Dentin Structure and Composition - Dentin consists of microscopic channels called dentinal tubules. - Dentin contains odontoblast processes and dentinal fluid. - Dentin has branching canalicular systems of different sizes. - Dentin is composed of 70-72% inorganic materials, mainly hydroxyapatite. - It contains 20% organic materials, primarily collagen type 1. - Dentin also contains dentin-specific proteins and ground substance. - Water makes up 8-10% of dentin. - Dentin is porous and yellow-hued.

Dentin Properties and Functions - Dentin is softer than enamel but provides support for it. - It decays more rapidly than enamel if not properly treated. - Dentin has a degree of permeability, which can increase pain sensation and tooth decay. - Dentin has elastic properties, preventing enamel fracturing. - Changes in dentinal fluid contribute to dentinal hypersensitivity.

Dentin Types - Dentin is classified into three types: primary, secondary, and tertiary. - Secondary dentin is formed after root formation is complete. - Tertiary dentin develops as a result of a stimulus, such as carious attack or wear.

Dentinogenesis - Dentinogenesis is the process of dentin formation in teeth. - It involves the differentiation and maturation of odontoblasts, which are responsible for producing dentin. - Dentinogenesis is regulated by various growth factors and signaling molecules. - The mineralization of dentin occurs through the deposition of hydroxyapatite crystals. - Dentinogenesis is essential for tooth development and repair.

Dentin Defects and Conditions - Dentinal sclerosis is a change in the structure of teeth characterised by calcification of dentinal tubules. - Dentinal sclerosis affects primary dentin. - Dentinogenesis imperfecta is a genetic disorder that affects the development of dentin. - It is characterised by the abnormal formation of dentin, resulting in weak and discolored teeth. - Odontoblasts are specialised cells found in the pulp of teeth. - They are responsible for the formation of dentin and the maintenance of tooth vitality. - Tooth development begins during embryogenesis and continues throughout childhood and adolescence. - Tooth development is regulated by a complex interplay of signaling pathways and genetic factors. - Dentin is a mineralised tissue that forms the bulk of the tooth structure. - The dentin substrate provides mechanical support to the tooth and helps in transmitting sensory stimuli.