Dental matrix retainer

1. A dental matrix retainer used as an aid when filling two-surface cavities in the molars, with a matrix holder ( 3 ) and a device for tensioning a matrix band ( 2 ) placed in the form of a loop ( 22 ) around the tooth which is to be treated, the matrix holder ( 3 ) being composed of a housing ( 5 ) with a circular opening ( 8 ), and ofa ˜inner body ( 9 ) which can turn in this opening ( 8 ) and which is provided with a gap ( 12 ), said gap ( 12 ) being able to be aligned with a slit ( 10 ) in the wall of the housing ( 5 ) such that the superposed ends of the matrix band ( 2 ) can be inserted into this slit ( 10 ) and into the gap ( 12 ) aligned therewith and can be tensioned on the tooth by turning the inner body ( 9 ), characterized in that a toothed wheel ( 13 , 27 ) is provided on the upper end of the inner body ( 9 ) protruding from the circular opening ( 8 ) of the housing ( 5 ), said toothed wheel ( 13 , 27 ) being able to be engaged immediately and to contact directly with a drive device ( 4 ) which has a laterally outwardly extended drive shaft ( 16 ), wherein the drive shaft ( 16 ) can be turned inside a tubular sleeve ( 20 ) with the aid of a rotary knob ( 19 ) provided at an end of the drive shaft ( 16 ) disposed remote from the drive pinion ( 17 ), wherein a support fork ( 21 ) protrudes forward underneath the drive pinion ( 17 ) and from the tubular sleeve ( 20 ) and can slide under an edge ( 7 ) protruding laterally from the upper end of the housing ( 5 ).

2. The matrix retainer as claimed in claim 1 , characterized in that the toothed wheel at the upper end of the inner body ( 9 ) is a crown wheel ( 13 ) which can be brought into proximate engagement with a drive pinion ( 17 ) belonging to the drive device ( 4 ), which drive pinion ( 17 ) can be turned via the laterally outwardly extended drive shaft ( 16 ).

3. The matrix retainer as claimed in claim 2 , characterized in that the drive pinion ( 17 ) is slightly beveled at its front face.

4. The matrix retainer as claimed in claim 1 , characterized in that the drive device ( 4 ) is composed of the drive shaft ( 16 ) and of the drive pinion ( 17 ) arranged at one end thereof.

5. The matrix retainer as claimed in claim 1 , characterized in that the matrix retainer is composed of two parts and comprises a matrix holder ( 3 ) and a separate drive device ( 4 ) attachable from a side to the matrix holder ( 3 ) and again disengageable from the matrix holder ( 3 ), wherein the drive device ( 4 ) includes a laterally outwardly extended drive shaft ( 16 ) and a drive pinion ( 17 ) disposed at an end of this drive shaft ( 16 ), wherein the drive pinion ( 17 ) can be engaged and disengaged with a crown wheel ( 13 ) of the inner body ( 9 ), and wherein the crown wheel ( 13 ) of the inner body ( 9 ) upwardly protrudes from the housing ( 5 ) of the matrix holder ( 3 ).

6. A matrix retainer used as an aid when filling two-surface cavities in the molars, with a matrix holder ( 3 ) and a device for tensioning a matrix band ( 2 ) placed in the form of a loop ( 22 ) around the tooth which is to be treated, the matrix holder ( 3 ) being composed of a housing ( 5 ) with a circular opening ( 8 ), and of a inner body ( 9 ) which can turn in this opening ( 8 ) and which is provided with a gap ( 12 ), said gap ( 12 ) being able to be aligned with a slit ( 10 ) in the wall of the housing ( 5 ) such that the superposed ends of the matrix band ( 2 ) can be inserted into this slit ( 10 ) and into the gap ( 12 ) aligned therewith and can be tensioned on the tooth by turning the inner body ( 9 ), characterized in that a toothed wheel ( 13 , 27 ) is provided on the upper end of the inner body ( 9 ) protruding from the circular opening ( 8 ) of the housing ( 5 ), said toothed wheel ( 13 , 27 ) being able to be engaged with a drive device ( 4 ) which has a laterally outwardly extended drive shaft ( 16 ), wherein

the drive device ( 4 ) is composed of a drive worm ( 26 ) which engages with the toothed wheel ( 27 ) of the spindle ( 9 ) and which can be turned via a laterally outwardly extended drive shaft ( 16 ).

7. A dental matrix retainer used as an aid when filling two-surface cavities in the molars, comprising a matrix holder ( 3 ) and a drive device ( 4 ) connectable and again disengageable with the matrix holder ( 3 ) for tensioning of a matrix band ( 2 ) placed like a loop ( 22 ) around a tooth which is to be treated

the matrix holder ( 3 ) being composed of a housing ( 5 ) with a circular opening ( 8 ), and of a inner body ( 9 ) which can turn in this opening ( 8 ) and which is provided with a gap ( 12 ), said gap ( 12 ) being able to be aligned with a slit ( 10 ) in the wall of the housing ( 5 ) such that the superposed ends of the matrix band ( 2 ) can be inserted into this slit ( 10 ) and into the gap ( 12 ) aligned therewith and can be tensioned on the tooth by turning the inner body ( 9 ), wherein a drive pinion ( 17 ) furnished at an end of a rotatable drive shaft ( 16 ) is bringable into engagement with a toothed wheel ( 13 , 27 ) provided on the upper end of the inner body ( 9 ) protruding from the circular opening ( 8 ) of the housing ( 5 ), characterized in that

the drive shaft ( 16 ) is rotatable within a tubular sleeve ( 20 ), wherein a support fork ( 21 ) projects in a front of the tubular sleeve ( 20 ) below the drive pinion ( 17 ), wherein the support fork ( 21 ) is disposed slidable under an edge ( 7 ) protruding from all sides at the housing ( 5 ) of the matrix holder ( 3 ), and wherein thereby the drive pinion ( 17 ) of the drive shaft ( 16 ) engages directly with the toothed wheel ( 13 , 27 ) at the inner body ( 9 ) of the matrix holder ( 3 ).

8. The matrix retainer as claimed in claim 7 , characterized in that the toothed wheel at the upper end of the inner body ( 9 ) is a crown wheel ( 13 ).

9. The matrix retainer as claimed in claim 7 , characterized in that the drive pinion ( 17 ) is slightly beveled at its front face.

10. The matrix retainer as claimed in claim 7 , characterized in that the drive shaft ( 16 ) can be turned inside a tubular sleeve ( 20 ) with the aid of a rotary knob ( 19 ) provided at an end of the drive shaft ( 16 ) disposed remote from the drive pinion ( 17 ).

11. The matrix retainer as claimed in claim 7 , characterized in that

the drive device ( 4 ) is composed of a drive worm ( 26 ) which engages with the toothed wheel ( 27 ) of the spindle ( 9 ) and which can be turned via a laterally outwardly extended drive shaft ( 16 ).

12. A dental matrix retainer used as an aid when filling two-surface cavities in the molars, comprising

a housing ( 5 ) having a wall, having a circular opening ( 8 ), and having a slit ( 10 ) in the wall;

a first edge ( 7 ) protruding laterally from an upper end of the housing ( 5 );

a second edge ( 7 ) protruding laterally from an upper end of the housing ( 5 ),

wherein the second edge ( 7 ) is disposed parallel to the first edge ( 7 );

a inner body ( 9 ) rotatable in this circular opening ( 8 ) and which inner body ( 9 ) is provided with a gap ( 12 ), said gap ( 12 ) being able to be aligned with the slit ( 10 ) in the wall of the housing ( 5 ) such that superposed ends of a matrix band ( 2 ) are insertable into this slit ( 10 ) and into the gap ( 12 ) aligned with the slit ( 10 ) and said matrix band ( 2 ) is tensionable on a tooth of a dental patient by turning the inner body ( 9 );

a toothed wheel ( 13 , 27 ) provided on an upper end of the inner body ( 9 ) protruding from the circular opening ( 8 ) of the housing ( 5 ),

wherein the housing ( 5 ), the edge ( 7 ) protruding from all sides at the housing ( 5 ), the inner body ( 9 ), and the toothed wheel ( 13 , 27 ) form a matrix holder ( 3 );

a rotatable drive shaft ( 16 );

a drive pinion ( 17 ) furnished at an end of the rotatable drive shaft ( 16 ) and bringable into engagement with the toothed wheel ( 13 , 27 ) provided on the upper end of the inner body ( 9 ) protruding from the circular opening ( 8 ) of the housing ( 5 );

a tubular sleeve ( 20 ) surrounding the rotatable drive shaft ( 16 ) and wherein the rotatable drive shaft ( 16 ) is rotatable within the tubular sleeve ( 20 );

a support fork ( 21 ) projecting in a front of the tubular sleeve ( 20 ) below the drive pinion ( 17 ), wherein the support fork ( 21 ) is disposed slidable under the first edge ( 7 ) and under the second edge ( 7 ) protruding from two opposite sides at the housing ( 5 ), and wherein thereby the drive pinion ( 17 ) of the drive shaft ( 16 ) engages directly with the toothed wheel ( 13 ) at the inner body ( 9 ),

wherein the rotatable drive shaft ( 16 ), the drive pinion ( 17 ), the tubular sleeve ( 20 ), and the support fork ( 21 ) form a drive device ( 4 ),

wherein the matrix holder ( 3 ) and the drive device ( 4 ) are connectable and again disengageable from the matrix holder ( 3 ) for tensioning of the matrix band ( 2 ) placed like a loop ( 22 ) around the tooth of a dental patient, which tooth is to be treated.

13. The matrix retainer as claimed in claim 12 , wherein the toothed wheel at the upper end of the inner body ( 9 ) is a crown wheel ( 12 ); and

wherein an axis of the drive shaft ( 16 ) intersects with an axis of the crown wheel at a right angle.

14. The matrix retainer as claimed in claim 13 , wherein the drive pinion ( 17 ) is slightly conically beveled at its front face, such that the drive pinion ( 17 ) is better guidable into engagement with the crown wheel ( 13 ).

15. The matrix retainer as claimed in claim 12 further comprising

a rotary knob ( 19 ) provided at a second end of the drive shaft ( 16 ) disposed remote from the drive pinion ( 17 ), wherein the rotary knob turns the drive shaft ( 16 ) inside the tubular sleeve ( 20 ).

16. The matrix retainer as claimed in claim 12 further comprising

a ribbing ( 15 ) furnished on the inner body ( 9 ) between the gap ( 12 ) and the toothed wheel ( 13 , 27 ), wherein the ribbing ( 15 ) serves to adjust the torque so that the matrix band cannot come loose when used as intended.

17. The matrix retainer as claimed in claim 12 further comprising

a rotary knob ( 19 ) attached to a second end of the drive shaft ( 16 ) for turning the drive shaft ( 16 ) inside the tubular sleeve ( 20 );

wherein the support fork ( 21 ) protrudes forward underneath the drive pinion ( 17 ) from the sleeve ( 20 ), wherein the drive device ( 4 ) is pushable with the support fork ( 21 ) under the edge ( 7 ) of the housing ( 5 ) of the matrix holder ( 3 ) and wherein the drive pinion ( 17 ) comes into engagement with the toothed wheel ( 13 ) of the inner body ( 9 ).

18. The matrix retainer as claimed in claim 12 wherein

the support fork ( 21 ) has two tines, wherein the two tines extend in a direction parallel to the drive shaft ( 16 ), wherein the two tines have a rectangular cross-section, wherein each tine is furnished as a straight bar, and wherein the support fork is disposed at a height level located below a lower periphery of a motion of the drive pinion ( 17 ).

19. The matrix retainer as claimed in claim 18 further comprising a third edge ( 7 ) protruding in a front from the upper end of the housing ( 5 );

a fourth edge ( 7 ) protruding in a rear from the upper end of the housing ( 5 ), wherein the fourth edge ( 7 ) is disposed parallel to the third edge ( 7 ); and

wherein the third edge ( 7 ) and the fourth edge ( 7 ) are disposed perpendicular to the first edge ( 7 ) and to the second edge ( 7 ), wherein the edges ( 7 ) all have the same length;

wherein a distance between the two tines is smaller than an outer distance between the first edge ( 7 ) and the second edge ( 7 ) and is larger than the outer diameter of the housing ( 5 ) immediately below the first edge ( 7 ) and the second edge ( 7 );

wherein the housing ( 5 ) has a fourfold rotation axis and wherein two mirror planes of the housing ( 5 ) contain the fourfold rotation axis; wherein the housing contains three additional vertical slits ( 10 ); wherein each vertical slit ( 10 ) is furnished with two bevels (6′, 6″) on the outside of the housing ( 5 ).

20. A dental matrix retainer used as an aid when filling two-surface cavities in the molars, comprising

a housing ( 5 ) having a wall, having a circular opening ( 8 ), and having a slit ( 10 ) in the wall;

an edge ( 7 ) protruding from all sides at the housing ( 5 );

a inner body ( 9 ) rotatable in this circular opening ( 8 ) and which inner body ( 9 ) is provided with a gap ( 12 ), said gap ( 12 ) being able to be aligned with the slit ( 10 ) in the wall of the housing ( 5 ) such that superposed ends of a matrix band ( 2 ) are insertable into this slit ( 10 ) and into the gap ( 12 ) aligned with the slit ( 10 ) and said matrix band ( 2 ) is tensionable on a tooth of a dental patient by turning the inner body ( 9 );

a toothed wheel ( 13 , 27 ) provided on an upper end of the inner body ( 9 ) protruding from the circular opening ( 8 ) of the housing ( 5 ), wherein the housing ( 5 ), the edge ( 7 ) protruding from all sides at the housing ( 5 ), the inner body ( 9 ), and the toothed wheel ( 13 , 27 ) form a matrix holder ( 3 );

a laterally, outwardly extended rotatable drive shaft ( 16 );

a drive worm ( 17 ) furnished at an end of the rotatable drive shaft ( 16 ) and bringable into engagement with the toothed wheel ( 13 , 27 ) provided on the upper end of the inner body ( 9 ) protruding from the circular opening ( 8 ) of the housing ( 5 );

wherein the rotatable drive shaft ( 16 ), and the drive worm ( 26 ) form a drive device ( 4 ),

wherein the matrix holder ( 3 ) and the drive device ( 4 ) are connectable and again disengageable from the matrix holder ( 3 ) for tensioning of the matrix band ( 2 ) placed like a loop ( 22 ) around the tooth of a dental patient, which tooth is to be treated.