The whole body is covered with teeth. The most terrible diseases that disfigure people. Rare tumor in baby's brain turns out to be a tooth
Dentistry
Human teeth
Tooth consists predominantly of dentin with a cavity, covered on the outside with enamel and cement. The tooth has a characteristic shape and structure, occupies a certain position in the dentition, is built from special tissues, has its own nervous apparatus, blood and lymphatic vessels. Normally, a person has from 28 to 32 teeth. The absence of third molars, called “wisdom teeth”) is the norm, and the 3rd molars themselves are already considered an atavism by an increasing number of scientists, but this is currently a controversial issue.
Inside the tooth there is loose connective tissue riddled with nerves and blood vessels (pulp). There are primary and permanent teeth - temporary and permanent dentition. In the temporary dentition there are 8 incisors, 4 canines and 8 molars - a total of 20 teeth. The permanent dentition consists of 8 incisors, 4 canines, 8 premolars and 8-12 molars. In children, baby teeth begin to erupt at the age of 3 months. During the period from 6 to 13 years, baby teeth are gradually replaced by permanent teeth.
In rare cases, additional, supernumerary teeth (both primary and permanent) are observed.
Tooth structure
Dental anatomy is a branch of anatomy that deals with the structure of teeth. The development, appearance, and classification of teeth are the subject of this section, but the bite or contact of teeth is not. Dental anatomy can be considered a taxonomic science as it deals with the classification of teeth, their structure and naming. This information is then put into practice by dentists during treatment.
The tooth is located in the alveolar process of the upper jaw or in the alveolar part of the lower jaw, consists of a number of hard tissues (such as tooth enamel, dentin, dental cement) and soft tissues (dental pulp). Anatomically, there is a distinction between the crown of the tooth (the part of the tooth protruding above the gum), the root of the tooth (the part of the tooth located deep in the alveolus, covered with gum) and the neck of the tooth - there is a distinction between clinical and anatomical necks: the clinical one corresponds to the edge of the gum, and the anatomical one is the place of transition of enamel into cement, which means that the anatomical neck is the actual transition point between the crown and the root. It is noteworthy that the clinical neck shifts with age towards the root apex (apex) (since gum atrophy occurs with age), and the anatomical one - in the opposite direction (since with age the enamel becomes thinner, and in the neck area it can completely wear out due to in the neck area its thickness is much less). Inside the tooth there is a cavity, which consists of the so-called pulp chamber and the root canal of the tooth. Through a special (apical) opening located at the apex of the root, arteries enter the tooth, which deliver all the necessary substances, veins, lymphatic vessels, which ensure the outflow of excess fluid and are involved in local defense mechanisms, as well as nerves that innervate the tooth.
Embryology
Orthopantomogram of teeth
Dental development in the human embryo begins at approximately 7 weeks. In the area of the future alveolar processes, a thickening of the epithelium occurs, which begins to grow in the form of an arcuate plate into the mesenchyme. Next, this plate is divided into anterior and posterior, in which the rudiments of milk teeth are formed. The tooth germs gradually separate from the surrounding tissues, and then the components of the tooth appear in them in such a way that epithelial cells give rise to enamel, dentin and pulp are formed from mesenchymal tissue, and cement and root membrane develop from the surrounding mesenchyme.
Tooth regeneration
X-ray image (from left to right) of the third, second and first molars in various stages of development
Human teeth do not regenerate, while in some animals, such as sharks, they are constantly renewed throughout life.
A recent study led by G. Fraser from the University of Sheffield examined the influence of various genes on the formation of dental lamina in humans and sharks (where teeth grow continuously throughout life). The team was able to identify a clear set of genes responsible for tooth differentiation and growth. It turned out that these genes in humans and sharks are largely identical, but in humans, after the formation of molars, for unknown reasons, the plate is lost. Scientists believe that discovering the genes responsible for tooth growth will serve as the first step in finding the possibility of their regeneration.
Biochemistry of teeth
Tooth structure
Teeth (lat. dentes) are organs that are located in the alveolar processes of the upper and lower jaws and perform the function of primary mechanical processing of food. The jaws of an adult human contain 32 permanent teeth. In their structure, dental tissues are close to bone tissue; the main structural and functional components of the tooth are derivatives of connective tissue.
In each tooth, there is a tooth crown (corona dentis), which protrudes freely into the oral cavity, a tooth neck covered with gums, and a tooth root (radix dentis) fixed in the bone tissue of the alveoli, which ends at an apex (apex radicis dentis).
Comparative characteristics of biochemical
composition of dental tissues.
Tartar.
The tooth is made up of three balls of calcified tissue: enamel, dentin and cementum. The tooth cavity is filled with pulp. The pulp is surrounded by dentin, the main calcified tissue. On the protruding part of the tooth, dentin is covered with enamel. The roots of the teeth, immersed in the jaw, are covered with cement.
The roots of the teeth, which are immersed in the alveolar sockets of the upper and lower jaws, are covered with periodontium, which is a specialized fibrous connective tissue that holds the teeth in the alveoli. The main periodontal tissue consists of periodontal ligaments (ligaments), which connect cement to the bone matrix of the alveoli. From a biochemical point of view, the basis of periodontal ligaments is type I collagen with some type III collagen. Unlike other ligaments of the human body, the ligamentous apparatus that forms the periodontium is highly vascularized. The thickness of the periodontal ligaments, which is approximately 0.2 mm in an adult, decreases in old age.
These components of the tooth differ in their functional purposes and, accordingly, in their biochemical composition, as well as in their metabolic characteristics. The main components of fabrics are water, organic compounds, inorganic compounds and mineral components, the content of which can be given in the following tablets:
(% wet weight of fabric component):
NECROSIS OF TEETH
| Compound teeth | Enamel | Dentine | Pulp | Cement |
|---|---|---|---|---|
| Water | 2,3 | 13,2 | 30-40 | 36 |
| Organic compounds | 1,7 | 17,5 | 40 | 21 |
| Inorganic compounds | 96 | 69 | 20-30 | 42 |
Biochemical composition of human dental tissues
(% dry weight of fabric component):
Remineralization of teeth.
| Ca | 36,1 | 35,3 | 35,5 | 30 |
|---|---|---|---|---|
| Mg | 0,5 | 1,2 | 0,9 | 0,8 |
| Na | 0,2 | 0,2 | 1,1 | 0,2 |
| K | 0,3 | 0,1 | 0,1 | 0,1 |
| P | 17,3 | 17,1 | 17,0 | 25,0 |
| F | 0,03 | 0,02 | 0,02 | 0,01 |
Organic components of the tooth
Leave your teeth cleaning to professionals.
The organic components of the tooth are proteins, carbohydrates, lipids, nucleic acids, vitamins, enzymes, hormones, and organic acids.
The basis of the organic compounds of the tooth, of course, are proteins, which are divided into soluble and insoluble.
Soluble proteins of tooth tissue:
Named tooth decay
caries, begin by dissolving
minerals in the tooth.
albumins, globulins, glycoproteins, proteoglycans, enzymes, phosphoproteins. Soluble (non-collagenous) proteins are characterized by high metabolic activity and perform enzymatic (catalytic), protective, transport and a number of other functions. The highest content of albumins and globulins is in the pulp. The pulp is rich in enzymes of glycolysis, the tricarboxylic acid cycle, the respiratory chain, the pentose phosphate pathway for the breakdown of carbohydrates, the biosynthesis of protein and nucleic acids.
Soluble enzyme proteins include two important pulp enzymes - alkaline and acid phosphatases, which are directly involved in the mineral metabolism of tooth tissue.
It manifests itself and is characterized by inflammation of soft tissues and mucous membranes.
Biochemical characteristics of individual
tissue components of the tooth
Enamel
Enamel is the hardest tissue of the human body,
95% composed of minerals.
the hardest mineralized tissue that is placed on top of dentin and externally covers the crown of the tooth. Enamel makes up 20-25% of dental tissue, the thickness of its ball is maximum in the area of the chewing apexes, where it reaches 2.3-3.5 mm, and on the lateral surfaces - 1.0-1.3 mm.
The high hardness of enamel is determined by the high level of mineralization of the tissue. Enamel contains 96% minerals, 1.2% organic compounds and 2.3% water. Part of the water is in bound form, forming the hydration shell of the crystals, and part (in the form of free water) fills the microspaces.
The main structural component of enamel are enamel prisms with a diameter of 4-6 microns, the total number of which ranges from 5 to 12 million depending on the size of the tooth. Enamel prisms consist of packed crystals, often hydroxyapatite Ca8 H2 (PO4)6 × 5H2 O. Other types of apatite are represented insignificantly: hydroxyapatite crystals in mature enamel are approximately 10 times larger than crystals in dentin, cementum and bone tissue.
The mineral content of enamel contains calcium 37% and phosphorus 17%. The properties of enamel largely depend on the ratio of calcium and phosphorus, which changes with age and depends on a number of factors. In the enamel of adult teeth, the Ca/P ratio is 1.67. In children's enamel this ratio is lower. This indicator also decreases with demineralization of the enamel.
Dentien
These tartar build-ups cause the surfaces of the gums to recede and the soft dentinal material that covers the roots of the teeth begins to break down.
mineralized, cell-free, avascular tissue of the tooth, which forms the bulk of its mass and in structure takes an intermediate position between bone tissue and enamel. It is harder than bone and cement, but 4-5 times softer than enamel. Mature dentin contains 69% inorganic substances, 18% organic and 13% water (which is 10 and 5 times more than enamel, respectively).
Dentin is built from mineralized intercellular substance, pierced by numerous dentin canals. The organic dentin matrix makes up about 20% of the total mass and is close in composition to the organic matrix of bone tissue. The mineral basis of dentin is made up of apatite crystals, which are deposited in the form of grains and spherical formations - calcospherites. Crystals are deposited between collagen fibrils, on their surface and inside the fibrils themselves.
Dental pulp
It is a highly vascularized and innervated specialized fibrous connective tissue that fills the pulp chamber of the crown and root canal. It consists of cells (odontoblasts, fibroblasts, microphages, dendritic cells, lymphocytes, mast cells) and intercellular substance, and also contains fibrous structures.
The function of the cellular elements of the pulp - odontoblasts and fibroblasts - is the formation of the main intercellular substance and the synthesis of collagen fibrils. Therefore, cells have a powerful protein-synthesizing apparatus and synthesize large amounts of collagen, proteoglycans, glycoproteins and other water-soluble proteins, in particular albumins, globulins, and enzymes. High activity of enzymes of carbohydrate metabolism, the tricarboxylic acid cycle, respiratory enzymes, alkaline and acid phosphatase, etc. was found in the dental pulp. The activity of enzymes of the pentose phosphate pathway is especially high during the period of active production of dentin by odontoblasts.
The dental pulp performs important plastic functions, taking part in the formation of dentin and providing trophism to the dentin of the crown and root of the tooth. In addition, due to the presence of a large number of nerve endings in the pulp, the pulp ensures the transmission of the necessary sensory information to the central nervous system, which explains the very high pain sensitivity of the internal tissues of the tooth to pathological stimuli.
Processes of mineralization-demineralization -
the basis of mineral metabolism of dental tissues.
The basis of the mineral metabolism of dental tissues is made up of three mutually determining processes that constantly occur in dental tissues: mineralization, demineralization and remineralization.
Mineralization of the tooth
This is the process of forming an organic base, primarily collagen, and saturating it with calcium salts. Mineralization is especially intense during the period of teething and the formation of hard dental tissues. The tooth erupts with non-mineralized enamel!!! There are two main stages of mineralization.
The first stage is the formation of an organic, protein matrix. The pulp plays a conducting role at this stage. In pulp cells, odontoblasts and fibroblasts, collagen fibrils, non-collagenous proteins proteoglycans (osteocalcin) and glycosaminoglycans are synthesized and released into the cellular matrix. Collagen, proteoglycans and glycosaminoglycans form the surface on which crystal lattice formation will occur. In this process, proteoglycans play the role of collagen plasticizers, that is, they increase its ability to swell and increase its total surface. Under the action of lysosomal enzymes, which are released into the matrix, heteropolysaccharides of proteoglycans are broken down to form highly reactive anions that are able to bind ions Ca²+ and other cations.
The second stage is calcification, the deposition of apatites on the matrix. Oriented crystal growth begins at crystallization points or nucleation points - in areas with a high concentration of calcium and phosphate ions. Locally, a high concentration of these ions is ensured by the ability of all components of the organic matrix to bind calcium and phosphates. In particular: in collagen, the hydroxyl groups of serine, threonine, tyrosine, hydroxyproline and hydroxylysine residues bind phosphate ions; free carboxyl groups of dicarboxylic acid residues in collagen, proteoglycans and glycoproteins bind ions Ca²+ ; residues of g-carboxyglutamic acid of the calcium-binding protein - osteocalcin (calprotein) bind ions Ca²+ . Calcium and phosphate ions concentrate around the crystallization nuclei and form the first microcrystals.
Toothpastes
An increase in the concentration of the dispersed phase to the limiting possible value in aggregation-resistant suspensions leads to the formation of highly concentrated suspensions, which are called pastes. Like output suspensions, pastes are aggregatively stable in the presence of a sufficient amount of strong stabilizers, when the particles of the dispersed phase in them are well solvated and separated by thin films of liquid, which serves as a disperse medium. Due to the small part of the dispersed medium in the paste, all of it is practically bound in solvation films that separate the particles. The absence of a free rare vase adds high viscosity and some mechanical strength to such systems. Due to numerous contacts between particles in pastes, spatial structures can form and thixotropy phenomena can be observed.
The most widely used are toothpastes. A little history. Our ancestors cleaned their teeth with crushed glass, charcoal, and ash. Three centuries ago in Europe they started brushing their teeth with salt, then switched to chalk. Since the beginning of the 19th century, chalk-based tooth powders have been widely used in Western Europe and Russia. Since the end of the 19th century, the world began to switch to toothpastes in tubes. In the 20s of the last century, the search began for a replacement for chalk as a dental abrasive. These searches led to the use of silicon dioxide, which is well compatible with fluorine compounds and other active components that have controlled abrasiveness, which allows the creation of pastes with a wide range of properties. And finally, we obtained the optimal pH value = 7.
But even now, some pastes use chalk as an abrasive with a reduced content of aluminum (Al), iron (Fe) and trace elements, but with increased abrasion ability.
In addition, some pastes include extracts of plantain, nettle and tree, vitamins, ascorbic acid, pantothenic acid, carotenoids, chlorophyll, flavonoids.
All pastes are divided into two large groups - hygienic and therapeutic and prophylactic. The first group is intended only for cleansing crops from food deposits, as well as giving the mouth a pleasant smell. Such toothpastes are usually recommended for those who have healthy teeth and no cause for dental disease, and who regularly visit the dentist.
The bulk of toothpastes belong to the second group - therapeutic and prophylactic. Their purpose, in addition to cleansing the surface of the teeth, is to suppress the microflora that causes caries and periodontitis, remineralize tooth enamel, reduce inflammation in periodontal diseases, and whiten tooth enamel.
There are anti-caries toothpastes that contain calcium and fluoride-containing toothpastes, as well as toothpastes with anti-inflammatory effects and whitening pastes.
The anti-carious effect is ensured by the presence of fluorides (sodium fluoride, tin fluoride, amino fluoride, monofluorophosphate) and calcium (calcium glycerophosphate) in toothpaste. The anti-inflammatory effect is usually achieved by adding herbal extracts (mint, shavliya, chamomile, etc.) to toothpaste. Whitening pastes contain sodium bicarbonate, or soda, which has a pronounced abrasive effect. It is not recommended to use such pastes every day due to the risk of damage to the enamel. It is usually recommended to use them 1-2 times a week.
There is also a list of substances that are included in toothpastes. They perform auxiliary functions. Thus, detergents, among which the most common is sodium lauryl sulfate, which is also used in the manufacture of shampoos, cause foaming. Abrasive substances, among which the most popular are aluminum hydroxide, chalk, sodium bicarbonate, and silicon dioxide, clean the surface of teeth from plaque and microbes. Acidity stabilizers are designed to increase the pH in the oral cavity, because an acidic environment promotes the development of caries. Other substances that make up toothpaste improve its consumer properties - thickeners, dyes, solutions, etc.
Main components of toothpastes:
1) abrasives;
2) detergents: previously they used soap, now sodium lauryl sulfate, sodium lauryl sarcosinate: the foaminess of toothpaste and the surface of touching substances depend on this component;
3) glycerin, polyethylene glycol - provide elasticity and viscosity of pastes;
4) binding substances (hydrocolloids, sodium alginate, starch, thick juices, dextrin, pectin, etc.);
5) various additives (plant extracts, salts, etc.).
In clinical practice in developed countries, synthetic hydroxyapatite is used as a bone tissue substitute. Reducing the sensitivity of teeth, protecting the surface areas of the enamel, hydroxyapatite has anti-inflammatory properties, adsorbing microbial bodies, and forestalls the development of purulent-inflammatory processes. In addition, hydroxyapatite stimulates the growth of bone tissue (osteogenesis), provides microprocessing of bone and dental tissues with calcium and phosphorus ions, “bricking” microcracks in them. It has high biocompatibility and is devoid of immunogenic and allergic activity. Synthetic hydroxyapatite has very small particle sizes (0.05 microns). Such parameters significantly increase its biological activity, since the sizes of its molecules are comparable to the sizes of protein macromolecules.
An effective additive is triclosan, which acts against a wide range of bacteria, fungi, yeast and viruses. The antimicrobial activity of triclosan is based on the disruption in its presence of the activity of the cytoplasmic membrane and the leakage of cellular components of low molecular weight.
Toothpastes also contain urea with components such as xylitol and sodium bicarbonate, which are therapeutic and prophylactic additives. This mixture neutralizes the effects of acids, mainly lactic acid, which is produced by plaque bacteria by fermenting carbohydrates found in foods and drinks. Bacteria produce, although in much smaller quantities, other acids, such as acetic, propionic and butyric. The formation of acids leads to a decrease in the pH of dental plaque: at a pH less than 5.5, the process of demineralization of tooth enamel begins. The longer the duration of such demineralization, the higher the risk of caries. Penetrating into dental plaque, urea neutralizes acids, being broken down by bacteria in the presence of the enzyme urease into CO2 And NH3 ; formed NH3 has an alkaline reaction and neutralizes acids.
General functions of teeth
Mechanical food processing
Food retention
Participation in the formation of speech sounds
Aesthetic - are an important part of the mouth
Types and functions of teeth
Based on their main function, teeth are divided into 4 types:
Incisors are the front teeth that emerge first in children and are used for grasping and cutting food.
Fangs are cone-shaped teeth that are used for tearing and holding food.
Premolars (small molars)
Molars (large molars) - the back teeth, which are used for grinding food, often have three roots on the upper jaw and two on the lower jaw
Tooth development (Histology)
Cap stage
Beginning of the bell stage
Acid phosphatase
has the opposite, demineralizing effect. It belongs to lysosomal acid hydrolases, which enhance the dissolution (absorption) of both mineral and organic structures of tooth tissue. Partial resorption of tooth tissue is a normal physiological process, but it especially increases during pathological processes.
An important group of soluble proteins are glycoproteins. Glycoproteins are protein-carbohydrate complexes that contain from 3-5 to several hundred monosaccharide residues and can form from 1 to 10-15 oligosaccharide chains. Typically, the content of carbohydrate components in a glycoprotein molecule rarely exceeds 30% of the mass of the entire molecule. The composition of glycoproteins of dental tissues includes: glucose, galactose, monose, fructose, N-acetylglucose, N-acetylneuraminic (sialic) acids, which do not have a regular rotation of disaccharide units. Sialic acids are a specific component of a group of glycoproteins - sialoproteins, the content of which is especially high in dentin.
One of the most important glycoproteins in teeth, as well as in bone tissue, is fibronectin. Fibronectin is synthesized by cells and secreted into the intercellular space. It has the properties of a “sticky” protein. By binding to the carbohydrate groups of sialoglycolipids on the surface of plasma membranes, it ensures the interaction of cells with each other and the components of the intercellular matrix. By interacting with collagen fibrils, fibronectin ensures the formation of the pericellular matrix. For each compound with which it binds, fibronectin has its own specific binding center, so to speak.
Insoluble proteins of dental tissues
are often represented by two proteins - collagen and a specific structural protein of enamel, which does not dissolve in EDTA (ethylenediaminetetraacetic acid) and hydrochloric acid. Due to its high resistance, this enamel protein acts as the skeleton of the entire molecular architecture of enamel, forming a frame - a “crown” on the surface of the tooth.
Collagen: structural features,
role in tooth mineralization.
Collagen is the main fibrillar protein of connective tissue and the main insoluble protein in dental tissues. As stated above, its content makes up about a third of all proteins in the body. The most collagen is found in tendons, ligaments, skin and tooth tissue.
The special role of collagen in the functioning of the human dental system is due to the fact that the teeth in the sockets of the alveolar processes are fixed by periodontal ligaments, which are formed precisely by collagen fibers. With scurvy (scurvy), which occurs due to a lack of vitamin C (L-ascorbic acid) in the diet, disturbances in the biosynthesis and structure of collagen occur, which reduces the biomechanical properties of the periodontal ligament and other periodontal tissues, and, as a result, they become loose and fall out. teeth. In addition, the blood vessels become brittle and multiple pinpoint hemorrhages (petechiae) occur. Actually, bleeding gums is an early manifestation of scurvy, and disturbances in the structure and functions of collagen are the root cause of the development of pathological processes in connective, bone, muscle and other tissues.
Carbohydrates of organic tooth matrix
composition of dental tissues.
Periodontal disease is a systemic lesion of the periodontal tissue.
The organic matrix of the tooth includes monosaccharides glucose, galactose, fructose, manose, xylose and the disaccharide sucrose. The functionally important carbohydrate components of the organic matrix are homo- and heteropolysaccharides: glycogen, glycosaminoglycans and their complexes with proteins: proteoglycans and glycoproteins.
Homopolysaccharide glycogen
performs three main functions in dental tissues. Firstly, it is the main source of energy for the processes of formation of crystallization nuclei and is localized in places where crystallization centers are formed. The glycogen content in tissue is directly proportional to the intensity of mineralization processes, since a characteristic feature of dental tissue is the prevalence of anaerobic processes of energy formation - glycogenolysis and glycolysis. Even with sufficient oxygen supply, 80% of the energy needs of the tooth are covered by anaerobic glycolysis and, accordingly, by the breakdown of glycogen.
Secondly, glycogen is a source of phosphorus esters of glucose - substrates of alkaline phosphatase, an enzyme that splits off phosphoric acid ions (phosphate ions) from glucose monophosphates and transports them on a protein matrix, that is, it initiates the formation of an inorganic tooth matrix. In addition, glucogen is also a source of glucose, which is converted into N-acetylglucosamine, N-acetylgalactosamine, glucorunic acid and other derivatives that take part in the synthesis of heteropolysaccharides - active components and regulators of mineral metabolism in dental tissues.
Heteropolysaccharides of the organic tooth matrix
represented by glycosaminoglycans: hyaluronic acid and chondroitin-6-sulfate. A large number of these glycosaminoglycans are in a protein-bound state, forming complexes of varying degrees of complexity, which differ significantly in the composition of protein and polysaccharides, that is, glycoproteins (the complex contains much more protein component) and proteoglycans, which contain 5-10% protein and 90- 95% polysaccharides.
Proteoglycans regulate the processes of aggregation (growth and orientation) of collagen fibrils, and also stabilize the structure of collagen fibers. Due to their high hydrophilicity, proteoglycans play the role of plasticizers of the collagen network, increasing its ability to stretch and swell. The presence of a high number of acidic residues (ionized carboxyl and sulfate groups) in glycosaminoglycan molecules determines the polyanionic nature of proteoglycans, their high ability to bind cations and thereby take part in the formation of mineralization nuclei (centers).
An important component of dental tissue is citrate (citric acid). The citrate content in dentin and enamel is up to 1%. Citrate, due to its high complexation ability, binds ions Ca²+ , forming a soluble transport form of calcium. In addition to tooth tissue, citrate provides optimal calcium content in blood serum and saliva, thereby regulating the rate of mineralization and demineralization processes.
Nucleic acids
Contained mainly in the pulp of the tooth. A significant increase in the content of nucleic acids, in particular RNA, is observed in osteoblasts and odontoblasts during the period of mineralization and remineralization of the tooth and is associated with an increase in protein synthesis by these cells.
Characteristics of the mineral matrix of the tooth
The mineral basis of tooth tissues is made up of crystals of various apatites. The main ones are hydroxypatite Ca 10 (PO4 )6 (OH)2 and octalcium phosphate Ca 8 H2 (PO4 )6 (OH)2× 5H 2 O . Other types of apatites that are present in tooth tissues are given in the following table:
| Apatite | Molecular formula |
|---|---|
| Hydroxyapatite | Ca10(PO4)6(OH)2 |
| Octalcium phosphate | Ca 8 H2 (PO4 )6 (OH)2× 5H 2 O |
| Carbonate apatite | Ca 10(PO4)6 CO 3 or Ca 10(PO4)5 CO 3(OH) 2 |
| Chloride apatite | Ca 10(PO4)6 Cl |
| Strontium apatite | SrCa 9(PO4)6 (OH) 2 |
| Fluorapatite | Ca 10(PO4)6 F 2 |
Certain types of dental apatites differ in chemical and physical properties - strength, ability to dissolve (destroy) under the influence of organic acids, and their ratio in tooth tissues is determined by the nature of nutrition, the body's supply of microelements, etc. Among all apatites, fluorapatite has the highest resistance. The formation of fluorapatite increases the strength of enamel, reduces its permeability and increases resistance to cariogenic factors. Fluorapatite is 10 times less soluble in acids than hydroxyapatite. With a sufficient amount of fluoride in a person's diet, the number of cases of caries is significantly reduced.
Oral hygiene
Main article: Teeth cleaning
Hygiene oral cavity is a means of preventing dental caries, gingivitis, periodontal disease, bad breath (halitosis) and other dental diseases. It includes both daily cleaning and professional cleaning performed by a dentist.
This procedure involves removing tartar (mineralized plaque) that can build up even with thorough brushing and flossing.
To care for a child's first teeth, it is recommended to use special dental wipes.
Personal oral hygiene items: toothbrushes, dental floss (floss), tongue scraper.
Hygiene products: toothpastes, gels, rinses.
Enamel is not capable of regeneration. It contains an organic matrix on which inorganic apatites seem to be attached. If apatites are destroyed, then with an increased supply of minerals they can be restored, but if the organic matrix is destroyed, then restoration is no longer possible.
When teething, the crown of the tooth is covered on top with a cuticle, which soon wears out without accomplishing anything useful.
The cuticle is replaced by pellicle - dental plaque consisting mainly of salivary proteins that have a charge opposite to the enamel.
The pellicle performs a barrier (passage of mineral components) and cumulative (accumulation and gradual release of calcium to the enamel) function.
The role of the pellicle in the formation of dental plaque (helps to attach) with the subsequent occurrence of caries is noted.
See also
Animal teeth
Dental formula
Tooth Fairy
Thirty Three (film)
Dental prosthetics(8, 9, 10, 11) are divided depending on the functions they perform: incisors (11), canines (10), small molars (9), large molars (8). A person’s teeth appear twice in life, the first are milk teeth, appearing in infants from six months to two years, there are only 20 of them. The second time teeth appear in children at the age of 6-7 years, and wisdom teeth after 20 years, there are 32 of them in total.
The elastic should be tight enough so that the flashlight does not come off spontaneously from the recoil of a shot or when pulled out of the grass.
The described mounting system is in some sense universal - the installation location can be chosen based on personal preferences. On pneumatic valves, the bracket can be secured by winding, clamps, and other methods.
If you make a special cradle, for example on the forearm, then the mount can be installed on it. In this case, to avoid snags, it is better to use “mother” on the gun and cradle. The result will be a universal lighting system, with the ability to quickly rearrange it to the desired “now” place.
The design has been tested in operation and has shown its best performance.
Problem one: germs in the mouth and heart
We have never talked about teeth yet, and it’s a shame, because according to modern ideas, teeth are connected with all internal organs. Even if we brush our teeth in the mornings and evenings, our mouth, to put it mildly, is not sterile: hundreds of species of microbes live in it. Some of them are useful, they protect us from harmful bacteria; others are useless, others can be harmful under certain circumstances. For example, if you have caries, then microbes from a hole in the tooth can enter the bloodstream and, along with the blood, travel from there to all internal organs, including the heart.
Sergei Tsukor (chief physician of the Dial-Dent dental center): For example, there is a hole in a tooth. There are microbes in this hole, if these microbes make their way through the tooth into the bone, a disease occurs in the bone. If microbes from the oral cavity somehow enter the bloodstream, then they can enter the heart through the bloodstream and such a terrible disease can develop - a complication of dental procedures, such as endocarditis. The endocarditis that Sergei is talking about is an inflammation of the inner lining of the heart. Even today - in the era of advanced medicine and antibiotics - this disease can be fatal. Therefore, in 2012, the Journal of the American Dental Association published recommendations for the prevention of infective endocarditis. The doctors who wrote them analyzed thousands of studies and concluded that people susceptible to endocarditis should be given an antibiotic before having their teeth drilled or extracted. However, these surgical interventions on the tooth are not the only risk of developing endocarditis.
Problem two: teeth, neck and headache
Events develop even more interestingly after the tooth is removed. The fact is that teeth are not just a device that helps us chew and speak. 28 teeth or 32 teeth is such a complex system in which each of these 32 elements is connected very closely with 2 surrounding teeth and with two more teeth opposite it. Also, all teeth are connected to the tongue, to the chewing muscles, to the spine, and to all the muscles of the nasopharynx. And as soon as something in this large system is broken in one place, it can lead to problems everywhere.
Sergei Tsukor: Why do dental problems lead to problems with general health and neuralgic problems? For example, some kind of obstruction in the nose, in this case the adenoids. The man stopped breathing through his nose and began breathing through his mouth. In order to breathe through the mouth, he needs to lower his tongue, that is, the tongue goes down the oral cavity and does not press on the palate. As soon as the tongue stops pressing on the palate, pressure from the cheeks begins to predominate, that is, there is no equalized pressure - the cheeks on the outside and the tongue on the inside should be equal in degree of pressure. As soon as the cheeks begin to dominate, the tongue no longer supports the jaw from the inside, crowding of the dentition occurs, and the person begins to swallow differently. As soon as swallowing becomes incorrect, the muscles that are involved in swallowing also work incorrectly - the tongue begins to fit between the teeth, it still does not press on the palate, as soon as the tongue was inserted between the teeth, these teeth remained lower, and the front ones moved upward . Due to this situation, dental problems associated with tooth wear occur. The teeth are no longer functioning properly. As soon as the teeth begin to function incorrectly, a problem arises in the temporal joint. The joint shifts and the disc may take an incorrect position.
Or, for example, if one, or even more so several teeth fall out, the entire system is rebuilt: the neighboring ones tilt towards the hole, the bone at the hole site gradually dissolves, and the gums that surround the teeth recede, exposing the teeth.
But the most important thing is that the tone of the masticatory muscles changes, so the jaw may become distorted over time.
Sergei Tsukor (chief physician of the Dial-Dent dental center): When a person has lost several teeth on one side, the jaw does this because the muscle is being pulled, but there is no support. The jaw will tilt and this will be fixed in muscle tone. A person needs to swallow, when he swallows, he closes his teeth, and thousands of times a day he swallows and a muscle tone occurs in him, which opens his jaw like this.
And the jaw is also not suspended in the air, like each tooth, it is part of the system. It is connected to the head, skull, neck, spine and the whole body. Sometimes nothing too dangerous happens: having lost a tooth, the body adapts to living without it. But it happens that it is not possible to compensate for the loss of teeth and then various symptoms arise: for example, headache, neck pain and a variety of neurological problems.
Sergei Tsukor: Headaches can be associated specifically with the bite, because when the position of the lower jaw relative to the skull is deformed, the muscles pull unevenly. The cranium consists of many bones that are connected by sutures, and as modern medicine has proven (but not everyone agrees with this), that the cranium is not a billiard ball, it is thousands of sutures that are constantly in motion. If you have more pressure on the right than on the left, then the cranium in this place will be more tense, and inside there is a dura mater that is connected to it, and if the right side of the ball is compressed and the left is relaxed, you have tension in the dura mater, which contains the brain. That is, roughly speaking, it pinches some side of the brain!
This is why a variety of neurological problems arise: headaches, visual and hearing impairments, and even problems may appear in areas far from the head, because the dura mater is a single sac that covers the brain and spinal cord all the way to the sacrum.
In this sad situation, the dentist has two options - simple and complex. Simple is suitable when there are no secondary symptoms, you can simply take a tooth and prosthetize it. If a person has a sore or distorted jaw, a headache and a change in posture, then simply inserting missing teeth will not be enough: first you need to correct all these secondary changes, correct the bite and posture, and only then prosthetize the tooth.
Problem three: teeth, snoring and sudden death
Now imagine what happens when a person, for example, loses his back teeth. There are no teeth, but the chewing muscles continue to pull the jaw and eventually they pull it down and back, the bite changes and the jaw begins to put pressure on the neck and throat. But we know that we have a lot of things inside the neck, for example, the carotid arteries, which begin to be slightly pinched by the muscles. The muscles of the neck and pharynx can also compress the trachea. And this happens especially noticeably when a person lies down, relaxes and falls asleep.
Sergei Tsukor:When a person falls asleep and relaxation occurs, the lower jaw falls back even more, almost completely closing the trachea, and the tongue (the root of the tongue) on top, like a cork in a bottle, seals the trachea completely. If the tongue seals it slightly, snoring occurs. If the situation is such that the extreme degree is the absence of teeth, malocclusion and jaw displacement, then this tongue, when relaxed, seals this trachea tightly like a cork in a bottle. The person stops receiving oxygen.
This is a rather scary situation, because such delays can last 10, 20 seconds or even more. As a result, the brain does not receive enough oxygen, the person does not get enough sleep, thinks much worse during the day and sleeps on the move. Even worse, a person with sleep apnea may fall asleep while driving. According to statistics, the culprits in car accidents in many cases are people suffering from sleep disorders. And five of the seven leading causes of sleep apnea are dental problems.
Sergei Tsukor: What does sleep apnea mean? The risk is that a person is constantly being strangled. That is, his risk of having a heart attack or stroke during sleep or in the early morning increases significantly.
There can be only one moral here: dental problems spread to the entire body, and even to a person’s entire life. Don't be lazy to solve them on time. The sooner you correct your bite, get rid of caries, or replace missing teeth, the greater your chances of a long and happy life. To your health!
And don’t forget that many dental problems can be avoided!
PHILIPS affiliate block
Our statistics show that more than 30% of patients brush their teeth for about 1 minute, and no more than 1 time a day. This is certainly not enough. And according to statistics, after 30 years, diseases of the hard tissue of teeth and periodontium occur in 90% of the population. With proper oral hygiene, we can avoid unpleasant consequences and reduce the number of visits to the dentist to a minimum. You need to brush your teeth in segments, paying attention to each segment separately for at least 30 seconds. Regardless of which brush you use, it is necessary to carry out sweeping movements from the gums to the edge of the tooth in order to clean out all food debris in the interdental spaces. Particular attention should be paid to the lingual surface of the lower jaw teeth, where much more plaque accumulates.
If you use a sonic brush, there is a very interesting effect: when you place a toothbrush with toothpaste to the gum edge, a wave movement of liquid with saliva, water and paste occurs in the interdental spaces. that is, roughly speaking, the brush combines the effect of a sonic brush and an irrigator
Toothbrush company PHILIPS has become for me the main product that I now offer to my patients for several reasons: First, the oscillation frequency of the bristles is 200 hertz, which is optimal and not as aggressive as ultrasonic brushes. The second point is very convenient time intervals of 30 seconds, which allow you to control the brushing process in segments and the end of brushing your teeth after 2 minutes. It is also worth noting that the PHILIPS brush has a pressure sensor in the brush head, which allows the patient not to worry about the traumatic nature of brushing teeth. This is a big plus compared to regular mechanical toothbrushes.
We have prepared an interactive map of the structure and a detailed description of all 23 sections of the tooth. Click on the corresponding number and you will receive all the necessary information. Using the diagram, it will be very easy to study all the features of the tooth structure.
The structure of human teeth
Crown
Crown ( lat. corona dentis) - the part of the tooth protruding above the gum. The crown is covered with enamel - hard tissue, 95% consisting of inorganic substances and subject to the most powerful mechanical stress.
There is a cavity in the crown - dentin (hard tissue 2-6 mm thick) comes closer to the surface, then pulp, filling both part of the crown and the root part of the tooth. The pulp contains blood vessels and nerves. Cleaning and removal of dental plaque is carried out specifically from the crowns of teeth.
Tooth neck
Cervix ( lat. collum dentis) the part of the tooth between the crown and root, covered by the gum.
Roots
Root ( lat. radix dentis) part of the tooth located in the dental alveolus.
Fissure
On the chewing surface of the back teeth, between the cusps there are grooves and grooves - fissures. The fissures can be narrow and very deep. The relief of the fissures is individual for each of us, but dental plaque gets stuck in the fissures of everyone.
It is almost impossible to clean the fissures with a toothbrush. Bacteria in the oral cavity, processing plaque, form acid, which dissolves tissue, forming caries. Even good oral hygiene is sometimes not enough. In this regard, it has been successfully used all over the world for 20 years.
Enamel
Tooth enamel (or simply enamel, lat. enamelum) - the outer protective shell of the coronal part.
Enamel is the hardest tissue in the human body, which is explained by the high content of inorganic substances - up to 97%. There is less water in tooth enamel than in other organs, 2-3%.
Hardness reaches 397.6 kg/mm² (250-800 Vickers). The thickness of the enamel layer differs in different areas of the crown part and can reach 2.0 mm, and disappears at the neck of the tooth.
Proper care of tooth enamel is one of the key aspects of human personal hygiene.
Dentine
Dentin (dentinum, LNH; lat. dens, dentis- tooth) is the hard tissue of the tooth, constituting its main part. The coronal part is covered with enamel, the root part of the dentin is covered with cement. Consists of 72% inorganic substances and 28% organic substances. Consists mainly of hydroxyapatite (70% by weight), organic material (20%) and water (10%), permeated with dentinal tubules and collagen fibers.
Serves as the foundation of the tooth and supports tooth enamel. The thickness of the dentin layer ranges from 2 to 6 mm. Dentin hardness reaches 58.9 kgf/mm².
There are peripulpal (internal) and mantle (external) dentin. In peripulpal dentin, collagen fibers are located predominantly condensally and are called Ebner fibers. In mantle dentin, collagen fibers are arranged radially and are called Korff fibers.
Dentin is divided into primary, secondary (replacement) and tertiary (irregular).
Primary dentin is formed during the development of the tooth, before its eruption. Secondary (replacement) dentin is formed throughout a person’s life. It differs from the primary by a slower pace of development, a less systemic arrangement of dentinal tubules, a larger number of erythroglobular spaces, a larger amount of organic substances, higher permeability and less mineralization. Tertiary dentin (irregular) is formed during tooth trauma, preparation, caries and other pathological processes, as a response to external irritation.
Dental pulp
Pulp ( lat. pulpis dentis) - loose fibrous connective tissue that fills the tooth cavity, with a large number of nerve endings, blood and lymphatic vessels.
Along the periphery of the pulp, odontoblasts are located in several layers, the processes of which are located in the dentinal tubules throughout the entire thickness of the dentin, performing a trophic function. The processes of odontoblasts include nerve formations that conduct pain sensations during mechanical, physical and chemical influences on dentin.
Blood circulation and innervation of the pulp are carried out thanks to dental arterioles and venules, the nerve branches of the corresponding arteries and nerves of the jaws. Penetrating into the dental cavity through the apical opening of the root canal, the neurovascular bundle breaks up into smaller branches of capillaries and nerves.
The pulp helps stimulate regenerative processes, which manifest themselves in the formation of replacement dentin during the carious process. In addition, the pulp is a biological barrier that prevents the penetration of microorganisms from the carious cavity through the root canal beyond the tooth into the periodontium.
The nerve formations of the pulp regulate the nutrition of the tooth, as well as the perception of various irritations, including pain. The narrow apical opening and the abundance of vessels and nerve formations contribute to the rapid increase in inflammatory edema in acute pulpitis and compression of the nerve formations by the edema, which causes severe pain.
Tooth cavity
(lat. cavitas dentis) The space inside formed by the cavity of the crown and root canals. This cavity is filled with pulp.
Cavity of the tooth crown
(lat. cavitas coronae) Part of the tooth cavity located under the crown and repeating its internal contours.
Tooth root canals
Root canal ( lat. canalis radicis dentis) - represents the anatomical space inside the tooth root. This natural space within the coronal part of the tooth consists of a pulp chamber, which is connected by one or more main canals, as well as more complex anatomical branches that can connect the root canals to each other or to the surface of the tooth root.
Nerves
(lat. nervae) Neuronal processes passing through the apex of the tooth and filling its pulp. The nerves regulate the nutrition of the tooth and conduct pain impulses.
Arteries
(lat. arteriae) Blood vessels through which blood from the heart flows to all other organs, in this case to the pulp. Arteries nourish dental tissues.
Vienna
(lat. venae) Blood vessels that carry blood from organs back to the heart. The veins enter the canals and penetrate the pulp.
Cement
Cement ( lat. - cementum) - specific bone tissue covering the root and neck of the tooth. Serves to firmly secure the tooth in the bone alveolus. Cement consists of 68-70% inorganic components and 30-32% organic substances.
Cementum is divided into acellular (primary) and cellular (secondary).
Primary cement is adjacent to the dentin and covers the lateral surfaces of the root.
Secondary cement covers the apical third of the root and the bifurcation area of multi-rooted teeth.
Root tips
(lat. apex radicis dentis) The lowest points of the teeth, located on their roots. At the tops there are openings through which nerve and vascular fibers pass.
Apical foramina
(lat. foramen apices dentis) Places of entry of vascular and nerve plexuses into the dental canals. The apical foramina are located at the apex of the tooth roots.
Alveolus (alveolar socket)
(alveolar socket) ( lat. alveolus dentalis) A notch in the jawbone into which the roots enter. The walls of the alveoli form strong bone plates impregnated with mineral salts and organic substances.
Alveolar neurovascular bundle
(lat. aa., vv. et nn alveolares) A plexus of blood vessels and nerve processes passing under the alveolus of the tooth. The alveolar neurovascular bundle is enclosed in an elastic tube.
Periodontium
Periodontium ( lat. Periodontium) - a complex of tissues located in the slit-like space between the cement of the tooth root and the alveolar plate. Its average width is 0.20-0.25 mm. The narrowest section of the periodontium is located in the middle part of the tooth root, and in the apical and marginal sections its width is slightly greater.
The development of periodontal tissue is closely related to embryogenesis and teething. The process begins in parallel with the formation of the root. The growth of periodontal fibers occurs both from the side of the root cement and from the side of the alveolar bone, towards each other. From the very beginning of their development, the fibers have an oblique course and are located at an angle to the tissues of the alveoli and cementum. The final development of the periodontal complex occurs after tooth eruption. At the same time, the periodontal tissues themselves are involved in this process.
It should be noted that, despite the mesodermal origin of the constituent components of the periodontium, the ectodermal epithelial root sheath takes part in its normal formation.
Gingival grooves
(lat. sulcus gingivalis) Gaps that form where the tooth crown meets the gums. The gingival grooves run along the line between the free and attached parts of the gum.
Gum
Gums ( lat. Gingiva) is a mucous membrane covering the alveolar process of the upper jaw and the alveolar part of the lower jaw and covering the teeth in the cervical area. From a clinical and physiological point of view, the gums are divided into interdental (gingival) papilla, marginal gum or gingival margin (free part), alveolar gum (attached part), mobile gum.
Histologically, the gum consists of stratified squamous epithelium and the lamina propria. There are oral epithelium, junctional epithelium, and sulcal epithelium. The epithelium of the interdental papillae and attached gingiva is thicker and can become keratinized. In this layer there are distinguished spinous, granular and horny layers. The basal layer consists of cylindrical cells, the spinous layer consists of polygonal cells, the granular layer consists of flattened cells, and the stratum corneum is represented by several rows of completely keratinized and nucleated cells that are constantly exfoliated.
Mucous papillae
(lat. papilla gingivalis) Fragments of gums located at their elevation in the area between adjacent teeth. The gingival papillae are in contact with the surface of the dental crowns.
Jaws
(lat. maxilla - upper jaw, mandibula - lower jaw) Bony structures that form the basis of the face and the largest bones of the skull. The jaws form the mouth opening and determine the shape of the face.
Dental anatomy is considered one of the most complex components of the human body; many scientific works are devoted to the structure of the oral cavity, but some aspects have not yet been thoroughly studied. For example, why do some people grow wisdom teeth while others don’t? Or why some of us suffer from toothache more often than others. Find more detailed information about individual structural features, possible pathologies and anomalies in the development of teeth on the pages of our website.
Culture
More and more often these days you can hear about new diseases that were previously scary to even imagine.
These terrifying illnesses of very dubious origin frighten us and make us thank our fate for the fact that most of us only suffered from the flu and sore throat.
There are dozens, hundreds of different exotic diseases that not only kill a person, but slowly cripple him. Here is a list of the most terrible diseases that pose a serious danger to people.
Fortunately, this disease disappeared many years ago.
What is known about it is that in the early 19th century, match industry workers were exposed to huge amounts of white phosphorus, a highly toxic substance that ultimately caused terrible jaw pain.
After some time, the jaw cavity filled with pus and simply rotted. From the huge amount of phosphorus that the body received, the jaw even glowed in the dark.
If the bone was not surgically removed, phosphorus continued to destroy the body, eventually leading to the death of the patient.
This disease occurs when the pituitary gland produces too much growth hormone. As a rule, this disease occurs in victims of benign tumors.
Acromegaly is characterized not only by enormous height, but also by a bulging forehead, as well as a large gap between the teeth.
The most famous case of this disease was identified in Andre the Giant. As a result of this disease, his height reached 2.2 meters.
The poor man's weight was 225 kg. If acromegaly is not treated in time, the heart cannot withstand such heavy loads associated with increased body growth. Andre the Giant died of heart disease at the age of 46.
Leprosy is perhaps one of the most terrible diseases known to medicine. The disease is caused by a special bacterium that destroys the skin.
A person with leprosy literally begins to rot alive. Typically, the disease primarily affects the face, arms, legs and genitals of a person.
Although the poor fellow does not lose all his limbs, the disease often takes away the leper's fingers and toes, and also destroys part of his face. Very often the nose is affected, resulting in a terrible face, and a shocking ragged hole in the place of the nose.
The attitude towards lepers is also terrible. At all times, people with such a disease were shunned; they were exiles from any society. And even in the modern world there are entire settlements of lepers.
After contracting smallpox, the body becomes covered in a rash in the form of painful pimples. The disease is terrible because it leaves behind huge scars. Therefore, even if you manage to survive from this disease, the consequences are quite sad: scars remain all over your body.
Smallpox appeared a very long time ago. Experts have proven that even in ancient Egypt, people suffered from this disease. This is also evidenced by the mummies found by archaeologists.
It is known that at one time such famous personalities as George Washington, Abraham Lincoln, and Joseph Stalin suffered from smallpox.
In the case of the Soviet leader, the disease was especially acute, leaving behind obvious consequences on the face. Stalin was embarrassed by the scars on his face and always asked to retouch the photographs in which he was depicted.
Porphyria is a genetic disorder that results in the accumulation of porphyrins (organic compounds that have various functions in the body; they also produce red blood cells).
The disease affects the entire body, primarily affecting the liver. This disease is also dangerous for the human psyche.
People suffering from this skin condition should limit themselves from sun exposure, which can aggravate their overall health. It is believed that it was the existence of porphyria patients that gave rise to legends about vampires and werewolves.
And soon the tiny and harmless bite turns into an ugly, purulent ulcer. Therefore, bites to the face are especially dangerous. It takes a long time for the wounds to heal.
Without proper treatment, a person may die. Many people in Afghanistan suffer from this disease.
The disease is common in tropical areas of Africa, and more than one hundred million people suffer from elephantiasis. Victims of this disease experience frequent headaches and nausea.
The most effective means of combating the disease are special antibiotics. In the worst and most advanced cases, the patient cannot avoid surgical intervention.
Minor cuts and abrasions are part of our lives. And they're pretty harmless as long as there aren't flesh-eating bacteria nearby. Then in a matter of seconds a small wound can become life-threatening.
Bacteria eat away living flesh, and only amputation of some tissues can stop the spread of the disease. The patient is treated with antibiotics. However, even despite intensive treatment, 30-40 percent of all cases of the disease are fatal.
Most fish in the world are covered with scales. It protects them and allows them to swim freely. But some, including sharks, belong to the class of so-called “cartilaginous fish”. Instead of bones, they have cartilage that supports the internal structure of the body. Cartilaginous fish are also unique in that they do not have regular scales. Instead, they have dermal denticles that completely cover their bodies.
The term “dermal denticles” roughly translates to “skin teeth,” and for good reason. Their composition is very similar to the teeth in the mouth. Like our teeth, these dermal denticles have vascular pulp in the center, dentin in the middle, and enamel on the outside. They may bleed and feel pain.
As a rule, dermal denticles are very small. When viewed with the naked eye, the fish appears to have smooth, uniform skin. However, under a microscope, everything looks completely different.
Dermal denticles grow from the outer layer of skin, like scales, but unlike scales, they grow to a certain size and then stop. Then a new layer of denticles grows on top of them, creating a kind of “underwater armor.”
Dermal teeth provide sharks with advantages that most scaly fish do not have. Due to their composition, they provide better thermoregulation than regular scales. In addition, the uneven surfaces of the teeth reduce water resistance.
As a result, sharks can swim faster and make less noise that would spook their prey. All this is so effective that manufacturers of swimming equipment began to use a similar scheme for their best sports suits.