Show Your Work: Strike Up the Band! by Dr. Arthur R. Volker

Show Your Work: Strike Up the Band! 

How to use a modified matrix band when creating direct composite anterior veneers


by Dr. Arthur R. Volker
with Dr. Shimaa Abdelhady and Nayerra Zahran


Direct composite is an efficient, effective way to treat a patient’s functional and aesthetic needs, and direct resin veneers can be a single-visit treatment method to address them. However, direct veneers can be both technique-sensitive and time-consuming, causing some clinicians to abandon their use, opting instead for indirect veneers.

A major concern about direct resin is the potential for air bubbles or voids created from multiple layers of room-temperature composite. In more extreme cases, these voids can harbor stain or caries.1 Because composite is not condensable like amalgam, air entrapment can occur from multiple passes with a hand instrument such as a plugger. Manipulating composite resin as if it were amalgam may not be the optimal way to efficiently achieve desired results; instead, we can take advantage of the physical properties of the resin, such as its flow characteristics, to efficiently create restorations. One way to do so is to use a preformed matrix and heated composite to injection-mold the composite resin.

Matrix options
Anterior matrices are typically made of metal or plastic, each with its advantages and disadvantages,2 and are either sectional or full-contour. Sectional matrices, as their name implies, shapes only a portion of the tooth; common examples include Bioclear, Fusion Garrison Anterior (Garrison), and flat Mylar. Full-contour matrices, meanwhile, traverse from one proximal surface to the other and include the gingival area. Some common examples are the Unica (Polydentia), Uveneer (Ultradent) and Greater Curve matrices.

There are several advantages in using a metal full-contour matrix over a plastic one. For example, the matrix can be stabilized with the use of a retainer, and the stiff metal can traverse irregular or wide contacts more easily than a plastic matrix. However, because light will not penetrate the metal surface, care must be taken when polymerizing the composite resin. As such, modifications to the matrix will be made to help facilitate a more complete curing of the material.

The Greater Curve band, aka the “Banana Band,” is an aggressively profiled matrix, especially when compared with a standard Tofflemire matrix (Fig. 1). This curvature creates a tight seal in the cervical region while also accessing adjacent tooth surfaces, resulting in tight interproximal contacts.3 Though originally created to solve issues with posterior Class II restorations, it has proven to be valuable in simplifying anterior composite protocols as well.

Show Your Work: Artie Volker Case
Fig. 1

Heated composite and injection molding
There are several advantages in using heated composite over an ambient temperature one, including greater degree of conversion,4 marginal adaptation,5 lower polymerization stress6 and decreased viscosity.7 Because the material will flow better and more quickly, an appropriately shaped and adapted matrix will help to form an anatomical restoration.

While many options exist for composite heaters, they should be able to heat composite between 150–160 degrees Fahrenheit. This temperature range has been shown to not adversely affect the pulp.8 Commercially available heaters include the Compex HD and Calacet (both from Addent) and HeatSync (Bioclear).

Some methods of injection molding, such as the Bioclear method, use a combination of uncured bonding agent, heated flowable and heated paste composite, which are co-cured in a preformed Mylar matrix.9 Other methods use a heavily filled flowable composite and a clear silicone template.10

Case study

A 56-year-old patient without any medical conditions presented to the office dissatisfied with the appearance of her upper left front tooth (Fig. 2). Clinical examination revealed two cavities on #10: a mesial Class IV and a distal Class III, both extending to the facial surface. No signs of pulpal inflammation or necrosis were observed, and the tooth responded positively to thermal stimuli. To begin the procedure, the patient received anesthesia with 1.8 cc of 3% mepivacaine without epinephrine. Moisture reduction, tongue retraction and keeping the patient’s mouth open were achieved using a small Isolite device. Caries and undermined enamel were removed using a round diamond bur. An irregular pattern bevel was created on the cavosurface line angle with a flame diamond bur, enabling better blending of the composite with the tooth structure and enhancing the adhesive interface for composite bonding (Fig. 3).

Show Your Work: Artie Volker Case
Fig. 2
Show Your Work: Artie Volker Case
Fig. 3


A Greater Curve matrix band was placed around #10, with the matrix retainer positioned palatally. The band’s curvature provided an excellent subgingival seal, isolation, easy access and improved visibility (Fig. 4). Wooden wedges were inserted on both proximal surfaces to secure the position of the matrix band and prevent unwanted material ingress (Fig. 5).

Show Your Work: Artie Volker Case
Fig. 4
Show Your Work: Artie Volker Case
Fig. 5


Using a diamond football bur, the matrix band was trimmed from the facial following the scallop of the gingival tissue, leaving 3–4 mm of the matrix coronal to the tissue. This is an essential step to the protocol, because it will help the heated compule achieve backpressure for injection molding and will allow adequate light-curing of the material (Fig. 6).

Next, the tooth surface was etched with 35% phosphoric acid to create microscopic roughness on the enamel and dentin, facilitating micromechanical retention of the bonding agent (Fig. 7). Two applications of a fifth-generation bonding agent (Prime & Bond NT, Dentsply) were applied and light-cured after air-thinning (Fig. 8).

Show Your Work: Artie Volker Case
Fig. 6
Show Your Work: Artie Volker Case
Fig. 7
Show Your Work: Artie Volker Case
Fig. 8


A heated flowable composite (Filtek Supreme Ultra Flowable, 3M) was placed in the most apical aspect of the matrix without curing (Fig. 9). Subsequently, a heated paste composite (A2B, Filtek Supreme Ultra, 3M) was applied (Fig. 10). Excess composite was removed with a microbrush (Fig. 11). It is important to remove the flowable and paste composite before curing to facilitate removal of the matrix band and simplify shaping. The composite was then polymerized (Fig. 12).
Show Your Work: Artie Volker Case
Fig. 9
Show Your Work: Artie Volker Case
Fig. 10
Show Your Work: Artie Volker Case
Fig. 11
Show Your Work: Artie Volker Case
Fig. 12


The matrix band was removed and the restoration received additional light-curing from multiple angles. A final cure was performed under a DeOx gel (Ultradent) to ensure complete polymerization and removal of the oxygen-inhibited layer (Fig. 13). Excess composite was removed, and the restoration was shaped using a flame-shaped bur. A combination of discs and polishers was used for the final finishing, achieving a natural appearance consistent with the adjacent teeth (Fig. 14).

Show Your Work: Artie Volker Case
Fig. 13
Show Your Work: Artie Volker Case
Fig. 14


Overall, the case presented involved the successful restoration of Tooth #10 using appropriate techniques and materials to achieve an aesthetically pleasing and functional outcome.

Authors’ note: We wish to thank Dr. Dennis Brown for his guidance in the writing of this article.


References
1. Mjör IA, Toffenetti F. “Secondary Caries: A Literature Review With Case Reports.” Quintessence Int. 2000 Mar; 31(3):165–179.
2. Volker AR, Kouros P, Köken S. “Matrixing Strategies for the Anterior and Facial Surfaces.” Dentaltown. March 2022; 27(3):42–46.
3. “Greater Curve Matrix Class II Restoration.” Dentistry Today. Accessible at dentistrytoday.com.
4. Daronch M, Rueggeberg FA, De Goes MF. “Monomer Conversion of Pre-Heated Composite.” J Dent Res. 2005 Jul; 84(7):663–667.
5. Fróes-Salgado NR, Silva LM, Kawano Y, Francci C, Reis A, Loguercio AD. “Composite Pre-Heating: Effects on Marginal Adaptation, Degree of Conversion and Mechanical Properties.” Dent Mater. 2010 Sep; 26(9):908–914.
6. Calheiros FC, Daronch M, Rueggeberg FA, Braga RR. “Effect of Temperature on Composite Polymerization Stress and Degree of Conversion.” Dent Mater. 2014 Jun; 30(6):613–618.
7. Lucey S, Lynch CD, Ray NJ, Burke FM, Hannigan A. “Effect of Pre- Heating on the Viscosity and Microhardness of a Resin Composite.” J Oral Rehabil. 2010 Apr; 37(4):278–282.
8. Daronch M, Rueggeberg FA, Hall G, De Goes MF. “Effect of Composite Temperature on In-Vitro Intrapulpal Temperature Rise.” Dent Mater. 2007 Oct; 23(10):1283–1288.
9. Clark D. “Injection Overmolding Aesthetics and Strength, Part I: Finishing Orthodontic Cases Using Direct Composite.” Dent Today. 2014 Aug; 33(8):86–89.
10. Geštakovski D. “The Injectable Composite Resin Technique: Minimally Invasive Reconstruction of Esthetics and Function. Clinical Case Report With 2-Year Follow-Up.” Quintessence Int. 2019; 50(9):712–719.


Author Bio
Dr. Ahmad Fayad Dr. Arthur R. Volker graduated from the Columbia University School of Dental and Oral Surgery. He is a member of the continuing education committee for the New York State Academy of General Dentistry. Volker is a diplomate of the World Congress of Minimally Invasive Dentistry, and is a fellow of the Academy of General Dentistry and the American College of Dentists. He has also published articles and lectures on such topics as cosmetic dentistry, minimally invasive dentistry, dental materials and dental implants. He practices in Sunnyside, New York.


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