Face Forward by Drs. Arthur R. Volker, Pantelis Kouros and Serhat Köken

Face Forward 

Matrixing strategies for the anterior and facial surfaces


by Drs. Arthur R. Volker, Pantelis Kouros and Serhat Köken


The purpose of a matrix is to function as a shape-former and facilitate the placement of materials such as amalgam or composite resin. Many options are available in terms of material selection and scope; this article will discuss various matrixing options as applied to anterior or facial composite restorations. Metal and plastic matrices will be discussed, specifically, as well as sectional and “full-contour” ones.

Plastic matrices: Mylar matrices are a ubiquitous part of every clinician’s armamentarium. Their many advantages include malleability, the ability to cure through, and the resultant highly polished surface when cured against composite.1,2 Issues can arise in areas of tight or irregular contacts, where the thin Mylar may not be able to traverse or may warp. Also, the thin strip may not hold its shape as readily as a metal matrix, though there are protocols to negate this effect,3 and stiffer anatomical Mylar matrices are available.

Metal matrices: Long used in posterior restorations, metal matrices are increasingly used in the anterior region. One reason is their stiffness, which will allow them to maintain their shape when placed. Additionally, metal matrices are often easier to place interproximally than plastic matrices. However, light will not pass through these matrices, so care must be taken when curing the composite restoration to ensure full polymerization.

Table 1
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Matrix style

Anterior and facial matrices are primarily used in two shape styles:

  • A sectional matrix is used to restore a specific portion of the tooth, such as a single proximal surface.

  • A “full-contour” matrix, in this context, refers to one that wraps around both proximal surfaces and encompasses the cervical portion of the tooth. These matrices can be used to restore proximal surfaces, as well as other restorations such as Class Vs and full-contour veneers.
The use of heated composite with an injection molding technique has been shown for both sectional matrices4 and full-contour ones.5 Advantages to employing heated composite include increased cavity adaptation, degree of conversion and reduced polymerization shrinkage.6 There are a number of heating units on the market, including the HeatSync (Bioclear), Calset (AdDent) and the Compex HD (AdDent).

Table 1 lists some advantages and disadvantages with various types of plastic and metal matrices. The following clinical vignettes demonstrate situations where a particular matrix may be utilized.


Example with plastic sectional matrix

The patient, in his late 30s and in good health, was unhappy with the black triangles present in his lower anterior (Fig. 1). He had been under the care of a periodontist for the past several years.

Because the area to be filled was very small, Bioclear matrices were chosen. A heavy, latex-free rubber dam was placed, and biofilm was removed with aluminum trihydroxide (Fig. 2). Small black triangle matrices (BT Matrices, Bioclear) were seated into the sulcular area (Fig. 3).

Using a combination of uncured bonding agent, heated flowable (Filtek Supreme Ultra Flowable, 3M) and heated paste composite (Filtek Supreme Ultra, 3M), the matrices were filled from #22 to #27 (Fig. 4). Fig. 5 demonstrates the two-day follow-up.

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Fig. 1
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Fig. 2
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Fig.5
 

Example with metal sectional matrix

The patient, 35 years old and in good general health, presented with large, failing composites on the central incisors, as well as a crown that needed to be placed on #10 (Fig. 6).

A rubber dam with floss ligatures was placed, and a stent was used to help create the palatal extent of the restoration and guide layering of composite (Fig. 7).

A nanohybrid composite (Micerium, Avengo, Italy) was used to build the composite toward the facial, and a sectional matrix (Tor VM, Moscow) was placed interproximally. The curvature of the matrix approximated the proximal surface, and a thin layer of composite was used to replicate this area (Fig. 8). Fig. 9 shows the area after curing of this composite layer. Subsequent layers were then added until the restoration was complete (Fig. 10).

Fig. 11 demonstrates a five-year follow-up.

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Fig.6
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Fig.7
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Fig.11


Example with plastic full-contour matrix

The patient, in her early 40s and in good health, was unhappy with the appearance of her front teeth. Caries were noted on Teeth #8, 10 and 11 (Fig. 12).

Because existing contacts were present, a flat Mylar matrix was employed. Contacts were smoothed with an interproximal sander (Contact EZ, DirectaDentalGroup). The Mylar was inserted into the sulcus at an approximate 45-degree angle and wood wedges were inserted to control unwanted ingress of material (Fig. 13). This angle created tension to slightly retract the gingival tissue, negating the need for retraction cord.

A small amount of heated flowable composite (Filtek Supreme Ultra Flowable) was placed (Fig. 14), but not cured. This was followed by heated paste composite (Filtek Supreme Ultra, Fig. 15). A hand instrument (OptraSculpt, Ivoclar Vivadent) was used to further adapt the composite to the tooth (Fig. 16).

Fig. 17 demonstrates the final result.

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Fig. 12
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Fig.13
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Fig.17


Example with metal full-contour matrix

The patient, in his mid-50s and in good health, presented with occlusal issues and multiple cervical lesions and wear, and complained of pain localized to #21.

Because strong and broad contacts existed, a flat Mylar might proved too fragile to pass through, and a metal Tofflemire matrix (Slick Bands, Garrison) was selected. Before placement, the Tofflemire was modified to provide a more anatomic contour.7

The matrix was placed into the sulcus at a slight facial angle with wedges (Fig. 18). To help stabilize the matrix, wooded wedges were placed, and the tooth was etched (Fig. 19) and bonded.

A heated flowable composite was placed but not cured (Fig. 20); then, a heated microfilled composite (Renamel Microfill, Cosmedent) was injected into the area (Fig. 21). After curing, excess composite was removed, and the restoration polished (Fig. 22).

Fig. 23 shows the immediate postoperative result.

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Fig. 18
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Fig.19
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Fig. 21
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Fig. 23



Conclusion

Whether composed of metal or plastic, matrices are available for any clinical situation and will help clinicians obtain their and their patients’ desired restorative outcome.
 

References
1. Bansal, K., Gupta, S., Nikhil, V., Jaiswal, S., Jain, A., and Aggarwal, N. “Effect of Different Finishing and Polishing Systems on the Surface Roughness of Resin Composite and Enamel: An In Vitro Profilometric and Scanning Electron Microscopy Study.” Int J Appl Basic Med Res. 2019 Jul-Sep;9(3): 154–158.
2. Uçtas¸li, MB, Arisu, HD, Omürlü, H., Eligüzelg?lu, E., Ozcan, S., and Ergun, G. “The Effect of Different Finishing and Polishing Systems on the Surface Roughness of Different Composite Restorative Materials.” J Contemp Dent Pract. 2007 Feb 1;8(2): 89–96.
3. Belvedere, PC. “Full-Mouth Reconstruction of Bulim-Ravaged Teeth Using Direct Composites: A Case Presentation.” Dent Today. 2009 Jan;28(1): 126–131.
4. Clark, D. “Restoratively Driven Papilla Regeneration: Correcting the Dreaded ‘Black Triangle.’ ” Tex Dent J. 2008 Nov;125(11): 1112–15.
5. Belvedere, PC, and Lambert, DL. “Creating the ‘Perfect’ Class V Composite: The Matrix Is Key.” Dent Today. 2016 Feb;35(2): 104–107.
6. Lopes, LCP, Terada, RSS, Tsuzuki, FM, Giannini, M., and Hirata, R. “Heating and Preheating of Dental Restorative Materials: A Systematic Review.” Clin Oral Investig. 2020 Dec;24(12): 4225–35.
7. Volker, AR, and El-Sayed Abdulhady, M. “The Use of a Modified Tofflemeyer Matrix for the Restoration of Cervical Lesions” The GP. In print.

Author Bio
Authors Dr. Arthur R. Volker practices in Sunnyside, New York.







Authors Dr. Pantelis Kouros practices in Thessaloniki, Greece.






Authors Dr. Serhat Köken practices in Istanbul, Turkey.





 

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