429 Too Many Requests

With over 30 years of experience as a dentist and researcher, Dr Paolo Baldissara of the University of Bologna in Italy could be forgiven for slowing down a bit. This is far from happening, however, as he continues to be at the forefront of ceramic restoration material developments and their integration into CAD/CAM workflows.

When presenting at a symposium held in Berlin in Germany by Kuraray Europe earlier this year, Dr Baldissara highlighted how the company’s patented multilayered zirconia technology allows the KATANA™ Zirconia Block to effectively mimic the shade gradation of natural teeth. He commenced his presentation by outlining the general shift towards metal-free restorations, which in his opinion has been driven by a number of factors, the high value now placed on aesthetics in dentistry chief among them.

“I began using zirconia back in 2005 for prosthodontics in my department at Bologna, and it has greatly improved in quality since then,” said Dr Baldissara. “Generally speaking, the shift towards zirconia only started when a high-strength substitute for metal that was able to be processed with CAD/CAM systems with high accuracy became available.”

It was at the 2015 International Dental Show in Cologne in Germany where Dr Baldissara was first introduced to KATANA™ Zirconia UTML and STML, both of which impressed him with their high levels of translucency. “I started to use them almost immediately, mainly in their monolithic form, for research and in clinical practice,” he said. “My opinion of them was very high, as they allowed me to make cost-effective single crowns and multi-unit restorations with excellent aesthetic properties with scattered and diffused light. This is, ultimately, what patients want.”

Dr Baldissara began using the KATANA™ Zirconia Block in 2018 and expressed his excitement with how its high-speed sintering allows for fast processing of restorations. He recommended dry milling for a number of reasons: not only does it allow for the translucency of the zirconia to be maintained, it also helps to avoid contamination from other ceramic powders that may persist in the milling unit. In addition, he encouraged attendees to frequently replace the burs of their milling units for optimal results and reduced risk of chipping.

“Dry milling and high-speed sintering of the KATANA™ Zirconia Block is an extremely promising technology,” said Dr Baldissara. “In my opinion, it is the correct way to make aesthetic and mechanically strong restorations for the patient.”

Steve Meeze definitely has it: a passion for dentistry. Yet, there was a time when he was unhappy in his job as a dental practitioner. Fundamental changes were necessary to lay the foundations for finding personal fulfillment in his work. We spoke to him about his motivation to do things differently and about the path he has chosen and is following down to the present day.

Many students of dentistry would like to run their own dental office one day. For you, this dream came true, but you ultimately decided to take a different path. Why did this change seem necessary?

After graduation in 1983, running my own dental office seemed to be a great plan: I wanted to be independent, grow my patient base, and become successful, which went very smoothly in the beginning. This economic success, however, did not protect me against starting to feel unhappy and burned-out after several years. Once I began to take my negative emotions seriously and to search for the underlying causes, I realized that is was not merely the workload that troubled me. The truth was that I was missing a sense of purpose in many of my daily tasks. This seemed to be the reason for my lack of energy and motivation to proceed with what I had started. Luckily, I was able to find my personal “why” after some time.

Where did you find your own fulfillment or sense of purpose?

I ultimately found it in the field of conservative dentistry. The reason is that direct restorative treatments with composite allow me to do amazing things in a non-invasive or minimally invasive way. Doing no harm and always being able to go back simply feels good, and my patients are incredibly grateful for what I do. Their gratitude is my reward. This is why I decided to dedicate myself exclusively to treating patients with composite.

How do you do this?

In 2009, I sold my own dental office and started working in different practices in Flanders. In this process, I established some highly valuable partnerships with colleagues, who appreciate my skills and refer their patients to me mainly in the course of interdisciplinary treatment. These orthodontists or surgeons need someone who puts the finishing touches to their work. And this is exactly what I do: I create a beautiful smile at the end of an often complex treatment. Other patients approach me on their own accord with fractured or misshaped teeth and the desire for esthetic improvement. In any case, I listen to them carefully before I start planning. Knowing what is on their minds, I can treat them with confidence. The most precious moment for me is when I hand over the mirror and let them evaluate my work. Their positive reaction, the glint in their eyes is what motivates me every day.

Is there a specific technique you use in your daily work?

Yes, I use the Light Facing Concept I developed to solve esthetic issues in the anterior region. This technique focuses of creating a harmony without the need to sacrifice large amounts of healthy tooth structure. With this concept, a fractured anterior tooth, for example, is restored in three steps: Initially, a single dentin shade of composite of the same color as the fractured tooth is used to create the desired tooth shape and make the fracture line disappear. In this step, shade selection is independent of the final color I would like to reach. Subsequently, I correct the color with an opaque material and try to match the shade of the adjacent teeth as exactly as possible. If necessary, I create mamelons and other individual characteristics in this layer. The final step is carried out on all anterior teeth whenever the appearance of the treated tooth differs from the others: A light facing – i.e. a very thin layer of more or less translucent composite – is added to mask the differences. In cases with minimal shade differences, a composite with a high translucency is used, while a more opaque material is preferable whenever the differences are more apparent.

What is your preferred material for the Light Facing Concept?

My personal experience shows that the best results are obtained with CLEARFIL MAJESTY ES-2 Premium composite from Kuraray Noritake. It simply offers the best mimetic (chameleon) effect of all composite materials I have tested so far, and I have tested many of them. The material tends to blend in with the surrounding tooth structure, and only four shade combinations are usually sufficient to cover the whole range of my patients’ tooth shades. I love this virtually magical effect!

What is your personal conclusion?

When I made the decision to start doing what really makes me happy, I could not be sure that I had chosen the right path. Retrospectively, I know that giving up my present career and taking steps towards personal fulfillment has been exactly the right thing to do. I love the fact that I can satisfy my patients’ desires without sacrificing healthy tissue, and my Light Facing Concept implemented with MAJESTY ES-2 make it easy for me to obtain the results they have been dreaming of.

CASE EXAMPLES

Fig. 1 : Case example: Color change with composite – initial clinical situation.

Fig. 2.: Case example: Color change with composite – treatment outcome.

Fig. 3: Case example: Shape correction with composite – initial clinical situation.

Fig. 4:  Case example: Shape correction with composite – immediate treatment outcome.

Combining ease of use and excellent viscosity, CLEARFIL™ CERAMIC PRIMER PLUS is a stable and universal prosthetic primer designed for all restorations. By incorporating Kuraray Noritake Dental’s original MDP monomer and a silane monomer, it is able to provide an enhanced adhesive surface for ceramics, hybrid ceramics, composites and even metals. CLEARFIL™ CERAMIC PRIMER PLUS is best used in conjunction with the adhesive resin cement PANAVIA™ V5 to ensure durable restorations.

The key to CLEARFIL™ CERAMIC PRIMER PLUS’s performance is in the monomers it possesses. The MDP monomer strongly bonds to metals and zirconia, while the silane coupling agent MPS efficiently adheres to composites and all silica-based ceramics. “What makes CLEARFIL™ CERAMIC PRIMER PLUS different to other primers is its stability,” says Peter Schouten, Technical Manager at Kuraray Noritake Benelux. “Normally, activated silanes are very unstable. However, the well-balanced formula of CLEARFIL™ CERAMIC PRIMER PLUS provides it with a shelf life of three years after production, making it easy and predictable to use.”

Procedural simplicity

Every element of CLEARFIL™ CERAMIC PRIMER PLUS is designed to deliver maximal procedural simplicity. It is packaged in an easy-to-squeeze bottle that dispenses the solution easily and accurately. Whereas other similar products need to be left in place for one minute or more, this primer is immediately effective upon application. “CLEARFIL™ CERAMIC PRIMER PLUS benefits the dentists by offering a reliable primer for all materials, without being difficult to apply or use,” says Schouten. “From titanium to zirconia, from lithium disilicate to composite—simply apply and dry, and you're done.”

PANAVIA™ V5

A resin cement with unrivalled procedural simplicity and predictability, PANAVIA™ V5 is a member of Kuraray Noritake Dental’s PANAVIA family. It sets a new standard for adhesion, allowing for self-cure dentine bond strengths equal to our gold-standard light-cure bonding agent, CLEARFIL SE BOND. PANAVIA™ V5 offers natural aesthetic stability in shading through its amine-free paste, which is available in five shades and has been scientifically proven to demonstrate a lower level of post-curing colour variance than amine-based cements.

CLEARFIL™ CERAMIC PRIMER PLUS and PANAVIA™ V5

Providing strong bonding to not just hydroxyapatite, but to metals and zirconia as well, PANAVIA™ V5 is designed for use in conjunction with CLEARFIL™ CERAMIC PRIMER PLUS. The cementation procedure is efficient and effective: use PANAVIA V5 Tooth Primer for the pretreatment of the tooth, CLEARFIL™ CERAMIC PRIMER PLUS for the priming of the restoration, and PANAVIA™ V5 for the cementation.

Manufactured from Kuraray Noritake Dental’s proprietary zirconia powder, new KATANA™ Zirconia Block delivers aesthetic, natural-looking restorations. However, it is not only aesthetic value that this all-ceramic solution provides. Its superior mechanical properties were designed for reliable, repeatable fabrication of full-contour prostheses.

Impressive flexural strength

The multi-layered KATANA™ Zirconia Block possesses a flexural strength of 763 MPa, which is far higher than that of lithium silicate (LS) glass-based ceramics. This means that restorations made with the KATANA™ Zirconia Block can be designed to have thinner walls than those made with LS glass. This has now resulted in great mechanical properties and beautiful aesthetics that are now possible for all single-unit anterior and posterior restorations.

Fast chairside processing

Thanks to its integration with Dentsply Sirona’s CEREC® CAD/CAM system and SpeedFire™ ovens, the KATANA™ Zirconia Block is perfect for chairside processing and the fabrication of prostheses. Dentists only require 15 minutes for dry milling a crown with the CEREC milling unit and an additional 18 minutes is required for the sintering of the block.

A highly precise material

Dr Hendrik Zellerhoff runs a dental practice in Laer, located in the North Rhine-Westphalia district of Germany. As a digital dentistry and CEREC specialist, he has used the KATANA™ Zirconia Block for more than 40 cases in his practice since March 2018 and praises its perfect balance of aesthetics and mechanical performance. “Its strength is a major advantage—the bend strength totals 763 MPa,” says Dr Zellerhoff. “This means that it can even be used to create extremely thin walls, which in turn means minimally-invasive work. In addition, the margins are even more slender than on glass ceramics.” 

“Due to the fact that zirconia shrinks to the final size during the sintering process, an approximately 25 per cent oversized restoration needs to be milled out,” continues Dr Zellerhoff.

“This is executed using very fine milling cutters. Therefore, a larger workpiece is processed using smaller instruments. This leads to high-precision margins and occlusal surfaces. Only after this does dense sintering take place. The exact shrinkage factor is stored in the barcode on the block. Almost no rework is required in the occlusal or approximal areas. We even do without a try-in after sintering—we glaze immediately. This fact alone is really fascinating, even for long-standing, ‘pampered’ CEREC users.”

NOW 18 Minutes Sintering using the CEREC SpeedFire

KATANA™ Zirconia Block, the innovative multi-layered zirconia block^*1, can be used with Dentsply Sirona's CEREC system^*2. Now the 18 minutes sintering program^*3 is developed and installed into CEREC SpeedFire. New sintering technology makes it possible to fabricate full zirconia restoration in approx. 35 minutes.

An ideal composite material should satisfy three basic requirements: function, aesthetics and biocompatibility. A member of the CLEARFIL MAJESTY family, Kuraray Noritake Dental’s CLEARFIL MAJESTY™ ES Flow combines excellent handling, polishability and mechanical strength to provide a solution for all cavity classes. This universal flowable composite employs silane and filler technologies to maximise both its procedural and aesthetic outcomes, allowing dentists to create long-lasting restorations with reduced chairside time.

A new standard for flowable composites

Traditionally, a composite’s flowability has been inversely related to its filler content. When flowable composites were first introduced in the mid-1990s, their lower viscosity was enabled by a filler level much lower than that of conventional composites. This, however, meant that these flowables fared poorly in a clinical setting, demonstrating inferior mechanical properties when compared to traditional hybrid composites.

With CLEARFIL MAJESTY™ ES Flow, dentists can now use a flowable composite with mechanical properties comparable to those of conventional alternatives. Thanks to Kuraray Noritake Dental’s silane technology, millions of submicron filler particles fit into the composite, reliably adhering to the resin and maintaining long-term stability. CLEARFIL MAJESTY™ ES Flow possesses a scientifically tested flexural strength of over 150 MPa, similar to that of a universal nano hybrid composite, making it suitable for use in Class I and II restorations.

Aesthetic restorations

However, the small, durable particles of CLEARFIL MAJESTY™ ES Flow provide more than just mechanical reliability. Special cluster fillers provide a light diffusion effect that is similar to that of natural teeth, meaning that the material blends effortlessly with the existing tooth structure. Unlike other flowables, CLEARFIL MAJESTY™ ES Flow is glossy immediately after curing. This gloss can be improved with remarkable simplicity—simply wipe the cured resin with an ethanol-moistened gauze or cotton roll to produce a smooth surface that is proven to maintain its gloss over time.

Ideal handling

CLEARFIL MAJESTY™ ES Flow’s low viscosity monomers ensure that it has excellent handling characteristics, promising better sculpting for the dentist. The flowable composite does not stick to the needle tip or to any instruments, only adhering to the area to which it is applied, while the proprietary design of the syringe itself minimises air bubbles when dispensing. Once dispensed, the paste possesses great consistency with its non-slumping formula, ensuring that it can maintain its shape. A truly universal composite, CLEARFIL MAJESTY™ ES Flow allows dentists to create highly aesthetic restorations with ease.

Obtain results in four simple steps

Creating aesthetic and durable restorations has never been more achievable. Simply prepare the cavity and apply bonding, dispense and sculpt the CLEARFIL MAJESTY™ ES Flow, light-cure and, finally, polish. It’s as easy as that.

DENTAL ADVISOR SIX-MONTH PROGRESS REPORT

Summary
Over a six-month period, 96 restorations were placed. The clinical performance at the time of placement was excellent for esthetics, handling, ease of adjustment, and ease of finish/polish. There were no reports of post-operative sensitivity or debonding. Based on the placement period, CLEARFIL Universal Bond Quick with CLEARFIL MAJESTY ES Flow received a clinical performance rating of 100%.

Description:

CLEARFIL MAJESTY ES Flow is a light-cured, universal flowable composite.

It contains submicron fillers that are treated with a proprietary silane

coupling agent to provide for low shrinkage and high mechanical

properties. The submicron fillers and high filler load provide for esthetics.

CLEARFIL Universal Bond Quick is a single-bottle, universal bonding agent

that contains a novel rapid bond technology and releases fluoride. It is

compatible with total-, self- and selective-etch techniques and with light-,

self- and dual-cured materials (with CLEARFIL DC Activator).

Clinical Evaluation Protocol (Six Months):

A total of 96 CLEARFIL Universal Bond Quick with CLEARFIL MAJESTY ES

Flow restorations were placed in 44 molars, 26 premolars and 26 anterior

teeth (Figure 1). The classification of restorations was recorded as 44 Class

I, 7 Class II, 1 Class III, 30 Class V, and 14 Class VI restorations (Figure 2).

Kuraray Noritake Dental Inc.

Results at Six Months:

There were no reports of post-operative sensitivity for CLEARFIL Universal

Bond Quick with CLEARFIL MAJESTY ES Flow. All 96 restorations received

excellent ratings of five for esthetics, handling, ease of adjustment, and

ease of finish/polish (Figure 3). No debonding was observed.

All restorations were evaluated at placement in the following areas: lack
of post-operative sensitivity, esthetics, handling, ease of adjustment, and
ease of finish/polish. Restorations were evaluated on a 1-5 rating scale:
1 = poor, 2 = fair, 3 = good, 4 = very good, 5 = excellent.

Consultants’ Comments
• “I love flowables - CLEARFIL MAJESTY ES Flow is in a class of its own.”
• “I use CLEARFIL MAJESTY ES Flow regularly in areas of incipient decay
- flows well, very esthetic and polishes easily.”
• “CLEARFIL MAJESTY ES Flow is my go-to flowable to repair small chips
in anterior teeth. It blends seamlessly with the tooth.”
• “Great to use in abfraction areas in conjunction with CLEARFIL
Universal Bond Quick. CLEARFIL MAJESTY ES Flow bonds well and is
very easy to finish and polish. Patients love the outcome.”

“The multi-layered aspect of KATANA Zirconia is excellent”

In recent years, zirconia has emerged as the preferred choice for dentists who wish to perform restorative procedures with a reliable and metal-free material. With the recent development of multi-layered aesthetic high-translucency options, zirconia’s popularity has further increased. In comparison to the opaque whiteness of older generations of zirconia, these newer versions have an enhanced appearance and functionality that makes them suitable for natural-looking anterior restorations.

Kuraray Noritake Dental’s KATANA Zirconia disc range is made with a proprietary zirconia powder—processed in-house—that gives it its natural appearance. Suitable for zirconia prostheses, from single crown to full arch, it is an ideal option for restorations in both the anterior and posterior regions. We spoke with Dr Imad Ghandour, a prosthodontist with a strong scientific background and a private practice in Le Cannet in France, about his experiences with the KATANA Zirconia range in restorative procedures.

Dr Ghandour, when did you first start using zirconia as a material for your restorations?

In 1998, when I was still sintering manually, I began using zirconia alumina. It was nice to have an alternative to metal alloys that was much more aesthetic. From 2003, however, I started with VITA blocks, but only for frameworks—I would still build up with ceramics. Now, with so much of dentistry being digitally focused, there is a need for a material that can be milled without changing anything in the morphology of the teeth. Why? Because we need to be able to reproduce the treatment plan as accurately as possible. Simply put, the KATANA Zirconia range solves this need for me.

With respect to dentistry being digitally focused, how has this changed the role of the dentist regarding performing restorative procedures?

Well, it is clear that we have entered the age of digital dentistry. Around 80 per cent of restorations are conducted via CAD/CAM systems and without dentists even touching the materials themselves. There are great advances being made in the technologies that are available for everyday use in dental practices worldwide, and many of them can be used to assist dentists performing restorative procedures. It is important, though, to keep in mind that these technological advancements alone will not lead to better results—they should supplement the requisite hands-on skills and techniques that all dentists must first learn. With this base of fundamentals, we can then use digital dentistry to make restorative procedures more predictable and reproducible. Of course, to ensure the best results in restorative procedures, dentists also need to use the materials that have the best aesthetic and mechanical properties.

For how long have you been using Kuraray Noritake Dental’s KATANA Zirconia range, and what has your experience been?

I have been using KATANA Zirconia for a little bit more than one year. In that time, I have primarily used the KATANA Zirconia STML (Super Translucent Multi Layered) line and have been pleasantly surprised by how natural-looking the restorations I have made with the material are. For example, when I sinter a crown made of Katana Zirconia STML, I am amazed at how much the sintered material is reminiscent of a pearl—it truly brings to mind the idea of one’s teeth being one’s pearly whites.

When using KATANA, how do you ensure that you select the correct shade to achieve a natural look?

Firstly, no one—not a dentist nor a dental technician—can be absolutely certain that the shade and chroma of the restoration that is in one’s hand will be the same once it is in position in the oral cavity. This is due to the complexities of the oral environment—the pinkness of the gingivae, for one, can have a large impact on how the restoration appears, often making it seem far duller than it does in the light of a dental laboratory. This can cause dental practitioners to compensate and make prostheses that appear far brighter than they will when they are in place.

With a product like KATANA and its related glazing materials, however, I can create crowns and other restorations that have an optimal fluorescence and translucency and are able to maintain their shading better than any other ceramic material I have used. I am able to select a shade with the confidence that it will look exactly the same once placed inside the mouth, with its chroma remaining unabsorbed by the gingiva. Achieving a natural look, then, depends on choosing a shade that is as close to that of the surrounding dentition as possible. Since KATANA Zirconia UTML (Ultra Translucent Multi Layered) is available in 16 standard shades and a further four enamel shades, there is no shortage of options in this regard.

How does the multi-layered technology of KATANA Zirconia help you to achieve optimal and natural-looking aesthetic results?

Well, firstly, the layering of the material is designed to replicate the colour and translucency progression of natural teeth, which allows for restorations to blend in as much as possible. This multi-layered technology has also proved itself to be very handy when I am sintering crowns made of KATANA Zirconia. Simply put, if one sinters a crown quickly, it will be a little more opaque. If one sinters it at a higher temperature and quite slowly, it will be much more translucent. The multi-layered aspect of KATANA Zirconia is excellent in that it gives me the ability to make restorations more or less translucent depending on what is required.

PANAVIA and KATANA: The perfect combination

Scientific research has demonstrated that, when bonding zirconia, optimal bond values can only be achieved with resin cements—specifically, MDP monomer-based resin cements. With PANAVIA V5, we offer a dual-cure resin cement with dentine bond strengths equal to our gold standard light-cure bonding agent CLEARFIL SE BOND, even when used in self-cure mode. Through our KATANA Zirconia range, Kuraray Noritake Dental presents a ceramic material for restorative procedures that has excellent translucency and shade options. Together, PANAVIA V5 and KATANA Zirconia make an ideal team for durable and reliable indirect restorations.

PANAVIA V5

In 1983, Kuraray introduced its patented MDP monomer in PANAVIA EX cement. With its clinically proven adhesion, our PANAVIA family has set the industry standard for adhesion for over 30 years. As the newest addition to the PANAVIA cement line, PANAVIA V5 provides strong bonding not just to zirconia but to hydroxyapatite and metals as well. Unlike other dual-cure resin cements, PANAVIA V5 offers improved bond strength to all tooth structures. Simple to use and with predictable results, PANAVIA V5 is unique in its user friendliness and procedural consistency. 

KATANA Zirconia

Our KATANA Zirconia discs are processed using a proprietary zirconia powder, allowing it to have as natural a translucency and colour as possible. The KATANA range consists of several options designed for full-contour zirconia prostheses, from single crown to full arch: KATANA Zirconia UTML (Ultra Translucent Multi Layered), STML (Super Translucent Multi Layered), ML (Multi Layered) and HT (High Translucent). The multilayered build-up of KATANA Zirconia STML provides a translucency and chroma that gradually decrease from the cervical to incisal regions, just like natural dentition. KATANA Zirconia UTML is perfect for anterior restorations, such as veneers, owing to its natural translucency and colour gradient. With a flexural strength considerably higher than that of lithium disilicate, KATANA Zirconia has the mechanical and aesthetic properties to achieve well-balanced restorations between natural teeth in the anterior zone.

An ideal team

PANAVIA V5 provides a strong and durable bond between KATANA Zirconia-based restorations and the tooth structure. PANAVIA V5 resin cement offers optimal margins and predictable restorations. Always use PANAVIA V5 Tooth Primer for the pretreatment of the tooth and CLEARFIL CERAMIC PRIMER PLUS for the priming of the restoration.

“We’re thrilled by the possibilities presented from the combination of PANAVIA V5 and KATANA Zirconia,” said Mitsuru Takei, Head of Technical Services at Kuraray Europe. “Together, they make achieving natural-looking restorations easier than ever.”