429 Too Many Requests

World’s largest dental trade show is coming to a close

Have you been one of the dental professionals who have visited the world’s largest dental trade show this year? We have all had a fantastic time and would like to thank you for your huge interest in our products and solutions. From our conversations with you, the whole team has gained new insights into what you like, value and desire. We will use this information to keep on innovating – to develop more groundbreaking new technologies and products for patient-centered dentistry.

For example, products like KATANA™ Zirconia YML which feature second-generation multi-layered technology. It enables dental technicians to solve all their zirconia cases with a single material thanks to its flexural strength, translucency and colour gradation in a single disc.

Experts like MDT Daniele Rondoni and MDT Nondas Vlachopoulous value the well-balanced properties that enable them to position the restoration quite flexibly in the blank. They are also enthusiastic about the aesthetic potential of this and other materials of the KATANA™ Zirconia Multi-Layered Series that allows for beautiful outcomes with no or just a small layer of porcelain.

In their presentations, both professionals revealed how to leverage the benefits of multi-layered zirconia. For MDT Daniele Rondoni, for example, multi-layered KATANA™ Zirconia is the perfect base for his 4.4.1 micro-layering technique demonstrated at the booth. Thanks to the extraordinarily well-balanced optical properties of the materials, he usually opts for a full-contour design or a slight vestibular cutback – depending on the region in the mouth and the aesthetic demands of the patient. Then, he combines different materials of the CERABIEN™ ZR portfolio in a micro-layer to create natural outcomes.

MDT Nondas Vlachopoulos uses the KATANA™ Zirconia Multi-Layered Series as a basis for his restorations finishing with the one-bake technique he demonstrated in his presentations – or for the incredible imitations of nature that only a few dental technicians are able to create.

Have you missed some of the presentations that were of interest you? All the lectures and hands-on demonstrations will be available OnDemand soon!

See you all in Cologne in 2025!

IDS and Kuraray Noritake Dental Inc. celebrating anniversaries

Did you know that not only the IDS is celebrating a double anniversary this year, but Kuraray Noritake Dental Inc. is, too? The PANAVIA™ brand was established 40 years ago, while the first ever zirconia disc with a multi-layered colour structure – KATANA Zirconia ML – was introduced ten years ago at the IDS 2013.

The success story of the brand PANAVIA began with the introduction of PANAVIA™ EX, the first resin cement containing the original MDP Monomer. Since then, the company never stopped innovating: new technologies were developed and combined with existing ones to create a portfolio of resin cements precisely geared to the era-specific needs of end users. All of this has resulted in the current portfolio of easy-to-use and highly aesthetic resin cements that provide top-level bond strength.

The latest member of the PANAVIA™ family is PANAVIA™ Veneer LC, a light-curing resin cement system from Kuraray Noritake Dental Inc. available in four shades. It consists of PANAVIA™ Veneer LC Paste, PANAVIA™ V5 Tooth Primer and CLEARFIL™ CERAMIC PRIMER PLUS. With its extended working time of 200 seconds* on the primer, PANAVIA™ Veneer LC is designed for a simultaneous veneer placement technique. Other beneficial features include a well-aligned paste consistency, a high colour stability, easy excess removal after tack-curing and an excellent bond strength over time.

Many visitors interested in this as well as the other two products of the current PANAVIA™ family – PANAVIA™ V5 and PANAVIA™ SA Cement Universal – had the chance to talk to Yui Otsuka, marketing specialist, from the Information Marketing Group of Kuraray Noritake Dental Inc. in Japan. “Many visitors know and trust the PANAVIA™ brand. As users of PANAVIA™ V5, they were either looking for a light-curing version – which they found in PANAVIA™ Veneer LC – or for a solution that would simplify their workflows in many situations. The desired simplification is easily achieved with PANAVIA™ SA Cement Universal, the self-adhesive resin cement that even bonds to glass ceramics very well,” she reports. Please be sure to look out for her at our booth to learn more interesting facts about the PANAVIA™ family!

For dental technicians, it might be worth having a look at the last day’s presentation programme: At 09:30 am, and MDT Daniele Rondoni will shed light on the “4.4.1 Micro-Layering Technique”. At noon, MDT Giuliano Moustakis will demonstrate how to achieve beautiful outcomes simply by carving and the use of Esthetic Colorant on KATANA Zirconia. And finally, MDT Andreas Chatzimpatzakis will focus on ”White-Pink Aesthetics” (1:30 pm).

See you tomorrow in Hall 11.3 at our Booth # E010/F019!

Just two more days to satisfy your thirst for knowledge!

We cannot quite believe how quickly three days of the world’s largest dental trade fair have passed! We have had some fascinating conversations with visitors and truly appreciate the insights and information they have been able to give us. So, with just two more days to go, please do not miss the opportunity to talk with our team – we promise you will not be disappointed; you will find them more than happy to make time for you and share their profound knowledge.

Today in the early afternoon, many CEREC users interested in our chairside materials – KATANA™ AVENCIA and KATANA™ Zirconia Block for CEREC – attended the hands-on demonstration of MUDr Josef Kunkela, PhD titled “KATANA™ Properties and CEREC Tips & Tricks”. He revealed that CAD/CAM materials should be carefully selected not only for aesthetic reasons, but also to provide for an accurate fit, high marginal stability and surface quality of the restorations produced. His knowledge stems from studies conducted in his own research laboratory. In these tests, KATANA™ materials outperformed other materials (of the same material class) in terms of dimensional stability, size of the cement gap and margin and surface quality.

These facts were new to a part of the audience, and confirmed by experienced users. As Ricarda Köbler, Area Sales Representative at Kuraray Noritake Dental, says: “I talked to several users of KATANA™ Zirconia Block, who were not surprised by the findings just presented. They love the processing properties of the material just as its aesthetic potential, and value the precise fit and smooth surfaces they obtain every time.” Ricarda is part of the team at our booth’s Indirect Restorative counter showcasing CAD/CAM blocks, resin cement systems and more.

The next – and final – opportunity to attend the demonstration of MUDr Josef Kunkela, PhD is tomorrow morning at 09:30 am at the Kuraray Noritake Dental booth (Hall 11.3, Booth # E010/F019). Popular presentations focusing on laboratory solutions and approaches from today will be repeated on Friday, starting with MDT Daniele Rondoni’s “4.4.1 Micro-Layering Technique” at 12:00 pm and continuing with MDT Nondas Vlachopoulos’ “One Bake Technique at 03:15 pm. On Saturday, MDT Daniele Rondoni will be on stage again at 09:30 am.

Successful kick-off of the presentation programme

What a day! Numerous visitors, a huge interest in all our product groups and the start of our lecture programme – this Wednesday at the IDS 2023 by far exceeded our expectations. While the morning lectures were full of tips and tricks for dental practitioners, everything around the use of our dental laboratory products took centre stage in the afternoon.

A particular highlight: The brand-new effect liquids Esthetic Colorant. Consisting of twelve shading liquids specifically developed for the KATANA™ Zirconia Multi-Layered Series, Esthetic Colorant is used to individualize the materials’ highly aesthetic multi-layered colour structure after milling, before the final sintering procedure. The liquids are applied to the zirconia surface with a metal-free brush, preferably the Liquid Brush Pen, to create characteristic shade effects or mask dark underlying structures (WHITE and OPAQUE). Final sintering fixes the liquids and reveals the desired optical effects.

The use of the liquids was demonstrated by MDT Giuliano Moustakis in his presentation titled “Zero Bake Technique: Carving and Esthetic Colorant on KATANA™ Zirconia”. Jens Witschel, Area Sales Representative at Kuraray Noritake Dental, works at the booth’s Laboratory Solutions counter. He reports: “The whole day, the interest in Esthetic Colorant and our KATANA™ Zirconia Multi-Layered Series was exceptionally high, but it was highest right after the hands-on demonstration of Giuliano Moustakis. People are fond of products that enable them to create beautiful restorations with less manual work, and the Zero Bake Technique presented in this lecture obviously hit a nerve!”

The next hands-on demonstration of MDT Giuliano Moustakis is on Friday, March 17, 2023 at 1:30 pm. Then, on Saturday, March 18, 2023, he will be on stage at noon. Also, you should definitely attend the following hands-on demo of MDT Andreas Chatzimpatzakis on white-pink aesthetics at 1:30 pm!

Do not miss the chance to participate and connect with Jens Witschel and colleagues for in-depth product information! We look forward to seeing you in Hall 11.3 at our Booth # E010/F019!

Exciting start: Trade Dealer’s Day at IDS 2023

Today, the International Dental Show in Cologne opened its doors for the 40th time. We were delighted to welcome many of our valued trade partners at our booth in Hall 11.3. It felt great to be meeting them all in person again! A concept many of our today’s visitors are fond of is universal excellence: Universally applicable products that offer the benefit of an intuitive, often simplified use.

Kuraray Noritake Dental offers an outstanding portfolio of universal products covering a wide range of diverse procedures, both for dental offices and laboratories. For direct restorative procedures, CLEARFIL MAJESTY™ ES-2 Universal, a composite for the anterior and posterior region in just three shades is a great choice. Blending in seamlessly with the surrounding tooth structure, it eliminates the need for laborious shade determination and selection. On the other hand, you may be interested in CLEARFIL MAJESTY™ ES Flow, a universal flowable composite suitable for every cavity class. Highly polishable, it allows you to create an enamel-like gloss in next to no time. To further streamline the direct restorative workflow, you may opt for CLEARFIL™ Universal Bond Quick, a universal adhesive suitable for every etching technique, shortening application times.

Our entire universal product portfolio is being showcased by our friendly, knowledgeable staff including Dr Jorge Espigares from the Information Marketing Group of Kuraray Noritake Dental Inc in Japan. An expert in these materials, Jorge says: “Especially the touch-and-feel experience on model teeth, e.g. with CLEARFIL MAJESTY™ ES-2 Universal, was very well received today – by dental practitioners as well as our trade dealers. Among the features they liked were the paste consistency, handling and aesthetics.“

Are you interested in our universal excellence products as well? Then, you should definitely come and visit our booth tomorrow morning, talk to Jorge and his colleagues and follow the first two lectures of the day. At 09:30 am, Dr Michał Jaczewski will shed light on how he uses CLEARFIL MAJESTY™ ES Flow in the context of the flowable injection technique. Afterwards, at noon, Dr José Ignacio Zorzin will focus on “Adhesion with Universal Products”.

In the afternoon, renowned dental technicians will present innovative techniques around the production of aesthetic indirect restorations.

Would you like to learn more? Visit our website for more information about Kuraray Noritake Dental Inc. at IDS 2023.

We look forward to meeting you in Hall 11.3 at Booth E010/F019!

KATANA™ Zirconia STML and PANAVIA™ SA Cement Universal

Photo: KATANA ™ Zirconia STML NW with CERABIEN ™ ZR FC Paste Stain
Sergio R. Arias DDS, MS Sung Bin Im, MDC, CDT

KATANA™ Zirconia STML is a highly popular material used in many dental laboratories around the world. Compared to traditional zirconia framework materials with a mainly tetragonal polycrystalline structure, the material has a higher yttria content, leading to a different material structure with an impact on the optical and physical properties (the translucency is increased, the flexural strength reduced). As a consequence, the indication range is limited to single-tooth restorations and two to three-unit bridges in the anterior and posterior regions. The greatest benefit lies in a much higher aesthetic potential, which is responsible for the fact that the material is predominantly used for the production of monolithic restorations or those with a micro cut-back individualized with a micro-layer of porcelain.

While the indications and technical procedure are well-known, there seem to be some obscurities regarding the handling in the dental office. Is conventional cementation possible and recommended or is an adhesive luting procedure preferable? Is the surface pre-treatment the same as for tetragonal zirconia or is a different procedure required? And what may be expected regarding the long-term behaviour of KATANA™ Zirconia STML restorations? A close look into the available scientific literature provides some guidance.

Definitive placement of restorations made of KATANA™ Zirconia STML

Conventional cementation or adhesive luting? In principle, both procedures are possible when the restoration to be placed has a retentive design. It is generally accepted that a full coverage crown provides sufficient retention for conventional cementation when the abutment tooth is at least 4 mm high and the convergence angle of the axial walls ranges between 6 and 12 or maximally 15 degrees.^1,2

The reason is that the flexural strength of the material is higher than 350 MPa,³ the critical value for conventional cementation. As conventional cements are opaque and available in a single shade, however, the use of a (self-)adhesive resin cement may be preferable with all high-translucency restorative materials for aesthetic reasons. Anyway, these products are mandatory whenever a macro-retentive preparation design is not feasible or wanted. To sum up, the use of a self-adhesive or adhesive resin cement is preferable in many situations. An argument in favour of self-adhesive resin cements is the lower effort involved in their use.

But what about the pre-treatment of the zirconia? No matter what type of dental zirconia is used, etching with hydrofluoric acid is ineffective due to the lack of glass matrix in the material. However, it is clear that surface modification is necessary to establish a strong and durable bond to any resin cement system.^4,5

The method generally recommended for high-strength zirconia is sandblasting with aluminium oxide particles or tribochemical silica coating.⁴ The particle size should be small (≤ 50 µm) and the pressure low (about 1 bar) to avoid a weakening of the material’s mechanical properties.^3,4 For lower-strength material variants, this risk of weakening the material seems to be higher,⁵ so that it becomes even more important to work with a low pressure and particle size.^5-8 In the case of KATANA™ Zirconia, however, it was reported that “alumina-sandblasting significantly increased the biaxial flexural strength of KATANA STML”.⁹ This means that proper sandblasting of restorations made of KATANA ™ Zirconia STML did not affect the flexural strength of the material, which was even increased because of the specific properties of zirconia from Kuraray Noritake Dental.

Based on these findings, the following procedures are recommended for high-translucency zirconia:

Option 1

Aluminium oxide air-abrasion followed by the use of a self-adhesive resin cement containing 10-MDP.⁶

Option 2

Tribochemical silica coating followed by silanization of the bonding surface.⁶

As the dual-cure self-adhesive resin cement PANAVIA™ SA Cement Universal contains the Original MDP monomer and the long carbon-chain silane coupling agent (LCSi Monomer), it is suited for both procedures.

PANAVIA™ SA Cement Universal is available in an automix syringe and a handmix system, which consist of a paste-paste formulation. One paste contains the Original MDP monomer in a hydrophilic monomer environment and the other contains the inactive LCSi Monomer in an environment of hydrophobic monomers. When extruding the pastes, they are mixed in the syringe’s mixing tip (automix) or dispensed on a mixing pad and mixed by hand (handmix). Afterwards, the material is simply applied to the intaglio of the restoration and the restoration is placed. Cleanup of excess cement is easiest after tack-curing (2 to 5 seconds).

Does this work well in the clinical environment?

The best way to check whether the described procedure is successful in the clinical environment is by conducting a clinical study. This is exactly what a group of researchers from the University Complutense of Madrid, Spain, has done with the material combination KATANA™ Zirconia STML and PANAVIA™ SA Cement Universal.¹⁰ Within the framework of the prospective clinical trial, 30 posterior crowns made of KATANA™ Zirconia STML were placed in 24 individuals in need of posterior tooth restorations. The teeth were prepared as recommended for all-ceramic restorations, allowing for a wall thickness of approximately 1 mm (recommended minimum wall thickness of KATANA™ Zirconia STML for crowns in the posterior region: 1.0 mm). The restorations were sintered, characterized and glazed as recommended by the material manufacturer and subsequently tried in. Prior to cementation, the intaglio of the restorations was pre-treated with aluminium oxide particles (50 µm, 1 bar pressure) followed by ultrasonic cleaning. The use of PANAVIA™ SA Cement Universal also was in line with the manufacturer’s recommendations.

A clinical evaluation of the crowns was performed after 6, 12 and 24 months using the California Dental Association (CDA) quality evaluation system. The parameters evaluated in this system are the surface and colour of the restorations, their anatomical form and the marginal integrity of the crowns. After 24 months, the success and survival rates were 100 percent. Regarding all three parameters, the crowns received a “satisfactory” (Score 3 or 4) rating, marginal integrity (the key parameter to judge the performance of the resin cement) received an “excellent (the highest possible Score 4) in all 30 cases.

Conclusion

The researchers concluded that “the excellent results obtained in this study suggest that the third-generation tooth-supported monolithic zirconia crowns in posterior regions seem to be a good alternative to metal-ceramic crowns, second-generation monolithic zirconia crowns, and veneered zirconia crowns. A long-term study is necessary to confirm this short-period study.” Hence, it seems that KATANA™ Zirconia STML and PANAVIA™ SA Cement Universal are a promising team, and that adhering to the recommended abovementioned protocols is likely to produce excellent results that are stable over many years.

References

1. Edelhoff D, Özcan M. To what extent does the longevity of fixed dental prostheses depend on the function of the cement? Working Group 4 materials: cementation. Clin Oral Implants Res. 2007;18 Suppl 3:193-204.
2. Güth JF, Stawarczyk B, Edelhoff D, Liebermann A. Zirconia and its novel compositions: What do clinicians need to know? Quintessence Int. 2019;50(7):512-20.
3. Kern M, Beuer F, Frankenberger R, Kohal RJ, Kunzelmann KH, Mehl A, Pospiech P, Reis B. All-ceramics at a glance. An introduction to the indications, material selection, preparation and insertion techniques for all-ceramic restorations. Arbeitsgemeinschaft für Keramik in der Zahnheilkunde. 3rd English edition, January 2017.
4. Comino-Garayoa R, Peláez J, Tobar C, Rodríguez V, Suárez MJ. Adhesion to Zirconia: A Systematic Review of Surface Pretreatments and Resin Cements. Materials (Basel). 2021 May 22;14(11):2751.
5. Mehari K, Parke AS, Gallardo FF, Vandewalle KS. Assessing the Effects of Air Abrasion with Aluminum Oxide or Glass Beads to Zirconia on the Bond Strength of Cement. J Contemp Dent Pract. 2020 Jul 1;21(7):713-717.
6. Chen B, Yan Y, Xie H, Meng H, Zhang H, Chen C. Effects of Tribochemical Silica Coating and Alumina-Particle Air Abrasion on 3Y-TZP and 5Y-TZP: Evaluation of Surface Hardness, Roughness, Bonding, and Phase Transformation. J Adhes Dent. 2020;22(4):373-382.
7. Alammar A, Blatz MB. The resin bond to high-translucent zirconia-A systematic review. J Esthet Restor Dent. 2022 Jan;34(1):117-135.
8. Soto-Montero J, Missiato AV, dos Santos Dias CT, Giannini M. Effect of airborne particle abrasion and primer application on the surface wettability and bond strength of resin cements to translucent zirconia. J Adhes Sci Technol, Online publication May 2022.
9. Inokoshi M, Shimizubata M, Nozaki K, Takagaki T, Yoshihara K, Minakuchi S, Vleugels J, Van Meerbeek B, Zhang F. Impact of sandblasting on the flexural strength of highly translucent zirconia. J Mech Behav Biomed Mater. 2021 Mar;115:104268.
10. Gseibat M, Sevilla P, Lopez-Suarez C, Rodríguez V, Peláez J, Suárez MJ. Prospective Clinical Evaluation of Posterior Third-Generation Monolithic Zirconia Crowns Fabricated with Complete Digital Workflow: Two-Year Follow-Up. Materials (Basel). 2022 Jan 17;15(2):672. (https://pubmed.ncbi.nlm.nih.gov/35057389/).

Every tooth has its unique internal shade structure. Esthetic Colorant enables you to easily and efficiently imitate a variety of these unique characteristics.

It is composed of just 12 shades. They facilitate inventory management yet establish that the typical effects - the lifelike colours of natural teeth can be expressed and controlled even before sintering for natural rendering and oral harmony.

Curious how it works? Check out the video to find out!

Lecture programme at the IDS booth of Kuraray Noritake Dental

Are you interested in a specific material and would like to know how it performs? Are you looking for recommendations on how to exploit its full potential? Or would you like to acquire knowledge about new techniques that support the development of your clinical or technical skills?

During the IDS 2023, eight renowned and experienced speakers offer valuable support by sharing their profound practical and theoretical knowledge in lectures and hands-on demonstrations. Every day between Wednesday and Saturday, an exciting, varied programme is offered at the Kuraray Noritake Dental booth in Hall 11.3 (Booth (E010/F019).

Clinical techniques and practice workflows

Dental practitioners may be particularly interested in a combined lecture and hands-on demonstration given by Dr. Michał Jaczewski and Dr. José Ignacio Zorzin as well as MUDr. Josef Kunkela, Ph.D.

Dr. Michał Jaczewski is a specialist in minimally invasive and digital dentistry with a private practice in Legnica, Poland. His topic: the flowable injection technique, to explore additional possibilities for direct restorations. He will explain when and why to opt for this non-invasive approach, reveal which materials and tools to select and demonstrate how to obtain aesthetic results.

Dr. José Ignacio Zorzin is an Assistant Professor at the Department of Operative Dentistry and Periodontology at the Friedrich-Alexander-University of Erlangen-Nürnberg in Erlangen, Germany. He will present (in German) proven protocols used to achieve reliable adhesion for more complicated cementation cases using universal products such as CLEARFIL™ Universal Bond Quick and PANAVIA™ SA Cement Universal.

MUDr. Josef Kunkela, Ph.D. founded KUNKELA Campus – a uniquely structured training institute for dentists and dental technicians – in 2012 and runs his own research lab in Jindřichův Hradec, Czech Republic. He will elaborate on KATANA™ Properties and CEREC Tips & Tricks in his presentation, to understand the latest zirconia materials and their potential in clinically. Attendees will learn in what way the material choice has an impact on the quality of indirect restorations.

Technical approaches

While the aforementioned presentation of MUDr. Josef Kunkela, Ph.D. may be interesting for dental technicians as well, there will be five speakers who focus exclusively on technical approaches.

Giuliano Moustakis, MDT, who currently runs a dental lab in Falkensee, Germany, will reveal how to produce aesthetic monolithic restorations using KATANA™ Zirconia, Esthetic Colorant and instruments for surface texturing. The dyeing liquids creating individual optical effects are applied immediately after milling and fixed during sintering – a Zero Bake Technique! His lecture will be in German.

A time-saving, yet highly aesthetic One-Bake Technique will be demonstrated by Nondas Vlachopoulos, MDT, the owner of AestheticLab in Athens, Greece, while Daniele Rondoni, MDT from Savona in Italy will introduce his approach to micro-layering to the audience – the 4.4.1 Micro-Layering Technique. Depending on the position in the mouth and the age of the patient, the speaker uses different cutback designs and material combinations from internal stains and luster porcelain to liquid ceramics to finish KATANA™ Zirconia Multi-Layered restorations.

A more complex layering approach will be presented by Alek Aronin, MDT, the owner of the Dental Laboratory and Morphology School in Spain. In a lecture and hands-on presentation titled Internal Stains on Refractory with Noritake EX-3, he equips the audience with knowledge on how to imitate nature as closely as possible with the aid of the Internal Stain Technique.

And last but not least, the owner of ACH Dental Laboratory in Athens, Greece – Andreas Chatzimpatzakis, MDT – will elaborate on White-Pink Aesthetics.

Plan your visit now!

To access the complete schedule, please visit our website, www.kuraraynoritake.eu. The website also offers in-depth information about the speakers. For those who are unable to attend a session that attracts their interest, the lectures and hands-on demonstrations will be broadcasted online and will also be available on demand.

Interview with Dr. Karim Nasr

Zirconia is a popular restorative material with highly beneficial mechanical and meanwhile also optical properties. Due to long processing times, especially sintering, the material was initially not suitable for single-visit dentistry. This changed with the availability of zirconia variants with shortened sintering times and special high-speed sintering furnaces.

We discussed with Dr. Karim Nasr, who is senior lecturer at the University of Toulouse in France and head of CAD/CAM postgraduate training, about his actual practice. His passion for CAD/CAM leads him to use CEREC since 2006 (former CEREC trainer) and to found also iAcademy, a training academy about digital dentistry. He shared his experience with us and we talked about his workflow and indication-specific material preferences as well as specific recommendations regarding the use of KATANA™ Zirconia Block in single-visit dentistry.

Dr. Nasr, which chairside CAD/CAM system do you currently use?

Karim Nasr: I am currently using a chairside CEREC Primescan AC system (Dentsply Sirona) combined with a MCXL milling machine (Dentsply Sirona) in my private practice. In my hospital practice and in the specialized esthetic dentistry consultation that I manage, we use a CEREC Primescan AC system combined with a CEREC Primemill milling machine (Dentsply Sirona).

Why did you opt for those components?

Karim Nasr: The choice of this entire system was guided by several criteria. Working on a proprietary chain certainly locks the possibilities of mixing the equipment, but brings real simplicity and fluidity of use. Moreover, the CEREC Software is certainly the most successful CAD software for a chairside use. It offers personalized and easily modifiable restorations in just a few steps. The simultaneous milling of the top (extrados) and bottom (intrados) surfaces without changing the burs ensures a very short milling time. Finally, a large number of materials are available and can be used with this system.

When did you start working with a chairside CAD/CAM system?

Karim Nasr: I discovered and started working with my first chairside system (CEREC 3) in 2005, shortly after graduating. At that time, everything was new in this field. The intraoral scanner, CAD software, milling unit and ceramic materials had just been introduced. All those components allowed us to deliver aesthetic dental treatments within a single treatment session for the first time.

How did the chairside CAD/CAM systems evolve over time?

Karim Nasr: Of course, with the advances in computer technology, the systems have become more efficient. While it was still necessary to powder the surfaces and possible to record one or two teeth in 2005, powder is no longer required in 2022 and complete arches can be scanned in less than two minutes with an accuracy of less than 20 μm. The design process is highly automated and very well assisted – artificial intelligence is used at all stages, making the work easier.

For what purposes do you use your system today?

Karim Nasr: In more than 15 years, the use of my system has evolved a lot. Nowadays, I reserve it for procedures that can be performed in a single session. This is of the greatest utility for my patients and it allows me to optimize my treatment time. For this reason, not only the milling time, but also the time needed for post-processing is crucial for the decision whether to use my chairside CAD/CAM system or to collaborate with a dental laboratory.

What kinds of materials do you process chairside?

Karim Nasr: I think I have tested all the materials available (at least in France), to be able to select the most suitable ones for daily procedures. Currently, I use different kinds of materials depending on the indications encountered: PMMA for temporary restorations, composites for inlays and onlays, glass-ceramics for onlays, overlays and crowns, and finally zirconia for crowns and bridges.

How do chairside CAD/CAM and zirconia go together?

Karim Nasr: In fact, quite simply. For me, a chairside equipment must be able to produce restorations in the same treatment session. Otherwise, it is a labside workflow. Thus, to use zirconia in chairside systems, the milling procedure must be fast and efficient, but above all, the post-processing (especially sintering) process must be fast. For short processing times, dry milling is recommended, as well as the use of a fast-sintering furnace (such as the CEREC SpeedFire from Dentsply Sirona).

What are the benefits of zirconia compared to other ceramic materials?

Karim Nasr: There are many of them. From a biomechanical point of view, the high mechanical strength of zirconia allows us to work with reduced wall thicknesses, which enables us to be more conservative in dental tissues or to choose any placement method (cementation or bonding). From a biological point of view, perfectly polished, zirconia is the most tolerant ceramic, as it is kind to antagonistic teeth and incredibly well tolerated by periodontal tissues. I prefer zirconia for my crowns on implants for this reason.

What was your first impression when you heard about KATANA™ Zirconia Block?

Karim Nasr: I caught a first glimpse of the new material during an event in 2018. KATANA™ Zirconia STML already existed in discs for laboratories and was well known for its aesthetic qualities. Its block version was highly anticipated. But the most amazing feature was the short sintering times announced (with the CEREC SpeedFire in particular). Testing it, I was immediately amazed by the quality of the ceramic and impressed that it is possible to obtain such an aesthetic result (translucency and shade gradation) within such a short time. This is aesthetic zirconia for everyone!

For which indications would you employ KATANA™ Zirconia Block?

Karim Nasr: I reserve the use of KATANA™ Zirconia Block for crowns and for 3-unit bridges. In some cases, I also use it to produce cantilever bridges with a single-retainer design to replace missing incisors (as described by M. Kern). I particularly like it in my cases where I employ a Biologically Oriented Preparation Technique (BOPT) or Vertiprep.

Are there any material features which are particularly interesting for you?

Karim Nasr: Its biomechanical qualities (which are those of zirconia, already mentioned above) already allow me to extend the indications of my chairside restorations. But, in my opinion, the most interesting property is the degree of translucency. Although it is translucent, KATANA™ Zirconia Block is slightly more opaque than glass-ceramics in their lowest degree of translucency. This allows me to use it on discoloured substrates with higher confidence and to avoid the gray effect without having to use an opaque resin cement.

Do you have any recommendations for an ideal processing of KATANA™ Zirconia Block?

Karim Nasr: The use of zirconia in chairside procedures requires certain precautions to be taken in order to achieve the expected results. I have carried out many tests to identify the mistakes not to be made.

First, dry milling is strongly recommended. Nevertheless, it is quite possible to mill in wet environment. However, in this case, it is fundamental to reserve a tank only for the milling of zirconia, never use any lubricant in water (ideally demineralized water), and to have the filters always clean, which means that they need to be cleaned after each milling procedure. After milling, it is important to remove all the powder of zirconia that may have remained on the surface. After dry milling, the restoration must be sprayed with air. The same is the case after the use of burs or polishers to finish the surface. After wet milling, a demineralized water and ultrasound bath may be indicated but is not mandatory.

(Very) fast sintering with CEREC SpeedFire, for example, gives very satisfactory results comparable to conventional slow sintering, which has also been confirmed by scientific literature. Without an appropriate furnace, it is impossible to perform restorations in the same treatment session. However, I do not use CEREC SpeedFire for staining, glazing or micro-layering, but rather a furnace that can be parameterized. Finally, I advise users to finish and glaze only what is necessary (occlusal grooves, vestibular surfaces if visible) and to polish the rest.

Do you have any tips on how to achieve optimal outcomes with KATANA™ Zirconia Block?

Karim Nasr: In anterior cases, I always recommend to perform shading and staining steps in the mouth because there is no better model than the patient himself. Micro-layering in anterior cases makes it possible to improve the aesthetic result with few steps. The 4.4.1. system, which has been specifically developed for KATANA™ Zirconia, makes micro-layering easy to achieve. For polishing, the use of “twist” polishers is recommended. They make it easier to polish all surfaces, especially the occlusal surfaces, both extra-orally and in the mouth. Just like their counterparts for composite, TWIST™ DIA for Zirconia for Zirconia polishers prove to be very effective.

Dr. Nasr, thank you very much.

DR. KARIM NASR

Stratos Chatzichristos just tested the brand-new Esthetic Colorant on restorations made of KATANA™ Zirconia. This is his verdict:

“For me, KATANA™ Zirconia plus Esthetic Colorant is a true killer combination that leaves nothing to be desired. I love to apply the dyeing liquids to my monolithic zirconia restorations to intensify characteristic features and create natural shade effects. Usually, those restorations just need a final layer of glaze to look amazing!”

Would you like to know more about Esthetic Colorant for KATANA Zirconia? Watch this short video explaining the product and highlighting its features and benefits: