When it comes to the anatomy of the mouth, the tongue and gums come to mind. These components work in unison to perform vital daily functions such as chewing, eating, and talking. But there are other components behind these parts of the mouth that are very important. The taste buds play a big role in food taste and which food you like or which you do not like. The enamel helps teeth stay strong and strong while protecting them from decay. Another component behind the curtain that plays a major role is the cementum.
What Are Cementum
The teeth are held in place by four periodontal tissues inside the jawbone:
- Alveolar bone or jaw bone
- Periodontal ligament fibres
It is a hard tissue devoid of blood vessels and contains tooth minerals that cover the entire surface of the anatomical roots of the tooth. The cementum starts at the neck of the tooth, at the junction of the crown enamel and the root Cément, and extends to the apex (end of the tooth root). The cementum is located at the junction of the fibres that connect the tooth to the surrounding structures. It can be defined as a specialized calcified tissue of mesodermal origin, a different shape of a bone that covers the anatomical root of the tooth. Due to its mediating position, which forms the connecting line between the dentin of the tooth root and the periodontal ligament fibres, the Cément is part of the tooth itself. Still, it is functionally one of the components of the tooth connection.
Physical Characteristics of Cementum
The hardness of the Cément of an adult tooth or a fully grown tooth is less than the hardness of the dentin. The yellow Cément is pale in colour and can be easily distinguished from tooth enamel by being darker but is somewhat lighter than dentin. As a result of stains that occur naturally and as a result of chemical-physical events on it, it has been proven that cementum cells are permeable. Unlike dentin and enamel, where there are noticeable differences between the proteins in these tissues, cementum does not contain any specific proteins. It appears to be substances common to bone and controlled by similar growth factors.
About 45 to 50 percent of the cementum of a permanent tooth is made up of inorganic materials, and 50 to 55 percent of it is made up of organic matter and water. The main constituent of organic matter is collagen. Its inorganic substances mainly contain calcium salts. Its molecular structure is hydroxyapatite, similar to the molecular structure of enamel and dentin of teeth and bones.
The Role of Cementum
One of the most important functions of the cementum is to connect the tooth to the surrounding bony cavity by attaching the main collagen fibres of the periodontal ligament fibres to the root surface. The second role is to compensate for the lost material of the tooth as it grows, which is lost as a result of abrasion of the occlusal surface. Its third task is to allow vertical growth and sliding the tooth towards the mesial with its continuous growth. Its fourth function is to make it possible to continuously rearrange the main fibres of the periodontal membrane.
Types of Cementum
Structurally, cementum can be divided into acellular and cellular. However, there is no functional difference between the two.
Acellular Cément forms before cellular Cément, and in fact, a large part of it is formed before the tooth reaches the occlusal surface. This part is more calcified, and Sharpe fibres are the most important ingredient. Cellular dentin cementum covers the root from the collar line to the end of the root but is often absent in the upper third of the root. In this part, the Cément may be completely cellular. The cellular It is thinner (20 to 50 microns) at the collar line of the tooth and thicker than the other at the root tip (150 to 200 microns). This cementum does not contain any cells; the apical border of the pulp cavity (the end hole in the root apex where the arteries and nerves enter the tooth) is surrounded by the cementum. In some teeth, the cementum extends slightly to the inner wall of the dentin, forming a liner for the root canal.
This forms after the cellular Cément and after the tooth reach the occlusal surface. This type of Cément, which covers the apical third of the tooth root, contains cementocytes, is less calcified, and covers a small part of the tooth.
The Clinical Significance
Cementum is more resistant to decay than bone, making orthodontic treatment possible. When a tooth is moved using an orthodontic appliance, the bone is absorbed from the opposite side under pressure, and a new bone is formed in the area under pressure. At the point where the tooth moves, the pressure on the bone and cementum is equal. In addition, as the pressure decreases, this tissue repairs itself, and the connective tissue around the tooth remains intact. Bone and Cément uptake can be predicted. However, in careful orthodontic treatment, it will usually be local and small if Cément uptake occurs. If the analysis and uptake of cementum are high, it could indicate a systemic disorder (possibly a endocrine system disorder).
Severe lateral pressure can compress the periodontal connective tissue between the bone and the Cément, causing bleeding, blood clots, and tissue death. Repair may be performed after absorption and degeneration of damaged tissues associated with bone resorption. After stopping the absorption of cementum, the damage heals spontaneously, which occurs with the formation of cellular or cellular cementum or both. Dental dentin may also be absorbed following severe absorption of cementum.
If the tooth is damaged, small or large parts of the Cément may separate from the dentin. This rupture most often occurs at the point where the cementum joins the dentin but may also be at the cementum or dentin. Transverse root canals can heal by forming new cementum and reconnecting the detached parts.
If the Cément does not cover the cervical part of the tooth root, after gingival resorption, the very sensitive dentin remains uncovered in the neck of the tooth. Therefore, with age and gradually, more cementum remains uncovered, and brushing also gradually wears out. Eventually, the tooth becomes sensitive to temperature, chemicals, and mechanical stimuli.