Zirconia has grown immensely popular over the years because of its easy-to use, high flexural strength and strong ceramic material. Many patients find the idea of metal-free restorations very appealing. The earliest zirconia restorations had a bone-white appearance that could be challenging to mask with porcelain. Often the opacious nature of the porcelain used to hide the substructure would create a restoration very similar to PFMs. Pre-shaded zirconia overcame part of this problem, but it still couldn’t create such lifelike results as lithium disilicate. The introduction of high translucent zirconia has overcome these difficulties, allowing technicians to create highly aesthetic restorations that meet or surpass patient expectations.
For many years the industry standard for fixed bridges were porcelain fused to metal, often called “PFM bridges.” These restorations provided good aesthetics and are resistant to wear. However, since technology and research has progressed, newer all-ceramic materials have been introduced, some of which were ideal for restorations within the aesthetic zone. Unfortunately, they lack the strength and durability required for posterior restorations. For example, lithium disilicate, is generally only suitable for anterior restorations. Sometimes, depending on circumstances, these dental ceramics will fail in the connector area. Therefore, Increasing the connector size could affect aesthetics and functionality.
Clinicians who wish to provide patients with excellent dental restorations often choose zirconia crowns. These crowns are chosen over conventional PFMs (Porcelain Fused to Metal) or full-gold crowns due to their superior strength, durability, and excellent aesthetics. Zirconia crowns require shoulder or chamfer margins for best results. They may be fabricated from solid full-contour zirconia or from layered zirconia and can be either screw-retained or cemented.
Zirconia is a durable and aesthetically pleasing material that can be used to provide patients with a well-fitting prosthesis. It is also a particularly desirable choice for edentulous patients wishing to replace a complete arch of teeth. Outlined below is an overview of the fabrication process, although the exact procedure can vary.
Since its emergence into the dental arena, Zirconia has increasingly become the material of choice for clinicians who wish to provide their patients with the most technologically advanced metal-free restorations. Zirconia has improved significantly with the introduction of a wider array of available milling pucks which allow for greater shade variation and translucencies that closely resemble natural dentition. In addition to improved esthetics, the Zirconia physical properties allow for durability, strength, and precision-fitting restorations. To maximize on the success of seating Zirconia restorations, and minimizing chair time, it is essential to ensure that proper preparation guidelines are being followed.
Over the past few years, there has been increased demand for metal-free restorations. Patients have become more concerned about the presence of metal in their mouths and want to receive the most esthetically pleasing restorations. This demand has been accommodated with the introduction of newer and stronger ceramics such as zirconia and e.max, replacing older style feldspathic and leucite-based restorations.
Dental Zirconia Applications
Clinical grade zirconia has been used throughout the dental industry for over a decade, but the interest level has accelerated recently due to its versatility as well as the ever increasing cost of noble alloys, especially gold. Yttria tetragonal zirconia polycrystal (Y-TZP) material, a zirconia oxide, is the standard form of zirconia that is currently utilized. Y-TZP is a monophasic material formed by sintering crystals directly together without interference. This allows the material to keep its inherent properties and stabilizes the overall structure.