Matrix (dentistry)
In dentistry, a matrix (lat. Mater mother) is understood to be an aid for placing a dental filling with plastic filling material on the one hand and the counterpart of a male mold on the other. Matrix and patrix form an attachment as a unit .
Die as a form aid
A matrix consists of a metal or plastic band that is placed around the tooth. For example, an amalgam filling or a composite filling in a soft (plastic) state is placed in the cavity of a tooth in order to reconstruct the defect. If this cavity is open and not completely surrounded by tooth enamel, the material would flow out of the cavity. As a molding aid, the matrix ensures that the filling compound is not distributed beyond the tooth. The ring band matrix (English: Tofflemire's ™ matrix) is one of the most common aids when placing an amalgam filling. When placed on the tooth, the thin, specially shaped, clamped steel sheets can be adapted to the external shape of the tooth.
Plastic matrix
With a plastic matrix, plastic fillings in the anterior region can be placed in a sealed manner. They are placed in the area of the space between the tooth to be treated and the neighboring tooth. This means that the filling can be placed on the neighboring tooth without sticking. Plastics are usually cured using blue light with a wavelength of 450–490 nm; the matrices must be transparent for this.
Matrix as part of an attachment part
On the other hand, the counterpart to a male mold is understood as a matrix. Matrix and patrix form a unit and are used in dental technology as attachments , as connecting parts between the fixed denture part and the removable denture part. There are a large number of such attachments, some of which can be made-up and some of which can be manufactured individually. A frequently used attachment is the T attachment , in which the male part engages in a longitudinal slot in the female part. The individually manufactured attachments include the grooved shoulder pin attachment (RSS), in which a tooth crown is milled parallel-walled on the inside and the secondary part is guided past it and the removable denture is attached by friction and additional pins.
Matrices are those parts of the attachment that can be activated and deactivated. This means increasing or decreasing the friction between the matrix and the patrix, which can influence the hold of the removable denture. For this purpose, the die can be slightly pressed together or expanded or ground out.
Patrix
A male (lat. Pater father) is the counterpart to the die. Attachments are used when removable partial dentures such as partial dentures are to be invisibly attached to teeth or implants . This avoids attachment using visible brackets. Both can, for example, interlock like a push button , with the male part being incorporated into the removable part of the dental prosthesis and the female part being incorporated into the tooth or implant. An attachment is an invisible holding and supporting element. The hold of the partial prosthesis is increased compared to a clamp prosthesis. Partial dentures anchored by snap fasteners are used primarily for severely damaged remaining teeth. The cartridge is attached to the root of the tooth by means of a pin ( pin structure ).
Individual evidence
- ↑ HJ Staehle, MJ Koch: Pediatric and Adolescent Dentistry. Deutscher Zahnärzte Verlag, 1996, ISBN 3-7691-4057-5 .
- ^ E. Hellwig, J. Klimek, Th. Attin: Introduction to tooth preservation. 5th edition. Deutscher Ärzte-Verlag, 2009, ISBN 978-3-7691-3371-4 , p. 236.
- ^ R. Marxkors : Textbook of dental prosthetics. 4th edition. Deutscher Zahnärzte Verlag, 2007, ISBN 978-3-7691-3353-0 .