Matrix bands are used for creating a temporary wall which can be adapted to reproduce the anatomical contours of a tooth. They are mostly used to aid the reconstruction of proximal walls, and are important for creating a proximal contact point. They are available in different thicknesses and width. Usually made from stainless steel, polyester, acetate.
Transparent bands(polyester/acetate) are used when restoring with light curing materials such as composite – this allows the light to be exposed to the material covered by the band
Opaque bands (metal) are used with materials that do not require light curing
Matrix retainers – mechanical devices which hold and secure the matrix band in position
- Siqveland retainer – probably the most common retainer used for posterior teeth. Designed to give a narrow circumference in the gingival region and can be used to restore more than one missing wall in on time. Used with either narrow or wide metal matrix bands. The retainer and band are secured together in such a way that they are usually removed together from the tooth.
- Tofflemire retainer – invented by American dentist, Benjamin F. Tofflemire, used for posterior teeth. A screw is used to secure the metal matrix band in place. The metal matrix band designed for the Tofflemire retainer have an annular shape. This retainer has the advantage of allowing the matrix band to be removed separately from the retainer with relative ease.
- Ivory retainer – used for posterior teeth but can only restore one proximal wall at a time. This retainer uses claws to grip the metal matrix band in position. The metal matrix band has pre-punched holes similar to a belt to allow the retainer to grip the band easily
- Sectional retainers – a modern design of retainer used for posterior teeth. These retainers use a ring to secure the matrix band in position. Limited to restoring one proximal wall at time. These retainers generally create a better proximal contact point and anatomical contour. Pre-wedging is used to improve the contact point. Used when restoring with composite in the posterior region.
Wedges – placed interproximally to create a better restorative emergence profile and prevent overhang of the restorative material – usually plastic or wooden. Pre-wedging is the act of pushing a wedge interproximally before cavity preparation, widening the interproximal space, the idea is that after the restoration is complete and the wedge is removed the teeth will return to their normal position thus creating a tighter contact point
Matrix systems – describes the combination of band, retainer and wedges – there are many commercial matrix systems available.
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