429 Too Many Requests

A strong and durable bond between the tooth and the restoration is a decisive factor influencing the long-term performance of dental restorations. The quality of the bond, however, is not only affected by the bonding agent or cementation solution used, but also by the condition of the bonding surface. For those who would like to ensure clean tooth and restoration surfaces in an easy way, Kuraray Noritake Dental has developed KATANA™ Cleaner, a universal cleaner with MDP salt and a pH of 4.5 for intra- and extra-oral application.

It has been proven that proteins present in saliva and blood have a negative effect on the performance of dental adhesives. Especially in indirect procedures, however, it is impossible to keep the bonding surfaces free of oral fluids. At try-in at the latest, the prepared tooth and the restoration are contaminated and need to be cleaned. Rinsing with water does not have the desired effect, and even with many available cleaners, a certain amount of proteins are usually left on the surface. Tests show that by using KATANA™ Cleaner or by sandblasting, the desired high cleaning effect needed is obtained, without compromising bond strength. This is true for KATANA™ Zirconia restorations, while KATANA™ Cleaner also leads to the desired results on dentin and enamel – surfaces in the oral cavity for which sandblasting and most of the other cleaners are not indicated.

The use of KATANA™ Cleaner offers yet another advantage: the cleaning procedure is extraordinarily simple, quick and neat. The universal cleaner comes in a bottle with an innovative flip-top cap, enabling single-handed dispensing onto the dish. It is then rubbed into the surface of the restoration and the prepared tooth structure or the abutment for ten seconds, rinsed with water and dried. Thanks to the high surface activity of MDP salt, these ten seconds are sufficient to remove the proteins on the substrate almost completely, creating conditions very similar to those found on a non-contaminated bonding surface. Subsequently, the selected bonding agent or cementation solution – e.g. PANAVIA™ V5 or PANAVIA™ SA Cement Universal – is applied according to the maufacturer’s usage instructions.

The result is a strong long-lasting bond, which gives users a peace of mind. Pilot users who have already tested the product agree that KATANA™ Cleaner is the easy way to optimise bond quality and streamline any adhesive procedure.

As co-editor-in-chief of the Journal of Adhesive Dentistry, Prof. Bart Van Meerbeek is one of the most respected authorities on the topic of dental bonding agents. Here, he discusses how they have advanced over the last three decades and what the future of adhesive dentistry might look like.

Prof. Van Meerbeek, how have bonding agents changed and advanced since you first began studying them?

I believe that the great progress dental adhesive technology has undergone in the last 30 years, and the progress in bonding agents in particular, has had a great impact on the field of dentistry and particularly on restorative dentistry, of course. Many of the current restorative dental procedures make use of adhesive materials and techniques and have advanced greatly compared with when I wrote my dissertation more than two decades ago on the topic of adhesion to dentine. Adhesion to enamel is, of course, relatively easy to achieve in comparison with adhesion to dentine, and when I first started researching this topic, I was limited to conducting clinical trials in which we were confronted with a relatively high number of restoration losses in the short term. I was lucky to have been able to witness first-hand the fast advancements dental bonding has made, having conducted research in this field now for nearly 30 years.

At a certain point, the research community started to realise that there is a smear layer in-between, which is created through cavity preparation, and that this layer interferes with bonding. If you want to achieve successful micromechanical and chemical bonding to the substrate, you first need to do something with this smear layer.

After this, we entered the era of conditioners and primers. In the past, the restorative community had been a little bit afraid of using phosphoric acid owing to its potential for pulp irritation. More and more, however, dental professionals began to use etchants with this chemical in them, as well as primers that effectively promoted bonding between the adhesive resin and dentine. While having achieved excellent bonding performance with multistep adhesives in the laboratory, as was later confirmed in clinical studies, further design and development of adhesive materials next focused on simplification and shortening of bonding procedures.

Out of this, two kinds of adhesives, making use essentially of two different bonding modes, arose: the etch-and-rinse adhesives and the self-etch, or etch-and-dry, adhesives. The newest generation of universal adhesives now enables dental practitioners to choose which of the two bonding modes to apply with one single adhesive formulation.

What advantages do bonded restorations offer over more traditional methods?

Bonded restorations are minimally invasive—the dentist doesn’t have to remove non-diseased tissue to create undercuts to keep the restoration in place, allowing for a more conservative approach. Keeping as much enamel as possible should be a goal of any restorative procedure, as it is simply the best tissue to bond to. Although bonding to dentine has always remained more challenging and has actually slowed down our adhesive endeavours for a long time, adhesively restoring teeth, involving also effective bonding to dentine, can today be achieved in a reliable, predictable and durable way.

Along with highly successful implantology to replace missing teeth, lessening the need for bridges, solitary tooth restorations have substantially increased in number. Bonding promoted the additional shift from conventional tissue-invasive crowns to tissue-preserving partial tooth restorations, as modern adhesives can hold such partial restorations in place on rather flat and even non-retentive surfaces. In addition, bonding procedures allow for more natural-appearing restorations to be achieved by techniques to adhesively lute aesthetic restorations made of glass-ceramics and even the strong zirconia ceramics that no longer can be considered non-bondable.

What is your opinion regarding the current generation of universal adhesive solutions?

I think that this generation is very good, but that they are still not always as good as the more traditional gold standard two-step self-etch and three-step etch-and-rinse adhesives when it comes to their intrinsic bonding potential to dental tissue. However, I do see it as a positive that many of these universal adhesives integrate the MDP monomer, which should be considered to be one of the best functional monomers available today, though it needs to be present at a high concentration and purity level.

The MDP monomer is, generally speaking, excellent at bonding to zirconia as well. When it comes to bonding to different kinds of ceramic as well as resin-based composite restorative materials, it is always helpful to know which universal adhesives contain silane and are claimed to no longer need further treatment of the restoration. This has the advantages of lower technique sensitivity and fewer procedural steps—provided that it does, of course, work. There is current scientific evidence that the silane incorporated in today’s acidic aqueous universal adhesives is, however, insufficiently stable. Fortunately, research is underway to develop new universal adhesives that contain other silanes with higher stability in water at higher acidity.

Overall, I believe that a restoration primer that contains a high concentration of silane along with the MDP monomer is still more effective than many universal adhesives for bonding to restorative materials, since these universal adhesives can contain many other ingredients that create a kind of competition within the material to reach and interact with the substrate surface, leading to lesser bonds.

Another shortcoming of universal adhesives is their thin film thickness and relatively high hydrophilicity, promoting water uptake and hence making them sensitive to hydrolytic degradation. In this light, it’s important to note that, when a viscous and hydrophobic flowable composite is applied on top of a universal adhesive, it can make up for this somewhat and allow for durable bonding to take place.

Is the MDP monomer crucial to the ultimate success of universal adhesives? Are there other factors that can influence this?

Well, it’s very clear that the MDP monomer is one of the most effective monomers available, given its primary chemical binding potential to hydroxyapatite. However, there are significant differences in the MDP monomer purity and concentration levels between these products, factors that are affected by whether or not the monomer is synthesised by the company itself or whether this process is outsourced. Essentially, a universal adhesive that contains a high concentration of very pure MDP monomer should perform the best.

Are there any specific advantages that a self-etch adhesive possesses?

The biggest advantage is that it doesn’t remove all hydroxyapatite and minerals present in dentine and so keeps the weaker dentinal collagen protected. Phosphoric-acid etching results in relatively deep and complete demineralisation with collagen exposure, making the bond more prone to degradation. Partially maintaining minerals around collagen using a mild self-etch adhesive additionally allows for strong ionic bond formation to take place when the adhesive in particular contains the functional monomer MDP. In addition, one should be aware that, while chemical binding doesn’t necessarily lead to higher bond strength, it can create better long-term bond durability.

What do you see as the next step in adhesive dentistry?

One possibility is to reduce the number of steps in the adhesion process with the final goal of having self-adhering restorative materials. There have been developments in this direction, including studies and commercial products, though the products haven’t always proved to be very effective and their bond durability is unclear. Now, however, there are newer materials coming to market with claims that they can be used with no pretreatment. Their clinical effectiveness, nevertheless, still needs to be proved and guaranteed before such self-adhering restorative materials could be used as true amalgam alternatives in routine dental practice.

Another possibility, and current R & D hype, is the development of bioactive adhesives. Many dental researchers and many companies want adhesives not only to deliver good bonding performance but also to have certain therapeutic benefits. What exactly a bioactive adhesive is depends on who you’re talking to. Some researchers believe that they should have antibacterial qualities, whereas others state that remineralisation of dentine and pulpal cell interaction are needed to qualify for the term “bioactive”. We certainly need to investigate whether we can give these materials these additional properties, but on one condition: that the adhesive material does not lose any of its original bonding abilities. That, in my opinion, is the biggest challenge for the future of adhesive dentistry.

In the category CEMENT: Self Adhesive; PANAVIA SA Cement Universal was awarded Top Award 2020 by Dental Advisor.

Bond Strength:

As tested in DENTAL ADVISOR Biomaterials Laboratories, bond strength to dentin
and enamel were best in class for a self-adhesive resin cement.

Universal:

Since it can be utilized on any substrate, DENTAL ADVISOR
Laboratories tested the bond to both lithium disilicate and zirconia and
results were outstanding.

Evaluator Comments:
• “This cement is very strong and has great adhesive properties.
There was virtually no post-op sensitivity.”
• “Very user-friendly and cleaned up well.”

As a company, Kuraray Noritake Dental is committed not just to creating innovative products, but also to building upon our successes. A perfect example of this approach is CLEARFIL Universal Bond Quick, our newest universal dental bonding agent. A descendant of the original CLEARFIL BOND SYSTEM F and CLEARFIL SE BOND, this one-step adhesive eliminates the need for waiting, rubbing or applying additional layers. With the introduction of a flip-top cap, CLEARFIL Universal Bond Quick is now more compact and efficient than ever.

Easier than ever to use

Thanks to the new flip-top cap, the bottle can easily be opened, manipulated and closed with just one hand. In addition, its unique nozzle allows for controlled dispensing of the adhesive and ensures that there is minimal wastage. Together, these improvements are intended to enable ideal results for both the dentist and the patient.

Rapid bond technology

Though its container may be different, the patented monomer technology of Kuraray Noritake Dental still forms the backbone of this product. Other adhesives tend to rely on “slow monomers” with relatively slow dentinal penetration, but CLEARFIL Universal Bond Quick combines Kuraray’s famous MDP monomer—scientifically proven to deliver stronger and more stable bonds than other manufacturers’ MDP—with hydrophilic amide monomers. This allows it to penetrate the dentine faster and more efficiently and provide a stable, moisture-resistant sealing of the cavity.

Combine with PANAVIA SA Cement Universal and CLEARFIL DC CORE PLUS

This universal adhesive pairs excellently with CLEARFIL DC CORE PLUS, a dual-cure, radiopaque core build-up material, to deliver durable, long-lasting restorations that dentists can trust. Delivered in a convenient automix system, CLEARFIL DC CORE PLUS possesses excellent compressive and flexural strength, with a filler loading weight of 74wt%.

CLEARFIL Universal Bond Quick is also suited for use with PANAVIA SA Cement Universal, a resin cement that similarly utilises MDP monomer technology for durable bonding. PANAVIA SA Cement Universal possesses a stable three-year shelf life at room temperature, effectively eliminating the need for refrigeration, and its improved endo tip allows for greater precision and control over cement placement during post cementation.

By combining excellence in performance with simplicity in use, Kuraray Noritake Dental’s CLEARFIL Universal Bond Quick represents an evolution in dental bonding agents. 

As a dental technician with many years of experience, Björn Roland has always pursued one goal in his lab: restorations that seamlessly mimic natural dentition and possess reliable functionality. Here, he discusses how he integrates Kuraray Noritake Dental’s dental solutions into his daily workflow and shares some tips for creating aesthetically-pleasing dental restorations.

Could you speak a little bit about your dental journey and how you were first introduced to Kuraray Noritake Dental’s range of products?

ROLAND: Well, I was first introduced to these products when I was in Japan about 15 years ago. I was there to undertake a course at the Osaka Ceramic Training Center of Shigeo Kataoka, but I had the possibility during this time to visit courses conducted by Hitoshi Aoshima. Aoshima is the person primarily responsible for Noritake Porcelain and who had the idea for the colouring, and he was also responsible for the idea of internal staining. I also had the possibility to complete a course with Aoshima and visit his dental lab in Tokyo, which enabled me to begin working with Noritake porcelain when I arrived back in Germany.

You spoke at IDS 2019 about the evolution of the KATANA™ Zirconia range, starting with the 2013 introduction of KATANA™ Zirconia ML. When did you first start working with this product?

When Kuraray Noritake Dental was formed in 2012, I was lucky enough to be one the first dental technicians to experience the multilayered technology that forms the backbone of KATANA™ Zirconia, to test it out before it was released to the German market. Prior to this, there was only a monocoloured zirconia material available, which you could stain yourself by dipping it into a staining solution, but I was never a big fan of it. From the moment that Kuraray Noritake came up with its multilayered approach, I could see the potential of KATANA™ Zirconia -simply put, it was easy to use and had a nice and aesthetic colour shift when used for restorations.

As a dental technician, do you use KATANA™ Zirconia in your everyday workflow?

In our laboratory we only use KATANA™. Of course, not everything is made from the multilayered variety—we have primarily used the monocoloured KATANA™ HT for the framework in the past, though we do use the multilayered option for monolithic restorations and for certain frameworks.

Do you use KATANA™ Zirconia in combination with CERABIEN™ ZR porcelain?

Yes, always. For me, it is a perfect combination. Not only are they easy to use together, but they also combine to create aesthetic restorations with great, natural colour and a high level of flexural strength. In our laboratory, everyone uses CERABIEN™ ZR porcelain, from those who are just starting with ceramics through to the experienced and highly skilled dental technicians. Even technicians who have come from other dental laboratories and tried other porcelain materials have adapted very quickly to using it and seem to really like it. The chipping risk with CERABIEN™ ZR porcelain is very low, and we truly admire the brilliance of the colour.

Is CERABIEN™ ZR porcelain a material, in your opinion, that can benefit those with expert knowledge of porcelains?

Of course. For those who are experienced in dealing with ceramic materials and understand how they behave, they can absolutely achieve high-end results with CERABIEN™ ZR. It’s important to remember, though, that even dental technicians who aren’t so familiar with ceramic veneering are also getting good results out of it - it’s not too difficult to use and get good results.

Do you use any other Kuraray Noritake Dental products in your dental lab?

Apart from KATANA™ and CERABIEN™ ZR, one product that I personally like and use from Kuraray Noritake Dental is Meister Cones, which are these small paper cones that assist with the finishing and polishing of porcelain surfaces. I brought them back with me to Germany from Japan and find them to be very handy in the laboratory. 

There is still some confusion among dental practitioners about how to cement zirconia restorations. In general, all types of cements – adhesive or self-adhesive resin cements and conventional cements – are compatible with all types of zirconia. The actual choice should be based on the restoration design (retentive or non-retentive), the translucency of the zirconia and the clinical situation (feasibility of working field isolation).

When to use which type of cement

The use of adhesive resin cements is mandatory whenever the highest possible bond strength is required. This is the case with one-wing Maryland bridges and other types of restorations lacking micromechanical retention, and with two-piece implant abutments.

In some other situations where retention is not an issue, adhesive or self-adhesive resin cements may have a beneficial effect. The major reason is their more esthetic appearance compared to conventional cements, which offers advantages whenever a highly translucent restorative material is used (e.g. KATANA Zirconia UTML). An important precondition for adhesive luting, however, is a dry working field. Consequently, conventional cements are preferable in the context of placing crowns, bridges and other types of restorations with retentive designs whenever opaque zirconia framework materials are used and / or it is difficult to ensure a dry working field.

How to pre-treat the tooth and the restoration

The highest bond strength of adhesive resin cements to zirconia is obtained after sandblasting with alumina (particle size max. 50 µm, pressure approx. 1 bar). Hence, this procedure is highly recommended. Subsequent steps may be different depending on the cement system employed and should be carried out according to the manufacturer’s instructions for use. On the side of the tooth, enamel etching is important independent of the products used.

Which products to use

In each of the cement classes, there are many different products to choose from. My recommendation is to select a proven and easy-to-use luting material. Among those products achieving the same high bond strength, the solution requiring the fewest application steps seems preferable as it reduces the risk of application errors. At Charité – University Medicine Berlin, we count on PANAVIA cements, which are based on many years of expertise in developing products for adhesive luting of zirconia.

Though one is a master dental technician and the other a dentist, Daniele Rondoni and Dr Nicola Scotti share a passion for discovering new materials and technologies to better provide aesthetic, durable restorations for patients. Here, they discuss their dental journeys and how they have integrated Kuraray Noritake Dental’s KATANA™ Zirconia range into their workflows.

How did you get started in dentistry, and what was it about dentistry that first interested you?
Dr Nicola Scotti: Well, my professional interest goes back 15 or 20 years at this point, but I was first introduced to dentistry as a child through my father, who was a dentist himself. I grew up looking at teeth, looking at models, and it was something that was just in my blood. When I had to decide what to study, I followed my heart and decided to become a dentist, and ever since I have remained dedicated to learning new things about it.

Daniele Rondoni: I have a similar story to Nicola. My uncle was a dental technician and that influenced my decision to become a dental technician and open up my own dental laboratory. Though there were many things that interested me, I have always focused on the major possibility that this profession offers, the opportunity not only to use your hands but also to combine this skill with the newest dental technologies available.

Regarding this combination of manual and digital skills, do you still see a role for the dental professional as a craftsperson in this increasingly digital industry?
Scotti: Dentistry, even if the digital influence continues to grow, will surely continue to be a profession defined by what we can do with our hands. You cannot complete a restoration, for example, without having these manual skills. There is also the matter of personalisation. Though machines can create flawless dental restorations in great numbers, it is the artistry of the dental technician that allows our patients to have customised solutions made with the materials and the shapes that suit them best. If you want to provide natural-looking restorations for your patients, digital dentistry is a great tool to use, but you need to have manual skills and a passion for the work as well.

Rondoni: As a dental technician, it is important to remember that my work depends on technology, and so in this way, digital dentistry and the new-generation dental materials have helped my work greatly. Using this technology for individual situations is an essential part of my role, and excellent materials like Kuraray Noritake Dental’s KATANA™ Zirconia range make my artistic vision regarding these situations more easily achievable.

Scotti: In my opinion, even if 90 per cent of the workflow is digital in nature, you need that artistic input and vision for the remaining 10 per cent in order to really create a successful restoration. With KATANA™ Zirconia, these two aspects come together and allow you to create something really amazing.

Speaking of the KATANA™ Zirconia range from Kuraray Noritake Dental, is this material a part of your everyday workflow at this point? What do you see as its benefits?
Rondoni: It is definitely a part of my everyday workflow. I have worked with Noritake materials for many years, but when Kuraray released its newest generation of zirconia, it totally changed my approach in the dental laboratory. Over the last five years, KATANA™ Zirconia has greatly influenced my workflow; it allows me to use certain technologies without forgoing artistic needs, and since it’s available in different translucencies and shades and so on, I can create aesthetic restorations for individual cases with ease.

Scotti: In the past, I didn’t regard zirconia as a material for dentists. We used to take the impression and then ask the dental technician to use zirconia to make a restoration, but we didn’t use the material ourselves. What the KATANA™ Zirconia Block for chairside has introduced is a totally new concept of how zirconia can be used by dentists themselves. Having a material that can create monolithic full-contour restorations, even single crowns, is incredible. Its aesthetic qualities are fantastic as well, as Daniele mentioned, and it gives us a truly new option for treating patients.

Earlier this year, Kuraray Noritake Dental invited dental professionals from all over Europe to a symposium in Berlin that highlighted the newest research and clinical findings with the KATANA™ Zirconia Block, the latest addition to the KATANA™ family. Among those to present was Dr Nicola Scotti, an assistant professor at the Department of Cariology and Operative Dentistry at the University of Turin’s Dental School and operator of his own private practice.

Dr Scotti began working with Kuraray Noritake Dental’s range of products in 2012, having been asked to test the CLEARFIL MAJESTY™ ES-2 composite resin before its launch, and soon afterwards began what he terms a “close collaboration” with the company. “I consider Kuraray Noritake Dental to be a very serious company, one built on strong scientific foundations and with a great interest in innovation and consulting with opinion leaders,” he added.

When Dr Scotti was presented with the opportunity to use the KATANA™ Zirconia Block in April 2018, it required a significant learning curve as he had never used zirconia for restorations before. “I am not a dental technician, and when I received the Block for the first time, I realised that I would have to add some skills to be able to work the material in the best possible way,” he said. With the assistance of master dental technician Daniele Rondoni—facilitated by Kuraray Noritake Dental—Dr Scotti was able to learn how to process and characterise zirconia, as well as understand the optical behaviour of KATANA™. “I must say that the material, overall, is easy to use and provides amazing aesthetic results,” he added.

As part of his presentation, Dr Scotti showed several case studies that had been conducted with KATANA™ Zirconia Block. One of these focused on a 24-year-old male patient referred to him with a discoloured upper incisor resulting from blunt trauma. “The patient had a fairly immediate aesthetic need, but in this case I was unable to perform external whitening to lessen the discolouration,” explained Dr Scotti. “However, I was able to solve the case by creating an adhesive crown made from a KATANA™ Zirconia Block. Though the cervical area still showed a slight colour difference to the neighbouring teeth, it was not visible in the patient’s smile and he was extremely happy with the result,” Dr Scotti continued.

Overall, Kuraray Noritake Dental’s KATANA™ Zirconia Block is a great step forward for zirconia restorations, according to Dr Scotti. “Ten years ago, no one would have imagined being able to make a central incisor restoration out of zirconia,” he said. “Thanks to the multi-layered technology behind the natural aesthetics of this block, today this is no longer a dream.”

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

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

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

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

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

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

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

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

With over 30 years of experience as a dentist and researcher, Dr Paolo Baldissara of the University of Bologna in Italy could be forgiven for slowing down a bit. This is far from happening, however, as he continues to be at the forefront of ceramic restoration material developments and their integration into CAD/CAM workflows.

When presenting at a symposium held in Berlin in Germany by Kuraray Europe earlier this year, Dr Baldissara highlighted how the company’s patented multilayered zirconia technology allows the KATANA™ Zirconia Block to effectively mimic the shade gradation of natural teeth. He commenced his presentation by outlining the general shift towards metal-free restorations, which in his opinion has been driven by a number of factors, the high value now placed on aesthetics in dentistry chief among them.

“I began using zirconia back in 2005 for prosthodontics in my department at Bologna, and it has greatly improved in quality since then,” said Dr Baldissara. “Generally speaking, the shift towards zirconia only started when a high-strength substitute for metal that was able to be processed with CAD/CAM systems with high accuracy became available.”

It was at the 2015 International Dental Show in Cologne in Germany where Dr Baldissara was first introduced to KATANA™ Zirconia UTML and STML, both of which impressed him with their high levels of translucency. “I started to use them almost immediately, mainly in their monolithic form, for research and in clinical practice,” he said. “My opinion of them was very high, as they allowed me to make cost-effective single crowns and multi-unit restorations with excellent aesthetic properties with scattered and diffused light. This is, ultimately, what patients want.”

Dr Baldissara began using the KATANA™ Zirconia Block in 2018 and expressed his excitement with how its high-speed sintering allows for fast processing of restorations. He recommended dry milling for a number of reasons: not only does it allow for the translucency of the zirconia to be maintained, it also helps to avoid contamination from other ceramic powders that may persist in the milling unit. In addition, he encouraged attendees to frequently replace the burs of their milling units for optimal results and reduced risk of chipping.

“Dry milling and high-speed sintering of the KATANA™ Zirconia Block is an extremely promising technology,” said Dr Baldissara. “In my opinion, it is the correct way to make aesthetic and mechanically strong restorations for the patient.”