With so many different adhesives, cements, and restorative materials available on the dental market, it seems difficult to decide which products are best suited to fulfil the individual requirements. A direct comparison obtained through testing of all products in the dental office is simply impossible due to the great number of available solutions. Laboratory investigations provide information about specific product properties, but usually cannot create the overall picture. Moreover, the results of different tests are barely comparable due to variations in the test conditions. Clinical study results are very useful as they shed light on the clinical (long-term) performance of selected materials, but they are usually published years after a product’s launch. Hence, they are not available in the early stages. A great source of information are practice-based evaluations, as they support potential users in identifying high-quality dental materials.

One of the institutions conducting and publishing practice-based clinical evaluations and product performance tests is the US-based DENTAL ADVISOR. Once per year, the dental materials and equipment with the best performance receive a Top Product or Preferred Product Award. The list of winners is published online (www.dentaladvisor.com) and in the January-February issue of the DENTAL ADVISOR. In 2020, numerous products from Kuraray Noritake Dental were among the award winners.

Top Product Awards

CLEARFIL™ SE Protect received a Top Product Award in the category Direct Restoratives, Bonding Agent: Self-Etch. The self-etch adhesive is based on the formulation of the gold standard two-step self-etch adhesive CLEARFIL™ SE Bond, but contains an extra MDPB monomer offering an antibacterial cavity-cleansing effect and fluoride for long-term fluoride release. The honoring of the DENTAL ADVISOR is based on a material test carried out by 13 DENTAL ADVISOR consultants and editors in their dental offices for six weeks. Due to its excellent performance, the antibacterial self-etch adhesive received a 98 percent clinical rating.

For the fifth year in a row, the Top Product Award in the category Direct Restoratives, Composite: Highly Filled Flowable went to CLEARFIL MAJESTY™ ES Flow. The universal flowable composite comes in three different levels of flowability, from high to super low*. This enables the user to choose the right viscosity for every clinical situation – with the high flowability variant being the perfect choice for cavity lining and repair procedures, and the super low flowability option being specifically suited for direct veneer procedures, build-up of posterior cusps etc. The universal flowable composite was tested by 29 consultants of the DENTAL ADVISOR in more than 900 clinical applications. The evaluated properties – placement/handling, esthetics, viscosity and polishability – were rated “excellent”. This led to a recommendation rate of 100 percent and a 98 percent overall clinical rating.

^{*DENTAL ADVISOR evaluated only the standard level of flowability (Low), because other two variants are not available in US.}

Our third product receiving a Top Product Award in 2020 is PANAVIA™ SA Cement Universal (category: Cement: Self-Adhesive). The self-adhesive universal resin cement contains the unique LCSi monomer. This monomer is a silane coupling agent, which has an unique long carbon chain in its molecule, that establishes a durable, chemical bond with porcelain, lithium disilicate and composite resin without the need for a separate primer. The other key technology present in the formulation is the original MDP monomer, which ensures chemical reactiveness with zirconia, dentin and enamel. Together, the technologies ensure that PANAVIA™ SA Cement Universal produces a strong and durable bond with virtually every restorative material without the need for a separate primer. Its handling characteristics, aesthetics and gingival friendliness received very good to excellent ratings from 31 clinical evaluators, who used the cement in 516 applications. The result of the overall clinical rating was 96 percent.

Preferred Products

Among the 2020 Preferred Products is CLEARFIL™ Universal Bond Quick. The universal bonding agent may be applied using the self-etch technique or – together with K-ETCHANT syringe – in the selective enamel etch or total-etch technique. Containing our rapid bond technology – a combination of the original MDP monomer with innovative hydrophilic amide monomers – the adhesive works instantly and without the need for extended exposure times, application of multiple layers or extensive rubbing into the tooth structure. The fast and easy application procedure was one of the main reasons for the consultants of the DENTAL ADVISOR to select CLEARFIL™ Universal Bond Quick as a Preferred Product. In 2017, it already became the DENTAL ADVISOR Editor’s Choice with a 98 percent score in a clinical evaluation.

For the second year in a row, the universal prosthetic primer CLEARFIL™ Ceramic Primer Plus and TEETHMATE™ DESENSITIZER for hypersensitivity treatment. CLEARFIL™ Ceramic Primer Plus contains the original MDP monomer and a silane monomer, which ensure excellent bond strength to all kinds of restorative materials, i.e. to silica-based ceramics, zirconia, composites and even metals. Users benefit from procedural simplicity as the product is just applied and dried to the bonding surface after the recommended pretreatment. After clinical testing, the product received a recommendation rate of 96 percent and a 96 percent overall score from the DENTAL ADVISOR consultants.

TEETHMATE™ DESENSITIZER was designed to create hydroxyapatite (HAp), which is able to occlude open dentinal tubules and enamel cracks. This leads to a significant reduction of hypersensitivities when applied to exposed, mechanically treated or freshly prepared dentin. When used in the context of restorative treatment, TEETHMATE™ DESENSITIZER does not have a negative effect on the bond strength of dental adhesives or cements. A clinical evaluation conducted by the DENTAL ADVISOR resulted in an excellent rating with a score of 96 percent.

Conclusion

Most of the Kuraray Noritake Dental products that received an award this year are based on resin technologies, one of our key competencies. In the 1980s, we developed the original MDP monomer, a functional monomer, which is an essential component of any adhesive product we introduced down to the present day, including the award-winning CLEARFIL™ SE Protect, PANAVIA™ SA Cement Universal, CLEARFIL™ Universal Bond Quick and CLEARFIL™ Ceramic Primer Plus. This is only one of our many areas of expertise. We also provide users with preventive products and a whole range of restorative materials – from composite filling materials like CLEARFIL MAJESTY^TM ES Flow to dental ceramics like KATANA™ Zirconia UTML, STML and HTML. We see the winning of the awards as a positive proof of a reliable product performance that supports dental practitioners in reaching their own goals.

When cementing a restoration during the trial fitting stage, it’s quite common to have reduced bond strength due to surface contamination caused by saliva, blood or even plaque in the dental cavity. To remove this contamination, you need a dental cleaning agent. Kuraray Noritake Dental is thus proud to introduce the KATANA™ Cleaner, a non-abrasive universal cleaner that delivers the bond strength your patients deserve.

Exceptional cleaning

The KATANA™ Cleaner has a high cleaning ability due in part to the surface active characteristic of its MDP-based salt. Hydrophobic groups of the salt adhere to the contamination, weakening the surface tension and causing it to break up. The contamination then floats from the tooth or restoration surface, and can be removed by rinsing with water.

This allows for establishment of the desired bond strength, ensuring that you can really be prepared to cement your restoration.

Unlike other dental cleaners, the KATANA™ Cleaner can be used both intra-orally and extra-orally owing to its relatively low pH value of 4.5.

Apply, rinse and dry

As is the case for many Kuraray Noritake Dental products, this cleaner is backed by extensive scientific research and is designed to be as simple to use as possible. The KATANA™ Cleaner comes with a single-handed delivery cap, and its application is straightforward: just apply with a rubbing motion for at least 10 seconds, rinse with water and air-dry before cementation.

A wide range of indications

The KATANA™ Cleaner is suitable for a wide range of dental and metal restorations. It can be used on enamel or dentine, on dental ceramics such as zirconia, on composite resins and on dental posts.

Pairing ideally with the KATANA™ Cleaner is PANAVIA™ V5, a resin cement with unrivalled simplicity and predictability. Together, these products highlight Kuraray Noritake Dental’s commitment to delivering optimal cementation.

But how does it compare?

Of course, you might say that it’s not just enough to promote the benefits of the KATANA™ Cleaner in a vacuum. For that reason, we’ve provided a handy chart that shows how it compares to other cleaners already on the market:

When cementing a restoration during the trial fitting stage, it’s quite common to have reduced bond strength due to surface contamination caused by saliva, blood or even plaque in the dental cavity. To remove this contamination, you need a dental cleaning agent. Kuraray Noritake Dental is thus proud to introduce the KATANA™ Cleaner, a non-abrasive universal cleaner that delivers the bond strength your patients deserve.

Exceptional cleaning

The KATANA™ Cleaner has a high cleaning ability due in part to the surface active characteristic of its MDP-based salt. Hydrophobic groups of the salt adhere to the contamination, weakening the surface tension and causing it to break up. The contamination then floats from the tooth or restoration surface, and can be removed by rinsing with water.

This allows for establishment of the desired bond strength, ensuring that you can really be prepared to cement your restoration.

Unlike other dental cleaners, the KATANA™ Cleaner can be used both intra-orally and extra-orally owing to its relatively low pH value of 4.5.

Apply, rinse and dry

As is the case for many Kuraray Noritake Dental products, this cleaner is backed by extensive scientific research and is designed to be as simple to use as possible. The KATANA™ Cleaner comes with a single-handed delivery cap, and its application is straightforward: just apply with a rubbing motion for at least 10 seconds, rinse with water and air-dry before cementation.

A wide range of indications

The KATANA™ Cleaner is suitable for a wide range of dental and metal restorations. It can be used on enamel or dentine, on dental ceramics such as zirconia, on composite resins and on dental posts.

Pairing ideally with the KATANA™ Cleaner is PANAVIA™ V5, a resin cement with unrivalled simplicity and predictability. Together, these products highlight Kuraray Noritake Dental’s commitment to delivering optimal cementation.

But how does it compare?

Of course, you might say that it’s not just enough to promote the benefits of the KATANA™ Cleaner in a vacuum. For that reason, we’ve provided a handy chart that shows how it compares to other cleaners already on the market:

“This profession requires incredible precision and focus”

Dr Magdalena Osiewicz has run her own private practice in Cracow in Poland since 2010 while also working as assistant professor at Jagiellonian University’s Department of Integrated Dentistry and as a researcher at the Academic Centre for Dentistry Amsterdam (Academisch Centrum Tandheelkunde Amsterdam) in the Netherlands. In this interview, she discusses what it takes to succeed in dentistry and why she relies on Kuraray Noritake Dental products in her dental practice.

Dr Osiewicz, how did you decide to enter the field of dentistry?

My father is a medical doctor and a great example for me. He argued that being a doctor would not be good for me because it would consume all my free time. Therefore, I decided that I would become a dentist, preferably a prosthodontist, and I have since specialised in dental prosthetics, restorative dentistry and treating temporomandibular disorders. However, I honestly think that being a dentist doesn’t leave you so much free time either. It’s an ongoing discussion that I have with my father during the holidays.

In your experience, are there any advantages or disadvantages to being a woman in dentistry? Has the situation changed over time?

I have been a dentist since 2005, and I must say that this profession requires incredible precision and focus as well as a very high level of physical fitness. In addition, it is a profession that demands that you have very good social skills and empathy for other people. Combined with all the other duties that a woman has, there can be big challenges for a woman working in dentistry.

How important is it to have peers and/or mentors with whom you can discuss problems?

I think it’s very important. Owing to the fact that we often work on our own, dentists can quickly forget that discussing issues with other professionals can improve their skills and help them serve their patients better.

What qualities and skills do you think are needed to succeed in the dental world?

To succeed in dentistry, you need to work with the best materials, constantly improve your knowledge and skills, and enjoy working with other people. You should always be open-minded and critically evaluate your work. Mistakes must not be repeated, and you should learn from them.

What advice would you have for women considering a career in dentistry?

I would advise them to maintain a healthy work–life balance and to take care of their physical and mental health.

How were you first introduced to Kuraray Noritake Dental’s wide range of solutions?

My first contact with Kuraray Noritake Dental’s products was during my postgraduate studies at the Academic Centre for Dentistry in Amsterdam, where we needed materials that could be used in the most extreme situations.

Which Kuraray Noritake products do you employ in your daily workflow?

To be honest, I use many Kuraray Noritake Dental products in my dental practice. CLEARFIL™ AP-X and PHOTO BRIGHT are great composites for patients with bruxism. I also use CLEARFIL MAJESTY™ ES-2 when we have a demanding patient for aesthetic work. I can recommend CLEARFIL™ PHOTO CORE, and I use PANAVIA™ for cementing prosthetic work as well as absolutely reliable adhesive systems such as CLEARFIL™ SE BOND or PHOTO BOND. I should also mention Kuraray Noritake’s range of KATANA™ Zirconia, which is the best zirconia on the market and is what I use for prosthodontics.

“This profession requires incredible precision and focus”

Dr Magdalena Osiewicz has run her own private practice in Cracow in Poland since 2010 while also working as assistant professor at Jagiellonian University’s Department of Integrated Dentistry and as a researcher at the Academic Centre for Dentistry Amsterdam (Academisch Centrum Tandheelkunde Amsterdam) in the Netherlands. In this interview, she discusses what it takes to succeed in dentistry and why she relies on Kuraray Noritake Dental products in her dental practice.

Dr Osiewicz, how did you decide to enter the field of dentistry?

My father is a medical doctor and a great example for me. He argued that being a doctor would not be good for me because it would consume all my free time. Therefore, I decided that I would become a dentist, preferably a prosthodontist, and I have since specialised in dental prosthetics, restorative dentistry and treating temporomandibular disorders. However, I honestly think that being a dentist doesn’t leave you so much free time either. It’s an ongoing discussion that I have with my father during the holidays.

In your experience, are there any advantages or disadvantages to being a woman in dentistry? Has the situation changed over time?

I have been a dentist since 2005, and I must say that this profession requires incredible precision and focus as well as a very high level of physical fitness. In addition, it is a profession that demands that you have very good social skills and empathy for other people. Combined with all the other duties that a woman has, there can be big challenges for a woman working in dentistry.

How important is it to have peers and/or mentors with whom you can discuss problems?

I think it’s very important. Owing to the fact that we often work on our own, dentists can quickly forget that discussing issues with other professionals can improve their skills and help them serve their patients better.

What qualities and skills do you think are needed to succeed in the dental world?

To succeed in dentistry, you need to work with the best materials, constantly improve your knowledge and skills, and enjoy working with other people. You should always be open-minded and critically evaluate your work. Mistakes must not be repeated, and you should learn from them.

What advice would you have for women considering a career in dentistry?

I would advise them to maintain a healthy work–life balance and to take care of their physical and mental health.

How were you first introduced to Kuraray Noritake Dental’s wide range of solutions?

My first contact with Kuraray Noritake Dental’s products was during my postgraduate studies at the Academic Centre for Dentistry in Amsterdam, where we needed materials that could be used in the most extreme situations.

Which Kuraray Noritake products do you employ in your daily workflow?

To be honest, I use many Kuraray Noritake Dental products in my dental practice. CLEARFIL™ AP-X and PHOTO BRIGHT are great composites for patients with bruxism. I also use CLEARFIL MAJESTY™ ES-2 when we have a demanding patient for aesthetic work. I can recommend CLEARFIL™ PHOTO CORE, and I use PANAVIA™ for cementing prosthetic work as well as absolutely reliable adhesive systems such as CLEARFIL™ SE BOND or PHOTO BOND. I should also mention Kuraray Noritake’s range of KATANA™ Zirconia, which is the best zirconia on the market and is what I use for prosthodontics.

KATANA™ Zirconia ML (Kuraray Noritake Dental) was the first zirconia on the dental market with integrated shade gradation. First presented at IDS 2013, this material has revolutionized the world of zirconia. Over the course of time, KATANA™ Zirconia UMTL, STML and the change from ML to HTML completed the product portfolio. This article highlights the differences.

By Attila Kun, Hüde in Lower Saxony, Germany

In daily clinical and laboratory routine, we become aware of the diversity of characteristics of natural teeth. Natural teeth impress with their individual optical properties and characteristics, as well as the variety in their shape and texture. The challenge of imitating these aspects with ceramic restorations is a task that we handle in the lab with passion and motivation.

Imitation of the natural tooth requires the appropriate framework material (e.g. KATANA™ Zirconia HTML), an appropriate veneering ceramic or stain system (e.g. Noritake CZR™), along with sensitivity and skill. Although modern materials lay an important foundation, implementation of the restoration is to a large extent an artistic skill. In order to select the appropriate material, depending on the indication, the dental technician should pay attention to the facts and material science (material properties, parameters). Dental sensitivity and craftsmanship are also required for aesthetic realization of the prosthetic. Whether monolithic restoration, thin-layer veneer or individually layered, zirconia offers various advantages as a restorative material (e.g. good mechanical properties, high biocompatibility). In recent years, zirconia has been further developed and optimised through material modifications, and now, new zirconia generations are available. These materials are remarkable due to their translucency and outstandingly aesthetic properties. For certain indications, monolithic restorations can be realized in such way that the optical properties hardly differ from those of a veneered restoration.

Looking back at KATANA’s history

KATANA™ Zirconia ML (Kuraray Noritake Dental) was launched in 2013. This was the first zirconia on the market with a polychromatic shade gradient (ML = Multi-Layered) and has revolutionized the market since. The chroma and saturation of KATANA™ Zirconia ML decrease from cervical to incisal. The market responded very well to the polychromatic discs, so Kuraray Noritake Dental took the next step. In 2015, the KATANA™ family grew with two new translucent materials: KATANA™ Zirconia STML (super-translucent) and UTML (ultra-translucent). Translucency studies have revealed the very high light transmission of KATANA™ Zirconia UTML (43%) and STML (38%). It should be noted that the strength of the material drops with rising translucency. In 2019, KATANA™ ML became KATANA™ HTML. This change included a shade extension from 6 to 14 shades and the adaptation to the VITAPAN Classical shades to ensure an even simpler shade selection for the dental technician for an even better communication between dentist and dental technician. A few years back, the new zirconia stains (CZR™ FC Paste Stain, Kuraray Noritake Dental) were also launched on the market, thus perfecting the KATANA™ potpourri for highly aesthetic yet durable zirconia restorations.

The KATANA™ Zirconia STML layered structure.

Same translucency level as glass-ceramic (e.max Press LT).

With higher flexural strength than glass-ceramic (e.max Press LT).

Comparison of KATANA™ HTML, STML, UTML with comparable ceramic products (Kuraray Noritake overview graphics)

The Japanese word KATANA™ denotes a special kind of traditional Samurai sword. A special feature is the exquisite raw material. The KATANA™ sword combines expedient form with artistic design. We dental technicians aspire to this in our work too. KATANA™ Zirconia offers us the optimal foundation here. The multi-layered KATANA™ materials show a smooth progression of shade and brightness from cervical to incisal. Our experience shows that a functional and aesthetic restoration can thus be implemented in an efficient way.

Application of polychromatic zirconia

Fully anatomical, partially anatomical or as a framework — the polychromatic KATANA™ materials can be used in a variety of ways. The integrated shade gradient displays gentle nuances of enamel, dentin and cervical shade and, in the case of STML, also a translucency gradient. Depending on the indication, the zirconia blanks open up different ways of achieving aesthetic restoration. Especially for complex repairs and anterior restorations, the set-up is an indispensable foundation for us, because the "right" material alone is no guarantee for success. Precise planning is called for. This why we have to first conceive an overall picture. The surface structure, shape and contour are built up manually in wax and after a double scan the wax-up is virtually reduced. This creates a dentin structure or framework that can be milled out of the respective zirconia.

KATANA™ multi-layered materials allow the framework to become a shade-bearing foundation. The CAD construction of the restoration is made in a reduced anatomical crown shape. A dentin core is then milled from zirconia. The ceramic veneer is reduced to a minimum. For a vivid result, the framework can also be characterised with internal stain. Shrinkage during baking is not likely. Shade stability comes from the framework. In addition, the thin veneer layer ensures low shrinkage and lays the secure foundation for high stability and a low risk of chipping. The result is a natural looking restoration. Shine, warmth, naturalness — the optical properties mainly come from the KATANA™ framework!

Differences between and indications for KATANA™ Zirconia HTML, UTML, STML.

KATANA™ Zirconia HTML

KATANA™ Zirconia HTML has high flexural strength. Crowns and bridges (also with a large span) are typical indications. KATANA™ HTML is available in numerous shades, which cover individual requirements in the lab. The material offers optimal optical properties for frameworks. The incident light is transmitted and yet the stump is concealed. The flexural strength is about 1125 MPa.

The framework is designed following a cut-back. The challenge of ceramic veneers (CERABIEN™ ZR, Kuraray Noritake Dental) lies in the subtle, often diffuse, shade variety of the neighboring natural teeth. These characteristics can be implemented using the internal stain technique. The intensive stains can be mixed, for example with Bright (Dilution). Shade depth and three-dimensionality are created once the layering is then covered with luster compound. Luster compounds are a special feature of the Kuraray Noritake ceramic system. The compounds envelop the actual layering like a fine cocoon. Depth and liveliness are achieved thanks to the opalescent properties.

KATANA™ Zirconia STML

Aesthetic restorations need light and translucency, which KATANA™ Zirconia STML offers. The zirconia is modified by the manufacturer adding yttrium oxide, by varying the particle sizes, and increasing its translucency. KATANA™ Zirconia STML also has a polychromatic shade gradient from cervical to incisal. In addition to the shade intensity, its translucency also varies. Therefore, this material is well suited for frameworks in the anterior region (up to three units). The lower translucency in the cervical area is optimal for the shade-bearing framework foundation. The balanced combination of graduated chroma and translucency allow the optical properties of natural teeth to be imitated to the best effect. The flexural strength is 748 MPa.

KATANA™ Zirconia UTML

UTML offers the highest translucency in the KATANA™ family. By modifying the material, the optical properties come close to those of a glass-ceramic. This extends the range of indications to include monolithic restorations in the esthetically visible region, e.g. veneers. KATANA™ UTML has less chroma than conventional zirconia. This is achieved through a consistently high degree of transparency, which brings out the intrinsic shade of the dentin (chameleon effect). KATANA™ UTML is indicated for veneers, onlays or full-contour crowns. The flexural strength is 550 to 600 MPa.

For the purpose of phantom work, we used KATANA™ UTML to produce full-contour veneers. The wafer-thin veneers were milled with a minimum thickness of 0.3 mm. Despite the thinness of the layer, there were no fractures or chipping at the edges. Individual characterization was achieved through the staining technique. The milled veneers display beautiful transparency. In order to perfectly bring out the optical properties, an adhesive bonding cement (e.g. PANAVIA™ V5, Kuraray Noritake Dental) can be used for such delicate restorations.

Wafer-thin veneers (0.3 mm) of KATANA™ Zirconia UTML on the model.

Light and shadow

Something that is often said also applies to aesthetic restorations: "What is essential is invisible to the eye". In order to obtain a perfect ceramic restoration, besides layering, the lifelike, the shape, contour and surface texture are important factors. Therefore—no matter whether monolithic or veneered—suitable preparation of micro- and macro-textures should never be overlooked. The application of gold powder, for example, has proven to be helpful. Even the finest structures become visible under the gold powder. As with black and white images, the eye is not distracted by shade effects. After incorporating the textures and the final touches, manual polishing and adjustment of the shine was undertaken.

Conclusion

The KATANA™ Zirconia series allows us flexible application and the possibility of reproducing the variety of natural teeth in an efficient way. The materials differ in their translucency and mechanical properties.

• KATANA™ Zirconia UTML is suitable for full-contour crowns in the anterior and posterior regions, veneers, inlays/onlays and single crowns in the posterior region.
• KATANA™ Zirconia STML is ideal for crowns and small posterior bridges.
• KATANA™ Zirconia HTML is a high strength framework material for crowns and bridges.

With this selection of zirconia materials, dental technicians are well-equipped and prepared for everyday work and can devote themselves to dental precision work based on individual specifications.

Dental technician Attila Kun
Hannker Dental
Ludwig-Gefe-Straße 28
49448 Hüde
info@hannker-dental.de

KATANA™ Zirconia ML (Kuraray Noritake Dental) was the first zirconia on the dental market with integrated shade gradation. First presented at IDS 2013, this material has revolutionized the world of zirconia. Over the course of time, KATANA™ Zirconia UMTL, STML and the change from ML to HTML completed the product portfolio. This article highlights the differences.

By Attila Kun, Hüde in Lower Saxony, Germany

In daily clinical and laboratory routine, we become aware of the diversity of characteristics of natural teeth. Natural teeth impress with their individual optical properties and characteristics, as well as the variety in their shape and texture. The challenge of imitating these aspects with ceramic restorations is a task that we handle in the lab with passion and motivation.

Imitation of the natural tooth requires the appropriate framework material (e.g. KATANA™ Zirconia HTML), an appropriate veneering ceramic or stain system (e.g. Noritake CZR™), along with sensitivity and skill. Although modern materials lay an important foundation, implementation of the restoration is to a large extent an artistic skill. In order to select the appropriate material, depending on the indication, the dental technician should pay attention to the facts and material science (material properties, parameters). Dental sensitivity and craftsmanship are also required for aesthetic realization of the prosthetic. Whether monolithic restoration, thin-layer veneer or individually layered, zirconia offers various advantages as a restorative material (e.g. good mechanical properties, high biocompatibility). In recent years, zirconia has been further developed and optimised through material modifications, and now, new zirconia generations are available. These materials are remarkable due to their translucency and outstandingly aesthetic properties. For certain indications, monolithic restorations can be realized in such way that the optical properties hardly differ from those of a veneered restoration.

Looking back at KATANA’s history

KATANA™ Zirconia ML (Kuraray Noritake Dental) was launched in 2013. This was the first zirconia on the market with a polychromatic shade gradient (ML = Multi-Layered) and has revolutionized the market since. The chroma and saturation of KATANA™ Zirconia ML decrease from cervical to incisal. The market responded very well to the polychromatic discs, so Kuraray Noritake Dental took the next step. In 2015, the KATANA™ family grew with two new translucent materials: KATANA™ Zirconia STML (super-translucent) and UTML (ultra-translucent). Translucency studies have revealed the very high light transmission of KATANA™ Zirconia UTML (43%) and STML (38%). It should be noted that the strength of the material drops with rising translucency. In 2019, KATANA™ ML became KATANA™ HTML. This change included a shade extension from 6 to 14 shades and the adaptation to the VITAPAN Classical shades to ensure an even simpler shade selection for the dental technician for an even better communication between dentist and dental technician. A few years back, the new zirconia stains (CZR™ FC Paste Stain, Kuraray Noritake Dental) were also launched on the market, thus perfecting the KATANA™ potpourri for highly aesthetic yet durable zirconia restorations.

The KATANA™ Zirconia STML layered structure.

Same translucency level as glass-ceramic (e.max Press LT).

With higher flexural strength than glass-ceramic (e.max Press LT).

Comparison of KATANA™ HTML, STML, UTML with comparable ceramic products (Kuraray Noritake overview graphics)

The Japanese word KATANA™ denotes a special kind of traditional Samurai sword. A special feature is the exquisite raw material. The KATANA™ sword combines expedient form with artistic design. We dental technicians aspire to this in our work too. KATANA™ Zirconia offers us the optimal foundation here. The multi-layered KATANA™ materials show a smooth progression of shade and brightness from cervical to incisal. Our experience shows that a functional and aesthetic restoration can thus be implemented in an efficient way.

Application of polychromatic zirconia

Fully anatomical, partially anatomical or as a framework — the polychromatic KATANA™ materials can be used in a variety of ways. The integrated shade gradient displays gentle nuances of enamel, dentin and cervical shade and, in the case of STML, also a translucency gradient. Depending on the indication, the zirconia blanks open up different ways of achieving aesthetic restoration. Especially for complex repairs and anterior restorations, the set-up is an indispensable foundation for us, because the "right" material alone is no guarantee for success. Precise planning is called for. This why we have to first conceive an overall picture. The surface structure, shape and contour are built up manually in wax and after a double scan the wax-up is virtually reduced. This creates a dentin structure or framework that can be milled out of the respective zirconia.

KATANA™ multi-layered materials allow the framework to become a shade-bearing foundation. The CAD construction of the restoration is made in a reduced anatomical crown shape. A dentin core is then milled from zirconia. The ceramic veneer is reduced to a minimum. For a vivid result, the framework can also be characterised with internal stain. Shrinkage during baking is not likely. Shade stability comes from the framework. In addition, the thin veneer layer ensures low shrinkage and lays the secure foundation for high stability and a low risk of chipping. The result is a natural looking restoration. Shine, warmth, naturalness — the optical properties mainly come from the KATANA™ framework!

Differences between and indications for KATANA™ Zirconia HTML, UTML, STML.

KATANA™ Zirconia HTML

KATANA™ Zirconia HTML has high flexural strength. Crowns and bridges (also with a large span) are typical indications. KATANA™ HTML is available in numerous shades, which cover individual requirements in the lab. The material offers optimal optical properties for frameworks. The incident light is transmitted and yet the stump is concealed. The flexural strength is about 1125 MPa.

The framework is designed following a cut-back. The challenge of ceramic veneers (CERABIEN™ ZR, Kuraray Noritake Dental) lies in the subtle, often diffuse, shade variety of the neighboring natural teeth. These characteristics can be implemented using the internal stain technique. The intensive stains can be mixed, for example with Bright (Dilution). Shade depth and three-dimensionality are created once the layering is then covered with luster compound. Luster compounds are a special feature of the Kuraray Noritake ceramic system. The compounds envelop the actual layering like a fine cocoon. Depth and liveliness are achieved thanks to the opalescent properties.

KATANA™ Zirconia STML

Aesthetic restorations need light and translucency, which KATANA™ Zirconia STML offers. The zirconia is modified by the manufacturer adding yttrium oxide, by varying the particle sizes, and increasing its translucency. KATANA™ Zirconia STML also has a polychromatic shade gradient from cervical to incisal. In addition to the shade intensity, its translucency also varies. Therefore, this material is well suited for frameworks in the anterior region (up to three units). The lower translucency in the cervical area is optimal for the shade-bearing framework foundation. The balanced combination of graduated chroma and translucency allow the optical properties of natural teeth to be imitated to the best effect. The flexural strength is 748 MPa.

KATANA™ Zirconia UTML

UTML offers the highest translucency in the KATANA™ family. By modifying the material, the optical properties come close to those of a glass-ceramic. This extends the range of indications to include monolithic restorations in the esthetically visible region, e.g. veneers. KATANA™ UTML has less chroma than conventional zirconia. This is achieved through a consistently high degree of transparency, which brings out the intrinsic shade of the dentin (chameleon effect). KATANA™ UTML is indicated for veneers, onlays or full-contour crowns. The flexural strength is 550 to 600 MPa.

For the purpose of phantom work, we used KATANA™ UTML to produce full-contour veneers. The wafer-thin veneers were milled with a minimum thickness of 0.3 mm. Despite the thinness of the layer, there were no fractures or chipping at the edges. Individual characterization was achieved through the staining technique. The milled veneers display beautiful transparency. In order to perfectly bring out the optical properties, an adhesive bonding cement (e.g. PANAVIA™ V5, Kuraray Noritake Dental) can be used for such delicate restorations.

Wafer-thin veneers (0.3 mm) of KATANA™ Zirconia UTML on the model.

Light and shadow

Something that is often said also applies to aesthetic restorations: "What is essential is invisible to the eye". In order to obtain a perfect ceramic restoration, besides layering, the lifelike, the shape, contour and surface texture are important factors. Therefore—no matter whether monolithic or veneered—suitable preparation of micro- and macro-textures should never be overlooked. The application of gold powder, for example, has proven to be helpful. Even the finest structures become visible under the gold powder. As with black and white images, the eye is not distracted by shade effects. After incorporating the textures and the final touches, manual polishing and adjustment of the shine was undertaken.

Conclusion

The KATANA™ Zirconia series allows us flexible application and the possibility of reproducing the variety of natural teeth in an efficient way. The materials differ in their translucency and mechanical properties.

• KATANA™ Zirconia UTML is suitable for full-contour crowns in the anterior and posterior regions, veneers, inlays/onlays and single crowns in the posterior region.
• KATANA™ Zirconia STML is ideal for crowns and small posterior bridges.
• KATANA™ Zirconia HTML is a high strength framework material for crowns and bridges.

With this selection of zirconia materials, dental technicians are well-equipped and prepared for everyday work and can devote themselves to dental precision work based on individual specifications.

Dental technician Attila Kun
Hannker Dental
Ludwig-Gefe-Straße 28
49448 Hüde
info@hannker-dental.de

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KURARAY NORITAKE DENTAL app is available on the Google play and App Store.

If you're looking for a new way to keep up to date with the latest news from Kuraray Noritake, we now have a brand new app.

Available for free on both iOS and Android devices, the clean and tidy interface is the easiest way to follow our news updates and make use of cementation guides, find procedures and make use of colour simulations.

We are committed to bringing our users the latest news, interviews, research, in-depth features and exclusive content for both Dental Technicians and Dentists.

Check it out for yourself!

KURARAY NORITAKE DENTAL app is available on the Google play and App Store.

Our commitment to you:

Kuraray Noritake dental products offer dental professionals all over the world high-quality products using simple procedures with long-lasting results. With the COVID-19 outbreak, all of us are now going through difficult times which we were not prepared for. Our thoughts are with all those people who are affected by the coronavirus pandemic.

We, at Kuraray Europe GmbH, as the European sales office of Kuraray Noritake Dental Inc., feel a strong responsibility towards our customers and partners, colleagues and communities and we would like to inform you that, in spite of the challenges we are now facing, we will do our best to provide you with the services that you require:

1. Business as usual.

It is both important that we continue to provide products and services to all our customers and at the same time secure the safety of our employees. With that in mind, we have transitioned most of our employees not involved in manufacturing to working remotely and eliminated all non-essential and cross-border travel. This change should not impact in any way how you, our dear customers, contact us. We are ready, willing and able to support you. Clearly, to keep face-to-face interactions to a minimum, we will focus our communication on what is most convenient for you – either a phone call, through email or video chat (Skype, FaceTime or Google Hangout). Whatever is convenient for you!

2. Delivery

As of today, we have sufficient inventory for both dentists and dental labs, as well as reliable logistics. Thanks to our global network of dealer-depots, dental professionals all over the world will continue to have direct local access to our wide range of Kuraray Noritake Dental products. Kuraray Europe GmbH will exert every effort possible to deliver your orders on time. Parallel to this, we kindly ask you to make sure that somebody in your office will be available to receive the parcel. In case, for whatever reason this is not possible, please notify your supplier in advance.

3. Technical Services.
   Our technical service is available to meet your needs.

If there is anything else that we can do to support you, please let us know.

We wish you all the best. Take good care and stay healthy.

Sincerely,

Kuraray Europe GmbH

BU Medical