Retraction cord

from Wikipedia, the free encyclopedia

A retraction cord is a dental aid used to displace and hold back the gums ( gingiva ) from the tooth neck . A 1–2 cm long thread is adapted around the ground tooth between the tooth and the gum, which is done before the impression is taken for the production of crowns or bridges . The retraction cord is also used for deep fillings or tooth neck fillings . A so-called retraction paste is also offered.

The retraction thread consists of a braided or twisted cotton thread with a diameter of 0.5–1.0 mm. The thread can be impregnated or soaked with vasoconstricting ( adrenaline ) and hemostatic agents ( aluminum chloride , aluminum sulfate , hexachloride , hexahydrate ).

application

After preparation (grinding) of the tooth to be crowned, the dentist aims to take a blood-free impression, whereby the preparation margin of the tooth is shown. The preparation margin can also be below the gum, which defines the crown margin. The dental technician can easily see the preparation margin on the model. The retention time of the retraction cord is 10–20 minutes. The hemostatic and vasoconstricting additives can act on the gums during this time. Before the impression is taken, the retraction thread is removed and the impression material is introduced.

Avoid damaging the Sharpey fibers that hold the tooth in the bone compartment. A so-called retraction paste has been available since 2001. This is placed in the gums and does not damage the gums. If the preparation margins are at the level of the gums, the retraction thread can be dispensed with. In this case, a good impression is possible without a retraction cord.

literature

  • Michael Ehrenfeld, Peter Gängler, Thomas Hoffmann, Norbert Schwenzer, Brita Willershausen (eds.): Conservative dentistry and periodontology. 3rd edition, Thieme Verlag, Stuttgart, ISBN 978-3-13-593703-8 .
  • Reiner Biffar, Michael Ehrenfeld, Wolfgang Gernet, Norbert Schwenzer (eds.): Dental prosthetics. 4th edition, Thieme Verlag, Stuttgart, ISBN 978-3-13-593604-8 .

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