontoblasts. There are three stages of odontoblast development: differentiation, secretory formation of predentin and dentin, and a resting stage. Dentin is composed of hydroxyapatite crystals embedded in a collagen matrix. It has tubules that house odontoblast processes and dentinal fluid. The structure and composition of dentin provides strength and protection for the pulp.
This document provides an overview of dentin, including:
- Its composition, formation process, and physical properties.
- The roles of odontoblasts and other components in dentinogenesis.
- The different types and structures of dentin, such as peritubular and intertubular dentin.
- Features like dentinal tubules, Von Ebner's lines, and the dentinoenamel junction.
- Its clinical significance, including use of the cementodentinal junction as a reference point in root canals.
- Potential developmental irregularities below the enamel-dentin junction that could predispose to caries.
Dentin is the tissue that makes up the bulk of the tooth beneath the enamel. It is less mineralized than enamel but more mineralized than bone. Dentin is made up of hydroxyapatite crystals, collagen, and water. It contains microscopic channels called dentinal tubules that originate from the dental pulp and extend outward. With age, secondary dentin deposition and sclerotic dentin formation cause the dentinal tubules to decrease in diameter or become blocked. Dentin provides structural support and shape to the tooth and transmits sensory input from the pulp via the dentinal tubules.
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.
BDS first year Dentin presentation by SDM dRanAndSan
- Dentin forms the bulk of the tooth and determines its shape and size. It is a living tissue composed of hydroxyapatite crystals embedded in an organic matrix.
- Dentin varies in thickness from 3-10mm, with the buccal surface being the thickest. It is harder than bone but softer than enamel.
- Dentin's organic matrix contains collagen fibers, proteoglycans and glycoproteins. Inorganic components include hydroxyapatite crystals that are smaller than those in enamel.
Dentinal tubules and its content final/cosmetic dentistry coursesIndian 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.for more details please visit
www.indiandentalacademy.com
This document discusses the structure, composition, development and clinical considerations of dentin. It notes that dentin provides support to enamel, is made up of collagen and hydroxyapatite crystals, and contains dentinal tubules that transmit impulses from enamel to the pulp. Dentin is formed through the action of odontoblasts and undergoes primary, secondary and tertiary deposition throughout life. Factors like dentin permeability and reparative formation affect its clinical properties and sensitivity.
The document discusses the structure and development of dentin. It describes dentin as the layer beneath enamel that provides shape and structure to teeth. Dentin forms in stages that mirror tooth development from the lamina bud stage through late bell stage. Key features of dentin include dentinal tubules that contain odontoblastic processes and layers like peritubular dentin, intertubular dentin, and predentin near the pulp. Dentin is laid down in primary, secondary, and tertiary forms throughout life.
This document provides an overview of dentin, including its history, stages of development, physical properties, composition, and age-related changes. Key points include:
- Dentin is the secondary layer of the tooth structure that provides bulk and form. It determines tooth shape and contains dentinal tubules containing odontoblast processes.
- Dentin develops through distinct stages including the lamina, bud, cap, and bell stages. This results in crown formation and root development guided by epithelial cells.
- Dentin is a living tissue composed of collagen, hydroxyapatite crystals, and water. It is harder than bone but softer than enamel. Dentin tubules radiate outward and contain o
The dentin-pulp complex refers to dentin and pulp as a single functional unit, as they are embryologically and histologically related tissues. Dentin and pulp have a common origin from the dental papilla. The pulp contains cells, fibers, and blood vessels surrounded by dentin, which is produced by odontoblast cells located within the pulp. Throughout life, dentin continues to form through the activity of odontoblasts.
Dentin is a hard yellowish substance that forms the bulk of teeth. It is composed of 70% hydroxyapatite crystals and 30% organic materials like collagen. Dentin is formed by odontoblasts cells differentiated from dental papilla cells. It determines the shape of teeth and contains microscopic tubules that house the processes of odontoblast cells. Dentin is harder than bone but softer than enamel. It has different layers with varying properties located at different regions of the tooth.
Dentin is the mineralized connective tissue that makes up the bulk of teeth. It surrounds the dental pulp. Dentin is formed by odontoblasts, cells originating from the dental papilla that differentiate during tooth development. As odontoblasts secrete collagen and other proteins, they become elongated and form dentinal tubules that extend from the pulp cavity to the outer surface of the tooth. Dentin is composed primarily of hydroxyapatite crystals embedded within an organic matrix. The dentin-pulp complex functions together to detect stimuli and initiate responses like additional dentin formation.
The document summarizes key aspects of the dentin-pulp complex. It describes how dentin and pulp have a common embryonic origin and are considered a single functional unit. It outlines the different types of dentin that form over time, including primary, secondary, and tertiary dentin. It also discusses the roles of odontoblasts and dentinal tubules. In less than 3 sentences, the document provides an overview of the embryological, histological, and functional relationship between dentin and pulp as a complex unit that forms over the life of a tooth.
Dentin is the secondary layer of the tooth located beneath enamel and above the pulp. It is composed mainly of hydroxyapatite crystals embedded in an organic matrix of collagen. Dentin contains microscopic channels called dentinal tubules that extend from the pulp cavity to the outer surface and contain odontoblastic processes, dentinal fluid, and nerve fibers. Dentin provides rigidity to the tooth and protects the innervating pulp. Care must be taken during tooth preparation to avoid damaging the dentin or building up excess heat, and dentin should be protected with liners, bases or bonding agents.
NEET MCQs On Nervous System.Impulses Leave A Neuronvasanthatpuram
Central nervous system
Nervous system parts
Nervous system function
Nervous system diagram
Types of nervous system
Autonomic nervous system
Nervous system Definition and function
Nervous system parts and functions
middle layer of tooth the dentin which has yellowish in colorRenu710209
dentin is the resilient structure of tooth which gives yellowish color and protect the underlying dentalpulp and innervated structures from external stimuli
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.
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.
This document discusses dentinogenesis, the formation of dentin by odontoblasts. It describes the different types of dentin formed at various stages - mantle dentin, primary dentin, secondary dentin, and tertiary dentin. It also discusses the regional distribution and structure of different zones of dentin, including mantle dentin, circumpulpal dentin, secondary dentin, tertiary dentin, predentin, interglobular dentin, and the granular layer of Tomes. Additionally, it compares intratubular and intertubular dentin, and provides notes on sclerotic dentin, dead tracts, incremental lines of Von Ebner and Andersen, lines of primary
Dentin forms the bulk of the tooth and contains dentinal tubules that run from the outer dentin to the pulp cavity. Dentinal tubules are hollow tubes that carry odontoblastic processes and nerves. They decrease in diameter and become more spaced out from the pulp cavity to the outer dentin. There are different types of dentin including primary dentin which surrounds the pulp and secondary dentin which is laid down after root formation. Tertiary dentin is formed in response to injury or trauma and can be reactionary or reparative depending on the stimulus. The dentin surrounding each tubule, called peritubular dentin, is more mineralized than the intertubular dentin
The document discusses the formation and types of dentin. It begins by explaining that dentinogenesis is initiated by odontoblasts and forms the bulk of each tooth crown and root. There are several types of dentin that form at different stages: mantle dentin forms first along the enamel layer, primary dentin makes up most of the tooth, and secondary and tertiary dentins are deposited throughout life. Tertiary dentin specifically forms in response to stimuli like decay. Dentin contains tubules that house odontoblast processes and provide sensitivity; it is made up of both organic and inorganic components including collagen and hydroxyapatite.
Dentin is the mineralized hard tissue that forms the bulk of the tooth beneath enamel and cementum. It is sensitive and continues to form throughout life at the expense of the pulp. Dentinogenesis begins when the dental papilla differentiates into odontoblasts. There are three stages of odontoblast development: differentiation, secretory formation of predentin and dentin, and a resting stage. Dentin is composed of hydroxyapatite crystals embedded in a collagen matrix. It has tubules that house odontoblast processes and dentinal fluid. The structure and composition of dentin provides strength and protection for the pulp.
This document provides an overview of dentin, including:
- Its composition, formation process, and physical properties.
- The roles of odontoblasts and other components in dentinogenesis.
- The different types and structures of dentin, such as peritubular and intertubular dentin.
- Features like dentinal tubules, Von Ebner's lines, and the dentinoenamel junction.
- Its clinical significance, including use of the cementodentinal junction as a reference point in root canals.
- Potential developmental irregularities below the enamel-dentin junction that could predispose to caries.
Dentin is the tissue that makes up the bulk of the tooth beneath the enamel. It is less mineralized than enamel but more mineralized than bone. Dentin is made up of hydroxyapatite crystals, collagen, and water. It contains microscopic channels called dentinal tubules that originate from the dental pulp and extend outward. With age, secondary dentin deposition and sclerotic dentin formation cause the dentinal tubules to decrease in diameter or become blocked. Dentin provides structural support and shape to the tooth and transmits sensory input from the pulp via the dentinal tubules.
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.
BDS first year Dentin presentation by SDM dRanAndSan
- Dentin forms the bulk of the tooth and determines its shape and size. It is a living tissue composed of hydroxyapatite crystals embedded in an organic matrix.
- Dentin varies in thickness from 3-10mm, with the buccal surface being the thickest. It is harder than bone but softer than enamel.
- Dentin's organic matrix contains collagen fibers, proteoglycans and glycoproteins. Inorganic components include hydroxyapatite crystals that are smaller than those in enamel.
Dentinal tubules and its content final/cosmetic dentistry coursesIndian 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.for more details please visit
www.indiandentalacademy.com
This document discusses the structure, composition, development and clinical considerations of dentin. It notes that dentin provides support to enamel, is made up of collagen and hydroxyapatite crystals, and contains dentinal tubules that transmit impulses from enamel to the pulp. Dentin is formed through the action of odontoblasts and undergoes primary, secondary and tertiary deposition throughout life. Factors like dentin permeability and reparative formation affect its clinical properties and sensitivity.
The document discusses the structure and development of dentin. It describes dentin as the layer beneath enamel that provides shape and structure to teeth. Dentin forms in stages that mirror tooth development from the lamina bud stage through late bell stage. Key features of dentin include dentinal tubules that contain odontoblastic processes and layers like peritubular dentin, intertubular dentin, and predentin near the pulp. Dentin is laid down in primary, secondary, and tertiary forms throughout life.
This document provides an overview of dentin, including its history, stages of development, physical properties, composition, and age-related changes. Key points include:
- Dentin is the secondary layer of the tooth structure that provides bulk and form. It determines tooth shape and contains dentinal tubules containing odontoblast processes.
- Dentin develops through distinct stages including the lamina, bud, cap, and bell stages. This results in crown formation and root development guided by epithelial cells.
- Dentin is a living tissue composed of collagen, hydroxyapatite crystals, and water. It is harder than bone but softer than enamel. Dentin tubules radiate outward and contain o
The dentin-pulp complex refers to dentin and pulp as a single functional unit, as they are embryologically and histologically related tissues. Dentin and pulp have a common origin from the dental papilla. The pulp contains cells, fibers, and blood vessels surrounded by dentin, which is produced by odontoblast cells located within the pulp. Throughout life, dentin continues to form through the activity of odontoblasts.
Dentin is a hard yellowish substance that forms the bulk of teeth. It is composed of 70% hydroxyapatite crystals and 30% organic materials like collagen. Dentin is formed by odontoblasts cells differentiated from dental papilla cells. It determines the shape of teeth and contains microscopic tubules that house the processes of odontoblast cells. Dentin is harder than bone but softer than enamel. It has different layers with varying properties located at different regions of the tooth.
Dentin is the mineralized connective tissue that makes up the bulk of teeth. It surrounds the dental pulp. Dentin is formed by odontoblasts, cells originating from the dental papilla that differentiate during tooth development. As odontoblasts secrete collagen and other proteins, they become elongated and form dentinal tubules that extend from the pulp cavity to the outer surface of the tooth. Dentin is composed primarily of hydroxyapatite crystals embedded within an organic matrix. The dentin-pulp complex functions together to detect stimuli and initiate responses like additional dentin formation.
The document summarizes key aspects of the dentin-pulp complex. It describes how dentin and pulp have a common embryonic origin and are considered a single functional unit. It outlines the different types of dentin that form over time, including primary, secondary, and tertiary dentin. It also discusses the roles of odontoblasts and dentinal tubules. In less than 3 sentences, the document provides an overview of the embryological, histological, and functional relationship between dentin and pulp as a complex unit that forms over the life of a tooth.
Dentin is the secondary layer of the tooth located beneath enamel and above the pulp. It is composed mainly of hydroxyapatite crystals embedded in an organic matrix of collagen. Dentin contains microscopic channels called dentinal tubules that extend from the pulp cavity to the outer surface and contain odontoblastic processes, dentinal fluid, and nerve fibers. Dentin provides rigidity to the tooth and protects the innervating pulp. Care must be taken during tooth preparation to avoid damaging the dentin or building up excess heat, and dentin should be protected with liners, bases or bonding agents.
Similar to Dentin Oral Histology Notes Dentin Salient Features Of Dentin (20)
NEET MCQs On Nervous System.Impulses Leave A Neuronvasanthatpuram
Central nervous system
Nervous system parts
Nervous system function
Nervous system diagram
Types of nervous system
Autonomic nervous system
Nervous system Definition and function
Nervous system parts and functions
Hemodynamic Disorders Question and Answersvasanthatpuram
This document discusses hemodynamic disorders and contains answers to 10 questions on related topics. It defines and classifies edema, discussing the etiopathogenesis and pathology of different types. It also discusses normal hemostasis mechanisms, Virchow's triad in thrombus formation, the morphology and fate of thrombi. Other topics addressed include heparin-induced thrombocytopenia, antiphospholipid antibody syndrome, types of embolism including Caisson disease, fat embolism, amniotic fluid embolism, the morphology of infarcts, and the definition, types, pathogenesis and morphological changes seen in shock.
Obturation Of Root Canal Obturation Of Root Canalvasanthatpuram
The document discusses obturation, which is the filling of the root canal system after chemomechanical preparation. Obturation aims to provide an impermeable seal within the root canal system to prevent reinfection from oral or apical microleakage. Ideal obturation extends to the cementodentinal junction and has a tapered funnel-like shape reflecting the root's morphology. Materials used for obturation include gutta-percha, silver cones, and various sealers. Gutta-percha is the most common material due to its biocompatibility and plasticity which allows it to fill canal irregularities.
How to Make a Field Mandatory in Odoo 17Celine George
In Odoo, making a field required can be done through both Python code and XML views. When you set the required attribute to True in Python code, it makes the field required across all views where it's used. Conversely, when you set the required attribute in XML views, it makes the field required only in the context of that particular view.
Exploiting Artificial Intelligence for Empowering Researchers and Faculty, In...Dr. Vinod Kumar Kanvaria
Exploiting Artificial Intelligence for Empowering Researchers and Faculty,
International FDP on Fundamentals of Research in Social Sciences
at Integral University, Lucknow, 06.06.2024
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How to Manage Your Lost Opportunities in Odoo 17 CRMCeline George
Odoo 17 CRM allows us to track why we lose sales opportunities with "Lost Reasons." This helps analyze our sales process and identify areas for improvement. Here's how to configure lost reasons in Odoo 17 CRM
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.
How to Setup Warehouse & Location in Odoo 17 InventoryCeline George
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ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...PECB
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Date: May 29, 2024
Tags: Information Security, ISO/IEC 27001, ISO/IEC 42001, Artificial Intelligence, GDPR
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A workshop hosted by the South African Journal of Science aimed at postgraduate students and early career researchers with little or no experience in writing and publishing journal articles.
বাংলাদেশের অর্থনৈতিক সমীক্ষা ২০২৪ [Bangladesh Economic Review 2024 Bangla.pdf] কম্পিউটার , ট্যাব ও স্মার্ট ফোন ভার্সন সহ সম্পূর্ণ বাংলা ই-বুক বা pdf বই " সুচিপত্র ...বুকমার্ক মেনু 🔖 ও হাইপার লিংক মেনু 📝👆 যুক্ত ..
আমাদের সবার জন্য খুব খুব গুরুত্বপূর্ণ একটি বই ..বিসিএস, ব্যাংক, ইউনিভার্সিটি ভর্তি ও যে কোন প্রতিযোগিতা মূলক পরীক্ষার জন্য এর খুব ইম্পরট্যান্ট একটি বিষয় ...তাছাড়া বাংলাদেশের সাম্প্রতিক যে কোন ডাটা বা তথ্য এই বইতে পাবেন ...
তাই একজন নাগরিক হিসাবে এই তথ্য গুলো আপনার জানা প্রয়োজন ...।
বিসিএস ও ব্যাংক এর লিখিত পরীক্ষা ...+এছাড়া মাধ্যমিক ও উচ্চমাধ্যমিকের স্টুডেন্টদের জন্য অনেক কাজে আসবে ...
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Chapter 4 - Islamic Financial Institutions in Malaysia.pptx
Dentin Oral Histology Notes Dentin Salient Features Of Dentin
1. Dentin Oral Histology Notes
Dentin
Dentin is the mineralized connective tissue that provides the bulk and form to the
tooth. It is covered by enamel in the crown and by cementum in the root
Table of Contents
Dentin
Salient Features Of Dentin
Physical Properties Of Dentin
Chemical Properties Of Dentin
Dentinoenamel Junction
Structure Of Dentin
Odontoblast, Odontoblastic Process And Enamel Spindles
Classification Of Dentin
Predentin
Primary Dentin
Secondary Dentin
Tertiary Dentin
Incremental Lines Of Von Ebner
Contour Lines Of Owen
Neonatal Line
Interglobular Dentin
Tomes Granular Layer
Dead Tracts
Sclerotic Dentin Or Transparent Dentin
Nerves In Dentin
Dentin Hypersensitivity
Dentinogenesis
Clinical Considerations
Dentin Synopsis
Salient Features Of Dentin
Dentin is laid down by odontoblasts. The cell bodies of the odontoblasts are present
outside the dentin along the outer border of the pulp lining the pulpal surface of
dentin.
Dentin consists of numerous tubules, which are laid down in a mineralized
collagenous matrix. The tubules contain the processes of odontoblasts and thus
dentin is considered a living tissue.
Dentin forms before enamel. It determines the shape of the crown and number and
size of the roots.
It is formed throughout the life.
2. Read And Learn More: Oral Histology Notes
Coronal dentin: Dentin present in the crown.
Radicular dentin: Dentin present in the root.
Dentin is similar to bone and is considered to be vital. However, there are a few
differences between the two
Even though dentin and enamel are calcified tissues, there are certain differences
between them which are described in table
Differences between Dentin and Bone
4. Light yellow in colour. The yellow dentin is seen through the
translucent enamel.
Dentin Darkens with age.
Dentin Hardness:
Dentin is viscoelastic in nature and subject to slight
deformation. The enamel overlying the dentin is brittle but does not fracture due to
masticatory forces as dentin acts as a cushion and distributes the forces.
Dentin is harder in the centre than at the periphery.
It is harder in permanent teeth than in primary teeth.
Cracks might occur in dentin which is weakened due to caries or due to cavity
preparation. The incidence of cracking increases with age.
Dentin Thickness:
Usually ranges from 3 to 10 mm.
It varies among teeth and also among surfaces.
Thicker on the buccal aspect than the lingual aspect.
Dentin Permeability:
Dentin is permeable, depending on the patency of the dentinal tubules.
The permeability decreases with age.
Chemical Properties Of Dentin
Organic and inorganic constituents of dentin
Chemical Constituents of Dentin
5. Dentinoenamel Junction
The junction between the enamel and dentin is known as the dentinoenamel junction
(DEJ).
It is scalloped with convexities facing the dentin. The scalloping is more often noticed
in the areas of the tooth under great stress.
The scalloping increases the surface area between enamel and dentin and helps in
increased adhesion between the two tissues.
The DEJ prevents the shearing of enamel and also the development of cracks along
the interface between enamel and dentin.
Chemical Content of Dentin by Volume and Weight
6. Structure Of Dentin
The collagen fibres of dentin are masked by the hydroxyapatite crystals as dentin
calcifies. The collagen fibres can be seen only at the ultrastructural level. The ratio
between the outer and inner surface of dentin is 5:1. Dentin consists of dentinal
tubules that extend along the entire thickness of dentin. The odontoblasts are
present along the pulp dentin border within the pulp with the odontoblastic processes
present within the dentinal tubule in the calcified matrix. Each odontoblast gives rise
to one odontoblastic process, which is a cytoplasmic extension, and is present within
each dentinal tubule. The tubules end at the cementodentinal junction (CDJ) or the
DEJ.
Dentinal tubules
Dentinal tubules run from the pulp dentin border to the DEJ or the CDJ.
The tubules are ‘S’ shaped and are at right angles to the pulp and the CDJ and DEJ.
Starting from the pulp, the first curvature of the ‘S’ is towards the apex or the root of
the tooth. The tubules are almost straight at the cusp tips, incisal edges and in the
root. The tubules are circular in cross section.
Primary curvature: The dentinal tubules are gently curved and follow a sigmoid
course and are ‘S’ shaped. This curvature is called primary curvature.
Secondary curvature: During the formation of dentin, the odontoblasts move away
from dentin in a spiral manner, which results in minute oscillations/sinusoidal
curvatures along the dentinal tubules. These are called secondary curvatures
Lamina limitans: The wall of the dentinal tubule is lined by an organic lining rich in
glycosaminoglycans. This lining is termed as lamina limitans. It is similar to the lining
of bone and cartilage.
Periodontoblastic space: The space between the odontoblastic process and
peritubular dentin is called periodontoblastic space.
Dentinal fluid: The fluid present in the periodontoblastic space is called dentinal fluid.
It has high content of K+ ions and low content of Na+ ions.
7. Dentinal Hypersensitivity Clinical significance
Dentinal hypersensitivity can be explained on the basis of the movement of this fluid.
Fracture of a tooth involving dentin causes this fluid to exude from the dentinal
surface as droplets, mostly due to outward pulpal pressure. This could help in
limiting the diffusion of chemicals and toxins from the dentin into the pulp.
Terminal branches:
8. o They are also called Y-shaped dentinal tubules.
o More common in radicular dentin than in the coronal dentin.
o They might terminate blindly or may unite with branches of other
tubules.
Sensitivity of Dentin Clinical significance
Terminal branches increase the sensitivity of dentin.
Lateral branches:
o Also called canaliculi or microtubules.
o These are at right angles to the dentinal tubule.
o Diameter: 1 micron.
o These communicate with the adjacent dentinal tubule or end
in intertubular dentin and may contain odontoblastic processes.
Salient features of the dentinal tubules:
Tubules are farther apart in the periphery than near the pulp.
Larger in diameter near the pulp (3–4 microns) than at the periphery (1 micron).
Ratio between the number of tubules per unit area on the outer surface to the inner
surface near the pulp is 1:4 (varies between 90,000 and 50,000 per square
millimetre).
More tubules are present in the crown than in the root.
9. Odontoblast, Odontoblastic Process And
Enamel Spindles
The life span of the odontoblasts is equal to that of the tooth.
The odontoblasts are 40 microns in length and 7 microns in diameter.
The odontoblastic processes are cytoplasmic extensions of the odontoblasts. They
are largest in diameter near the pulp (4 microns) and smallest (1 micron) at the
periphery. They are composed of microtubules and intermediate filaments and may
contain mitochondria, micro vesicles and coated vesicles.
The processes might extend
o Till the outer surface of the tubule.
o Partly along the length of the tubule or degenerate and its remains might become a
part of the matrix.
Enamel spindles: Sometimes the odontoblastic processes cross the DEJ and extend
into the enamel. These are called enamel spindles.
Classification Of Dentin
Peritubular dentin and intertubular dentin
10. The dentin that surrounds the dentinal tubules is called peritubular dentin. It forms
the walls of the tubules in the entire dentin. It is absent in the dentin near the pulp. It
is more calcified than the intertubular and also differs in matrix composition.
Peritubular dentin is two times thicker in the outer dentin than in the inner dentin.
There is an increased mineral density in the peritubular dentin. Due to the deposition
of minerals in the inner wall of the dentinal tubule, intra tubular dentin is a more
suitable term for this type of dentin.
Intertubular dentin is the dentin present in between the tubules or between the zones
of peritubular dentin and forms the main bulk of dentin. It is retained after
decalcification just like bone and cementum is, but peritubular dentin is not. The
collagen fibres are randomly organized around the dentinal tubules. The
hydroxyapatite crystals are arranged parallel to the collagen fibres. The differences
between peritubular and intertubular dentin are mentioned in Table.
Differences between Peritubular Dentin and Intertubular Dentin
12. Predentin a layer of mineralized dentin located adjacent to the pulp.
The width of this layer varies from 10 to 40 microns depending on the rate at which it
is deposited by the odontoblasts.
In a demineralized section stained with haematoxylin and eosin, the predentin
appears pale. It is due to the difference in the composition of its unmineralized matrix
and the mineralized matrix of the circumpulpal dentin.
A new layer of predentin is laid down circumpulpally as the matrix at the predentin–
dentin border is mineralized.
Primary Dentin
The dentin formed before root completion is called primary dentin. There are two
types of primary dentin.
Mantle dentin
Circumpulpal dentin
Mantle dentin:
The first formed and the outermost layer of primary dentin, which is found below the
DEJ is called mantle dentin. It is soft and acts as a cushion for the tooth.
Thickness: 20 microns
Mantle Dentin Organic matrix:
Large collagen fibres (larger than in circumpulpal dentin) are loosely packed and
perpendicular to the DEJ.
von Korff’s fibres: Large-diameter type III collagen fibrils of 0.1–0.2 microns diameter
which are argyrophilic (silver stained) are present in mantle dentin.
The organic matrix is less mineralized than circumpulpal dentin
13. Mantle Dentin Mineralization:
Mineralization of mantle dentin is by the matrix vesicles and happens in a globular or
linear pattern. The defects are lesser than in circumpulpal dentin. The mineralization
front appears uniform if the rate is slow and the pattern of mineralization is said to be
linear.
Circumpulpal dentin:
Circumpulpal dentin forms the rest of the bulk of primary dentin.
Organic matrix:
The collagen fibres are smaller in diameter (0.05 micron) and closely packed.
It is more mineralized than mantle dentin.
Secondary Dentin
The dentin formed after root completion is called secondary dentin. There is a
change in direction of dentinal tubules at the interface with primary dentin. It differs
from primary dentin as
14. It is formed throughout life.
It is formed slowly.
It contains lesser dentinal tubules.
Tubular pattern is less regular.
It is not formed uniformly. Greater quantity is formed on the roof and floor of the pulp
chamber, which protects the pulp from the exposure in older teeth.
Incremental lines are closer.
In older individuals, the pulp chamber becomes smaller and the root canals narrow
due to continuous deposition of secondary dentin.
Regular secondary dentin: The secondary dentin has regular arrangement of
dentinal tubules.
Tertiary Dentin
When dentin is formed due to caries, trauma or damage to the pulp during cavity
preparation, it is termed as tertiary dentin. The formation of tertiary dentin is
described in Flowchart
15. Reparative dentin has lesser and more twisted tubules.
Osteodentin: The dentin wherein the odontoblasts might be trapped within the
intercellular substance is called osteodentin.
Irregular secondary dentin: The dentin which contains both osteodentin and tubular
dentin is called irregular secondary dentin. It has irregular dentinal tubules.
Incremental Lines Of Von Ebner
The incremental lines in dentin are fine striations perpendicular to the dentinal
tubules and are called incremental lines of on Ebner. The lines are 4–8 microns
apart.
They are indicative of the daily rhythmic deposition of dentin.
The deposition of dentin decreases after the tooth reaches its functional position.
Contour Lines Of Owen
Accentuated incremental lines are called contour lines of Owen
16. Concept Of The Contour Lines Of Owen:
1. Contour lines of Owen are formed due to the disturbance in the mineralization of
the matrix. Longer the disturbance, wider are the lines. They may be considered
hypocalcified structures.
2. They are also considered to be formed due to the coincidence of the secondary
curvatures.
Neonatal Line
The accentuated incremental line that separates prenatal dentin and postnatal dentin
is termed neonatal line. The line is formed due to abrupt change in environment at
birth.
Commonly seen in deciduous teeth and permanent first molar.
Prenatal dentin is of better quality.
The neonatal line is considered to be a zone of hypocalcification.
17. Interglobular Dentin
During the mineralization of dentin, the minerals are deposited in globules or
calcospherites, which later fuse to form a uniformly homogenous calcified mass.
Sometimes when these globules fail to fuse, the zones of hypomineralization
between the globules are called interglobular spaces or interglobular dentin. The
dentinal
tubules pass through interglobular dentin. This proves that the defect is in the
mineralization rather than matrix formation.
Interglobular Dentin Appearance:
In transmitted light, the interglobular dentin appears dark due to internal reflection of
light in ground sections.
Interglobular Dentin Location:
1. Circumpulpal dentin.
2. Seen in the cervical and middle third of the root and in the coronal one-third of the
crown in decreasing order of occurrence.
Tomes Granular Layer
The peripheral zone of dentin in the root next to the cementum appears granular.
This is called the Tomes’ granular layer. This area is unmineralized and rich in
calcium and phosphorus.
18. Tomes Granular Layer Cause:
It is due to the profuse branching and further coalescing and looping of the terminal
portion of the dentinal tubules due to the turning of the odontoblasts on themselves.
Recent studies suggest that the special arrangement of collagen and
noncollagenous matrix at the CDJ is the cause for the granular layer.
Tomes Granular Layer Appearance:
In transmitted light, the air spaces between the loops cause internal reflection
leading to a granular appearance.
Dead Tracts
The empty dentinal tubules with the absence of the odontoblastic process are filled
with air and appear black in transmitted light and white in reflected light. These are
called dead tracts
19. Dead Tracts Cause: The dentinal tubules in a vital tooth might be empty due to
The loss of the odontoblast process due to caries, abrasion, attrition or cavity
preparation or
Retraction of the odontoblasts before the dentinal tubule is occluded by the
peritubular dentin.
The tubules are then filled with air.
Dead Tracts Appearance:
Dead tracts appear black in transmitted light and white in reflected light.
Dead Tracts Occurrence: Older individuals.
Clinical significance: Decreased sensitivity of dentin. Dead tracts may lead to
sclerotic dentin in the future.
Sclerotic Dentin Or Transparent Dentin
The dentin especially in roots sometimes appears transparent and this is called
transparent or sclerotic dentin.
20. Transparent Dentin Reason: As a defensive response to caries, abrasion, attrition,
toxins and cavity preparation, the apatite crystals and collagen fibres appear within
the dentinal tubules. The tubules are eventually occluded.
Transparent Dentin Appearance:
Transparent in transmitted light as the refractive index of dentin in
which the tubules are blocked are equalized. They appear dark in reflected light.
Transparent Dentin Location: Mostly in roots.
Transparent Dentin Occurrence: Older individuals, slow progressing caries.
Physical and chemical properties:
More mineralized and harder than normal dentin.
Decrease in fracture toughness.
Crystals are smaller than normal dentin.
Transparent Dentin Clinical significance:
1. The formation of sclerotic dentin decreases the permeability of dentin and preserves
the vitality of the pulp.
2. It requires longer etching time due to the increased mineral density.
Nerves In Dentin
Nerve bundles enter the pulp from the apical foramen and terminate as free nerve
endings in the subodonto blastic zone. Axons which lose their Schwann cell sheath
enter the dentinal tubules and pass next to the odontoblastic process. It is suggested
that there
is a communication between the odontoblastic process and the nerve endings by
means of a synapse-like junction. The nerve endings may not be seen in all the
dentinal tubules and may not extend throughout the thickness of dentin.
Dentin Hypersensitivity
This is also called dentin sensitivity or cervical sensitivity.
Definition of dentin hypersensitivity: Dentin hypersensitivity is ‘characterized by a
short, sharp pain arising from exposed dentin in response to stimuli typically thermal,
evaporative, tactile, osmotic, or chemical and that cannot be ascribed to any other
form of dental defect or pathology’ (Holland).
Theories of dentin hypersensitivity:
21. There are three theories that explain the conduction of pain in dentin:
1. Direct neural stimulation
2. Transduction theory
3. Fluid or hydrodynamic theory
Direct neural stimulation theory:
1. Drawbacks of this theory Nerve fibres do not extend through the entire thickness of
dentin.
2. Application of a local anaesthetic agent topically does not reduce the sensitivity.
Transduction theory:
22. Points in favour of this theory:
1. Odontoblasts originate from neural crest cells and might retain transducing and
propagating properties.
Transduction Theory Drawbacks:
1. The membrane potential is too low to conduct and transmit an impulse.
Fluid or hydrodynamic theory (most accepted theory)
23. Points in favour of this theory
1. It explains the inability of a local anaesthetic agent to reduce pain.
2. It also explains the increased sensitivity of dentin near the DEJ. This could be due to
extensive branching of dentinal tubules near the DEJ and displacement of a huge
volume of dentinal fluid due to any stimuli.
Dentinogenesis
The process of formation of dentin is called dentinogenesis.
Dentin is laid down by odontoblasts.
It begins in the late bell stage.
It begins at the cusp tips below the folds of the inner enamel epithelium (IEE).
Dentin formation continues till the entire coronal dentin is formed (4 microns).
Dentinogenesis can be explained under the following steps
24. 1. Differentiation of odontoblasts.
2. Formation of mantle dentin.
3. Formation of circumpulpal dentin.
4. Mineralization of dentin.
Differentiation of odontoblasts:
Cells of the dental papilla are separated from the inner enamel epithelium (IEE) by
an a cellular zone that contains fine collagen fibres. Changes occur in the cells of the
dental papilla after the cells of the IEE undergo reversal of polarity.
The cells of the dental papilla differentiate into odontoblasts in three stages:
1. Induction
2. Competence
3. Terminal differentiation
Dentinogenesis Induction:
The IEE secretes growth factors that bind to the heparin sulfate in the basal lamina.
The basal lamina now has the capacity to induce.
Dentinogenesis Competence:
25. The cells of the dental papilla assume competence after a certain number of
divisions after which they attain receptors for growth factors.
Mitotic spindles are formed perpendicular to the basal lamina that lead to the
formation of the daughter cells that are superimposed.
Dentinogenesis Terminal differentiation:
The ectomesenchymal cells close to the acellular zone enlarge and differentiate into
preodontoblasts and then odontoblasts. They change shape from ovoid to columnar.
The amount of cytoplasm increases to accommodate the increasing number of cell
organelles such as the Golgi apparatus, ribosomes, mitochondria and the rough
endoplasmic reticulum.
The odontoblasts increase in size and occupy the acellular zone, which is thus
eliminated. The nuclei of the newly differentiated cells are away from the IEE.
Formation of mantle dentin:
Once differentiation of the odontoblasts is complete, the organic matrix of dentin is
laid down.
The appearance of distinctly large-diameter type III collagen fibres (0.1–0.2 mm)
known as von Korff’s fibres is the first sign of dentin formation. These fibres originate
deep among the odontoblasts. They extend towards the IEE and are seen in the
structure-less ground substance below the epithelium.
The odontoblasts produce type I collagen fibres as they increase in size, which get
oriented parallel to the future DEJ. Thus, a layer of mantle predentin is formed.
As the deposition of collagen happens:
The odontoblasts adjacent to the ameloblasts extend processes into the extracellular
matrix. Some of these processes are termed enamel spindle when they lie between
the cells of the IEE and cross the DEJ.
The odontoblasts then give off matrix vesicles which are small membrane bounded
vesicles, which lie near the basal lamina.
The odontoblasts start moving backwards towards the pulp and develops a cellular
process called the Tomes’ fibre, which is a odontoblastic process found within the
dentinal tubule.
The mineral phase is initiated within the matrix vesicles. The crystals within the
vesicles grow. Once the vesicles rupture, the crystals are spread in the matrix which
later fuse to form a layer of continuous mineralized matrix.
Mineralization lags the deposition of organic matrix.
A layer of organic matrix is always found between the odontoblasts and the
mineralization front called the predentin.
After mineral seeding, the odontoblasts produce the noncollagenous matrix that
regulates mineral deposition.
26. Thus, a 15–20-micron thick layer of mantle dentin is laid down. The circumpulpal
dentin is laid over the primary mantle dentin.
Formation of circumpulpal dentin:
The formation of circumpulpal dentin is similar to that of mantle dentin with the
following exceptions:
The collagen fibres are smaller in diameter (0.05 micron) than in mantle dentin. They
are closely packed and are perpendicular to the DEJ.
The ground substance is exclusively laid down by the odontoblasts (in mantle dentin,
part of the ground substance is incorporated from the dental papilla).
Mineralization does not involve matrix vesicles as it spreads from the preexisting
mineralized mantle dentin.
Mineralization of dentin:
The patterns of mineralization depend on the rate of dentin formation.
1. Globular pattern:
Seen in mantle dentin.
The crystals are deposited in discrete areas of the matrix.
These crystals then fuse with each other and form globular masses that further
enlarge to form a calcified mass of tissue.
2. Linear pattern:
27. When the rate of mineralization slows down then the mineralization front appears
uniform. This pattern is referred to as linear.
In the circumpulpal dentin, both globular and linear patterns are seen. It is globular in
the dentin adjacent to the mantle dentin and in the rest of the bulk of circumpulpal
dentin it is a combination of both.
Thus, the dentinal matrix is laid down and mineralized.
Clinical Considerations
Exposure of dentinal tubules:
o Caries, restorative procedures, tooth wear and fractures lead to
exposure of dentinal tubules. One square millimetre of exposed dentin may lead to
damage of 30,000 odontoblasts.
o Treatment: Seal the exposed dentin with a protective nonirritant substance.
Rapid spread of caries:
o Caries might lead to undermining of the enamel when it reaches the DEJ due to the
spaces created at the DEJ by enamel tufts, enamel spindles and the opening and
branching of dentinal tubules at the DEJ.
o The dentinal tubules might act as a passage for the caries causing bacteria.
Dentinal tubules in caries/trauma/erosion:
1.
1. In areas of carious dentin, the tubules might be enlarged due to the microorganisms.
Pain is experienced once the pulp is infected resulting in pulpal inflammation or
pulpitis.
2. Trauma from motor-driven instruments might damage the pulp.
3. Air-driven instruments might cause aspiration of the odontoblasts from the periphery
of the dentinal tubules.
4. The sensitivity of dentin is increased in patients with periodontal problems.
Teeth involved: Maxillary premolars, maxillary molars and incisors.
5. Acidic soft drinks lead to erosion of peritubular dentin and removal of smear plug and
increase in sensitivity. Brushing after consumption of acidic drinks induces smear
layer formation and decreasing sensitivity.
6. Treatment of sensitivity aims at
– blocking the dentinal tubule
– blocking pulpal nerve response
– Lasers such as Nd: Yag and Er:Yag lasers may be used (success rate: 5.2%–
100%).
Radicular dentin:
o The radicular dentin near the pulp and its outer surface is less
permeable than coronal dentin. Thus, it acts as a barrier to bacteria and fluids and
decreases sensitivity.
Smear layer:
o The crystalline debris generated during operative procedures such as cavity
preparation is known as the smear layer. It also contains small dentinal shavings,
28. microorganisms, saliva and sometimes blood and its pigments. This layer interferes
with the bonding of the restorative material.
o Hence, acid etching helps in removal of the smear layer and improves
bonding by creating a rough porous surface.
Dentin Synopsis
Dentin is the mineralized connective tissue that provides the bulk and form to the
tooth. It is covered by enamel in the crown and by cementum in the root. It is laid
down by the odontoblasts. Dentin forms before enamel. It is laid throughout life and
determines the shape of the crown and number and size of the roots.
Dentin is similar to bone and is considered to be vital. It is light yellow in colour,
viscoelastic in nature and subject to slight deformation. It has 65% inorganic
content.
Dentin contains dentinal tubules that run from the pulp dentin border to the CDJ
and the DEJ. The tubules are at right angles to the pulp and the CDJ and DEJ.
Dentinal tubules have primary and secondary curvatures.
The space between the odontoblastic process and the peritubular dentin is called
periodontoblastic space. Dentinal fluid is present in the periodontoblastic space is
called dentinal fluid. Dentinal hypersensitivity can be explained on the basis of the
movement of this fluid.
The dentin that surrounds the dentinal tubules is called the peritubular dentin.
Intertubular dentin is the dentin present in between the tubules or between the zones
of peritubular dentin.
Predentin is a layer of unmineralized dentin located adjacent to the pulp.
Primary dentin is the dentin formed before root completion.
Mantle dentin is the first formed and the outermost layer of primary dentin, which is
found below the DEJ.
Circumpulpal dentin forms the rest of the bulk of primary dentin.
Secondary dentin is the dentin formed after root completion.
Tertiary dentin is the dentin formed due to caries, trauma and damage to the pulp
during cavity preparation.
The incremental lines in dentin are fine striations perpendicular to the dentinal
tubules and are called incremental lines of von Ebner.
Accentuated incremental lines are called contour lines of Owen.
Neonatal line is the accentuated incremental line that separated prenatal dentin and
postnatal dentin.
Sometimes during mineralization when globules fail to fuse, the zones of
hypomineralization between the globules are called interglobular spaces or
interglobular dentin.
The peripheral zone of dentin in the root next to the cementum appears granular.
This is called Tomes’ granular layer.
The empty dentinal tubules with the absence of the odontoblastic process are filled
with air and appear black in transmitted light and white in reflected light. These are
called dead tracts.
The formation of dentin is called dentinogenesis. The organic matrix is initially laid
down, which is later mineralized.