Ch. 49 - Matrix Systems for Restorative Dentistry

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Ch. 49 - Matrix Systems for Restorative Dentistry

  1. 1. Matrix Systems for Restorative Dentistry Chapter 49 Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.
  2. 2. Chapter 49 Lesson 49.1 Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.
  3. 3. Learning Objectives <ul><li>Pronounce, define, and spell the Key Terms. </li></ul><ul><li>Describe the use of matrix systems in class II, III, and IV restorations. </li></ul><ul><li>Describe the type of matrices used for posterior restorations. </li></ul><ul><li>Describe the purpose and use of a wedge. </li></ul><ul><li>Discuss alternative methods of matrix systems used in restorative dentistry. </li></ul><ul><li>Assemble a universal retainer and matrix band. </li></ul><ul><li>(Cont’d) </li></ul>Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.
  4. 4. Learning Objectives <ul><li>(Cont’d) </li></ul><ul><li>Place and remove a matrix band and wedge for a class II restoration. </li></ul><ul><li>Place and remove a matrix band and wedge for a class III restoration. </li></ul>Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.
  5. 5. Introduction <ul><li>A matrix system provides a “temporary wall” for the restoration process in class II, III and IV preparations. </li></ul>Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.
  6. 6. Posterior Matrix System <ul><li>Universal retainer </li></ul><ul><li>Also referred to as Tofflemire retainer </li></ul><ul><ul><li>Holds the matrix band in position </li></ul></ul><ul><ul><li>Positioned most commonly from the buccal surface of the tooth being restored </li></ul></ul>Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.
  7. 7. Components of Universal Retainer Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.
  8. 8. Matrix Bands <ul><li>Thin, flexible stainless steel </li></ul><ul><li>Common designs </li></ul><ul><ul><li>Universal </li></ul></ul><ul><ul><li>Extension </li></ul></ul><ul><li>Guidelines for placement </li></ul><ul><ul><li>Larger circumference: occlusal edge </li></ul></ul><ul><ul><li>Smaller circumference: gingival edge </li></ul></ul>Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.
  9. 9. Fig. 49-2 Most commonly used posterior matrix bands. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.
  10. 10. Wedges <ul><li>Positioned into the lingual embrasure of a class II preparation after band placement </li></ul><ul><ul><li>Positions the matrix band firmly against the gingival margin of the preparation </li></ul></ul><ul><li>Various sizes </li></ul><ul><ul><li>Triangular/round </li></ul></ul><ul><ul><li>Wood/plastic </li></ul></ul>Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.
  11. 11. Fig. 49-5 Assortment of precontoured wedges. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.
  12. 12. Anterior Matrix Systems <ul><li>Plastic matrix </li></ul><ul><ul><li>Also referred to as: </li></ul></ul><ul><ul><li>Celluloid matrix </li></ul></ul><ul><ul><li>Mylar strip </li></ul></ul><ul><ul><li>Used in Class III and IV restorations </li></ul></ul>Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.
  13. 13. Fig. 49-7 A clear matrix system. (Courtesy of Premier Dental Products.) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.
  14. 14. Using an Anterior Matrix <ul><li>Placed interproximally before the etching and bonding of a tooth. </li></ul><ul><li>After the placement of composite material, a matrix is pulled tightly around the tooth to help reconstruct its natural contour. </li></ul><ul><li>A clear plastic matrix allows curing light to penetrate the material and complete the curing process. </li></ul>Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.
  15. 15. Automatrix System <ul><li>The automatrix system is an alternative to a universal retainer. </li></ul><ul><li>No retainer is used to hold the band in place. </li></ul><ul><li>Preformed bands available in assorted sizes in both metal and plastic. </li></ul><ul><li>Each band has a coil-like auto-lock loop. </li></ul><ul><li>A tightening wrench is inserted into the coil and turned clockwise to tighten the band. </li></ul><ul><li>When the band is to be removed, a tightening wrench is inserted into the coil and turned counterclockwise to loosen the band. </li></ul><ul><li>Removing pliers are used to cut the band. </li></ul>Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.
  16. 16. Fig. 49-9 Automatrix system. (Courtesy of Dentsply Caulk.) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.
  17. 17. Sectional Matrices <ul><li>A thin, polished palodent-type band and tension ring produce tight anatomic contact for composite resin materials in class II restorations. </li></ul>Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.
  18. 18. Fig. 49-10 Sectional matrices. (Courtesy of Garrison Dental Solutions.) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.
  19. 19. Matrix Systems for Primary Teeth <ul><li>T-band </li></ul><ul><ul><li>When formed, the top portion of the T allows the straight portion to adjust and fit the circumference of the primary molar. </li></ul></ul><ul><li>Spot-welded band </li></ul><ul><ul><li>Form-fitted band placed around a prepared tooth; removed and placed in a smaller form of a welder, fusing the metal together to make a custom band. </li></ul></ul>Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.
  20. 20. Fig. 49-11 Copper T-band used for primary molars. Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.
  21. 21. Preparing the T-Band Matrix <ul><li>The wings of the T-band are bent to form a U-shaped trough. </li></ul><ul><li>The free end of the band is slipped loosely through the U formation. </li></ul><ul><li>The wings are closed, and the free end is pulled to make a small circle of the band. </li></ul><ul><li>Holding the free end toward the facial surface, place the band on the tooth to be prepared. </li></ul>Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.
  22. 22. Fig. 49-12 Spot welder used for primary molars. (Courtesy of Unitek, Monrovia, Calif.) Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.
  23. 23. Preparing a Spot-Welded Matrix Band <ul><li>Measure ¾ to 1 inch of stainless-steel matrix material. </li></ul><ul><li>Fit the matrix band around the prepared tooth. </li></ul><ul><li>Adapt the band, making sure that the ends of the matrix material are at the facial surface for the sake of visibility and control. </li></ul><ul><li>Using Howe pliers, hold the ends tightly and remove the band in an occlusal direction. </li></ul><ul><li>Place the band in the spot welder. </li></ul><ul><li>Spot-weld the matrix at three positions. </li></ul>Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

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