Inside Dentistry
Nov/Dec 2006
Volume 2, Issue 9

Relyx™ Fiber Post: A Revolutionary Cementation Solution

With increasing focus on productivity and efficiency in today’s high-tech practices, dental professionals must exercise vigilance in choosing the materials and techniques they employ to deliver the highest-quality patient care. Emerging technologies and innovative materials are continuously evolving to make this task easier. Accordingly, 3M ESPE presents a revolutionary new approach to post cementation that simplifies steps and saves time without compromising the quality of the procedure. For better clinical results and long-lasting restorations, 3M ESPE has partnered the RelyX™ Fiber Post, a strong and durable glass fiber-reinforced post, with clinically proven RelyX™ Unicem Self-Adhesive Universal Resin Cement and the innovative RelyX™ Unicem Aplicap™ Elongation Tip (Figure 1). The RelyX Unicem cement “system approach” offers a total cementation solution, ensuring clinical success and satisfaction for both dental professionals and their patients.


RelyX fiber posts are indicated for endodontically treated teeth with significant loss of tooth structure to increase stability and retention of subsequent coronal restorations. In general, fiber posts offer several advantages over metal posts. First, fiber posts offer enhanced esthetics and firm retention in combination with adhesive cementation. Fiber posts also eliminate the risk of corrosion that may occur with metal. Clinical research shows that the elasticity of the RelyX fiber post is similar to human dentin, which presents a much lower risk of root fracture because of the “wedge effect.” In addition, the RelyX fiber post exerts greater fatigue resistance than other leading fiber posts.

Application of RelyX Unicem cement with the RelyX Unicem Aplicap elongation tip ensures the maximum potential for long-term stability. The RelyX Unicem Aplicap elongation tip is designed to reach into the root canal, making the application process reliable and easy. The unique tip ensures precise application from bottom to top, virtually eliminating cement voids that can compromise bond strength. Preparatory work such as etching, priming, or bonding is unnecessary when using RelyX Unicem cement, which allows for significant time-savings. There also is no need to prime or silanize the post when using RelyX Unicem cement. If endodontic retreatment is required, dental professionals can be confident that RelyX fiber posts can be removed easily, without damaging the tooth.

RelyX Unicem cement is a one-step cement, clinically proven for bonding posts. In a 3-year clinical review of 1,250 restorations, RelyX Unicem cement has earned a top “5+” rating and the distinction of “Editors’ Choice” from The Dental Advisor, reaffirming a proven record of excellent results and consultants’ praise. Clinical observations reported low incidences of postoperative sensitivity, microleakage, and debonding over the 3-year period.


Begin with an endodontically treated root canal and select the universal drill to remove the root filling. It is best to leave a minimum of 4 mm of filling apically. The appropriate color-coded post size and corresponding drill should be selected and used to widen and shape the canal. Next, insert the post to check the fit in the prepared canal. As the post moves down into the canal, the colored gauge indicator should be used to determine where to cut the post. The post can then be easily removed and shortened to the required length using a diamond disk and suction system. Scissors, scalpels, or similar tools should not be used to cut the post because they will crush the post, ruining the structure and stability.

The post should then be disinfected with alcohol and allowed to dry with air, free of water and oil. It is important to note that primer is not needed when cementing with RelyX Unicem cement. Clean the canal with 2.5% to 5.25% sodium hypochlorite solution (NaOCl). Hydrogen peroxide (H202), other disinfectants, or ethylenediaminetetracidic acid (EDTA) solutions should not be used because their residues can impair the adhesion strength and curing reaction of RelyX Unicem cement. Rinse immediately with water and dry with paper points.

Once the canal is prepared for the post placement procedure, insert the RelyX Unicem cement capsule into the Activator. Press the handle down completely and hold for 2 to 4 seconds. Next, insert the activated capsule into the RotoMix™ Capsule Mixing Unit (3M ESPE) for 10 seconds or mix for 15 seconds at the highest speed in other mixing devices. Attach the RelyX Unicem Aplicap elongation tip onto the nozzle and listen for an audible “click.” Lentulo spirals should not be used to apply the cement in the root canal as this will cause the cement to set faster.

At this point, begin apically in the root canal and dispense RelyX Unicem cement. The elongation tip should remain immersed in the cement throughout the entire cement application process, as this will avoid trapped air in the cement and eliminate voids that can compromise bond strength (Figure 2).

Seat the post immediately (Figure 3). Twist slightly and apply moderate pressure to hold it in position. Apply moderate pressure while removing excess cement with the appropriate instruments or a cotton pellet. Light-cure the cement for 40 seconds or allow it to self-cure for 5 minutes from the start of the mix.

A core build-up is recommended after the post is placed and secured. Any core build-up material may be used; however a composite material such as Filtek™ Z250 Universal Restorative (3M ESPE) is recommended because of its strength property. Apply adhesive to the post and surrounding tooth structure. Light-cure the adhesive for 20 seconds (or for the time recommended by the manufacturer). Incrementally, place the composite material and light-cure each increment according to the time specified by the manufacturer (Figure 4). Finally, prepare the core build-up for an impression and temporary (Figure 5). The impression can then be sent to the laboratory for fabrication of the indirect restoration.


The RelyX Unicem cement “system approach” dispels the perception of post cementation as a difficult, complex procedure. The reduced number of steps in the process leaves marginal room for error—ensuring consistent, efficient results. RelyX fiber post, RelyX Unicem cement, and the RelyX Unicem Aplicap elongation tip are part of the RelyX family of high-quality, reliable products designed to meet virtually all cementation needs.

As the global category leader in cement solutions, 3M ESPE continues to provide innovative products to achieve esthetic and functional restorations—pleasing clinicians and patients alike.

For More Information
Phone: 1-800-634-2249
Web: www.3MESPE.com/relyxfiberpost

Figure 1 The RelyX Unicem cement capsule, Aplicap elongation tip, and the drills and corresponding RelyX fiber posts that comprise the new "system approach."   Figure 2 Dispensing RelyX Unicem cement using the RelyX Unicem Aplicap elongation tip.
Figure 3 RelyX fiber post seated in the canal.   Figure 4 Composite material placed and light-cured.
Figure 5 Core build-up in preparation of an impression.    

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