Introducing the Ultimate PFM...   George Tysowsky, DDS
Vice President of Technology

Introducing the IPS d.SIGN restorative system
Clinicians now have an esthetic and durable metal-ceramic restorative system, that can be placed using the same preparation and cementation technique already in use for conventional porcelain-fused-to-metal restorations (PFM). The IPS d.SIGN system combines esthetic and life-like porcelains with the support of a metal base providing esthetic solutions with the peace of mind that comes from using time-tested, proven techniques.

Ivoclar Vivadent’s IPS d.SIGN porcelain offers a variety of clinical benefits. First, its optical properties are similar to those of natural teeth and its physical properties are stronger and more durable than the typical feldspathic porcelains. Further, the wear characteristics of this material are similar to natural tooth structure.

Specifically, IPS d.SIGN features an innovative fluorapatite-leucite glass-ceramic material coordinated with specific alloys to be used according to the treatment plan and/or corresponding indication. The patented ceramic formula replicates the needle-like shape of the hydroxy apatite crystals found in natural teeth and the manner in which they disperse light (see photos below). Clinicians can now go beyond the limitations of prescribing traditional PFM restorations and place restorations that demonstrate a high degree of luminous reflectance and high translucency.

Natural Tooth Structure

IPS d.SIGN Fluorapatite-Leucite Glass Ceramic

Feldspathic Porcelain

The above SEM photos show the similarity of crystals found in natural tooth structure and new IPS d. SIGN fluorapatite-leucite material. This type of crystal is not found in feldspathic porcelain. University of Buffalo, Instrumentation Center, P. Bush. Data on file.

“The inherent quality of the fluorapatite crystals scatters light in such a way that it allows us to build a significant amount of translucency without losing the value, the brilliance.” Don Cornell IPS d.SIGN Development Consultant

The Single Central—A Match Made in Heaven
Today, patients are as cost-conscious as they are esthetically oriented, so clinicians are hard-pressed to prescribe the appropriate restoration to satisfy both esthetic and economic concerns. Yet, such situations may only require the treatment of a single anterior tooth, requiring superior matching of the visible restoration to the adjacent natural teeth. This match is among the hardest feats for dentists to accomplish, but the IPS d.SIGN System makes it much less challenging.

Unlike typical feldspathic porcelains, IPS d.SIGN comes closer to mimicking all of the properties of natural teeth, allowing for the replication of a true-to-nature esthetics and superior shade reproduction.

Dr. Bruce Adams, from Elmhurst, IL, was recently faced with restoring a single anterior tooth when a 16-year-old female presented with a temporary restoration on tooth #8 (Fig. 1). Clearly, a full-coverage crown restoration was required, and a d.FM (d.SIGN-fused-to-metal) restoration provided an ideal choice.

According to Adams, he chose d.SIGN for this case due to the highly esthetic results that could be achieved, given the fact that precise internal and external colors and optical effects had to be recreated. The high gold alloy base selected ensured a warmer inner structure that helped radiate the selected colors in a natural way.

Here, IPS d.SIGN allowed Dr. Adams to deliver a restoration that was not only the correct shade, but which also replicated the subtle value differences and individual characterizations of the patient’s natural teeth. Overall, the final restoration demonstrated exceptional color, translucency, value, shape and texture (Fig. 2).

Figure 1: Before

Figure 2: After

Historically, porcelain-fused-to-metal (PFM) restorations provided clinicians with a means to esthetically treat teeth structurally compromised by trauma or caries. However, problems with gingival inflammation due to poor marginal integrity and unpleasing esthetics (opaqueness, excessive translucency) around the cervical one-third and along the gingival margins developed. Although a variety of techniques attempted to compensate for such shortcomings, a shadow would become apparent surrounding the margins, giving the gingiva a dark or purplish look.

Today, however, the IPS d.SIGN System enables clinicians to place d.FM restorations that take advantage of the relative refractive light indices of the porcelain to create restorations that are virtually indistinguishable in the mouth. In particular, IPS d.SIGN features specially designed porcelain powders suitable for building up certain aspects of the restoration in order to produce the most true-to-nature esthetics. These powders include a shoulder porcelain that facilitates easy fabrication for excellent marginal integrity and allows the appropriate amount of light to pass through to the root to create life-like tooth and gingival effects.

Specifically, the concentration of fluorapatite crystals within the various IPS d.SIGN porcelain powders controls the light scattering ability of the restoration. Therefore, no opaque additives are necessary to create high value effects. Rather, the concentration of crystals is simply increased to raise the refractive index and decrease translucency. However, when maximum translucency is desired, the concentration of fluorapatite is decreased to lower the refractive index and increase light transmission. The results are exceptionally beautiful restorations that closely mimic the brightness found in natural teeth.

Wear Compatability and Esthetics
A major concern of clinicians when placing posterior restorations is the amount of wear that will occur to opposing natural dentition or restorations. Many conventional ceramics used to fabricate PFM restorations can be very esthetic, but also very abrasive. The composition of IPS d.SIGN provides the physical properties ideal for posterior restorations. In fact, simulated 5-year wear studies have demonstrated that IPS d.SIGN ceramic wears less than bovine enamel, which is used as a comparative standard. Therefore, natural dentition may actually wear the IPS d.SIGN ceramic, rather then the IPS d.SIGN ceramic wearing dental enamel.

Keeping our promise to you! In the last ten years, the dental industry has experienced more innovation than the previous twenty-five. New attitudes of change and opportunity continue to lift the limits of innovation. We are experiencing an Esthetic Revolution focused clearly on the patient where the patient is not only the beneficiary of innovation, but the cause. Throughout the more than 100 countries in which our products are used, our employees are dedicated to making you more successful by providing world-class technical and customer support. It's our way of keeping our promise to you–to continue delivering the products and services that will empower you to succeed in the ongoing Esthetic Revolution. Robert A. Ganley President Ivoclar Vivadent

Dr. Gideon Nussbaum, a restorative dentist in the Seattle, Washington area, described an example of a posterior rehabilitation case in which d.FM restorations were used in combination with pressed ceramics to restore the patient’s posterior teeth. The female patient, in her sixties, presented with a preoperative condition that exhibited multiple defective amalgam restorations that required treatment (Fig. 3).

A complete diagnostic workup and an occlusal analysis preceded the comprehensive treatment plan, which consisted of joint stabilization and elimination of centric interferences, as well as the establishment of good canine and anterior guidance. It is also important to note this patient presented with minimal preoperative wear and was not a bruxer. Dr. Nussbaum determined this patient would be an ideal candidate for d.FM restorations, since she did not present with conditions contraindicated for porcelain restorations.

Posterior restorations must not only satisfy the patient’s esthetic requirements, but also the patient’s occlusal requirements. Therefore, this case required restorations that would provide the occlusal morphology and dental anatomy necessary to stabilize the occlusion and the TMJ.

Figure 3: Before

Figure 4: After

From a practical perspective, IPS d.SIGN porcelain polishes easily, eliminating the need to reglaze following minor occlusal corrections that may be necessary. According to Dr. Nussbaum, the wear characteristics of today’s dental porcelain, such as IPS d.SIGN, has improved significantly, while still providing excellent esthetics. In particular, because the drawbacks of wear and abrasiveness have almost been eliminated, combined with the true-to-nature esthetics and life-like characteristics that mimic natural teeth, d.FM restorations were the ideal restorative choice in this case (Fig. 4).

Conclusion
With d.FM (IPS d.SIGN-fused-to-metal) restorations, clinicians can now satisfy individual patient needs with restorations that exhibit true-to-nature esthetic properties and gentle wear against opposing natural dentition. The IPS d.SIGN System enables the creation of beautiful metal-ceramic crowns and bridges that meet the requirements for esthetic anterior restorations and the occlusal and strength requirements of posterior restorations, without excessive adjustments. Further, clinicians can now confidently prescribe d.FM restorations and achieve consistent and predictable prosthetics that demonstrate a more vital appearance, one that is identical to natural dentition.

For additional information on IPS d.SIGN or any other Ivoclar Vivadent products, please call (800) 533-6825 or fax your request to (716) 691-2285. Be sure to visit www.ivoclarvivadent.us.com.

Acknowledgements & Disclosure
The clinicians whose cases are featured in this article have not received compensation from Ivoclar Vivadent for participating in this presentation.

Ivoclar Vivadent and the clinicians represented in this article would like to recognize Mr. Lee Culp, Mr. Uwe Brosamle, Mr. Don Cornell and Mr. Olivier Tric for their outstanding laboratory work, and for their continued commitment and dedication to the art and science of dental technology.