The name zirconium is derived from the Arabic word “Zargun,” or golden in color, which is further derived from the Persian words “zar” for gold and “gun” for color. Zirconium is a naturally occurring element with an atomic number of 40 and is a transitional metal found in nature as the mineral Zircon. It is purified to Zirconium, a silver-colored metal that is corrosion-resistant and has properties like titanium. When combined with oxygen, it forms zirconia, a strong and highly biocompatible ceramic. Zirconium was initially discovered in the 18th century.
The introduction of stronger and more durable ceramics over the past few years has greatly increased the clinician’s choice of materials when fabricating an all-ceramic three unit bridge. The latest generation of zirconia is suitable for three unit bridges and can restore teeth anywhere in the mouth, and IPS e.max is suitable for anterior teeth.
Patient demand for dental restorations with a natural esthetic has increased considerably over the past few decades. This is partially due to greater interest in and awareness of cosmetic dentistry. For many years, clinicians used PFM crowns and bridges to provide patients with durable, long-lasting restorations that offered reasonable esthetics. However, although still a popular option, the opacity of the PFM materials cannot always satisfy esthetic demands.
A zirconia screw-retained bridge is a popular choice for clinicians who wish to provide patients with the most ideal esthetics. This type of restoration offers several advantages. One of the most appealing qualities of this bridge is its easy retrievability. An easily retrievable restoration is a good solution if the patient is likely to require regular maintenance or removal of the bridge for professional cleaning. Additionally, zirconia attracts less plaque, making it easier for the patient to maintain good oral hygiene and healthy implants. Zirconia screw-retained bridges are CADCAM designed and milled, which eliminates casting distortion and offers a predictable, precision-fitting appliance.
Porcelain-fused-to-metal crowns (PFMs) have been successfully used for many years, providing clinicians with reliable, esthetically pleasing, and long-lasting restorations. However, over the past few years, an increasing number of clinicians are choosing zirconia restorations. The number of PFM crowns requested by clinicians is lower compared with all-ceramic and zirconia restorations. Some dentists use zirconia or all-ceramic restorations almost exclusively, particularly when restoring only a single unit. The switch from one material to another has been relatively quick, so there is little long-term research into the reliability of zirconia restorations. By comparison, PFMs have been used successfully for over 60 years, and their durability has been extensively evaluated.
Titanium dental implants have been used for decades; it’s widely regarded as the ideal choice for many reasons. Although titanium dental implants have proven to give good long-term clinical outcomes in terms of functional success and rigid fixation, complications due to soft tissue recession are widespread. Using zirconia abutments can potentially minimise soft tissue recession and will hide the metal colour of the titanium, but over the past few years, several new zirconia dental implant systems have been introduced onto the market. Initial clinical studies into zirconia implants look promising, but more research is needed, particularly in the long term effects of these systems. Clinicians may also require a better understanding of the potential technical challenges of using this material to reduce the possibility of mechanical failure of zirconia implants.
Since receiving FDA approval in 2011, zirconia dental implants are becoming used by more and more clinicians. These implants have been used in Europe for over a decade and can provide excellent biocompatibility and stability. Although not suitable for everyone, sometimes zirconia dental implants may be a better choice for particular clinical situations.
Historically, implant abutments were always manufactured from metal and were either prefabricated or custom-made. Zirconia implant abutments provide a highly aesthetic solution, especially for specific clinical situations. Zirconia abutments are very versatile, as they can be designed entirely using CAD/CAM technology or by scanning a wax-up before milling the abutment. Both options allow a zirconia abutment to be efficiently designed and created.
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.