| 摘要 |
435,004. Dental matrix holders. HARPER, W. E., 6541, Yale Avenue, Chicago, U.S.A. Nov. 9, 1934, No. 32268. [Class 81 (ii)] A dental matrix holder comprises a pair of pivoted arms each having a pair of resilient jaws, comprising converging walls divided into horizontal sections, secured to its free end, and a supplemental wedge member movably positioned within each of said pair of jaws. The arms 1 are pivoted at 2 and held closed by a spring 3. The free ends are turned to form circular apertures 11, Fig. 4, which receive the shanks 12 of members 13 secured by washers 14 and nuts 15. Each member 13 is slotted at 16 to receive the flat portion of a flexible jaw 18, Fig. 7, which is secured by a wedge member 20, the slotted shank 21 of which passes through apertures in the member 13 and jaw 18. The jaw apertures 19 are positioned below the jaw centres. A matrix band is positioned between two teeth and the jaws 18 also positioned with the band between them and the cavity. A clamping bar 4, slotted to receive the arms 1, and cut away to permit removal and reversal, is provided with a screw 6 for actuating the arms. The jaws 18 which are slotted at 18a shape the matrix band to the tooth. The shanks 21 of the wedge members 20 can then be pressed inwardly to force the jaws and therefore the matrix against the tooth. The holder can be removed by removing the bar 4 and forcing apart the arms 1 by rubber dam forceps, the ends of which are positioned in notches 1<a>. |
