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Inside Dentistry
March 2013
Volume 9, Issue 3

ENA HRi Nano Composite: The Natural Choice

Optical qualities to simplify direct composite restorations

The ability to achieve the highest level of esthetics in direct composite restorations is hampered by the optical characteristics of virtually all light-cured composites. It has been shown that direct composites have a light refraction index that is different than natural enamel.1 It is this difference that creates challenges for clinicians, as light refracts differently through the composite and enamel surfaces, leading to what is commonly known as the “glass effect,” a greying at the margin or interface between the natural tooth material and the restorative composite2 (Figure 1). The glass effect can be overcome or minimized, but only through the use of technically challenging and complicated multiple layering techniques.

Innovative Solution

In 1995, Micerium S.p.A. and Dr. Lorenzo Vanini cooperated to introduce the first opalescent and fluorescent composite material, Enamel Plus HFO, which is marketed in North America by Ultradent under the brand name Vit-l-Escence®. In 2008, Micerium S.p.A. and Dr. Vanini introduced an innovation designed to address the challenge of the glass effect, a direct composite with the same light refractive index as natural enamel, or 1.62. The improvement and innovation in the HFO formulation and layering techniques developed by Dr. Vanini was named Enamel Plus HRi and is marketed in North America under the name ENA HRi (HRi stands for high refractive index).

ENA HRi System

The ENA HRi system is a multi-component system suitable for all direct restorations. The enamel component is a highly polishable nano-hybrid composite that uses a value-based, achromatic shading logic that mimics the variations in value seen in natural enamel, resulting in a system requiring only three enamel shades: high value, medium value, and low value. The light refractive index of the material allows the surface or veneer layer of the restoration to be placed without concern for creation of a visible margin or the glass effect (Figure 2). This simplifies the overall process for clinicians, allowing them to work more quickly and predictably. The enamel component also contains natural blue and amber opalescent properties, further enhancing the overall esthetic effects. ENA HRi enamel is especially well suited for small restorations requiring the replacement of natural enamel only, and it allows clinicians to deliver more conservative and patient-centered dentistry that is highly esthetic and preserves the greatest amount of natural dentition possible.

When using the ENA HRi, system hue and chromatic effects come from the dentin component, just like in natural dentition. Research done by Dr. Vanini3 shows that, except for pathological cases like tetracycline staining, human dentin is all in the “A” shade or hue when using the Vita Classical shade guide as a reference, and varies only in saturation or chromacity. ENA HRi dentin is a micro-hybrid that is naturally fluorescent and comes in nine universal shades that are all the same hue and vary only in chromacity. When used together, the enamel and dentin components have the necessary optical qualities to mimic natural dentition and allow clinicians to create restorations that are highly esthetic in a simplified manner.


1. Neuber M, Sarembe S, Schadel M, Kiesow A. Optical properties of enamel and composites determined by spectroscopic ellipsometry. Presented at AADR General Session. Iguacu Falls, Brazil. June 22, 2012.

2. Vanini L. Conservative composite restorations that mimic nature: a step-by-step anatomical stratification technique. J Cosmetic Dent. 2010;26(3):80-98.

3. Vanini L, Mangani F, Klimovskaia O. Conservative restoration of anterior teeth. 2005;ACME.

For more information, contact:

Synca Direct Inc.
Phone: 888-582-8115

The preceding material was provided by the manufacturer. The statements and opinions contained therein are solely those of the manufacturer and not of the editors, publisher, or the Editorial Board of Inside Dentistry.

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