When art meets technology;
Logical evolution of design and techniques: Microlayering with Kuraray Noritake new porcelains. 

DANIEL RONDONI
Born in Savona in 1961, he lives and works in his hometown where he has been the manager and director of his own laboratory since 1982.

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:

By Dr. PhD. Jusuf Lukarcanin

Is it possible to fulfil high aesthetic demands by restoring anterior teeth with composite resin? It is – provided that several important factors are respected. One of these factors is the faithful reproduction of the natural tooth morphology, which has a decisive impact on aesthetics and function. Moreover, success is determined by the selection of the right shades of high-quality composite resin and their purposeful combination using proper layering techniques.

Introduction

The aesthetic appearance of direct anterior restorations is affected by proper shade selection on the one hand and the creation of a natural shape and texture on the other¹. Hence, the dental practitioner’s own artistic skills play a decisive role. According to Fahl, information about the tooth morphology and function, and the optical properties of the tooth should be taken into consideration when the most suitable restorative material and shade are selected².

These minimally invasive composite restorations are no longer a temporary solution for the anterior region. Instead, they are regarded as an adequate alternative to indirect restorations, as they are both durable and able to closely imitate the natural tooth structure³⁴.

Clinical case example 1

This 45-year-old female patient presented with a diastema and a disproportion in the size and shape of her maxillary central incisors (Fig. 1). In the first step, a detailed case history was taken and an intra-oral examination was carried out. Subsequently, the initial situation was recorded by taking intra-oral photographs, which would allow for a computer-aided morphological evaluation and treatment planning (Fig. 2).

Fig. 1: Pre-operative image.

Fig. 2: Digital mock-up.

The patient’s second visit started with a professional tooth cleaning procedure followed by isolation of the maxillary anterior teeth. Afterwards, the tooth shade was determined and appropriate composite shades were selected. In this case, the shades A2E, Amber Translucent and A3D of CLEARFIL™ Majesty ES-2 Premium (Kuraray Noritake Dental, Japan) appeared to be most suitable. In addition, a mock-up was created using mock-up resin in order to produce a silicone key.

Opting for a minimally invasive procedure, no mechanical tooth preparation using drills was performed after removal of the mock-up. Instead, the enamel was merely etched with 35% phosphoric acid gel (K-Etchant, Kuraray Noritake Dental) to increase the surface roughness. After rinsing and drying, the adhesive agent (CLEARFIL™ Universal Bond, Kuraray Noritake Dental) was applied to the etched surfaces. Composite layering started with the build-up of palatal shells with the aid of the silicone key. Following light-curing of the shells, a small amount of composite in the dentin shade A3D was applied to the proximal surfaces using a thin spatula and a brush. The aim was to reduce light transmission in the area of the dentin core. The restoration was completed with a combination of the composite shades A2E (enamel) and Amber Translucent, which were applied using a modeling brush.

Finishing and polishing was accomplished using flexible rubber polishing discs containing diamond particles (CLEARFIL™ Twist DIA, Kuraray Noritake Dental) with a low-speed handpiece. No additional finishing and contouring was necessary due to the use of a brush during layering, which ensured the creation of a natural shape and surface texture. Figure 3 shows the outcome of the restoration procedure.

Fig. 3: Treatment outcome immediately after polishing.

Oral hygiene training was provided and follow-up examinations were performed after three, six and twelve months (Fig. 4). Healthy hard and soft tissue conditions were observed during these visits.

Fig. 4: Clinical situation at the one-year recall.

Clinical case example 2

This 30-year-old female patient had a diastema, irregularly shaped anterior teeth and showed signs of abrasive tooth wear (Fig. 5). Following a detailed anamnesis and intra-oral examination, the tooth shade was determined and the composite CLEARFIL™ Majesty ES-2 Premium selected in the monochromatic shade Universal A1.

Fig. 5: Pre-operative clinical situation.

Following the isolation of the working field, 35% phosphoric acid etchant (K-Etchant) was applied to the enamel of all teeth between the maxillary right canine and the maxillary left first molar. The surfaces were then treated with a universal bonding agent (CLEARFIL™ Universal Bond) as recommended by the manufacturer. Modeling was carried out with a thin spatula and a modeling brush for composite. Neither a silicone key nor any wetting or modeling resin were used in the procedure. For polishing, the flexible polishing discs CLEARFIL™ Twist DIA were used at low rotational speed. Thanks to the use of the modeling brush, no additional finishing with diamond-coated instruments was necessary. Figures 6 and 7 show the final restoration at baseline and one week after completion of the treatment.

Fig. 6: Treatment outcome at the day of the restorative procedure.

Fig. 7: Clinical situation after one week.

This patient also received oral hygiene training and presented for recalls three, six and twelve months after the treatment. The patient maintained an exemplary oral hygiene behaviour, so that it came as no surprise that the soft tissues were healthy and the restorations were in a perfect condition after one year (Fig. 8).

Fig. 8: Clinical situation one year after the restorative treatment.

Discussion

Nowadays, direct composite restorations are becoming increasingly popular. Especially for young patients and all those who do not want to sacrifice large amounts of healthy tooth structure, the technique is an ideal treatment option⁵. In many cases, aesthetic outcomes are possible without mechanical tooth preparation, but a selective etching procedure only⁶.

The clinical lifetime of these restorations depends on many factors. Important prerequisites for high-quality outcomes include the selection of a suitable composite material with the required surface hardness, appropriate finishing and polishing, a good oral hygiene behaviour, and proper maintenance measures during periodical follow-up visits. As a matter of course, the manual skills of the dental practitioner and the use of selected materials according to the manufacturer’s instructions for use also have a direct impact on the long-term success of the restorations⁷⁸⁹. A user’s inability to meet one of these requirements and failure to carry out all working steps correctly may have a direct impact on the quality of the restoration.

Conclusion

Composite resin is a popular material class for the production of aesthetic anterior restorations die to their straightforward use and rapid application, good repair options and high aesthetic potential when used properly . The two case examples illustrate that a treatment with composite resin is often the best treatment option when a non-invasive procedure completed within a single visit is desired.

About the author

Dr. Jusuf Lukarcanin is a Certified Dental Technician (DCT) and a Doctor of Dental Science (DDS). He studied dentistry at the Ege University Dental Faculty in Izmir, Turkey, where he obtained a Master's degree in 2011. In 2018, he received a PhD degree from the Department of Restorative Dentistry of the same university, where he also worked as a researcher for six years. Between 2012 and 2019, Dr. Lukarcanin was the head doctor and general manager at Ozel Gen Dental Clinic (OZEL GEN Ağız ve Diş Sağlığı Polikliniği) in Izmir. Currently, he works at Tinaztepe GALEN Hospital in the Tinaztepe Health Group of Tinaztepe University and in the Department of Research & Development of GULSA Company in Izmir.

References

^{1. Heymann HO (1987) The artistry of conservative esthetic dentistry Journal of the American Dental Association 115(Supplement)14-23.}

^{2. Fahl N Jr (2012) Single-shaded direct anterior composite restorations: A simplified technique for enhanced results Compendium of Continuing Education in Dentistry 33(2) 150-154.}

^{3. Barrantes, J. C. R., Araujo Jr, E., & Baratieri, L. N. (2014). Clinical Evaluation of Direct Composite Resin Restorations in Fractured Anterior Teeth. Odovtos-International Journal of Dental Sciences, (16), 47-61.}

^{4. Vargas M (2011) Clinical techniques: Monocromatic vs. polycromatic layering: How to select the appropriate technique ADA Professional Product Review 6(4) 16-17.}

^{5. Ferracane, J. L. (2011). Resin composite—state of the art. Dental materials, 27(1), 29-38.}

^{6. Norling, N. A. (2010). Combining “prep-less” and conservatively prepared veneers to correct enamel defects and asymmetry. Journal of Cosmetic Dentistry, 2010.}

^{7. Ölmez, A., & Kisbet, S. (2012). Kompozit rezin restorasyonlarda bitirme ve polisaj işlemlerindeki yeni gelişmeler. Acta Odontologica Turcica, 30(2), 115-22.}

^{8. Senawongse, P., & Pongprueksa, P. (2007). Surface roughness of nanofill and nanohybrid resin composites after polishing and brushing. Journal of Esthetic and Restorative Dentistry, 19(5), 265-273.}

^{9. Giacomelli, L., Derchi, G., Frustaci, A., Bruno, O., Covani, U., Barone, A., Chiappelli, F. (2010). Surface roughness of commercial composites after different polishing protocols: an analysis with atomic force microscopy. The open dentistry journal, 4, 191.}

^{10. Hickel, R., Heidemann, D., Staehle, H. J., Minnig, P., & Wilson, N. H. F. (2004). Direct composite restorations. Clin Oral Invest, 8, 43-44.}

^{11. Korkut, B., Yanıkoğlu, F., & Günday, M. (2013). Direct composite laminate veneers: three case reports. Journal of dental research, dental clinics, dental prospects, 7(2), 105.}

“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

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

By Daniele Rondoni, RDT

A middle-aged patient sought dental advice because she felt uncomfortable with the aesthetic appearance of her upper front jaw, specifically regions 11, 12, 21 and 22. Additionally, she was not happy about the diastema between her upper central incisors.

Fig. 1: Initial situation.

The oral examination showed four crown regions (12-22) and revealed that all of them have deteriorated. Tooth 21 had undergone an endodontic treatment, while teeth 11 to 22 have been newly built up. Due to the deteriorated conditions, all affected teeth were taken into consideration in the planning and designing of new restorations, including the intention to close the diastema between the width-to-length-ratio for the incisors.

The best suitable material for a natural look in combination with a close gingival attachment to the restoration is, in this case, zirconia, because of its biocompatibility and gentleness to the gingival region. The KATANA^TM Zirconia series from Kuraray Noritake Dental, offers a line-up of high-quality materials combined with true-to-life aesthetics, due to its natural color gradient within the material.

Fig. 2: Preparations, showing discoloration in the cervical area of tooth 21.

Fig. 3: Occlusal view of the preparations.

Fig. 4: The four zirconia crowns after designing followed by milling.

Fig. 5: Result directly after sintering.

To achieve an even more natural-looking and aesthetic restoration, CZR FC Paste Stains were used externally on the zirconia surface.

Fig. 6: Characterization of the restoration.

As often done, Cervical 2 was used to give an orange tint to the cervical area, to accentuate even better the natural tooth gradation. For the incisal areas, Grayish Blue in combination with Value was used to enhance transparency and opalescence. Same procedure applied to the approximal areas. Mamelon Orange 2 was used to reproduce dark orange stain on the mamelons.

Fig. 7: Result after cementation of the four new zirconia crowns. Their shape and chroma blend harmoniously with the arch.

Fig. 8: The vestibular view showing natural-looking characterization.

During a period of five years, annual check-ups showed intact crowns and a healthy gingiva. Additionally, the durability of the restorations, including their mechanical and optical properties revealed no signs of deterioration.

As the manager of a dental practice and the co-founder of the Deutsches Zahnärztinnen Symposium (DZÄS), an event that provides a forum for female dentists in Germany, Dr Frederike Fehrmann is an extremely busy woman. In this interview, she discusses her experiences as a woman working in dentistry and offers advice for those who are considering entering the field.

How did you decide to enter the field of dentistry?

I knew very early that I wanted to study dentistry. My mother is an orthodontist and I always liked what she was doing. During my studies, though, things looked different—I wanted to do oral and maxillofacial surgery for a period. But then I was offered the dental practice where I now work, and though it was different from what I had expected, I was still able to develop my skills in many directions, arriving finally at CAD/CAM and laser dentistry, which have been my favourite areas in recent years.

My professional life is constantly changing and developing, and that is what makes it exciting. High-tech dental surgery is exactly what I want to do and work with.

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

I think dentistry is great, but it’s the same in this field as in many other professions in which women work. We often have a double burden simply because of our responsibility to bring the next generation into the world. This is a topic that has been on my mind for a long time. In fact, the DZÄS will be hosting a symposium in Frankfurt later this year where we will highlight the balancing act between technology and mindfulness, between career and family. I’m looking forward to it very much.

In my experience, women tend to have certain advantages—for example, we often find it easier to deal with children as patients than male dentists do. However, we still have to assert ourselves constantly. But things are changing. At the university near us, there are hardly any male dental students. It is time to rethink and adapt dental education to empower women to fulfil their potential.

How important is it to have peers and mentors with whom you can discuss dental issues?

Having other women with whom one can exchange ideas is worth its weight in gold. Sometimes you discuss your problems and suddenly find there is a simple answer that you yourself would not have thought of, one that makes your life easier. It’s possible to do without a mentor, of course, but things do become more difficult. Both peers and mentors make you strong and help you progress continuously. Besides, women often talk and listen differently and understand even without words.

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

I have had feedback from many patients who say that they like to see women providing treatment, as we can often read between the lines and might be more likely to recognise when they are afraid, for example.

Nevertheless, we frequently have to prove ourselves repeatedly. How often haven’t I heard the questions, especially as a young professional, “Are you able do that? Are you strong enough to remove that tooth?” I don’t think that a male dentist would be asked this.

Do you have any advice for girls and women considering a career in dentistry?

Just do it! Network and never, ever give up. Find a focus, something you do better than everyone else. Find mentors and colleagues who can help and guide you when needed. Educate yourself and find out what you’re passionate about.

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

I use both KATANA™ AVENCIA™ Blocks and KATANA™ Zirconia Blocks in my CEREC workflow to produce CAD/CAM dentures. A colleague who works a lot with Kuraray Noritake told me about these blocks, and so I tried them out. The zirconia blocks impressed me by being super-translucent and variable in their colour texture. Their fit is excellent and the CEREC workflow is easy. The AVENCIA™ blocks are very simple to use because after milling they only need to be polished, not fired. This is particularly useful when supplying inlays.