Abrasio dentium
| Classification according to ICD-10 | |
|---|---|
| K03.1 | Abrasion of the teeth |
| ICD-10 online (WHO version 2019) | |
Abrasio dentium ( German abrasion of the teeth ; from Latin abrasio 'wear', 'abolition') in dentistry denotes a loss of hard tooth substance through friction. Attrition and demastication are sub-forms.
Definitions of the DGZMK
The term is often used as a synonym for all types of loss of hard tooth substance . According to the German Society for Dentistry, Oral and Maxillofacial Medicine ( DGZMK ), however, the following definitions apply:
- Abrasion: general loss of hard tooth substance due to friction.
- Erosion : an indistinct loss of hard tooth substance due to the action of acids and / or abrasives in toothpastes.
- Attrition: Loss of hard tooth substance through reflective touching of the teeth.
- Demastication: Loss of hard tooth substance on the chewing surfaces due to abrasive food during the chewing process.
- Bruxism (English bruxism): Parafunction (grinding, pressing) with non-physiological effects on teeth, periodontium , masticatory muscles and / or jaw joints.
attrition
| Classification according to ICD-10 | |
|---|---|
| K03.0 | Pronounced attrition of the teeth |
| ICD-10 online (WHO version 2019) | |
The Attrition is a form of abrasion, in which the loss of tooth substance occurs by contact with other teeth. In the case of pure jaw-closing movements , attrition occurs due to tooth contact between the two jaws, especially on the occlusal surfaces of the posterior teeth. The incisal edges (incisal edges) of the front teeth are also affected during feed and grinding movements, in the upper jaw together with the palatal (palatal) surfaces and in the lower jaw connected with the vestibular ( oral auricle ) surfaces.
Since the teeth are suspended in the alveolus (bony tooth socket) by a collagen fiber apparatus (especially Sharpey's fibers), contact with neighboring teeth when the occlusal surface is stressed through jaw closure leads to a loss of substance. The approximal area (area of the neighboring tooth contacts) is still punctiform in young teeth, but can become more and more flat in the course of life. If this is the case, the teeth slowly move mesially (towards the center of the dental arch, forwards), so that the dental arch shortens.
Demastication
The Demastikation is also a form of abrasion. In this case, the cause of the loss of substance lies in the chewing of abrasive (abrasive) or contaminated food . Rounded and flattened cusps and pits on the occlusal surfaces of the posterior teeth are typical of demastication. Due to the rather soft diet in the western world, the proportion of this type of abrasion is rather low compared to attrition. However, they are often found in primitive peoples as well as in historical skull finds. Since the enamel layer on the chewing surfaces is only of limited thickness (1–2 mm), the dentin is exposed if it is more pronounced. Dentine is much softer than tooth enamel and is rubbed off even faster as a result. Real flat holes are formed on the chewing surface. Often thermal and mechanical sensitivity then occurs when chewing. In extreme cases, 50% of the tooth is "chewed away". The pulp reacts with the formation of tertiary dentine and withdraws.
In elephants , which eat a lot and very abrasive grass, demastication is a life-limiting factor. When their teeth are chewed, they can no longer eat and die.
In the past, extremely increased demastication was observed in villages where the millstone did not run completely smoothly when grinding grain. Due to the imbalance of the millstone, it was rubbed off so severely that it dissolved very quickly during grinding and was baked as part of the flour with the bread.
Physiological course
A certain loss of tooth structure is physiological (normal). Although tooth enamel is one of the hardest substances in the body, traces of wear and tear appear over the course of life in the form of polished facets on the teeth. These initially only affect the enamel. If this is completely removed in some places, the dentin is exposed. This is much softer than the enamel, which is why further wear progresses faster. Overall, this process continues relatively slowly over decades. The body therefore has a lot of time to adapt to the changes. Massive disorders in the functional masticatory system that require treatment only rarely occur.
To compensate for the loss of substance, slight changes can take place at various points in the chewing system. In this way, the body tries to support and protect the teeth in all directions at all times in order to enable complete chewing and sensory performance. In order to maintain the original height of the teeth, cement is deposited in the area of the root tip and the tooth is gradually pushed out of the bone compartment ( elongation ). In the area of the tooth sockets , modifications can also be made by the bone cells. The distal (rear) teeth are shifted slightly mesially (front) and a missing contact area on the approximal surfaces, for example due to attrition, is compensated for ( mesial drift ).
After all, the dentin, as a pulp-dentin unit, is connected to the nerve supply of the tooth. Once the protective enamel coat has been removed, pain stimuli such as cold, hot and sweet are perceived earlier. The body defends itself against this by forming secondary and tertiary dentine (irritant dentine). On the one hand, this protects the pulp due to its thickness, and tertiary dentine also cuts off the dentinal tubules and thus interrupts the transmission of stimuli.
Unphysiological forms
A pathological loss of hard tooth substance due to abrasion must be distinguished from this. Although the grinding marks are similar in the clinical picture, there are nevertheless differences over time and in the appearance of the grinding facets. Although there are many individual causes of substance loss, most of them are related to either bruxism or improper toothbrushing technique.
The wrong brushing technique (commonly known as scrubbing ) leads, especially in combination with toothpastes with high abrasiveness (high RDA value), to changes in the hard tooth substance very quickly. Although these are mainly found in the area of the tooth necks, there can also be an increased loss of substance on the chewing surfaces. In addition to the typical gingival recessions, those affected often also suffer from hypersensitivity (oversensitivity) in the enamel-free areas. Many also disturb the yellowish appearance of the exposed dentin.
In addition to the loss of substance, bruxism usually also leads to other, often painful changes in the chewing system. These include, for example, headaches, muscle tension and clicking noises in the temporomandibular joint. Often the grinding marks are not equally pronounced on all teeth in the upper and lower jaw. Rather, facets are found on individual teeth that indicate the characteristic grinding or pressing movements that are unconsciously performed by the patient. This loss of substance often progresses very quickly. Although there is compensation over time, those affected often suffer from the various symptoms that are typical of bruxism beforehand.
The occupational disease number 2111 of the Occupational Diseases Ordinance , namely "increased tooth abrasion due to several years of exposure to quartz dust", is also one of the non-physiological substance losses . There is also abrasion on prostheses .
therapy
Whether a loss of hard tooth substance due to abrasion has to be compensated for by dental measures depends primarily on the extent and the aesthetic perception of the patient. Depending on the situation, plastic fillings or prosthetic measures are possible in order to restore the original shape and color of the tooth.
In the case of unphysiological reasons for the loss of substance, however, it is much more important to recognize and eliminate them. While switching to the wrong toothbrushing technique often works without problems, in the case of bruxism, in addition to the physical symptoms, above all the psychological causes must be explored and treated. Sometimes the cooperation of different specialists is necessary to stop the progression.
Web links
- Abrasion values of toothpaste ( Memento from March 10, 2007 in the Internet Archive )
- Study to measure dental abrasion
