The tooth consists of a protruding part called the crown and a part immersed in the jawbone called the root.
The outer layer of dental crowns is called enamel, and the outer layer covering the roots is called cementum.
The middle layer is called dentine.
The inner layer is the dental pulp.
Dental enamel is the hardest substance in the human body, as mineral compounds constitute about 96% of its composition, and the rest is some organic materials and water. Hydroxylapatite is the main component of dental enamel and has the chemical formula: (Ca5(PO4)3(OH).
The dentin constitutes the basic mass of the tooth, and the dentin is characterized by its yellowish-brown color, and it is sensitive, meaning that its exposure to the oral medium may cause painful symptoms that vary in intensity according to the nature and intensity of the stimulus.
The dental pulp, or the vascular network: The dental pulp is located inside the so-called pulp chamber. The blood vessels and nerve fibers enter from the root foramen and reach this chamber through the root canals of the teeth, called the root canals.
The line where the enamel meets the dental cementum is called the cementoenamel junction.
On the periphery of the pulp chamber are cells called odontoblasts. These cells have cellular extensions called tubules that communicate the sensation of heat, cold, and other sensory stimuli to nerve endings. These channels extend near the amelo-dentino junction. .
Dental cementum forms a casing around the root of the tooth that connects the tooth to the surrounding alveolar bone. It is sheathed with connective fibers called Charpy’s fibers coming from the surrounding bone. The periodontal ligament is assigned the task of attaching the tooth to the surrounding bone in a flexible way that enables it to dampen the occlusal efforts resulting from the masticatory activity of the tooth.[8][9]
Types of teeth
justice
Lower jaw teeth and their types from front to back: two incisors, a canine, two premolar, three molars (the last of which is the wisdom tooth)
Teeth in humans (as in other mammals) take the following forms:
Incisors: double, quadruple
fangs
Premolars or molars
molars (also known as molars or molars)
