Abrasion (dental)

Curettage dentium ( German abrasion of the teeth, from the Latin abrasio, wear ',' abolition ') referred to in dentistry a loss of tooth substance by friction. Attrition and Demastikation are sub-forms.

Definitions of DGZMK

Often the term is used as a synonym for all types of loss of tooth structure. According to German Society of Dental Oral and Maxillofacial Surgery ( DGZMK ) However, the following definitions apply:

• Abrasion: general dental hard tissue loss due to friction.
• Erosion ( erosion engl. ): ill-defined loss of tooth structure by the action of acid and / or abrasives in toothpastes.
• Attrition (English attrition ): loss of tooth structure by reflexive touching the teeth.
• Demastikation (English demastication ): loss of tooth structure to the chewing surfaces by abrasive foods during mastication.
• Bruxism (English bruxism ): parafunction ( grinding, pressing) with non-physiological effects on teeth, periodontium, masticatory muscles and / or jaw joints.

Attrition

The attrition is a form of abrasion, in which the loss of tooth substance by contact with other teeth done. For pure jaw closing movements Attrition occurs by tooth contact of the two jaw especially on the occlusal surfaces of the posterior teeth. For feed and grinding movements the incisal edges ( cutting edges) are additionally affected the front teeth in the upper jaw connected with the palatine ( palate side ) areas and in the lower jaw with the vestibular (mouth atrial side ) surfaces.

Since the teeth (especially Sharpey's fibers) are suspended in the alveolus ( bony tooth socket ) over a collagen fiber apparatus also leads the contact of adjacent teeth at Kauflächenbelastung by jaw closure to loss of substance. The proximal region (area of ​​the adjacent tooth contacts) arises in the adolescent dentition still punctiform is, but can always be flat over the course of life. If this is the case, the teeth slowly move mesially ( for arch center forward ), so that the shortened dental arch.

Demastikation

The Demastikation is also a form of abrasion. In this case, is the cause of the loss of substance in the chewing of abrasive ( abrasive ) or contaminated foods. Typical of the Demastikation are rounded and flattened cusps and fissures on the occlusal surfaces of the posterior teeth. Due to the rather soft foods in the western world, the proportion of this type of abrasion compared to the attrition is rather low. But one often finds among primitive peoples as well as historical skeletal remains. Since the melting layer on the chewing surfaces has only a limited thickness (1-2 mm ) is exposed dentin in more pronounced. Dentin is softer than enamel and is abraded more rapidly as a result. They form regular flat holes on the occlusal surface. Often occurs on thermal and mechanical sensitivity when chewing. In extreme cases, 50 % of the tooth are " weggekaut ". The pulp reacts with the formation of secondary and withdraws.

When elephants eat very much and very abrasive grass, the Demastikation is a life- limiting factor. If their teeth are worn down, then they can no longer eat and die.

Formerly an extremely reinforced Demastikation was in villages where the millstone when grinding grain was not quite round, observed. He was so badly rubbed that he very quickly disintegrated during milling and was baked as part of the flour with the bread by the imbalance of the millstone.

Physiological History

A certain loss of tooth structure is physiologically (normal). Although tooth enamel is one of the hardest substances in the body that show signs of wear in the course of life in the form of wear facets on the teeth. This initially affect only the enamel. Is this removed completely in some places, the dentin is exposed. This is much softer than the enamel, which is why a more wear progressing more quickly. Overall, this process is relatively slowly progressive over decades. Therefore, the body has plenty of time to adapt to the changes. Rarely there are massive, requiring treatment disturbances in functional masticatory system.

To compensate for the loss of substance, slight changes can take place at various points in the masticatory system. So that the body tries to support the teeth at any point in all directions and protect so as to allow the complete chewing and sensory performance. To maintain the original height of the teeth, in the region of the root tip cement is attached and pushed the tooth gradually from the bone compartment ( elongation). In the area of ​​dental subjects also alterations can be made by the bone cells. Thus, the distal ( posterior ) teeth are shifted slightly to the mesial (front) and a lack of contact area on the proximal surfaces, for example due to attrition is compensated ( mesial ).

Finally, the dentin is the pulp - dentinal complex with the innervation of the tooth in conjunction. If the protective enamel coat removed, pain stimuli such as cold, hot and sweet earlier perceived. The body defends itself against this by secondary and tertiary dentin ( irritation dentine ) is formed. This protects the pulp on the one hand by its thickness, tertiary dentin also cuts off the dentinal tubules and thus interrupts the transmission of impulses.

Non-physiological forms

Of these, to be distinguished is a pathological tooth wear by abrasion. Although the grinding marks are similar to the clinical picture, but there are differences in the time course and the appearance of the wear facets. Although there are many causes for the loss of substance in detail, affecting most either bruxism or an incorrect brushing technique.

Incorrect brushing technique ( colloquially scrub ) leads, especially in combination with toothpastes with high abrasiveness ( RDA high value), very fast to changes in the tooth structure. These are found mainly in the area of ​​the tooth necks, but it can also occur on the chewing surfaces to an increased loss of substance. Besides the typical gingival recession which affected suffer often at a hypersensitivity (hypersensitivity ) in the melt -free areas. Many also interferes with the yellowish appearance of the exposed dentine.

By bruxism occurs in addition to the loss of substance usually also to other, often painful changes in the masticatory system. These include headaches, muscle tension and popping sounds in the jaw joint. Often the grinding marks are not equally strong on all teeth in upper and lower jaw. Rather be found on individual teeth facets that indicate the characteristic crunch or pressing movements that are performed by the patient unconscious. This substance loss often progresses very quickly. While it also comes here over time to a compensation, but often the patient suffers previously at various typical of bruxism symptoms.

Therapy

Whether a loss of tooth structure needs to be balanced due to abrasion caused by dental measures, depends primarily on the extent and the aesthetic sensibilities of the patient. Depending on the situation, plastic fillings or prosthetic measures are possible, to restore the original shape and color of the tooth again.

In non-physiological reasons for the loss of substance, but it is much more important to detect and eliminate these. While in a false tooth brushing technique a change often works well, especially the psychological causes must be explored and treated with bruxism in addition to the physical symptoms. In this case, sometimes the cooperation of different specialists is necessary to stop the progression.