Kuraray celebrates its 90th anniversary in 2016. We take the opportunity of this occasion to offer you a glimpse of the history of Kuraray from a new perspective. The name Kuraray represents more than 8,300 employees and an annual turnover of approximately 3.7 billion euros. Kuraray was founded in Kurashiki, Japan, in June 1926, by Magosaburo Ohara. Kuraray began with the domestic production of Rayon, a synthetically produced cellulose fibre referred to as artificial silk, a new and innovative product at the time. 

The name KURARAY is derived from the location: Kurashiki and the product manufactured: Rayon. The development of this branch of production developed very quickly in Japan, with many other major manufacturers establishing themselves during this period. Whereas others recruited their technicians and experts from elsewhere, Kuraray established the Kyoko Research Laboratory, which was managed by the University of Kyoto to generate expertise and support for the development of the required technologies. Ohara also committed himself to cultural and social projects. The building of an art gallery and the financing of an orphanage represent only two of his many projects in Kurashiki. The Ohara Museum of Art was the first private museum of Western art in Japan.

Ohara considered the dreadful conditions in which employees commonly worked and lived at the time to be unacceptable; he was not a profit-driven employer, and attempted to solve such issues. He ensured that decent accommodation, fitness facilities and nursery schools were built to provide young employees, or families who had left their homes to work for Kuraray, with everything they needed for education and a healthy and culturally rich lifestyle.
One of the largest general hospitals in the west of Japan, the Kurashiki Central Hospital, was originally founded by Kuraray to promote the well-being of employees and their families. It is still considered to be one of the most famous hospitals in Japan.

With the production of Kuralon in 1950, developed from the in-house manufactured products PVA and vinyl acetate, Kuraray expanded to become the specialist chemical company it is today. Always intent on making a contribution to the good of society, Kuraray addressed the subject of environmental protection very early on. The visionary Ohara was aware of the seriousness of environmental pollution, and made great efforts to prevent it.

Internationally too, Kuraray has remained aware of its social responsibilities. After the war, a production facility was opened in China which helped to improve the poor post-war living conditions of the Chinese population.
Today, Kuraray is a leading global manufacturer of the specialist chemicals used in many aspects of daily life. Kuraray has always viewed its employees as its most important asset, and continues to do so to this day.

In 1978, Kuraray shook up the dental market with the introduction of CLEARFIL BOND SYSTEM F, the world’s first total-etch adhesive system. Having inaugurated the era of adhesive dentistry, we steadily introduced new dental products over the following years. In 1983, Kuraray introduced the PANAVIA EX resin cement. By utilising our patented MDP monomer technology developed in-house, PANAVIA EX enabled Kuraray to set the industry standard for adhesion—a position we have held in the decades since. This year marks the 40th anniversary of Kuraray’s entry into the commercial dental products market, providing a perfect opportunity to reflect on how far we have come since.

Kuraray—Rooted from a true trailblazer 
Founded in June 1926 by Magosaburo Ohara in Kurashiki in Japan, Kuraray has transcended our humble origins as a producer of rayon to become a leading global manufacturer of medical products, materials, textiles, chemicals, resins and much more. Our commitment to research and development in the fields of chemistry and engineering has led to many market firsts and a reputation as a pioneer of new products and technologies. 

A history of innovation
From the very beginning, Kuraray has been focused on the manufacture of high value-added products. At the time of the business’s birth, rayon was a new type of synthetic material, and over the ensuing years, Kuraray was able to master its production. In 1950, we became the first company in the world to develop the technology to mass-produce POVAL (polyvinyl alcohol), paving the way for the production of the new synthetic fibre Vinylon in the same year. CLARINO, a water-resistant synthetic leather substitute for shoes, bags and other items, was released in 1964 after extensive research and testing, and quickly collected international awards for its technology.

Kuraray’s continued emphasis on independently developed proprietary technologies and techniques, rather than relying on imported alternatives, has enabled our company to provide original, high-quality products for a variety of different industries. High on this list is dentistry.

The Kuraray Noritake Dental era
In April 2012, Kuraray Medical and Noritake Dental Supply merged to form Kuraray Noritake Dental. By bringing together the materials and technologies developed by each of these market-leading companies, Kuraray Noritake Dental has continued to deliver dental bonding agents, ceramics and other reliable products to over 90 countries worldwide. The KATANA Zirconia range, for example, employs our unique multi-layered zirconia technology to provide a ceramic restorative material with superior translucency and perfect blending properties, while rapid bond technology ensures that CLEARFIL Universal Bond Quick delivers a lasting bond faster and easier than ever. 

Through a focus on research and production, Kuraray Noritake Dental is ideally positioned to continue providing leading-edge solutions to dental issues both now and in the future. 
 

As the operator of his own dental practice in the German town of Laer and a member of the Digital Dental Academy in Berlin, Dr Hendrik Zellerhoff is clearly a very busy man. Fortunately, his integration of Kuraray Noritake Dental’s KATANA Zirconia Block into his daily workflow means that he is able to deliver high-quality restorations to his patients faster than ever. In this interview, Dr Zellerhoff explains how he uses the block and how his patients have responded to it.

Dr Zellerhoff, can you tell us a little bit about your background as a dentist?
In 2003, I began working as an assistant and at this time I worked with the CEREC system, a system for which I am now a certified trainer. In 2005, I opened my own dental practice in Laer, which I continue to operate to this day.

When did you first begin to work with Kuraray Noritake Dental’s range of products?
I think it was about four or five years ago that the laboratory that I worked with told me how good Kuraray Noritake’s KATANA Zirconia discs were for sintering and fabricating full-zirconia crowns. At that point, however, I was only looking for materials that would work with CEREC, and so it wasn’t until early 2018, when I went on a course in Leipzig in Germany where the KATANA Zirconia Block was being demonstrated, that I really saw how I could use this product in my practice. The block’s integration with the CEREC system means that it is now possible for me to provide high-strength aesthetic zirconia restorations for my patients accurately and quickly.

How frequently do you use the KATANA Zirconia Block during your daily work as a dentist?
I think around once a day, on average. It varies—sometimes I may make restorations for three different patients on one day, and then it’s four days until I use it again. My CEREC is only able to conduct wet milling, however, which is obviously slower than the 15-minute time span made possible through dry milling, and this limits how often I can use it.

What do you like most about this zirconia solution?
For me, it both feels and looks very real, so it has this aesthetic function going for it. Its multilayered, highly translucent appearance definitely helps to achieve more natural-looking restorations. However, the mechanical strength of the material is also something that I like, as it means that it can be used for restorations with thinner walls and sharper margins than those made with glass-ceramics.

With the release of the KATANA Zirconia Bridge Block, do you expect to use this zirconia solution more?
Oh, absolutely! The ability to make aesthetic bridges in the molar area and in a single visit is a revelation to me.

What has the response from your patients been?
They love it! These procedures can be realised on the same day as their initial appointment, and this means that my practice has patients coming from far outside of the small town in which I live. We even get people coming all the way from Switzerland to receive KATANA-based treatments—that’s how positive the response has been.

With this focus on digital dentistry, is there still a role for the dentist as a craftsperson?
I love to work with an entirely digital workflow. If a machine can do something better or faster than I am able to, then that is all right with me. As far as I can see, the future of dentistry will be digital. At the end of the day, the goal stays the same—to provide my patients with results that they are happy with.

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.

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.

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.”