A unique anatomical matrix and composite techniqueTony Beale looks at this new matrix system

50 www.dentistry.co.uk Dentistry MArkeTplAce

Appropriate uses The ClarkMatrix system is a new and extremely useful aid for all dental practitioners.

Whilst being very appropriate in cosmetic dentistry, it also offers restorative dentists the opportunity to correct several common dental problems.

Among these, the so-called ‘Black Triangle’ disease (Triangularis Nigra) is very common, and is regarded as being difficult to rectify. It can be observed in approximately 30% of adult patients, usually in lower anteriors, and can spoil the appearance of an otherwise good dentition. It can cause food trapping and plaque accumulation, making good oral hygiene more difficult, as well as creating an appearance of premature ageing.

Diastemas are also quite commonplace, with patients requesting some form of closure to improve their overall aesthetic appearance. Peg laterals are another example, where cosmetic correction is desirable, but ideally should not involve extensive tooth structure removal, and subsequent fabrication of a crown. In all these instances, the ClarkMatrix system can be easily utilised.

Description of the systemThe ClarkMatrix was developed in the USA by dental innovator and educator, Dr David Clark. His applied dental techniques often involve a minimally invasive approach, together with the use of composite resins.

The ClarkMatrix technique centres on a range of ‘ready-to-use’ transparent matrices that are anatomically contoured, with a defined shoulder that can then be filled with composite resin. Conventional light curing of both labial and lingual tooth aspects can then be easily undertaken. The matrices enable correctly shaped mesial and distal tooth aspects to be reproduced. This can result in the correction of gingivally deficient interproximal areas together with the restoration of tooth contact points, and subsequent improved aesthetic appearance.

The matrices offer many advantages over more conventional types, which cannot be properly shaped to reproduce correct anatomical configurations. Each ClarkMatrix form has the correct amount of cervical curvature, and a positioning tag that permits easy placement and orientation.

How to useIn using ClarkMatrix, it is essential that the areas to be treated be thoroughly cleaned. The use of an air-polishing device, such as Optident’s EMS Air Flow, with sodium bicarbonate is recommended. No invasive preparation of the teeth is necessary.

A suitable ClarkMatrix form should be selected, and the positioning tag used to orientate the matrix on the tooth. The selected

The ClarkMatrix system is marketed in the USA under the name Bioclear.The ClarkMatrix system is available from Optident Ltd, International Development Centre, Valley Drive, Ilkley, LS29 8AL Tel: 01943 605050 Email: sales@optident.co.uk Web: www.optident.co.ukThe clarkMatrix display stand containing a

complete range of clarkMatrix forms

examples of large and small lower anterior clarkMatrix forms

Two clarkMatrix forms shown in situ in a cosmetic correction of the lower anteriors

being used at medium speed with a water spray to avoid overheating of the composite.

The above described technique is recommended for use in ‘black triangle’ cases, diastema closures, and for peg lateral rebuilding. However, in cases where gingival margins are open, it is recommended that use be made of a Clark Interproximator, or Sabre Wedge to seal the gingival margin.

The ClarkMatrix can also be used in posterior cases in combination with the Clark TetraRing matrix clamp.

matrix must have the correct degree of cervical contour. An excessive degree of contour will result in the matrix inverting. The matrix must also be pushed under the gingival margin to create an effective marginal seal.

Once it is correctly positioned, an explorer can be used to pull back the flexible wall of the matrix allowing application of an etching gel (e.g. Optident ‘Ultra Etch’). The gel must reach the gingival areas.

Placement of a bonding resin should then follow. Dr Clark suggests that a flowable composite be used in a syringe, and injected under the matrix, but this should not be cured. Paste composite resin can then be injected into the uncured pool of flowable composite, thus allowing both labial and lingual curing in a single operation. This method is time saving for both patient and operator. Any excess resin material can be removed with a dry brush before curing. Shaping of both labial and lingual aspects of the tooth must then be completed before curing.

Following light curing an explorer can be used to tease away the matrix form and a micro haemostat employed to roll it out of contact. Conventional finishing and polishing can then follow, with ‘brownie’ or similar points