Dental Matrix Systems: Tofflemire, Siqveland and Sectional Matrices

Why matrix systems matter

When you restore a Class II cavity — one that involves a proximal surface — the natural wall of the tooth is gone. A matrix system temporarily rebuilds that wall so the restorative material can be packed against a defined surface, producing a tight contact point, the correct contour and a smooth gingival margin. Choosing the right system is the difference between a restoration that floss snaps cleanly through and one with an open contact or an overhang.

Circumferential (band-and-retainer) matrices

These wrap a band right around the tooth and are held by a retainer.

Tofflemire (Universal) retainer

The most widely used system. A metal band is loaded into the retainer and a knurled knob adjusts the loop to fit the tooth. Tofflemire retainers come in junior and adult sizes and suit both amalgam and composite. They are simple, reliable and economical.

Siqveland matrix

A self-adjusting retainer: as you tighten it, the band automatically conforms to the tooth contour. Available in narrow and wide forms for different tooth sizes.

Ivory and retainerless systems

The Ivory matrix holds a band for single-tooth access, while retainerless coiled bands suit situations where a bulky retainer is awkward.

Sectional matrix systems

Modern posterior composite work often favours sectional matrices: a small, curved, contoured metal band is placed only at the proximal box, then a separating ring (often nickel-titanium) seats over the wedge to hold the band and gently separate the teeth. The result is excellent anatomical contour and a tight, well-shaped contact — key for composite, which does not pack laterally like amalgam.

• Sectional band — pre-contoured for natural proximal anatomy.
• Separating ring — provides separation force to compensate for band thickness and create a tight contact.
• Wedge — seals the gingival margin and prevents overhangs.

The role of wedges

Whatever system you use, the wedge is essential. It adapts the band to the gingival margin, provides slight tooth separation and helps prevent material flowing past the margin. Wooden and plastic wedges are both common.

Choosing the right system

• Amalgam Class II — a Tofflemire or Siqveland circumferential system works well, since amalgam is condensed firmly against the band.
• Posterior composite — a sectional matrix with a ring usually gives the best contact and contour.
• Large or broken-down teeth — circumferential systems offer full-coverage support.

Material and care

Retainers and bands are made from autoclavable stainless steel; separating rings are typically nickel-titanium. Bands are often single-use, while retainers and rings are cleaned and sterilised between patients. Inspect rings for loss of springiness over time.

Dental Expert supplies Tofflemire, Siqveland and Ivory matrix retainers and related restorative instruments to clinics across Italy and Europe.