Oral Health Group

A Novel Mercury-Free Restorative Material: The Silver Filling

July 1, 2014
by Anapaula Campos; Kellyana Quattrini, BSc; Jenna Schmitt, BSc

“Made in Canada” means more than just development and manufacturing. Research and analysis are significant contributors to the Canadian “face” of the dental profession. Dental students and recent graduates put a tremendous amount of effort into table clinics and posters. These presentations are often overlooked by practitioners. In this space, the editor has selected a particularly interesting poster that was presented at the Pacific Dental Conference in March 2014. – G.F

Even though dental amalgam has been considered the “gold standard” in restorative dentistry, it does have some limitations. This metal restorative material has been used successfully for more than 150 years, but has been publicly probed for its mercury content and its alleged adverse health effects.


The need and demand for a new alternative was the premise of the present research. Our goal was to develop a novel restorative material through compositional modifications of conventional amalgam with the intention of creating an easy to use, antimicrobial, mercury-free alternative restorative material. In developing a restorative material that was free of mercury, we aimed to preserve mechanical properties comparable to those of amalgam. 

Our experimentation involved discarding the mercury content of amalgam and replacing it with a proprietary antimicrobial silver solution and unsialinized titanium dioxide ceramic nanoparticles for strength, with a favorable, easy to manipulate consistency. Prepared maxillary premolar controls were filled with Permite amalgam and compared to an experimental group filled with the novel material. Both groups were then thermocycled, cross-sectioned, and studied through scanning electron microscopy (SEM). After studying the SEM images, it was concluded that the addition of the silver solution and ceramic nanoparticles to mercury-free regular-set Permite alloy yielded a product that exhibits improved marginal adaptation with less application of condensation pressure, when compared to regular-set Permite amalgam.

FIGURE 1A. Amalgam 100µm.

FIGURE 1B. New material 100µm.

FIGURE 2A. Amalgam 10µm.

FIGURE 2B. New material 10µm.

Although the novel filling material adapted well to the walls of the prepared teeth following thermocycling, it is necessary to further test it for corrosion, wear, creep, and toxicity following the standard test protocols set by Health Canada and the Food and Drug Administration. Toxicity tests must be first, as they will determine the utility of this novel filling. They include materials leaching tests using inductively coupled plasma mass spectroscopy (ICP-MS), and administering doses of the material to experimental rats. OH

Anapaula Campos completed two years in the College of Arts and Science at the University of Saskatchewan. Kellyana Quattrini: Bachelor of Science — Health Sciences from Brock University. Jenna Schmitt: Bachelor of Medical Sciences from the University of Western Ontario.

Oral Health welcomes this original article.

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