Pathology of tooth decay

2021-02-02 12:00 AM

Strong acids are often available from outside sources such as carbohydrates in soft drinks, strengthened soft drinks, lemon juice squeezed and stomach fluids or heartburn.

The basic concepts

Tooth decay: A bacterial infection of the tooth, it leads to local dissolution and destruction of the calcium tissue of the tooth.

Dental treatment: restoration of tooth loss (due to decay or other causes).

Endodontic: treating tooth marrow with irreversible marrow disease.


Injury to tooth decay occurs only under a colon of bacteria capable of creating enough acid in place to lose tooth structure mineral. Bacterial gelatin clumps that stick to tooth surfaces are called plaque. Bacterial plaque metabolizes refined carbohydrates for energy and organic acids as a by-product.

The acid product may be the cause of tooth decay due to the dissolution of the tooth structure crystals. Caries lesions progressively strong and weak depending on the pH level on the teeth surface with the metabolic changes of plaque. Tooth decay is active during the high metabolic activity of bacteria and pH at place reduced under 5.5.

Ca2 + and PO43- ions in saliva serve as the source of raw materials for the re-mineralization process.

Tooth decay is a disease with many causes and is simply described through the Keyes diagram: is the result of a mutual impact between 3 main factors: host (tooth & saliva), oral microbiology (bacteria), carbohydrates. In addition, the time factor is the condition for the development of cavities

Improved Keyes diagrams

Bacteria, Cabohydrate, sensitive teeth: 3 essential factors that cause tooth decay.

Time: conditions for tooth decay.

Current opinion

Plaque pathological bacteria

As mentioned above, plaque is a soft, transparent substance that adheres to the teeth surface. It is true that we have to say bacterial plaque because it consists of bacteria and quality.

There are many types of bacteria that live in the oral environment (200 - 300 types). Some float freely in the mouth, pushed out of the mouth by the outflow of saliva and often swallowed. Only some of the most remarkable organisms, the streptococci, can adhere to oral surfaces such as mucosa and tooth structures. The bacteria have special receptors that can attach to the tooth surface and it also forms a sticky matrix to help them stick together. Clinging to teeth and clinging to each other helps bacteria gather on the teeth surface.

When the bacteria first attach to the teeth, they multiply and spread horizontally to create a coating on the tooth surface. Bacteria continue to grow and spread along the tooth surface. When streptococcus plaque has formed, other organisms can attach such as lactobacilli, a wire-shaped, spiral-shaped organism that normally cannot attach directly to the tooth surface.

Thus, there are many types of bacteria that live in the oral termite, but only a few can clump on the surface of the teeth, forming plaque by special receptors. Among them, the group of streptococci, such as Streptococus mutans, live on. Sucrose to assemble into extracellular polysaccharide is the main culprit causing tooth decay, followed by Lactobacilli. Bacterial plaque is the main cause of the fermentation of carbohydrates in foods and beverages to become acid ions on the tooth surface. The salivary buffering efficiency of this acidity is inversely proportional to the plaque thickness.

This plaque is kept in grooves, deep pits, between side faces, especially the point of contact of each tooth, around the rough surface or around the residual fillings. With the method of mechanical oral hygiene, it is less effective in removing plaque in the above-mentioned locations, so most of these areas will be the starting point of tooth decay.


As a basic substrate for nutrition and bacteria.

Polysaccharide (Starch): Cereals, vegetables.

Disaccharide (Sucrose): Sugar cane.

Mono Saccharide (glucose / fructose): confectionery, processed sugar, sugar in fruit.

Unprocessed vegetables and whole grains cause less tooth decay. Processed starches are very easy to convert to organic acids ® that are susceptible to tooth decay.

The sugar in the fruit also causes tooth decay, but less because of the negligible amount.

Strong acids are often available from outside sources such as carbohydrates in soft drinks, strengthened soft drinks, lemon juice squeezed and stomach fluids or heartburn. Frequent or prolonged presence of these fluids can lead to rapid mineral loss and can range from mild cavities to widespread cavities. Specifically, in young children drinking bottles of milk and juice while sleeping. The pH drops quickly and it can stay that way over a long period of time leading to widespread decay. they still feel normal or at least they accept and does not become a problem for the oral health).

Food protection factors:

Certain foods form factors that counteract mineral loss. Plaque will reduce the degree of tooth surface attack in the presence of fat. Dairy products, especially cheese and possibly seeds, are found in these foods. Foods that require crushing and chewing on fibrous vegetables can be seen as protective, as gum increases saliva flow, so they are considered buffering. It is this factor that quickly causes plaque pH to become completely neutral.

Host factor

Teeth: hard tissue of sensitive teeth, easily dissolved by acid. In addition, in deep grooves, enamel surface is not smooth, crowded teeth increase storage of plaque ® easy to decay.

Saliva: Saliva plays an important role in protecting teeth against acid attack. One convincing clinical fact is the rapid serious damage to tooth structures, caused by the sudden loss of saliva, which may be the result of certain situations, such as when medication is needed, or due to head, face and neck radiation therapy, prolonged tress or salivary gland pathology.

Mechanism of protection of saliva: 

Saliva sealing provides a very good protective barrier against acid challenge. It acts as a barrier:

Preventing the penetration of acid ions into the teeth.

Prevent the movement of dissolved apatite substances from the teeth.

Prevent the mineralization of apatite to dental stone when Ca2 + and PO43- ions are highly saturated in saliva.

The bicarbonate buffering system is very effective in stimulating a high level of saliva flow in combating organic acids as well as corrosive acids on tooth surfaces.

Brushing effect: saliva flow and oral cleansing affect the removal of food debris and microorganisms. It should be noted that a high level of saliva flow can also remove some of the fluorosis placed on teeth, so it is important to increase the amount required to the maximum extent required for tooth protection.

The fluorine ion contained in the saliva is low (0.03 ppm or 1.6 mmol / l average) but it still retains the job of protecting and correcting tooth calcification.

Fluorine plays a distinctly large role in demineralization and remineralization, especially as it promotes re-mineralization. In an acidic environment, fluorine ions react strongly with Ca2 + ions and PO43- ions to form fluoroapatite crystals Ca10 (PO4) 6 (OH.F) 2, in which fluoride replaces a few hydroxyl ions. Fluorapatite is less soluble than pure hydroxyapatite because of its more robust secondary clusters.

In addition, fluoride also prevents the metabolism of bacteria.


Tooth decay only develops when the acid production reaction is prolonged and repeated over a period of time. Regularly fermenting carbohydrates, it is easier for tooth decay than the total amount of carbohydrates in 1 time.

Progressive tooth decay

Deep yeast

Yeast is damaged (loss of minerals), may or may not be a hole.

No pain.

Usually not self-detect.

Ivory worm

Deep hole progresses to the dentin.

Pain with stimulation (Mechanical, temperature ...) and pain ceases when stimulus ceases.


Lesions spread to the pulp.

Severe pain, especially while resting (at night).

Pain is spontaneous or stimulating, and pain persists when the stimulus is gone.

The marrow died

Necrotic marrow, with a characteristic odor.

The patient is not in pain.


Root root infection (periarticular abces, granulomatosis or root cyst).

Inflammation of the bone.



Sinus inflammation of the jaw.

Cavernous sinus thrombophlebitis.

Direction of treatment

Biological studies have found that the development of cavities symptoms encompass a wide range of changes, from the dissolution of crystals in microscopic structures to cavities. visible to the naked eye. Thus, the stage that is considered to be the former onset is, in fact, only a manifestation of a slow, but not visible, development of symptoms.

Modern dental health requires an in-depth knowledge of the relative importance of the environmental factors in the oral sinuses that determine the development and progression of cavities. the most appropriate approach to individualized disease progression control, with the ultimate goal of eliminating mere symptom treatment.