Synchro Matrix

Building contours and contacts in anteriors is always a challenge, in this article we can learn how to achieve both in a very simple way. It is not only the matrix strategy which leads to success of simple anterior restorations, but the composite mass selection and its opacity which allows us to fully concentrate on the modeling technique and composite placement.

Some years ago I had terrible problems while layering 2 or more masses in anterior proximal cavities as the ones depicted below. These restoration represented a big challenge by being extremely difficult to calibrate and anticipate the color outcome by the mixture of two superposition masses as enamel and dentin. There were 3 possible outcomes:

1 – Restoration too translucent because of an enamel excess
2 – Restoration too opaque because of a lack of enamel and much display of the dentin
3 – Perfect outcome with perfect balance

Being the third situation the most unpredictable and the less common.

It has been already 8 years since I haven’t used 2 or more masses in this kind of restorations for many reasons, one of them is because by using a single shade with balanced opacity solves most cases with the precision shown in this final picture.

Achieving a precise contact point and a nice contour is possible by focusing all our concentration in modeling. Using a single mass helps to do so as it will be no longer necessary to think about thickness of the material. I would like to present you a simple case, that if managed wrongly could become a daily problem or vice versa.

Materials:
Garrison Slick Bands SM Bands
or
Garrison Composi-Tight M Bands
or
Garrison Composi-Tight Gold Bands

 

styleitaliano style italiano third class composite restoration single mass matrix placement wedge curved proximal

Fig.1

Initial situation, distal of 11 and mesial of 12 with two stained old composites. Besides the aesthetical problem, the patient referred food trapping, loose contact point and floss breaking. We decided to substitute the old restorations completely rather than only repairing them.
We will make a single shade personalised shade guide with a Body shade and we will choose the color with the best match. Depending on the composite system is not necessary to build a shade guide, the color correspondence with VITA allow to use the Vita Classical and use the correspondent body shade.
styleitaliano style italiano third class composite restoration single mass matrix placement wedge curved proximal

Fig.2

Before any proximal intervention we always advise to insert a tight wedge, this has 3 aims:
a) separate teeth
b) protect the rubber dam
c)temporarily displace the papilla
styleitaliano style italiano third class composite restoration single mass matrix placement wedge curved proximal

Fig.3

The access to the cavity, contrary to the old concept, is now done through the less destructive path. In this case the vestibular composite is the perfect way to access both cavities in order to remove and clean properly. A good tip to be able to do this is by cutting the wedge almost at the level of the teeth, making it short and not capable of interfering with the bur and turbine.
styleitaliano style italiano third class composite restoration single mass matrix placement wedge curved proximal

Fig.4

Cavity design following a very useful rule. If the cavity extends beyond the transitional angle is strongly advised to perform a bevel. On the contrary case, if the cavity does not extend beyond the transitional angle we can leave the cavity with no further prep. Here we can see both examples, on the tooth 12 the cavity without bevel and in the 11 the cavity with a short bevel.
styleitaliano style italiano third class composite restoration single mass matrix placement wedge curved proximal

Fig.5

After finishing the cavities, the preparation wedge (the short wedge that we previously cut) is taken out. Further cleaning of the area outside the cavity can be done in case necessary.
styleitaliano style italiano third class composite restoration single mass matrix placement wedge curved proximal

Fig.6

This is the main tip of the article. Since many yearsI have been using exclusively posterior matrices in upper anterior teeth rather than any king of transparent strip. These matrices perform excellently providing an ideal proximal contour and are rigid enough to make them very easy to place. It is important to choose correctly the matrices, a very convex matrix (as is very common to find on the market) will represent a disadvantage as they tend to deform during placement. On the other hand a flat matrix will eliminate all the advantages of using a curved matrix. I personally use Garrison Slick Bands SM Bands which I found to have the ideal curvature balance.
At this stage, we place the matrices simultaneously, one per cavity, facing each other on the convex side. This strategy gives the advantage of self stabilization of the matrix even in more extreme cases. One matrix supports the other and vice versa. There are very few cases that do not allow the synchronized placement of the matrices.
We will describe how to obtain a very strong contact point with this strategy, using all time concepts.
styleitaliano style italiano third class composite restoration single mass matrix placement wedge curved proximal

Fig.7

We choose one cavity and fill it up. We can do this with as many increments as necessary. Generally if the cavity is small, we do one increment on the proximal and one on the centre of the cavity.
styleitaliano style italiano third class composite restoration single mass matrix placement wedge curved proximal

Fig.8

After curing, we will remove with strong tweezers the matrix of the completed restoration and immediately we will do a very important step which consists in pushing the wedge strongly, not how the teeth separate slightly. This procedure will create space in order to compensate the thickness of the second matrix.
styleitaliano style italiano third class composite restoration single mass matrix placement wedge curved proximal

Fig.9

Once the second cavity is completed, thanks to the pressure of the wedge the contact will be very strong once removed. Note how the contours are rounded and will most probably look natural after finishing.
styleitaliano style italiano third class composite restoration single mass matrix placement wedge curved proximal

Fig.10

The wedge is removed and the contact is verified with floss. The finishing stage is done with the burs from the kit Finishing Style, specially the low speed diamond bur, discs and Spiral wheels with paste and for the last step a felt wheel.
styleitaliano style italiano third class composite restoration single mass matrix placement wedge curved proximal

Fig.11

 

Final aspect of the restoration after one year. Gloss, shape and adjustment will most probably determine the longevity and success of these restorations.

Conclusions

Working with a trustworthy protocol of a single shade and focusing on the shape and modeling rather than on the color will help us very much on achieving daily success in such a challenging restorations. The systematic use of body shades as a single mass for class III and class V restorations transformed these cavities from being challenging to being again and easy and repeatable daily protocol.

Bibliography

1. Devoto W, Saracinelli M, Manauta J. Composite in everyday practice: how to choose the right material and simplify application techniques in the anterior teeth. Eur J Esthet Dent. 2010 Spring;5(1):102-24.
2. Manauta J, Salat A. Layers, an Atlas of Composite Resin Stratification, Quintessence 2012.