While dental crowns were previously almost entirely made from gold, patients looking for dental restoration now have a much wider variety of options. Of these, the leucite reinforced system, also popularly known as the Empress crown, is a popular metal-free crown option.

What’s the Difference?

The leucite reinforced system’s success stems from its superficial similarity to the tried and true (but aesthetically jarring) gold crown technique. Much like with a gold crown, the leucite reinforced system begins with a hollow investment pattern. At this point, the process differs in that the leucite-reinforced ceramic is molded via a pressable-porcelain-oven. From there, the ceramic restoration is cast and thus amenable to staining, glazing, shaving, and layering with feldspathic ceramic to match the patient’s natural teeth.

A recent study by the Department of Dental Materials Science at Umeå University in Sweden sought to study the effectiveness of leucite-reinforced crowns. The study, titled “Clinical examination of leucite-reinforced glass ceramic crowns (Empress) in general practice: a restrospective study” was led by the acclaimed professor, practitioner, and research professional Goran Sjogren.

Empress Crowns vs. Traditional Dental Crowns

The research began with 110 Empress crowns being implanted in 29 patients who regularly visited their general practitioners. Over time, the researchers studied the patients’ occurrences of plaque and gingival conditions in comparison with the standards set up by the California Dental Association’s quality evaluation system.

The results definitely spoke in favor of the leucite reinforced system. 86% of the implanted crowns received “excellent” ratings for margin integrity, according to the CDA’s evaluation system, and 92% were ranked “satisfactory.” Only 6% of the 110 crowns showed signs of fracture, with no correlation between fracture and anterior versus posterior crown placement. The Empress Crown did not show significant differences in plaque and probing bleeding from the control crowns.


The study concluded that the small percentage of fractured crowns could be attributed to their placements on molars and premolars. For this reason, the researchers still believe that there is some clinical significance in location of Empress crowns and fracturing. The researchers recommend that the Empress crowns be considered fully before being placed on high stress level areas in the mouth.

If you’re looking to replace your old gold crowns with Empress ones, send your dental scrap to Cash for Dental Scrap today. We accept failed, damaged, or deteriorated gold or silver crowns, bridges, PFM’s, PFG’s, Inlays, Onlays, Gold Partials, and much more.