Using an Auto-Dispensed Composite Core Build-Up Material

Historically, when endodontic treatment was performed, the cast post-and-core was a standard procedure. However, the literature indicates that the possibility of root fractures and excessive removal of sound tooth structure, resulting in a weakened tooth, can occur.^3,4 If conservative endodontic therapy is performed with a minimal access opening, then a post is not necessary. Composite resin can be used to restore the opening.

When indirect alternatives are selected, multiple appointments and laboratory fabrication expenses increase the cost of the procedure. As a possible result of this, it is this author’s observation that there has been increased use of direct core build-up fabrication procedures using composite resin. For both endodontically-treated and vital teeth, the use of composite resin as a direct core build-up material has gained popular acceptance over the last several years.⁵

A new material to aid the dentist when confronted with deciding which core build-up technique to use has recently been introduced. The CosmeCore system (Cosmedent,® Inc., Chicago, IL) is an auto-mix composite core material specifically designed for the fabrication of core build-ups.

This material is dispensed with an application gun and auto-mix tip, eliminating the need for hand mixing. It is easily placed in the tooth and will not slump, often eliminating the need to use a matrix band. The mix is predictably consistent because the base and catalyst are auto-dispensed in equal amounts. Therefore, clinicians only use the amount of material needed, without encountering the problems of too little, too much, or wasted material.

This core build-up composite is available in 3 shades (blue, white, and A-2). The blue material is used under all metal or porcelain-fused-to-metal (PFM) restorations; it is easily distinguished from tooth structure. The white and A-2 shades are ideal under all-ceramic restorations or for endodontic access closure.

CosmeCore is a dual-cure material that stacks well, according to the manufacturer. The material will bond to itself, so additional material can be added to it once it is initially cured.

When placing a post, this core build-up material can be injected into the canal space following standard bonding protocol, thereby eliminating a separate cementation procedure. The manufacturer notes that the material demonstrates a high compressive strength, which contributes to durable, long-lasting restorations. A 4-year study involving 200 patients has demonstrated that a fiber-reinforced core resin system is superior to the traditional cast post-and-core procedure.⁵

A patient presented with a fractured maxillary left bicuspid that required core build-up and placement of a full-coverage crown restoration. In pbodyicular, the buccal cusp was fractured (Figure 1 and Figure 2).

A rubber dam was placed (Figure 3) and the amalgam restoration removed (Figure 4). A matrix band was placed (Figure 5), after which the tooth was etched for 15 seconds (Figure 6).

A fourth generation bonding agent was used, for which the primer (All-Bond® 2, Bisco, Inc., Schaumburg, IL) was applied to the preparation in multiple coats for 20 seconds (Figure 7). Then, a dentin/ enamel resin was placed (Figure 8) and light-cured for 20 seconds (Figure 9).

To fabricate the core build-up, the blue CosmeCore material was auto-mixed, injected into the preparation, and light-cured for 40 seconds (Figure 10 and Figure 11). Final preparation of the build-up was completed immediately after polymerization (Figure 12). Once complete, the core build-up—due to the use of the blue material—was easily discerned from the tooth structure.

The case presented here demonstrated the manner in which the CosmeCore system’s intraoral tips eliminated the need for loading the material into a different syringe for placement. Rather, the material was dispensed directly from the cbodyridge into the preparation. Additionally, it prepared similar to dentin while simultaneously releasing fluoride. According to the manufacturer, because this material can be bulk filled and cured to a depth of 5 mm in 40 seconds, the tooth can be prepared without having to wait for several minutes. In this case, the ability to prepare the build-up within 40 seconds after polymerization contributed to an efficient restorative procedure.

The author is the developer of CosmeCore and receives royalties from the sale of this product.

Robert C. Margeas, DDS
Adjunct Professor
University of Iowa College of Dentistry
Depbodyment of Operative Dentistry
Iowa City, Iowa

Private Practice
Des Moines, Iowa