WEBINAR BY PROF. DR. SVEN RINKE

Enhance your knowledge and skills in the field of all-ceramic restorations! We invite you to watch the recording of the recent webinar titled "Cementation of All-Ceramic Restorations" by the esteemed Professor Dr. Sven Rinke.

Whether you currently incorporate all-ceramic restorations in your daily practice or aspire to offer them, this webinar recording is a valuable resource that you shouldn't miss. Professor Dr. Rinke, an expert in the field, delves into the key aspects of implementing an all-ceramic treatment concept that guarantees predictable long-term success and superior aesthetic outcomes while utilizing a limited number of materials and straightforward treatment strategies.

During the webinar, two types of cementation techniques are showcased: self-adhesive cement (PANAVIA SA Cement Universal, Kuraray Noritake Dental Inc.) and adhesive composite material (PANAVIA V5, Kuraray Noritake Dental Inc.). Professor Dr. Rinke provides a comprehensive step-by-step concept that offers easy-to-follow instructions, which you can readily incorporate into your daily routine.

The webinar recording covers a wide range of important topics, including:

• An update on material-specific recommendations for preparing all-ceramic restorations, ensuring you stay up-to-date with the latest advancements.
• Established procedures and materials for adhesive cementation of glass-ceramic and zirconia restorations, enabling you to implement best practices in your clinical work.
• A discussion on the relevance of conventional cementation and its viability in today's dental landscape.
• Valuable tips and strategies for avoiding failures and flaws in all-ceramic restorations, ultimately improving your treatment outcomes.

Don't miss out on this chance to elevate your skills and expand your expertise in all-ceramic restorations. We are confident that the knowledge shared in this webinar recording will have a positive impact on your daily practice and help you achieve superior outcomes.

Watch now at your own convenience!

DR. SVEN RINKE

Sven Rinke’s vast experience and expertise in the field of Prosthodontics and Implantology has seen him taking on a wide range of roles in universities, private practice, and the dental industry.

In 1992, he joined the School of Dentistry Department of Prosthodontics, Georg-August-University, Göttingen, and later worked as Senior Lecturer for Material Sciences and Prosthetic Dentistry before taking on the role of Associate Professor. Sven has also been a Visiting Assistant Professor at the Harvard School of Dental Medicine’s Department of Restorative Dentistry.

Since 1996 Sven has run a private practice specializing in prosthodontics and implantology as well as being a scientific consultant for Degussa Dental. He was Head of Clinical Research at Degussa Dental GmbH where, from 2002, he headed up the Foundation of EC EviDent Consulting (Clinical research and scientific transfer management).

Other achievements include membership of the Assigned Board Specialist of Oral Implantology and Assigned Board Specialist of Periodontics plus a MSc in Oral Implantology and another in Periodontology.

Since 2013, Sven has worked in the Venia Legendi for Dentistry, Georg-August-University, Göttingen, Germany, and the university’s Department of Prosthodontics.

He has also won numerous awards, recognising his extensive expertise in Prosthodontics and Implantology.

LabLine magazine is an English language publication catering to the field of lab-side dentistry. It provides comprehensive coverage of the latest techniques and trends in dental laboratory technology and materials, showcasing them via sophisticated, challenging and aesthetic clinical cases done by some of the most known experts in Europe. With its expertly curated content, LabLine serves as an invaluable resource for dental professionals seeking to enhance their knowledge and stay at the forefront of the industry.

In the SPRING edition of LabLine you can find a wonderful AESTHETIC CASE by Mikel Villar Gonzales and DT Pilar Ballesteros Galan. The patient, a 21-year-old female had a hypoplasia defect on her permanent teeth, 1.1 and 1.2., presumably due to trauma on her deciduous anterior teeth. Click the image below and check out how the case was done!

The 46^th congress of European Prosthodontic Debates, also known as EPA2023, will take place in Vilnius, Lithuania 14-16^th of September, 2023.

It stands as a pinnacle gathering for dental professionals and researchers in the field of prosthodontics. This highly anticipated event serves as a platform to exchange knowledge, share insights, and engage in lively discussions on the latest advancements, achievements and challenges in prosthodontics.

EPA2023 promises to be an extraordinary occasion, attracting more than 50 experts from across Europe and beyond. Renowned speakers will present the newest advances in clinical prosthodontics and restorative dentistry. Daniele Rondoni, Matthias Kern, Nicola Scotti and Kazuyoshi Baba are only some of experts at the event; check out complete speaker line-up on the website www.epa2023.lt.

The event will feature thought-provoking debates, where experts will engage in intellectual discourse on current topics of prosthodontics, stimulating a lively exchange of ideas and perspectives. Special attention will be given to the successful application of digital solutions.

Beyond the scientific program, EPA2023 will provide ample opportunities for networking and collaboration. Attendees will have the chance to interact with colleagues, forge new partnerships, and establish connections with industry leaders, further enriching their professional networks.

As the European Prosthodontic Debates event continues to push the boundaries of prosthodontics, EPA2023 is expected to be a landmark occasion, empowering dental professionals to advance their knowledge, skills, and expertise in the ever-evolving field of prosthodontics.

Register now for EPA2023: www.epa2023.lt

Shortly before KATANA™ Zirconia ML was launched at the IDS in Cologne ten years ago, I had the pleasure to be invited to Japan. We visited the KATANA™ Zirconia production facilities and learned from Kazunobu Yamada and Takuro Nagura how the new material worked. So far, all dental zirconia I had used was white and quite opaque.

I was immediately impressed by the complexity of the production procedure including all the measures taken by Kuraray Noritake Dental to provide for an extremely high material and blank quality. The blanks appeared to have an extremely homogeneous multi-layered structure and a high density responsible for stable edges and smooth surfaces. What we were told in the manufacturing plant was confirmed by Kazunobu Yamada, who shared his experience and showed us several full-contour cases. I was pleasantly surprised by the fact that he was able to produce impressive outcomes without adding any colour. Moreover, Kazunobu Yamada was obviously able to polish the surface of his restorations within seconds. The perfectly smooth surface would allow us avoid the use of glaze, which usually wears off very quickly, leaving a potentially rough surface that may harm the antagonist.

Based on what I had learned in Japan, I went back to Italy and started experimenting with the amazing new material. While Kazunobu Yamada had identified KATANA™ Zirconia ML as the solution for monolithic restorations in the posterior area, I started using it in every region of the mouth – with different design concepts from full-contour to micro-cutback with micro-layering in the vestibular area. The occlusal contact area was always held in plain, polished zirconia.

Fig. 1. Early example of anterior restorations made of KATANA™ Zirconia ML individualized with CERABIEN™ ZR using the new micro-layering technique.

Fig. 2. Possible cutback design.

During the testing period, I learned a lot about the new zirconia, which was so different from earlier generations. The most important insight was that that the processing conditions have a huge impact on the final outcome. Kuraray Noritake Dental provided valuable support e.g. in the form of sintering protocols and processing and finishing recommendations. This helped me develop my own workflow and concept based on a full-contour design in the posterior and different micro-cutback options with micro-layering in the anterior region. For me, this is a perfect combination of the new type of zirconia (KATANA) and the traditional porcelain material (CERABIEN™ ZR Luster Porcelain and Internal Stain).

In May 2013, at a meeting of the Noritake Study Club in Florence, Italy, I presented the new approach for the first time. Many colleagues were enthusiastic about it and started adopting it. While further developments like more translucent (cubic) material variants and a new generation multi-layered zirconia with a flexural strength and translucency gradient increased the application options and aesthetic potential, micro-layering became a truly popular approach used by dental technicians all over the world. In 2016, it was recognized as a relevat workflow during a closed meeting of the European Academy of Aesthetic Dentistry.

Fig. 3. Perfectly polished palatal zirconia surfaces of anterior restorations.

Fig. 4. More recent case showing a patient who received restorations made of KATANA™ Zirconia STML …

Fig. 5. … finished with CERABIEN™ ZR Internal Stains and a micro-layer of CERABIEN™ Luster Porcelain LT1.

But what is the major reason for the success of the concept and of multi-layered zirconia with KATANA™ Zirconia ML as the pioneer? In my opinion, it should not be implemented for greater simplicity or economic reasons, as one might assume at first thought. The time saved in the layering procedure should be spent on other tasks such as surface texturing and a fine-tuning of the processing procedure. The real benefit is that KATANA™ Zirconia ML and its successors allow for better solutions adapted to the patient’s needs. First of all, they enable us to save natural tooth structure, as the required wall thickness is reduced. They also offer mechanical advantages, as chipping is avoided, and the occlusal contact area remains smooth over time. In my dental laboratory, we changed our workflows completely and – preferring a more conservative approach whenever indicated for the case on hand – we often abandon full layering.

KATANA™ Zirconia can be considered as a great contribution to the digital workflow in the dental laboratory and office, which increases the efficiency of prosthodontic procedures. With the KATANA™ Zirconia Multi-Layered series, it is easy to hold our promise of delivering the best possible quality and aesthetics. The reason is that the materials support us in an ideal way, delivering the perfect combination of tradition and innovation.

TIPS AND TRICKS

Case by MDT Daniele Rondoni and MDT Roberto Rossi

Recently, Kuraray Noritake Dental Inc. has introduced Esthetic Colorant for KATANA™ Zirconia – dyeing liquids applied after milling of the company’s multi-layered zirconia. Enthusiastic users of the KATANA™ Zirconia Multi-Layered Series may wonder when and how to use the innovation: In combination with external stains, veneering porcelains or liquid ceramics, or as a replacement of those products? On the monolithic surface or on a dentin structure (framework)? And how much liquid produces the desired effect? Some technical guidance is provided in this article.

The good news: Esthetic Colorant fits perfectly into any existing approach, no matter whether you prefer a full-contour or cutback design. You may apply the liquids solely in a zero-bake technique – just individualize the milled restorations with Esthetic Colorant, fix the colours during the final sintering procedure and polish the surface. On the other end of the spectrum of options is the use underneath different layers of internal stains, porcelains and glaze.

WE UTILIZE ESTHETIC COLORANT MAINLY FOR THREE PURPOSES:

1. To add specific individual characteristics to the restoration, which are not generated by the multi-layered material structure, yet difficult to create with internal stains (examples are a more chromatic body area of a canine in comparison to the adjacent lateral incisor or pronounced mamelon structures). As the liquids diffuse into the structure, a depth effect is created.
   
   Eight liquids are available for the abovementioned purpose: A, B, C and D Plus for changing the brightness and creating shadows, BLUE, GRAY, ORANGE and BROWN for general characterization.

2. To pre-treat tissue areas to produce a perfectly shaded basis for the application of liquid ceramics (CERABIEN™ ZR FC Paste Stain) or Tissue Porcelain.
   
   Two liquids are available for this purpose: PINK AND VIOLET.

3. To prevent a greyish effect caused by the shining through of discoloured abutment teeth or metal parts (posts or implant abutments) – in this case, Esthetic Colorant OPAQUE or WHITE is applied to the intaglio of the restoration. The effect: the incoming light is blocked on the side of the dark element, while the natural translucency in the outer surface area of the restoration is maintained.

PURPOSE 1

An example of how to add specific individual characteristics to the surface of the restoration is the following full-arch case. After sintering, we just added a micro-layer of CERABIEN™ ZR Luster Porcelain and CERABIEN™ ZR FC Paste Stain Clear Glaze.

Fig. 1a. Frontal view of the complex restoration made of KATANA™ Zirconia HTML Plus after milling and the application of different shades of Esthetic Colorant.

Fig. 1b. Occlusal view of the complex restoration after milling and the application of different shades of Esthetic Colorant. Important: Every restoration characterized with Esthetic Colorant should be left to dry for at least 30 minutes prior to sintering.

Fig. 1c. Frontal view of the restoration after the final sintering procedure.

Fig. 1d. Occlusal view of the restoration after sintering.

Fig. 1e. Addition of a micro-layer of CERABIEN™ ZR Luster Porcelain.

FINAL SITUATION

Fig. 1f. Frontal view of the definitive restoration finished with CERABIEN™ ZR FC Paste Stain Clear Glaze.

Fig. 1g. Occlusal view of the final restoration.

Fig. 1h. Great incisal translucency.

PURPOSE 2

The effect of a pre-treatment of the tissue area of a complex restoration is illustrated with the aid of the following example case. Again, we opted for a nearly monolithic design with a minimal cutback in the incisal area of the teeth. The appearance of the originally tooth-coloured tissue area is modified visibly through the application of Esthetic Colorant in the shades PINK and GRAY. Some individual effects are added to the teeth as well.

Fig. 2a. Vestibular view of the milled restoration (material: KATANA™ Zirconia YML).

Fig. 2b. Palatal view of the milled restoration.

Fig. 2c. Vestibular pattern of application of Esthetic Colorant.

Fig. 2d. Palatal pattern of application of Esthetic Colorant.

Fig. 2e. Vestibular view of the restoration after the final sintering procedure.

Fig. 2f. Palatal view of the restoration after the final sintering procedure.

PURPOSE 3

Comparison of restorations on an implant abutment with and without Esthetic Colorant (EC):

HOW TO APPLY ESTHETIC COLORANT?

Essentially, Esthetic Colorant may be applied with any metal-free brush or pen. In our opinion, the best results are obtained by using the Liquid Brush Pen that has been specifically developed for the dyeing liquids. The pen’s housing is filled with the selected shade of Esthetic Colorant and allows for a controlled application, as the tip always dispenses the right amount of liquid and does not dry out. We utilize a separate Liquid Brush Pen for every shade that is frequently in use.

SINTERING PARAMETERS

After drying, which is essential for a good outcome, the restorations treated with Esthetic Colorant may be put into the sintering furnace and sintered according to the schedule recommended for the KATANA™ Zirconia Multi-Layered series. The parameters do not need to be adjusted.

CONCLUSION

The controlled application of Esthetic Colorant is easily accomplished by using the appropriate equipment, while the desired effects are obtained predictably. The liquids’ ease of use, the appropriate number of shades available and the achievable effects are just a few of the many benefits you will find when trying out the new system in your dental laboratory.

Dentists:

Some companies mainly make use of basic technologies developed by others to improve their products and introduce new ones, while other companies conduct fundamental research and technology development inhouse. Is this difference relevant for someone who uses the resulting products in the dental practice or laboratory on a daily basis? It is – as companies with a deep understanding of the underlying components, chemistry and technologies are able to solve existing problems and respond to market needs flexibly and quickly. This article describes the impact of several basic technologies developed by Kuraray Noritake Dental Inc. on the cementing of indirect restorations.

Adhesive cementation then and now

The possibility of milling dental restorations from different kinds of ceramics has opened up new opportunities in prosthodontics: highly aesthetic restorations can be produced and placed. What is often undervalued in this context is the role of adhesive cementation systems, which not only support the aesthetic appearance of the translucent, tooth-coloured restorations, but also pave the way for less invasive preparation and restoration designs. Early systems that provided for chemical adhesion between teeth and indirect restorations unfortunately offered a compromised long-term behaviour and high technique-sensitivity, while the application procedure was extremely complex. Technology development at Kuraray Noritake Dental Inc. made significant contributions to an improved long-term bonding performance of the systems and a simplified handling.

Optimizing the long-term bonding performance

In order to achieve long-term bonding of early cementation systems to tooth structure (especially dentin), Kuraray, a parent company of Kuraray Noritake Dental Inc., decided to focus on the development of a more powerful adhesive monomer in the 1970s. As a first step on its road to excellence, it introduced the phosphate monomer Phenyl-P in 1976. Five years later, continued efforts in improving and refining its molecular structure led to the introduction of the popular MDP Monomer that is capable of establishing a particularly strong and long-lasting bond to enamel, dentin, metal and zirconia.

The fact that it is still part of every adhesive and adhesive cementation system from Kuraray Noritake Dental Inc., and meanwhile also used by other manufacturers to optimize the bond strength and bond durability of their products, stresses the ingenuity of the invention. Compared to MDP synthesized elsewhere, the Original MDP Monomer from Kuraray Noritake Dental Inc. stands out due to an unmatched level of purity. Independent Studies show that this level of purity has a positive effect on its bonding behaviour¹. By offering stability in a moist environment, the MDP Monomer has contributed to a more consistent performance of the products containing it.

Different MDP Monomers offer different levels of purity and a different bonding performance.

Three experimental self-etch primers were prepared consisting of 15 wt.% 10-MDP provided by different sources: KN (Kuraray Noritake Dental), PCM (Germany) or DMI (Designer molecules Inc., USA). Data courtesy of Dr. Kumiko Yoshihara.

For adhesive resin cement systems to deliver a strong bond with an outstanding marginal seal, however, simply containing an adhesive monomer is not enough. Effective polymerization of this monomer is necessary as well – and not always that easily accomplished. In order to provide for an effective light-cure and dark-cure performance of PANAVIA™ V5, Kuraray Noritake Dental Inc. developed the Touch-Cure Technology. The key part of this technology is a newly developed, highly-active polymerisation accelerator in PANAVIA™ V5 Tooth Primer that is able to coexist with the acidic MDP Monomer promotes polymerisation starting from the interface between the tooth and the cement as soon as PANAVIA™ V5 Paste is applied to the already primed tooth surface. In PANAVIA™ Veneer LC – a light-curing resin cement system that works with the same primers – the polymerisation accelerator in PANAVIA™ V5 Tooth Primer shows the same mechanism of action. It contributes to the polymerization of the adhesive interface, while PANAVIA™ Veneer LC Paste offers excellent ambient light stability and is polymerized by light curing.

For example, this phenomenon was evaluated for PANAVIA™ F2.0, the predecessor of PANAVIA™ V5. The result of the study: PANAVIA™ F2.0 showed much better marginal sealing properties than other cement systems evaluated². This documented secure sealing of the interface leads to a lower incidence of marginal leakage, to a very high polymerisation ratio even in the self-cure mode (without light curing or wherever the light is blocked by the restorative material) and hence to a particularly strong bond.

An additional benefit arising from the incorporation of the polymerisation accelerator is its function as a strong reductant. It neutralizes sodium hypochlorite, which is commonly used as an irrigation solution during endodontic treatment, and thus eliminates its negative effect on the bond strength of the subsequently applied cement paste.

A highly active polymerisation accelerator in PANAVIA™ V5 Tooth Primer promotes effective polymerisation of the cement at the adhesive interface.

Simplifying glass-ceramic cementation

Fewer bottles, fewer steps and streamlined cementation procedures: that is why self-adhesive resin cements have been developed and introduced in the early 2000s. Most of these products, however, have a limited indication range. They work well on zirconia, metal, enamel and dentin, but are either not recommended or need an extra silane primer for glass-ceramic bonding. The MDP-containing PANAVIA™ SA Cement Universal is different due to another proprietary technology from Kuraray Noritake Dental Inc.: the LCSi Monomer, a Long Carbon-chain Silane coupling agent. This monomer forms a strong chemical bond with resin composite, porcelain and silica-type ceramics (like lithium disilicate), so that the need for a separate silane component (a primer or adhesive) is eliminated. By leveraging the benefits of this technology, PANAVIA™ SA Cement Universal clearly sets itself apart from other self-adhesive resin cements as a true single-component cementation system even for restorations made of glass ceramics.

If desired, the product’s bond strength to tooth structure can be increased by use of the popular universal adhesive CLEARFIL™ Universal Bond Quick featuring Rapid Bond Technology. This technology has been developed by Kuraray Noritake Dental Inc. to solve problems related to the slow penetration of tooth structure, especially wet dentin, typical for universal adhesives. In order to provide proper penetration, these adhesives need to be actively rubbed into the tooth structure for a long time or users have to wait for some time before light-curing the layer. Consisting of the Original MDP monomer combined with hydrophilic amide monomers, the proprietary Rapid Bond Technology provides for a high affinity to water leading to a rapid and deep penetration of wet dentin. As a consequence, application times are shortened and handling is simplified without negatively affecting the bonding performance.

Conclusion

Technologies developed by Kuraray Noritake Dental Inc. have strongly contributed to an improved bonding performance of adhesive cementation systems and a truly universal use of self-adhesive resin cements. As a consequence, the company offers a streamlined portfolio of high-performance resin cements for every user, for the typical clinical situations. Fewer components and fewer steps are necessary and procedures simplified – for fewer errors and aesthetic restorations that last. Apart from the technology-related benefits, the products mentioned offer many additional beneficial features. A detailed description is found online at kuraraynoritake.eu.

References

1) Functional monomer impurity affects adhesive performance.; Yoshihara K, Nagaoka N, Okihara T, Kuroboshi M, Hayakawa S, Maruo Y, Nishigawa G, De Munck J, Yoshida Y, Van Meerbeek B. Dent Mater. 2015 Dec;31(12):1493-501.
2) Touch-Cure Polymerization at the Composite Cement-Dentin Interface.; Yoshihara K, Nagaoka N, Benino Y, Nakamura A, Hara T, Maruo Y, Yoshida Y, Van Meerbeek B.J Dent Res. 2021 Aug;100(9):935-94.

Case by Michal Jaczewski

This patient came to the clinic to improve the aesthetics of her smile. After an aesthetic and functional analysis, it was decided to align and restore the teeth using a minimally invasive protocol with flowable composite.

INITIAL SITUATION

Fig. 1. The patient had worn teeth, visible abrasion, erosion and crowding in the lower arch.

Fig. 2. Situation after orthodontic treatment, full arch ready to restore.

Fig. 3. A silicon mould is used for the Flowable Injection Technique to restore the teeth with flowable composite. The silicone injection mould had injection channels prepared and was placed to check for proper fit.

Fig. 4. For this case it was decided to use CLEARFIL MAJESTY™ ES Flow Low in shade XW.

Fig. 5. Teflon tape was used, in order to separate the teeth.

Fig. 6. The restoration is completely additive; the teeth are not prepared at all. Total etching of the enamel is the best pre-treatment in this situation. K-Etchant Syringe (35% phosphoric acid) was applied for 10 seconds.

Fig. 7. A surgical suction tip was used in order to carefully remove the phosphoric acid gel and protect the isolations on the teeth. Followed by rinsing off completely with water in the usual manner.

Fig. 8. Each tooth was gently air dried for 10 seconds. CLEARFIL™ Universal Bond Quick was applied with a rubbing motion without additional waiting time. Followed by drying of the entire bonding treated surfaces by blowing mild air for more than 5 seconds until the bonding no longer moves.

Fig. 9. Light curing of each bonded tooth for 10 sec.

Fig. 10. The silicon mould is used to inject CLEARFIL MAJESTY™ ES Flow Low (optimal flowability, and properties for a case like this).

Fig. 11. Using the protocol „Treat one, skip one” several teeth are restored simultaneously.

Fig. 12. Situation directly after first round of injections.

Fig. 13. Situation after restoring all teeth, before polishing.

Fig. 14. To create a natural gloss the following polishing protocol was used: 1.) Sof-Lex™* discs, 2.) CLEARFIL™ Twist DIA for Composite polishing wheels, 3.) diamond paste and finally zinc oxide paste.

*Not a brand name of Kuraray Noritake Dental.

Fig. 15. High-shine results after polishing.

FINAL SITUATION

Fig. 16. Final restoration, immediately after treatment.

Fig. 17. Final restoration after 2 days.

Dentist:

MICHAL JACZEWSKI

Michał Jaczewski graduated from Wroclaw Medical University in 2006 and today runs his private practice in the city of Legnica, Poland. He specializes in minimally invasive dentistry and digital dentistry and is the founder of the Biofunctional School of Occlusion. Here he lectures and runs workshops with focus on full comprehensive patient treatments.

THE COMBINATION OF EFFECT LIQUIDS AND MICRO-LAYERING ON HIGHLY AESTHETIC ZIRCONIA IS THE EFFECTIVE WAY TO ACHIEVE OUTSTANDING RESULTS

Case by Leonidas Dimitriou, MDT

As an addition to its well-aligned portfolio of multi-layered zirconia (KATANA™ Zirconia Multi-Layered series) and veneering porcelain for zirconia (CERABIEN™ ZR), Kuraray Noritake Dental Inc. has recently introduced a set of dyeing liquids. Esthetic Colorant for KATANA™ Zirconia is applied to the surface of the monolithic or anatomically reduced zirconia restoration prior to the final sintering procedure. In this way, it is possible to imitate typical internal colour effects of natural teeth quite easily. Depending on the desired outcome, users may add just a final layer of glaze, liquid ceramics or stains and porcelains to their zirconia restorations treated with Esthetic Colorant. The following two case examples are used to demonstrate two different procedures involving the use of the effect liquids.

CASE EXAMPLE 1

In the first case, we produced three two-unit splinted crown restorations for six maxillary anterior teeth. The zirconia crowns (made of KATANA™ Zirconia YML) were anatomically reduced and individualized with Esthetic Colorant mainly in the incisal and cervical areas immediately after milling. For the application of the selected liquids, we used the Liquid Brush Pen specifically developed for Esthetic Colorant. The restorations were dried for half an hour, placed in the sintering furnace for sintering according to the recommended protocol for KATANA™ Zirconia and subsequently finished with CERABIEN™ ZR porcelains. Finally, CERABIEN™ ZR Paste Stain Glaze was applied for the final high-gloss finish.

Fig. 1. Pre-sintered anatomically reduced crowns after milling.

Fig. 2. Esthetic Colorant applied to the milled restorations.

Fig. 3. Appearance of the individualized restorations after the final sintering procedure.

Fig. 4. Restorations after porcelain layering.

FINAL SITUATION

Fig. 5. Final restorations with a natural appearance. The effects created with Esthetic Colorant shine from deep within the restorations.

Fig. 6. Lateral view of the final restorations from the left.

Fig. 7. Lateral view of the final restorations from the right.

CASE EXAMPLE 2

In this second case, two three-unit restorations were produced using KATANA™ Zirconia YML in the colour A3. We designed and milled them in full contour, then reduced them with hand instruments by 0.2 mm and added some texture effects to the surface before applying Esthetic Colorant. In this case, we played with different shades of Esthetic Colorant. Even when applied on a minimally reduced or monolithic surface, the liquids are able to create a nice depth effect as they diffuse into the zirconia structure. The amount of liquid applied is easily controlled with the Liquid Brush Pen, so that the intensity of the colours is predictable. After sintering, we added some internal stains, CERABIEN™ ZR Luster Porcelain and a final layer of CERABIEN™ ZR FC Paste Stain Glaze to finish the restorations. The outcome speaks for itself.

Fig. 8. Milled monolithic restorations with a pronounced surface texture.

Fig. 9. Vestibular and palatal surfaces individualized with Esthetic Colorant to create and intensify some natural colour effects.

Fig. 10. Appearance of the restorations immediately after sintering.

Fig. 11. Restorations after internal staining.

Fig. 12. A layer of luster porcelain applied to the minimally reduced restorations.

FINAL SITUATION

Fig. 13. Final outcome after glazing.

Dentist:

LEONIDAS DIMITRIOU, MDT

Interview with Yoshihisa Yamada
General Manager, Technology Division of Kuraray Noritake Dental Inc.

KATANA™ Zirconia ML was introduced ten years ago, at the IDS 2013 in Cologne, as the dental industry’s first zirconia product with a multi-layered colour structure. Since that event, KATANA™ Zirconia ML blanks have become very popular. Continued development efforts have led to the current line-up of multi-layered materials, KATANA™ Zirconia UTML, STML and HTML PLUS, and our latest product – KATANA™ Zirconia YML. Our new technology with colour, translucency and strength gradation is found in KATANA™ Zirconia YML.

Photo credits to MDT Giuliano Moustakis.

How important was the invention of the Kuraray Noritake Dental’s original multi-layered technology for the dental market?

Our impression is that the material has had a significant impact on the dental market. Being the first zirconia material with a multi-layered colour structure, KATANA™ Zirconia ML was our first product of its class to offer the properties needed for the efficient production of full-contour zirconia restorations with a natural look. Before its introduction, the “full-contour zirconia” concept had not been widely accepted due to the aesthetic properties of the zirconia materials available so far: Many of them lacked the desired level of translucency, while others needed to be treated with dyeing liquids or stains in a complex procedure to obtain a natural shade appearance. With the launch of multi-layered zirconia blanks, which successfully added natural colour gradation to the structure, aesthetic full-contour zirconia restorations started to become popular among dental technicians worldwide. The high potential of the technology was confirmed at the IDS 2013 show, when we saw not only end-users, but also engineers from competing companies come to look at this product.

4-layer colour structure of KATANA™ multi-layered discs.

Photo credits to MDT Daniele Rondoni.

What changes were driven forward by the introduction of KATANA™ Zirconia ML?

After the introduction of KATANA™ Zirconia ML, many companies started developing multi-layered zirconia discs, creating a new dental product category with an added technical and clinical value. We are convinced that the invention of Kuraray Noritake Dental has played a major role in the shift from zirconia exclusively used as a framework material to alternative approaches including full-contour zirconia restorations. If only monochromatic zirconia discs had been available, we imagine that an increased number of dental technicians would have embraced the concept of using liquid colourants to achieve a natural appearance of full-contour crowns and bridges. That would have prevented monolithic zirconia restorations from becoming as popular as they are today.

How did the KATANA™ Zirconia ML technology evolve over the past ten years?

Based on our unique core technology developed for inventing KATANA™ Zirconia ML, we have been continuing making efforts to create even better products. One of Kuraray Noritake Dental’s great strengths is its ability to develop all the raw materials for its zirconia products inhouse. This makes it possible for us to adjust the boundaries between the layers as inconspicuously as possible, even when discs consist of multiple layers. This enabled us to provide multi-layered discs with the required strength and aesthetic qualities, and with a stable, predictable shrinkage rate. In the past ten years, we have focused on adding new materials with different levels of translucency and strength to offer a portfolio that meets the demands of virtually every dental technician, practitioner and patient.

For example, the advent of KATANA™ Zirconia STML, which has even better aesthetic qualities than KATANA™ Zirconia ML, has made it possible to use it all by itself to create highly aesthetic restorations, with no need to characterize or individualize the restorations. Of course, if you use KATANA™ Zirconia Multi-Layered discs and treat the restorations with a surface staining agent, such as CERABIEN™ ZR FC Paste Stain, you can create even more aesthetic restorations in a shorter time.

What are the benefits of Kuraray Noritake Dental’s multi-layered technology, as compared with other manufacturer’s solutions?

KATANA™ Zirconia multi-layered discs offer the advantage of delivering the proper colour even when they are sintered at high speed. There are two reasons for this. First, we developed unique raw materials with suitable characteristics for high-speed firing. This allows the creation of restorations with the same strength, stability, and aesthetics to be achieved after both short- and long-time firing. The second reason is that we possess the technical know-how concerning excellent shading that Noritake Dental Supply, one of Kuraray Noritake Dental’s predecessors, cultivated during its many years spent developing ceramic materials. Noritake Co., Ltd., parent company of Noritake Dental Supply, is a long-established ceramic manufacturer that is famous for its tableware and other outstanding products. It is this background that allows us to properly control pigment coloration using our inorganic pigment know-how and to provide unique firing schedules. These two strengths enable us to bring unique advantages to our products. That is, they remain stable and retain appropriate colouration even under rapid firing schedules.

CERABIEN™ ZR FC Paste Stain being applied to KATANA™ Zirconia restoration.

Photo credits to MDT Roberto Rossi.

How did you manage to shorten the sintering times so significantly, resulting in your speedy sintering with uniform protocols?

When shorter sintering times became possible, Kuraray Noritake Dental recommended that KATANA™ Zirconia ML be sintered for seven hours. After that, when a new furnace claiming being capable of short-time firing was launched, we used it to fire KATANA™ Zirconia ML on a trial basis. We found, happily, that our zirconia material was uniquely compatible with rapid firing. This was the beginning of our full-fledged study of short-time firing of our zirconia material. You could say that we began investigating short-time firing almost by accident. Then, while developing KATANA™ Zirconia STML and KATANA™ Zirconia UTML, successors of KATANA™ Zirconia ML, we focused on incorporating short-time firing into their features and made various adjustments, finally achieving the optimal combination of factors for the successful short-time firing of zirconia.

What are the benefits of Kuraray Noritake Dental’s second-generation multi-layered technology, as compared with other manufacturer’s solutions?

One advantage of KATANA™ Zirconia YML is that it can be applied to treat a wider range of cases without complex limitations on position within the disc. The reason: it delivers this high level of aesthetics while still maintaining great strength. This advantage of being appropriate for a wider range of cases also simplifies inventory management. In addition, users benefit from our expertise in developing raw materials and reproducing colour with ceramics. This expertise enabled us to develop a zirconia product in which each layer has a different level of translucency, while great strength and admirable aesthetics are maintained throughout the whole blank.

The sintering recommendation is only a guideline; some adjustments may be required depending on each individual furnace. If the furnace cannot be set according to the 54- or 90-minute sintering schedule, speed sintering cannot be used.

* The restorations may be removed at 800°C or less depending on the circumstances.
** For the sintering schedule of KATANA™ Zirconia HT, please refer to the Handy Chart in product packaging.

Is it really possible to address every case using only KATANA™ Zirconia YML?

For every case that can be treated either with KATANA™ Zirconia STML, KATANA™ Zirconia UTML, or KATANA™ Zirconia HTML PLUS, KATANA™ Zirconia YML is also an option. Hence, it is possible to use only KATANA™ Zirconia YML for all your zirconia cases – which is probably one of the reasons for its great popularity. It features both great strength and excellent aesthetics, and – being so versatile – it helps simplify inventory management. Of course, Kuraray Noritake Dental’s other multi-layered materials feature outstanding properties as well. Depending on the features you need, it would also be an option to select from these products - KATANA™ Zirconia STML, KATANA™ Zirconia UTML, or KATANA™ Zirconia HTML PLUS – to realize your ideal restorations.

KATANA™ Zirconia YML, finished with CERABIEN™ ZR.

Photo credits to MDT Giuliano Moustakis.

Why is the KATANA™ brand in general so popular among dental technicians around the world?

We think that dental technicians choose KATANA™ because they find that they can create highly aesthetic restorations using simple, straightforward steps.

Is there any further development potential in multi-layered technology?

On the basis of our technical know-how, there is always room for improvement. That is why we never stop innovating and listening to the voice of our customers. Developing what supports them in improving their outcomes while providing for more predictable, less stressful procedures is our ultimate goal. Right now, we expect to develop products with even greater strength, increased translucency, and outstanding aesthetics that will have a natural look resembling real teeth, even when the material used is full-contour zirconia.

Dentist:

YOSHIHISA YAMADA

We are thrilled to share with you our latest brochure – KATANA Zirconia Restoration System, featuring Kuraray Noritake Dental Inc’s product line-up that is dedicated to creating true-to-live restorations.

The KATANA Zirconia Family brochure features a range of lab-side products that are designed to meet the needs of modern dental professionals.

Our zirconia materials offer excellent strength and aesthetics, making them a top choice for prosthetic dentistry. In the new KATANA Zirconia Family brochure, you can read detailed information, key technical parameters, and suggested indication ranges for all our zirconia products - KATANA Zirconia UTML, STML, HTML PLUS, YML and HT. Also, we look at other products from our range such as CERABIEN ZR Porcelain, FC Paste Stain and  Esthetic Colorant that are and excellent choice for characterization of zirconia restorations, provide an overview of the sintering programs of KATANA Zirconia multi-layered discs and offer useful tips and tricks on how to best handle our zirconia.

With the KATANA Zirconia Family brochure, you will have all the basic information you need to make informed decisions about materials suitable for your dental lab.

Have a read, learn more and stay up to date!