| 摘要 |
<p>The gingival retention cord is for use when taking dental impressions, and comprises a single roughened twisted or woven thread (1) of metal, or synthetic or natural fibres. It incorporates retention portions (2) of metal, or synthetic or natural fibres, joined elastically to it at intervals. The design holds the recesses in the gum open for the impression material, so that the stumps below the surface can be used for the impression as well as the stumps of teeth that protrude well above the surface.</p> |
