Practice Solutions: Providers and Patients Benefit from VOCO’s Rebilda Post GT

INNOVATIVE POST DESIGN PRESERVES MAXIMUM TOOTH STRUCTURE

Featuring an innovative design, the new Rebilda Post GT from VOCO is a glass fiber-reinforced resin post that offers enhanced strength and adaptability. Its unique design helps clinicians maximize the preservation of healthy tooth structure. One of the drawbacks of using root posts — a common clinical necessity when repairing endodontically treated teeth — is the required removal of healthy tooth structure in order to have enough space to place the root post. Additional common challenges include atypical root canal anatomy (such as strongly curved canals, oval root cross-sections and pronounced conicity) that also requires further mechanical preparation, potential loss of additional dentin and extended chairtime.

VOCO’s Rebilda Post GT offers an innovative practice solution to these common issues. The Rebilda Post GT is available as a post kit, but is also packaged in a Rebilda Post GT System Kit that includes VOCO’s award-winning Rebilda DC (core buildup/post cement) and Futurabond U (adhesive), plus supporting products, so clinicians have a complete post-and-core system.

Recognizing the frequency with which operators face these challenges, VOCO developed a glass fiberreinforced resin root post that consists of a bundle of fine individual posts (0.3 mm in diameter) in varying numbers, depending on post size. Rebilda Post GT features high radiopacity (408% Al), as well as high flexural strength and fracture resistance (1040 MPa), while its elasticity (31.5 GPa) is similar to dentin (Figure 1). While indicated in support of the typical everyday post situation, Rebilda Post GT, unlike traditional root posts, is also engineered for all root situations — offering further clinical value due to the enhanced strength and flexibility of Rebilda Post GT’s individual fine posts.

So, whether it’s used for treating a tooth with atypical anatomy or a mechanically prepared root canal, Rebilda Post GT is highly effective. Once the sleeve is removed, the bundle is spread and the fine individual posts are distributed in the entire root canal. Again in contrast to conventional root posts, this provides homogeneous reinforcement of the entire core buildup. Rebilda Post GT also offers advantages in the subsequent treatment procedure that include:

No need for a special drill to suit the size of the post: The post bundle adapts to the root canal, so when using Rebilda Post GT, no additional tooth substance needs to be sacrificed and there is no further weakening of the tooth structure.

Simple insertion into the root canal: The bundling of the fine individual posts with the color-coded sleeve makes selecting the Rebilda Post GT as easy as selecting a conventional root post.

Adapts to atypical root canal morphology: After insertion of the post, and prior to curing the post cement, the sleeve that’s used to bundle the posts should be removed and the individual posts spread out in the root canal with a suitable instrument (e.g., a spreader). This ensures more homogeneous reinforcement of the post cement.

Buildup reinforcement: Distribution of the fine individual posts spreads them out in the area of the core buildup. This increases the available surface area between the post and core buildup restoration, increasing the adhesion and retention values, and resulting in a post-and-core restoration that provides enhanced strength and longevity.

EFFECTIVE SYSTEMATIC CORONAL BUILDUP

The aim of a post-assisted core buildup is to absorb any force peaks occurring in the buildup or coronal restoration via the reinforcing root post. The bond strength shown in Table 1 simulates a core buildup and measures the shear force required to cause the overall construction to fail. It is evident that the bond strength of Rebilda Post GT (which is comprised of 12 fine individual posts) is comparable to, or better than, single-post systems of equivalent diameters.

In addition, the absorption of force peaks from the complete buildup by Rebilda Post GT can be calculated in a finite element method analysis. This simulates the maximum loads occurring in the root post and the surrounding buildup material caused by an applied force of 50 N. The calculated “von Mises stresses” show that even the smallest size of Rebilda Post GT (No. 4) is equivalent to a single master post (ST post) of the same material and a diameter of 1.5 mm.

As the number of individual posts increases, the intended result is achieved even more effectively: The stress peaks in the core buildup material decrease with the increase in post numbers, which means the force peaks are absorbed by the individual posts — which are capable of accepting considerably higher loads. As a result, the entire buildup is significantly reinforced.

BUNDLED, GLASS FIBER-REINFORCED RESIN

Indications: Core buildup restorations with root posts for endodontically treated teeth Advantages:

• Bundled fine posts facilitate easy placement within any root canal morphology
• Minimizes the need to mechanically prepare root canals, thus preserving healthy tooth structure and saving valuable chairtime
• Increases surface area within a buildup restoration, thereby maximizing adhesion and retention values
• Offers optimal adaptation to atypical canal anatomies for easier use
• All materials in the are coordinated to maximize the success of the restoration procedure
• Futurabond U
• – Reliable self-curing
• – High bond strength, without a separate etching step
• Rebilda DC
• – Suitable for post cementation
• – Cuts like dentin, so it minimizes ditching
• – Its excellent physical properties enhance longevity
• – Has a low setting temperature

CONCLUSION

The unique design of VOCO’S new Rebilda Post GT allows clinicians to preserve maximum tooth structure because it minimizes the need for mechanical preparation — and that saves chairtime. In addition, the small individual glass fibers that make up the conventional post size have greater adaptability and flexibility than a conventional post. And they can be staggered to create the support and strength needed for the individual case.

This is truly a product and system for every post procedure, whether it’s a simple root canal restoration, or a more challenging — but common — case of atypical root anatomy. A final consideration and clinical advantage is that once the individual posts are spread out above the endodontic access hole, the Rebilda Post GT offers a much greater surface area to bond and cement to; in turn, this ensures superior adhesion and retention of the core buildup restoration, which translates to predictable long-term outcomes.

From Decisions in Dentistry. November 2017;3(11)52–53.