Introduction

In modern dentistry, patients are increasingly seeking an aesthetic alternative to amalgam for restoring posterior teeth1. Composite is widely recognised as a material that can be used for posterior restorations to give superior aesthetics2-4, and there has been an increase in the teaching of posterior composites worldwide5–8.

However, the placement of composite in posterior interproximal cavities can be difficult. The procedure is tech-nique sensitive that requires control of the operating field with a rubber dam, good adaptation of a matrix band interproximally and incremental placement/setting of the material to reduce polymerization shrinkage9. Additionally, establishing a favourable contact point with the adjacent tooth can be challenging 9, 10, since com-posite resins cannot be condensed like amalgam11.

Therefore, the adaptation of an inter-proximal matrix band and placement of a wedge are vital to optimise the restoration’s proximal contour and contact point. Restorations exhibiting poor contact points and contour can lead to subsequent problems includ-ing food trapping, caries and peri-odontal disease.

Ideally, when restoring an interproxi-mal surface with composite, an incre-mental technique should be adopted. This allows the application of ad-ditional pressure at the contact area with a hand instrument when placing the first layer of composite.

College News Spring/Summer 2012

Kiwi Composites Interproximal composite contouring for posterior teeth

J. Dickie, BDS, MFDS RCPS (Glas), Senior House Officer in Restorative Dentistry, Glasgow Dental Hospital and School

This leads to tighter proximal contacts than a bulk-fill technique with no ad-ditional pressure11. Wirsching et al.12 recently concluded that sectional matrix systems resulted in statistically significantly tighter proxi-mal contacts than a circumferential matrix system in Class II cavities. They also supported the use of a separation ring that is designed to actively sepa-rate the teeth. This was also advocated in a study by Loomans et al11.

The V3 System (Triodent) (Figure 1), originating from New Zealand, is a technique which uses a sectional matrix band, a wedge and a separation ring to produce tight contact points when restoring interproxmial tooth surfaces. This article aims to describe the use of this system and provide a video demonstration of the technique in practice.

Technique

1. Isolate the tooth under rubber dam.

2 Prewedge the interproximal area – this depresses the gingivae and pre-vents any iatrogenic trauma that can result in blood contamination.

3. Prepare the interproximal cavity / occlusal-interproxmial cavity.

4. Use the Pin-Tweezers to bend the tab of the matrix mesially for mesial cavities or distally for distal cavities to create a “contra-angle” which facili-tates matrix placement

5. Place the matrix with the Pin-Tweezers between the wedge and the tooth. The tab should point mesially for mesial cavities and distally for distal cavities. This is then folded over the occlusal surface of the adjacent tooth.

Figure 1 – The V3 Sectional Matrix System; a) Yellow (narrow) and green (universal) rings; b) Pre-formed matrices of varying sizes; c) Wave-wedges of varying sizes; d) Pin-Tweezers; e) Forceps

NOTE: Alternatively, the cavity can be cut first before placing the matrix and then the wedge (see video).

6. Use the V3 forceps to place the V3 ring over the wedge. The ring’s two V-slots allow it to overlap the wedge interproximally (Figure 2). Keep finger pressure on the matrix tab as the for-ceps are released to prevent displace-ment.

7. Check the ring position– the loop should project mesially for mesial cavities and distally for distal cavi-ties. The ring must contact the wedge (Figure 3).

8. If necessary, a second wedge can be placed from the other side of the tooth.

9. Restore the interproximal wall and marginal ridge using an incremental C-factor technique. The composite should be well packed against the matrix.

10. Restore the remaining occlusal cavity, again using a C –factor tech-nique to build the occlusal anatomy.

11. Remove the V3 ring and wedge(s).

12. Separate the matrix from the com-

posite with a probe. Grip the matrix with the Pin-Tweezers and slide out.

13. Finish the restoration – usually very little finishing is required.

References

1. Swarbrigg J. Competence breeds confidence. Premium Practice Den-tistry Magazine 2012 Jan: 40-41.2. Sidelsky H. Resin composite contours. British Dental Journal 2010 May; 208 (9): 395-401.3. Burke FJ, Shortfall AC. Successful restorations of load-bearing cavities in posterior teeth with direct-replace-ment resin-based composite. Dental Update 2001; 28: 388-98.4. Mair LH. Ten-year clinical assess-ment of three posterior resin compos-ites and two amalgams. Quintessence International 1998; 29: 483-490.5. Lynch CD, McConnell, RJ, Wilson NHF. Trends in the Placement of Pos-terior Composites in Dental Schools. Journal of Dental Education 2007; 71 (3):430–434.6. Lynch CD, McConnell, RJ, Wilson NHF. Teaching the placement of pos-terior resin-based composite restora-tions in U.S. dental schools. Journal of the American Dental Association 2006 May; 137: 619–625.

7. Hayashi M, Seow LL, Lynch CD, Wilson NHF. Teaching of poste-rior composites in dental schools in Japan. Journal of Oral Rehabilitation 2009; 36: 292-298.8. Gilmour ASM, Latif M, Addy LD, Lynch CD. Placement of posterior composite restorations in United King-dom dental practices: techniques, problems, and attitudes. International Dental Journal 2009 Jun; 59(3):148-54.9. Doukoudakis S. Establishing Ap-proximal Contacts in Class 2 Com-posite Resin Restorations. Operative Dentistry 1996; 21: 182-184.10. Krauss S. Achieving Optimal Inter-proximal Contacts in Posterior Direct Composite Restorations. Journal of the American Dental Association 1998 Oct; 129: 1467.11. Loomans BA, Opdam NJK, Roeters JFM, Bronkhorst EM, Plass-chaert AJM. Influence of Composite Resin Consistency and Placement Technique on Proximal Contact Tight-ness of Class II Restorations. Journal of Adhesive Dentistry 2006; 8 (5): 305 -310.12. Wirsching E, Loomans B A, Klai-ber B, Dörfer C E. Influence of matrix systems on proximal contact tightness of 2- and 3-surface posterior com-posite restorations in vivo. Journal of Dentistry 2011 May; 39(5): 386-90.

Figure 2 (top left) – The V3 ring’s V-slots should overlap the wedge interproximally on both the buccal and lingual/palatal sides. Figure 3 (bottom left) – The assem-bled V3 system in situ. Figure 4 (above) – Multiple matrices, wedges and V3 rings can be used (and stacked if necessary) for multiple interproximal restorations.Figures 2, 3 and 4 courtesy of Optident UK.