Ceramic CAD/CAM materials have become popular among dentists whose patients are looking for a metal-free or more natural-looking material for indirect restorations, but with so many different options, selecting the best one for the job can be challenging, especially for newer dentists.
Flexural strength is an important trait to consider when selecting a ceramic option, and one of the primary factors in a manufacturers’ clinical recommendations, but it doesn’t tell the whole story. All-ceramic CAD/CAM materials differ in composition, material properties, processing methods and clinical indications, all of which work together when determining a material’s best use. For this reason, it is imperative that dentists understand the different classes of ceramic CAD/CAM materials available to them.
The latest issue of the ADA Professional Product Review helps you navigate through the world of CAD/CAM ceramics by exploring five of the most common indirect restorations, the commonly-used traditional materials, and several ceramic CAD/CAM alternatives.
1) Inlays, Onlays, and Veneers:
Most materials meet the minimum strength requirement for inlays, onlays and veneers. However, adhesive cementation and esthetics are crucial factors to consider when choosing the best material for your patient. Lithium disilicate ceramics (LDS) and resin-ceramic composites (RCC) are often chosen for several reasons: LDS provides better mechanical properties and esthetics, while RCC is easy to fabricate and requires less chair time.
2) Anterior Single Crowns:
For anterior single crowns, LDS restorations provide an excellent combination of esthetics and strength. They provide better mechanical properties than feldspathic or leucite-reinforced porcelains and improved esthetics compared to the traditional porcelain-fused-to-metal (PFM).
3) Posterior Single Crowns:
With its high strength and low cost, full-contour zirconia provides an alternative to conventional full-metal crowns and PFMs. As a single layer restoration, it requires less manufacturing time than PFM, but provides less translucency. LDS is preferred for low retention preparations over zirconia because of its improved bonding, and should also be considered for patients whose wide smiles call for a more natural appearance in the molar region.
4) Anterior Three-Unit Fixed Dental Prostheses (FDP):
The adequate strength and excellent esthetics of LDS make it a good option for anterior three-unit FDPs, while a bi-layered option – such as porcelain-fused-to-zirconia (PFZ) – can be used in situations where strength is more important than esthetics.
5) Posterior Three-Unit Fixed Dental Prostheses / Multi-Unit:
Strength is a primary requirement in the posterior region. Full-contour zirconia is a high-strength, single-layer restorative material that can be used instead of more conventional metal or PFM options. The bi-layered PFZ also provides adequate strength and esthetics in such situations.
There are a wide variety of materials available for CAD/CAM restorations, each differing in terms of their microstructure, strength, translucency, and clinical indications. While moving away from more traditional materials can be daunting, the benefits of CAD/CAM materials can pay off, and provide you and your patient with more flexibility.
To download a printable ceramics chart, or to learn more on CAD/CAM ceramics, visit www.ada.org/ppr