Article by Mike Hussey as featured in the January 2012 edition of eLaborate magazine
As a dental ceramist, it is essential that I keep asking myself the question, “what is the future of this industry?”, knowing full well that, should I find the answer, it may change tomorrow. My answer at the moment lies in two important technologies that have taken our industry, hence our laboratory, to new heights: all-ceramic and monolithic zirconia systems.
Having been a ceramist for more years than I care to remember, I have seen many all-ceramic systems develop over the years, all producing excellent aesthetic results. Historically, however, they all came with an underlying “but”. That “but” was comparative weakness to PFM restorations. Not anymore.
More and more dentists are requesting all-ceramic restorations, and why wouldn’t they? The end result is an incredibly strong, translucent restoration with superior aesthetics.
The technological advantages of Ivoclar Vivadent’s e.max® lithium disilicate ceramic ingots have totally changed the way all ceramic restorations are constructed. The restoration is waxed to the full anatomical contour using the lost wax process (which is a similar process applied to waxing a full veneer gold crown). It is then processed in an Ivoclar Vivadent Programat pressing furnace. The product is a solid (monolithic) lithium disilicate restoration, to the full anatomical contour, that boasts a flexural strength of 400MPa and has the advantage of having no veneering ceramic, thus eliminating the risk of delamination. Chipping concerns are also eliminated due to the monolithic structure. It is the perfect choice for veneers, inlays, onlays, partial crowns, anterior and posterior crowns, anterior three unit bridges, and over implant substructures.
Furthermore, the aesthetic results of this material are, to say the least, outstanding. There is no core structure to hide and a large selection of coloured ingots are available in A-D shades. The pressing ingots are available in high and low translucency and medium and high opaque. There is an ingot to cover any clinical indication that may arise.
This enablement is of course subject to the capability of the shade-taker. That said, I would strongly recommend to dentists who prescribe this type of restoration to use the IPS Natural Die Material Shade Guide to determine the shade of the preparation. This will enable the technician to determine the suitable ingot to achieve the best possible true-to-nature results.
So, as a ceramist, I am satisfied that I have a material that is both strong and beautiful. But what about a material for bruxers, or those tricky cases whereby a minimal tooth preparation is required? Traditionally, I would default to inclining towards a full gold restoration in certain cases. My second answer, however, is monolithic zirconia.
Monolithic zirconia came with its own “but” and that was its dullness due to its lack of translucency. It has, however, appeared to have evolved at a rate of knots in recent times. I am sure we have all been wooed by its incredible strength, yet beauty is now creeping into the equation with thanks to new radical technological advancements.
I have recently started using BruxZir® Solid Zirconia, which we employ the services of Stoneglass Industries to mill. Although new to Australia, BruxZir® Solid Zirconia has proved to be a popular choice in the United States for quite some time. I am very excited about what this material has to offer. There appears to be advantages for the technician, dentist and patient alike.
The technician is happy because he or she can offer a pretty restoration with a flexural strength of up to 1,465MPa, providing the confidence that it is strong enough to suit the circumstances of the case. The dentist is happy because he or she can be more conservative at the tooth preparation stage and can also use conventional cementation techniques. The patient is happy for the same reasons that the technician is happy.
As sure as night follows day, we can expect technology to keep advancing. That is why I am keeping a keen eye on monolithic zirconia systems. They keep getting stronger and more attractive.
For now, I have the perfect tag team: all-ceramic and monolithic zirconia systems. I don’t know what tomorrow will bring, or if either of the systems will pave the way for the future, but I can’t wait to find out.
I will continue to discuss new technologies within my blog at www.ceramicstudio.com.au.
Mike Hussey