All-Ceramic Crowns

Jamie J. Alexander on February 18, 2021

If you had teeth crowned with conventional porcelain on metal (PFM) restorations, you may notice some gray showing through and a dark line at the base of the crowns where metal is showing.

“All-ceramic crowns have qualities that eliminate color issues and metal showing at the gum line,” says Boynton Beach dentist Dr. Jamie Alexander. “This is why all-ceramic crowns are so popular with patients. But there are additional reasons why dentists and patients prefer all-ceramic crowns. Advances in dentistry have provided us with a variety of ceramic materials to choose from to get a stronger, more reliable, and more esthetically-pleasing crown than ever before.”

Types of All-Ceramic Crowns

Leucite Reinforced Pressable Porcelain Crowns: These crowns were originally introduced 15 years ago. The IPS Empress pressable crowns have a flexural strength of 160MPa and have proven to be a durable option while providing excellent esthetics. Using this material, our dental lab creates custom-fit restorations that closely replicate natural teeth. The IPS Empress crowns appear so natural because they have a high translucency. This helps them to transmit the shade from adjacent teeth, making it possible to get an exact shade match.

Lithium Disilicate Porcelain Crowns: This type of crown is made from biocompatible lithium disilicate ceramic glass ingots. IPS e.maxbb crowns have the quality of being resilient to fracturing, with a flexural strength of 400MPa – three times stronger than IPS Empress crowns. These crowns can either be pressed or milled to offer a good fit as well as function. IPS e.max Ceram is a beautiful and durable material for full-contour crowns and porcelain inlays, onlays, and veneers. IPS e.max crowns are not as translucent as IPS Empress crowns.

Solid Zirconia: Solid zirconia crowns, also called “monolithic zirconia crowns” because they are CAD/CAM milled from a single block of zirconia are highly effective for the restoration of molars. This is because they are extremely strong, with a flexural strength of 1200MPa. These crowns are virtually unbreakable. Many dentists recommend zirconia crowns to patients with bruxism, but because solid zirconia so strong, these crowns may excessively wear down opposing natural teeth.
Please note that the treatment of bruxism and selection of crown materials requires knowledge of the patient’s entire masticatory function and consideration for the health of the patient’s opposing teeth. A comprehensive approach to tooth alignment, occlusal equilibration, and matched restorations on opposing teeth, when indicated, will produce the most predictable results.

High Translucent Zirconia: High translucent zirconia can be used for CAD/CAM milled crowns and can be layered. It has more natural “lifelike” translucency than the previously described solid zirconia. Because of its more natural beauty, it is the preferred type of all-zirconia crown for anterior (front) teeth that show when you smile. It has a flexural strength between 590 and 720 MPa. This material is highly biocompatible, promoting a healthy response with the surrounding tissue. It also offers good aesthetics blends well with adjacent natural teeth.

“When a crown restoration is required to preserve the health, function, and natural esthetics of a tooth, I discuss the relative costs and advantages of various types of crowns with my patient,” says Dr. Alexander. “I recommend the type or types that are most appropriate for their mouth, with a comprehensive understanding of the patient’s oral health circumstances. All restorative dentistry is a process of discovering together with the patient what will be best for the patient and meet the goals of lasting oral health, comfort, function, and a beautiful smile.”