I love it when continuing education lecturers are quick to say that they don't do anything but indirect restorations. Cool story. I am not sure what world these people live in. Maybe they practice in the one zip code in the country where no one needs direct restorations, and everyone can afford indirect restorations for everything. Or maybe they have associates who get stuck with all the mesial-occlusal-distal (MOD) composites. Whatever the case, that's not the world I live in. I do direct resin composite restorations every single day. You probably do too. Sectional matrices are one of the most important tools in my bag for the days I spend slumming it with resin composite.
Sectional matrix systems offer so many advantages over old-school matrix bands, especially in today's age of resin composite. When we used amalgam, we were able to pack it forcefully into the contact area and produce anatomically correct contours as we went along. Amalgam could also be carved more easily than resin composite, making it simpler to remove flash. While you can certainly finish resin composite with a bur, removing flash and refining contours are significantly more difficult with posterior interproximal restorations. Sectional matrix systems significantly reduce the amount of flash and yield contours more anatomical than those achieved with traditional matrix bands. This has an important clinical implication: the less flash and more anatomical contours we get during our fill, the less time we spend finishing and refining the restoration. Sectional matrices make me faster, which makes me more profitable.
We also get improved interproximal contacts with sectional matrix systems compared to traditional matrix bands. Anatomical matrices, wedges, and rings that apply pressure to the adjacent tooth all contribute to this. Traditional matrix bands leave us with straight, nonanatomical walls that lead to point contacts, instead of the solid contact areas we get with sectional matrices.
If it sounds like I have trashed my Tofflemires for good, that's not entirely accurate. There are situations when I might dust one off. One of those situations would be a Class II restoration with no adjacent tooth. In order to use a sectional matrix system, an adjacent tooth must be present to hold the ring and matrix in place. Things work out OK with a band in those situations because we aren't concerned with getting an interproximal contact, and with open access to the entire restoration, we can easily refine contours.
One common complaint I hear from other clinicians about sectional matrix systems is how the arms of the ring can get in the way of restoring the tooth. This can be true and is a valid complaint. But I found a solution: The new Waterpik ClearView sectional matrix system has universal rings with longer arms to help offset the ring from the tooth and allow access to the entire tooth. This is handy for MOD restorations, too, which can involve a lot of hardware—two matrices and two rings—in a small area. Before using this system, I would routinely handle the interproximal portion of the restoration, then remove the ring to access the occlusal and either the buccal or lingual extensions of the preparation or another interproximal box. This was an extra step that ate time and introduced a risk of blood or saliva contamination. With the ClearView system, I have not once had to remove a ring to finish a restoration.
The ClearView matrix system comes with nonstick matrices in an array of different sizes and a selection of anatomical plastic wedges. There is a learning curve in applying a sectional matrix system that may take you some time to master. I always recommend prewedging and preparing the tooth with a wedge in place. After the preparation is finished, remove the wedge and place the appropriate matrix.
You will know immediately what size matrix you need after you become familiar with the system, but until then you might need to measure the depth of the box with a probe. The matrix should be slightly taller than the box is deep. Slide your chosen matrix into place and try to slip it into the gingival sulcus. You will probably need to wrap it around the line angles and push gingivally to get it to slide into the sulcus around the facial and lingual. The matrix should end at or slightly above the height of the adjacent marginal ridge. This will help you shape your composite to the correct height to minimize occlusal adjustments.
After the matrix is in the correct position, apply the wedge, making sure that it pushes against the matrix and the matrix doesn't slip coronal to the wedge. I often need to keep apical pressure on the matrix during this step to keep it from riding up. If the wedge isn't putting pressure on the gingival portion of the matrix, you could end up with substantial flash, an overhang, or contamination during the fill.
Once the wedge and matrix are in place, apply the universal ring. With the Waterpik ClearView system, the long-armed rings almost make the direction of the bow of the ring irrelevant. Either way, it won't be in your way during the restoration. Once the assembly is in place, I burnish the interproximal contact area slightly to make sure the matrix is pressed firmly against the adjacent tooth.
After the restoration is placed and cured from the occlusal, I remove the universal ring. Once the ring is removed, I use an explorer to bend back the matrix, exposing the facial and lingual line angles of the restoration. This is a good opportunity to make sure there are no visible voids and cure from another angle. I then cure the restoration again for a few seconds from the facial and lingual aspects. Once this is completed, I remove the wedge and matrix.
The nonstick coating on the matrices in the Waterpik ClearView system makes them easy to remove. Provided I applied the matrix with care, finishing and polishing are quick and easy, and the patient leaves with an anatomical Class II restoration with a good interproximal contact!
If you are interested in transitioning from traditional matrix bands to a sectional matrix system, there are several great systems on the market. I could not recommend making this switch any more strongly. It is a tremendous way to increase your speed, your profitability, and the quality of your Class II restorations.
Joshua Austin, DDS, FAGD, is an editorial director for Pearls for Your Practice: The Product Navigator, an e-newsletter from DentistryIQ and Dental Economics. He also writes the Pearls for Your Practice column in Dental Economics. After graduating from the University of Texas Health Science Center Dental School, Dr. Austin associated for several years. In October , he opened a solo general practice in a suburban area of San Antonio, Texas. Dr. Austin is involved in all levels of organized dentistry and can be reached at [ protected].
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