Tagged with 'Prosthodontics'

Micro-layering: a new era in porcelain layering

Interview with Mathias Fernandez Y Lombardi

 

INTRODUCING CERABIEN™ MiLai LOW-FUSING PORCELAINS AND INTERNAL STAINS

Highly aesthetic lithium disilicate or zirconia-based framework materials combined with a micro-layer of porcelain are becoming the new standard for producing lifelike all-ceramic restorations. For those wondering why it’s worth adopting the new technique, how to start, how to improve and which materials to use, we had a conversation with a true expert in all things ceramic: Mathias Fernandez Y Lombardi, Head of Technical Marketing – Europe at Kuraray Europe GmbH.

 

Mathias Fernandez Y Lombardi, do you believe in micro-layering as a technique that is capable of streamlining procedures in the dental laboratory while fulfilling high aesthetic demands?

Yes, I truly believe that micro-layering is the next step in the evolution of indirect restorative techniques and materials. This evolution is driven by improvements in the area of framework materials, which are becoming more and more tooth-like in their appearance. We have moved from metal to opaque, high-strength zirconia and – more recently - high-translucency multi-layered zirconia and lithium disilicate, which no longer require thick porcelain layers to achieve lifelike outcomes. In this context, it’s only natural that a new technique has emerged.

 

Kuraray Noritake Dental Inc. is well-known as a pioneer in multi-layered zirconia technology and veneering porcelains. Are there any products particularly suitable or specifically developed for micro-layering?

We offer a series of high-translucency, multi-layered zirconia perfectly suited for micro-layering on the one hand and an aligned portfolio of internal stains and porcelains specifically developed for micro-layering on the other. The zirconia portfolio includes three different blank types with a multi-layered colour structure (KATANA™ Zirconia UTML, STML and HTML Plus), one variant with flexural strength, translucency and colour gradation (KATANA™ Zirconia YML), but also the timeless classic HT for the frameworks should be mentioned. While the first three offer a uniform strength and are chosen based on the indication, KATANA™ Zirconia YML with its multi-layered strength is a universal material suitable for an extremely wide range of applications.

 

The set of internal stains and porcelains specifically designed for the micro-layering technique that we just introduced is CERABIEN™ MiLai. With this addition to the CERABIEN™ family, we offer a perfect complement to the KATANA™ Zirconia Multi-Layered series, and with it, a revolutionary workflow that significantly deviates from traditional methods, enabling us to deliver greater efficiency, cost savings, and more flexibility. However, CERABIEN™ MiLai is not only compatible with KATANA™ Zirconia, but also with aesthetic zirconia from other manufacturers and reinforced silicate ceramics such as lithium disilicate with a CTE value within 9.5-11.0×10-6/K (50 °C – 500 °C).

 

Fig. 1. Overview of CERABIEN™ MiLai Low-Fusing Porcelains.

 

Fig. 2. Overview of CERABIEN™ MiLai Internal Stains.

 

Why should a dental technician start using the micro-layering technique and invest in a new set of porcelains for this purpose?

The reasons to start micro-layering are obvious: depending on the design, micro-layering can eliminate or minimize the chipping risk. Moreover, the technique is highly efficient, as the number of layers and bakes is drastically reduced. This results in a reduced thickness of the restoration facilitating minimally invasive preparations and a less complex layering procedure that even beginners are able to learn and implement very quickly. A new set of porcelains specifically developed for micro-layering like CERABIEN™ MiLai can further support the feasibility of the technique and the quality of the outcomes achieved even by beginners. Due to the shortage of skilled workers in dental laboratories, this aspect is becoming increasingly important.

 

How does CERABIEN™ MiLai support users in achieving aesthetic, high-quality outcomes right from the start?

With traditional porcelain systems, it can be challenging to create all the desired individual shade effects in a layer of only 0.03 mm to 0.6 mm thickness. With CERABIEN™ MiLai, this isn’t the case as the system is specifically designed for this purpose. The saturation and translucency of the porcelains are matched to the framework materials and adjusted to the volume of the porcelain layer. The compact line-up makes it quite easy to select and combine the right shades for satisfying results right from the start. More experienced users can mix the different components for additional effects, so that there are no limits to their creativity.


Images courtesy of MDT Daniele Rondoni.

Fig. 3. Virtually unlimited design options: crown with a full micro cut-back, crown with a vestibular cut-back and monolithic restoration.

 

Furthermore, the versatility of CERABIEN™ MiLai is a key feature that results in great outcomes. The system can be used on lithium disilicate and zirconia, a monolithic surface, a vestibular cut-back or a full micro cut-back. With this broad application spectrum, dental technicians are likely to use CERABIEN™ MiLai daily, which allows them to develop a true understanding of the components and to establish work routines very quickly. As a consequence, the outcomes become predictable and controllable. This is further supported by consistent handling and optical properties – all the result of a single core technology.

 

Please tell us more about this technology.

The core technology used in CERABIEN™ MiLai is synthetic feldspathic ceramic technology. Originally developed for Super Porcelain EX-3 and adjusted to the specific needs of CERABIEN™ ZR in the first step and CERABIEN™ MiLai more recently, this technology is responsible for consistent properties. This is because the formulation never needs to be aligned due to changing natural components. However, I believe that the greatest benefit of using feldspathic porcelain lies in the elimination of shadow effects. Everyone familiar with layering natural feldspathic porcelains on ceramics will know the typical greyish shadows appearing in restorations after several firing cycles. They originate from inhomogeneities in the material caused by micro-movements during firing. Showing no movements in this phase, synthetic felspathic porcelains from Kuraray Noritake Dental Inc. are the first and only porcelains preventing this effect. Finally, the further developed version of the technology allowed us to realize a low firing temperature of just 740 °C while maintaining the desired coefficient of thermal expansion. This is essential for the material’s compatibility with lithium disilicate.

 

Are there any other benefits arising from the low firing temperature?

The low firing temperature definitely offers an economic benefit, as the process consumes less energy and takes less time compared to high-temperature firing cycles. Moreover, the wear of the furnace is reduced. Finally, the low temperature is of interest for users of CERABIEN™ ZR in specific indications: Some ceramists like to combine the systems especially in cases with artificial gingiva. They create the porcelain work on the teeth with CERABIEN™ ZR first and then individualize the gingival area with CERABIEN™ MiLai. Due to the low firing temperature, the form, colour and surface of the previously applied veneering porcelain will remain stable.

 

Image courtesy of MDT Ioulianos Moustakis.

Fig. 4. Application of CERABIEN™ MiLai Tissue Porcelains on a complex restoration with the teeth already finalized.

 

Image courtesy of MDT Ioulianos Moustakis.

Fig. 5. Application of CERABIEN™ MiLai Internal Stains on a zirconia bridge.

 

Do you have any application technique recommendations for CERABIEN™ MiLai?

The best aesthetic outcomes are obtained by using the internal stain technique. By applying the stains first, it is possible to create natural depth effects despite the minimal thickness of the porcelain layer. The stains are easy to use and the outcomes are impressive. The micro-layer of porcelain applied on top acts like a window imitating the enamel, which contributes to a tooth-like appearance. Due to the compact line-up and easily manageable effects, this technique is even suitable for beginners.

 

Is the procedure different depending on the base material (lithium disilicate versus zirconia)?

Most of the steps are identical. However, surface conditioning may be different depending on the material used (as described in the material manufacturer’s instructions for use). Moreover, Value Liner 1 or Value Liner 2 is typically used on lithium disilicate for wash baking, whereas Translucent or Luster are recommended for this step on zirconia. When space is limited, internal stains may be applied directly. All following steps – the optional but highly recommended application of internal stains, the building-up of Translucent or Luster and baking, morphological corrections, the glaze bake and finishing – are identical.

 

What are the options for glazing?

CERABIEN™ MiLai porcelains offer a self-glaze effect obtained by fine-polishing (with PEARL Surface C) followed by glaze baking. This leads to a natural gloss, while maintaining the anatomical details. Alternatively, CERABIEN™ ZR FC Paste Stain Glaze or Clear Glaze can be applied and fixed by baking. These liquid ceramics allow users to add some structural details, while the surface appears glossier. However, the procedure is more time-consuming due to the additional application step.

 

 

Do you have any recommendations regarding the indication-specific selection of the framework or base material?

Traditionally, lithium disilicate has been the material of choice for aesthetic single anterior restorations, while zirconia was predominantly used for multi-unit restorations and restorations in the posterior area. With the availability of KATANA™ Zirconia STML / UTML and CERABIEN™ MiLai, zirconia is becoming increasingly attractive for the production of minimally invasive veneers, crowns and the like. A thin-walled restoration made of KATANA™ Zirconia, speed-sintered in just a few minutes and combined with a thin layer of CERABIEN™ MiLai, results in an incredibly strong restoration with several aspects that lithium disilicate simply cannot match. The preparation technique for zirconia is much more favourable for dentists - for example marginal adaptation and biocompatibility, especially regarding gingival healing, are superior. Aesthetically, there is no risk of a greyish effect when using zirconia with CERABIEN™ MiLai, while lithium disilicate needs to be treated with Value Liner to prevent this. Additionally, the ease of cementation with PANAVIA™ SA Cement Universal further enhances the quality of the restoration in the fastest possible timeframe, allowing for quick and flexible responses to dentists’ needs.

 

You mentioned speed sintering as a factor contributing to a streamlined workflow. Studies have shown, however, that this step might weaken the mechanical and aesthetic properties of zirconia. Do you recommend speed sintering despite this fact?

Indeed, speed sintering does affect the translucency and flexural strength of some zirconia variants. This is probably the reason why dental technicians have been reluctant to change their established practices of sintering overnight – despite the availability of high-speed furnaces. However, KATANA™ Zirconia is an exception: Due to our unique powder formulation, we are able to offer zirconia with a composition that is completely independent from other brands of dental zirconia. With this, we are able to fundamentally change the traditional workflow of an end-user and offer more flexibility, speed and efficiency, resulting in less energy consumption, stress and costs. In a study conducted at the Division of Biomaterials at the University of Alabama at Birmingham1, three different high-translucency zirconia materials including KATANA™ Zirconia Block (KATANA™ Zirconia STML) were sintered according to a traditional and a high-speed sintering schedule. Prior to sintering and afterwards, the three-point bending strength, translucency and grain structure were analysed. The material from Kuraray Noritake Dental Inc. was the only zirconia with properties that remained unaffected after speed sintering. Internal testing confirmed this finding for all variants of the KATANA™ Zirconia Multi-Layered series. As a result, we do recommend speed sintering of our materials, delivering true economic and time advantages.

 

With highly potent materials for micro-layering now available, do you think that full ceramic layering is going to be a thing of the past?

I am convinced that in the near future the great majority of dental restorations will be produced using aesthetic framework materials and simplified micro-layering techniques. However, full porcelain layering is here to last. There will always be a demand for a few highly-skilled ceramists serving the needs of individuals with the highest aesthetic demands. It is like tailor-made versus off-the-peg suits: the tailor-made ones are the best you can buy, but most people wear off-the-peg ones, which are perfectly adequate in virtually every environment.

 

Thank you very much!

 

 

Reference

1. Lawson NC, Maharishi A. Strength and translucency of zirconia after high-speed sintering. J Esthet Restor Dent. 2020 Mar;32(2):219-225. doi: 10.1111/jerd.12524. Epub 2019 Sep 13. PMID: 31515932.

 

Mathias Fernandez Y Lombardi

 

EU Scientific Manager
Dental Ceramics & CAD/CAM Materials
Kuraray Europe GmbH

 

2013
Successful completion of an apprenticeship as a dental technician at Seuthe dental laboratory in Plettenberg, Germany

 

2018
Successful completion of dental technology studies at the University of Osnabrück, Germany. Graduation as an engineer in dental technology

 

Since March 2018
Employee of Kuraray Europe GmbH

 

The development of CERABIEN™ MiLai Porcelain and Internal Stain

Interview with Tomohiro Emoto.

 

Kuraray Noritake Dental Inc. Launched its first porcelain for porcelain-fused-to-metal restorations – Noritake Super Porcelain AAA*, still available after more than 30 years under the name Noritake Super Porcelain EX-3* – in 1987. The knowledge acquired since then formed the basis for the development of CERABIEN™ ZR and the brand-new CERABIEN™ MiLai portfolio. How much of Noritake Super Porcelain is found in CERABIEN™ MiLai?

*Noritake Super Porcelain AAA and Noritake Super Porcelain EX-3 were designed and launched by Noritake Company Ltd., the predecessor of Kuraray Noritake Dental Inc.

Naturally, the knowledge we have acquired on developing porcelain products has been fully applied in the development of CERABIEN™ MiLai. The methods used to handle Synthetic Feldspar - such as low firing technologies, stable thermal expansion even with multiple baking, particle distribution control – are amongst the most important findings we have acquired since the development of Noritake Super Porcelain AAA. This expertise has been utilized to create both the design concept and development of CERABIEN™ MiLai.

 

WHAT ARE THE MOST DECISIVE DIFFERENCES FROM OTHERS?

The most decisive difference between CERABIEN™ MiLai and others is that we focus on micro-layering technique with this product. CERABIEN™ MiLai enables you to express life-like colours even with thin layers of porcelain. Also, this is the first porcelain we have launched which is compatible with lithium disilicate as well as zirconia.

 


Photo: MDT Andreas Chatzimpatzakis

 

WITH CERABIEN™ ZR BEING AVAILABLE AND CLINICALLY SUCCESSFUL, WHY DID YOU DECIDE TO DEVELOP A NEW LINE OF PORCELAINS AND INTERNAL STAINS?

The best way that we propose to create aesthetic restorations is Porcelain Fused to Zirconia (PFZ) with CERABIEN™ ZR. However, this method requires high levels of expertise and experience which is a lengthy learning curve for beginner dental technicians. As a result, Full Contour Zirconia (FCZ), which does not require such advanced skills and expertise, and which allows virtually anyone to create (albeit not perfect but nevertheless acceptable) restorations, is becoming increasingly popular. CERABIEN™ MiLai sits in the middle of these two methods. It enables technicians to create more aesthetic restorations with a simple, single micro-layering technique, making it ideal for those who wish to produce aesthetic restorations but without the high learning-curve associated with the traditional method, or those who use lithium disilicate materials.

 

CERABIEN™ MiLai enables you to express life-like colours even with thin layers of porcelain.

 

IS CERABIEN™ MILAI THE ANSWER TO THE NEW GENERATION OF MILLABLE CERAMIC MATERIALS THAT HAVE IMPROVED A LOT IN TERMS OF MECHANICAL BUT ALSO OPTICAL PROPERTIES IN RECENT YEARS, SUCH AS THE ENTIRE KATANA™ ZIRCONIA LINE-UP, TO OFFER FOR THIS KIND OF MATERIALS A FASTER AND ALSO HIGHLY AESTHETIC FINISHING OPTION?

Yes, it is. Formerly, zirconia materials were mono-coloured and not translucent. However, the improvement of zirconia materials, which began with KATANA™ Zirconia ML followed by KATANA™ Zirconia STML/UTML and KATANA™ Zirconia YML, has been an ongoing process and the aesthetics of the material itself is now very high thanks to improvements in translucency. This has led to the development of CERABIEN™ MiLai, a simple process that can achieve highly aesthetic restorations with thin layers, making the most of the high translucency of the zirconia materials.

 

WHAT ARE THE SPECIFIC NEEDS OF USERS FAVORING THE MICRO-LAYERING TECHNIQUE WITH RESPECT TO FEATURES OF THE VENEERING PORCELAIN?

When dental zirconia materials were first launched, chipping issues with porcelains for dental zirconia materials were a problem. At that time, dental porcelains were built up on a zirconia framework, the design of which failed to take into account the final shape. As a result, dental technicians were prone to building excessive thickness into porcelain layers which were unable to resist high occlusal pressure. Nowadays, it is standard for the final shape to be taken into account in the framework design resulting in reduced chipping issues. I must mention here that CERABIEN™ ZR, which was launched at that time, showed a higher endurance ratio than others in trials and was well accepted by the market.

 

What we want to offer with CERABIEN™ MiLai is a similar or developed version concept of this framework design. You can reduce the risk of problems post-installation of the restoration by minimizing the porcelain thickness while maximizing the area of dental zirconia which has such strong properties that almost no chipping issue can be expected.

 

As a result, the micro-layering technique, which can prevent post-installation problems, should prove ground-breaking for dental technicians.

 


Photo: MDT Giuliano Moustakis

 

WHAT DID YOU DO TO MEET THESE DEMANDS?

The thinking behind the development of CERABIEN™ MiLai has been to focus on delivering thin layering that replicates the enamel structure, thus allowing technicians to achieve desired shades regardless of the depth of a layer.

 

HOW DID YOU MANAGE TO DECREASE THE FIRING TEMPERATURES AND WHAT IS THE EFFECT OF THIS FEATURE?

Up to now, it has generally been tricky to achieve low firing temperature while maintaining a low coefficient of thermal expansion, because they contradict each other. However, thanks to the technologies and knowledge we have cultivated since the development of Noritake Super Porcelain AAA, we could finally be breaking through this obstacle. As a result, CERABIEN™ MiLai can even be used with lithium disilicate materials, which should be baked at low temperature to avoid damaging the material.

 

DUE TO THE FACT THAT CERABIEN™ MILAI CAN BE APPLIED NOT ONLY TO ZIRCONIA BUT ALSO TO LITHIUM DISILICATE MATERIALS, E.MAX FOR EXAMPLE, HAVE NEW SHADES/MASSES BEEN SPECIALLY DEVELOPED THAT HAVE BEEN PERFECTLY ADAPTED FOR LITHIUM DISILICATE MATERIALS?

The Value Liner has primarily been developed to achieve high aesthetics from lithium disilicate materials, even lithium disilicate which has high translucency compared to zirconia materials. Also, the key for adapting for lithium disilicate is the firing temperature which I mentioned earlier. To match the colour of restoration with the tooth, the selection of framework colour is important both for lithium disilicate materials and zirconia materials. We recommend selecting one shade brighter than the target shade taking into consideration the utilization of internal stain to express the detailed character of a tooth.

 

CERABIEN™ MiLai can even be used with lithium disilicate materials, which should be baked at low temperature to avoid damaging the material.

 

WHAT DID YOU DO TO ENABLE THE IMITATION OF VIRTUALLY EVERY TOOTH SHADE WITH JUST 16 PORCELAINS AND 15 INTERNAL STAINS?

We have prepared Value Liner porcelains, which can be utilized for adjusting the value of restorations. These Value Liner porcelains and internal stains are important to adjust colour and express detailed characters. As micro-layering does not require body porcelains, since it is expected that the framework material itself – either zirconia or lithium disilicate – would express the dentine structure, adjusting the colour and value respectively with internal stains and Value Liners is essential. To reproduce the enamel structure, users can use the 16 shades of porcelains as they are, or they can mix the shades to find the desired colour. These 16 porcelains and 15 internal stains have been through trials conducted with KOLs across the world, including Europe, so we want to reassure you that even the world’s most skilled KOLs have tested and confirmed quality and effectiveness of CERABIEN™ MiLai.

 


Photo: MDT Giuliano Moustakis

 

WHAT IS THE BENEFIT OF THIS SLIM LINE-UP?

The biggest benefit of CERABIEN™ MiLai is a simple procedure. Thanks to its simplicity, not only Kuraray Noritake Dental porcelain users but also new users and beginners can achieve excellent results with this porcelain series without struggling with complicated procedures.

 

HOW LONG DID IT TAKE YOU TO DEVELOP CERABIEN™ MILAI (FROM THE INITIAL IDEA TO THE AVAILABLE PRODUCT)?

We initially came up with the concept in 2015 when KATANA™ Zirconia STML and UTML were launched. The development project itself was started in 2019.

 

We created CERABIEN™ MiLai believing that the micro-layering technique would become the standard in porcelain restorations and that CERABIEN™ MiLai would become the material of choice for dental technicians.

 

DID YOU COME ACROSS ANY SPECIFIC CHALLENGES DURING THE DEVELOPMENT PROCESS?

The biggest challenge we faced was the development of a material which would be compatible with lithium disilicate. We had already produced porcelains which are compatible with zirconia or metal, but up to that point we had not created porcelains for lithium disilicate before CERABIEN™ MiLai. Not only did we have to develop the material within our R&D department, but also alter the production and inspection processes in collaboration with many other departments.

 

THE PRODUCT NAME CERABIEN™ MILAI IS DERIVED FROM THE WORD "MIRAI", WHICH MEANS AS MUCH AS "FUTURE" IN JAPANESE. HOW MUCH FUTURE IS THERE IN THIS MATERIAL OR, TO BE MORE PRECISE, IS THIS MATERIAL A PIONEER FOR THE FUTURE PRODUCTION OF HIGHLY AESTHETIC RESTORATIONS?

We created CERABIEN™ MiLai believing that the micro-layering technique would become the standard in porcelain restorations and that CERABIEN™ MiLai would become the material of choice for dental technicians.

 

Building up dental porcelains is not an easy process; it takes time to acquire the knowledge and master the technique. On top of this, dental technicians have long been plagued with post-installation problems such as chipping.

 

Micro-layering with CERABIEN™ MiLai enables every dental technician, from newcomers through to those with many years’ experience, to create better restorations. It is our hope that dental technicians everywhere will get to experience the ease at which aesthetic restorations can be realised with CERABIEN™ MiLai, just adding one step of micro-layering.

 

 

WHAT IS YOUR VISION WITH REGARD TO FUTURE DEVELOPMENTS IN THE AREA OF PORCELAIN FOR CERAMIC LAYERING?

Personally, I think the trend will continue to shift towards easier handling while maintaining good aesthetics, as can be seen by the recent increase in popularity of the micro-layering technique.

 

WHAT ABOUT THE POTENTIAL OF NEW CERAMIC CAD/CAM MATERIALS AND THEIR SUITABILITY FOR MONOLITHIC USE?

We believe that monolithic use will increase further, because the perception of aesthetics is changing among patients as well as dentists and dental technicians. Before, a "natural" restoration was considered acceptable; now it can also be "cosmetically" aesthetic. Formerly, it was said that monolithic use was not suitable as it could not reproduce life-like restorations. Now, we believe it will be increasingly embraced as patients show a demand for cosmetically aesthetic restorations.

 

Our KATANA™ Zirconia has mechanical advantages: high strength and high translucency, and high potential in longevity. Since dental zirconia appeared in dental material market, its aesthetics have been improved remarkably. And we, at Kuraray Noritake Dental Inc., have been developing outstanding CAD/CAM materials and will continue creating innovative materials from now on too.

 

We are convinced that developing better products for monolithic use is crucial for releasing dentists and dental technicians from complicated procedures while at the same time giving patients a sense of safety as well as aesthetic satisfaction.

 

WHY SHOULD A DENTAL TECHNICIAN TEST CERABIEN™ MILAI?

We are convinced that, once dental technicians who use either zirconia materials or lithium disilicate to make restorations, experience the ease at which they can achieve aesthetically-pleasing restorations with CERABIEN™ MiLai, demand will grow. We would therefore like to encourage all dental technicians to give it a go and see the results for themselves!

 

IS THERE ANYTHING ELSE YOU WOULD LIKE TO ADD FOR CUSTOMERS?

Thank you so much for reading this article to the end. I am very honoured to finally launch CERABIEN™ MiLai. This product is the result of many struggles. I am firmly convinced that it is the answer for any dental technician eager to realise high levels of aesthetics in a restoration in just a simple step. I would ask them to please try out CERABIEN™ MiLai for themselves and experience what will become standard practice in the future, right now.

 

TOMOHIRO EMOTO


R&D Department Technical Group Manager
Japan Academy of Esthetic Dentistry Executive Member
Academic Lecture Committee Member

 

CERABIEN™ MiLai: Stunning new line-up of low-fusing porcelains and internal stains for micro-layering

With highly aesthetic ceramic materials available for the production of indirect restorations, it is no longer necessary to always design high strength frameworks and add multiple layers of porcelain. Nowadays, due to the rapid technological and optical improvements of zirconia and Lithium Disilicate (LiDiSi), a restoration may be manufactured with a monolithic design or minimal cut-back. Using appropriate materials, a less complex micro-layering technique will produce the desired outcomes, even if the aesthetic expectations are high. A new porcelain system specifically designed for this purpose is CERABIEN™ MiLai from Kuraray Noritake Dental Inc. The compact line-up of low-fusing porcelains and internal stains for micro-layering supports effiicient, economic finishing procedures leading to outstanding aesthetics at the first go.

 

 

The CERABIEN™ MiLai system consists of 16 base shades and 15 internal stains, which are easy to select and manage, and may even be mixed for additional shade effects. Due to the low firing temperature of all system components (740° C / 1,364° F), CERABIEN™ MiLai is not only compatible with zirconia, but also with silicate ceramic (such as IPS e.max) substructures. This means that fewer lines of porcelain are needed, the porcelain inventory is reduced once again, and fewer decisions need to be taken.

 

 

In order to provide for persistent handling properties and predictable outcomes, CERABIEN™ MiLai, like all other porcelains from Kuraray Noritake Dental Inc., are based on synthetic feldspathic porcelain technology. It is special in that its material structure and particle distribution resemble those of natural teeth, and its properties remain stable even after multiple firing cycles – giving dental technicians exactly what they expect. CERABIEN™ MiLai (tooth shades) are fluorescent, which adds to the vitality and life-like appearance of the restorations.

 

 

With these properties, CERABIEN™ MiLai is the outstandinig solution for every dental technician who would like to turn the finishing of zirconia and lithium disilicate restorations into a straightforward, efficient and economic procedure that produces predictably beautiful outcomes every time.

 

 

Dentist and dental technician: Communication in prosthodontic workflows

No matter whether you are a dental practitioner or dental technician, there is one thing you surely want to avoid: failure of indirect restorations. While it is clear that on both sides, the use of high-performance materials and appropriate techniques will contribute to achieving the desired outcomes, there is one aspect that should generally be given more attention: proper communication and exchange of information between the dental practice and laboratory.

 

As a dental professional: Are you aware of the information and details your case partners need to know in order to achieve the best possible result regarding fit, function and aesthetics?

For both, dental practitioner and dental technician, it is essential to know what precisely the respective partner does need to produce the desired outcomes. Hence, if it is not clear what information is needed and how it should be delivered, it is essential to sit down with your partner and find out. The goal of this personal or virtual meeting should be the establishing of a standardized flow of information between your companies. The necessary information might differ depending on the complexity of the case, but most details are always the same.

 

During the meeting, it is essential to focus on every step in the procedure that benefits from interaction between the practice and laboratory. It starts after the patient’s initial appointment and ends when the restoration is in place. In the following sections, the required information for indirect restoration planning, possible ways of communication to provide for a healthy flow of required information and important details are listed.

 

Teamwork starts before the actual treatment

Most dental technicians know a lot about the different restorative materials available and their suitability for specific clinical situations. Leverage this knowledge by involving your partner early – ideally before tooth preparation. This is most important for complex reconstructions, but also relevant when a single tooth needs to be restored: The restorative material and restoration design (monolithic, cutback, framework) have an impact on the space required and hence on the amount of tooth structure that needs to be removed. Aiming to opt for the least invasive treatment possible, it is essential that tooth preparation is limited to the necessary minimum.

 

INFORMATION IMPORTANT FOR MATERIAL SELECTION AND TREATMENT PLANNING INCLUDES:

  • Clinical findings
  • Position of required restoration in the mouth
  • First restoration / restoration replacement
  • Natural tooth or implant as an abutment
  • Level of decay / destruction
  • Level of discolouration / colour of abutment
  • Material sensitivity – allergy history of patient

 

The better the records, the better the fit of the final restoration

When it comes to taking records of the initial situation and the situation after tooth preparation, dental practitioners are often confronted with challenges. Limited mouth opening, a lack of time, or difficult moisture conditions are only some of the numerous factors that might prevent a clinician from taking a precise impression and bite registration. Nevertheless, it is decisive for the work in the dental laboratory to receive accurate records with all the necessary details such as the preparation margin. Understanding what exactly a dental technician needs to deliver a precisely fitting restoration will surely have a positive impact on the motivation to get the records right from the start, independent of the challenges.

 

INFORMATION IMPORTANT FOR THE PRODUCTION OF THE RESTORATION INCLUDES:

  • Impression
  • Bite records
  • Facebow records / functional analysis (complex rehabilitations)
  • Intraoral images
  • Extraoral images (aesthetic zone)
  • Tooth shade information

 

Personally seeing the patient provides valuable additional information on a patient’s facial characteristics, on the status and appearance of the teeth and on their internal colour structure. These details can support a dental technician optimally in producing true-to-life dental restorations.

 

Structured try-in feedback facilitates targeted adjustments

Whenever try-in reveals that adjustments are required, well-structured feedback is important. It helps modify the restorations exactly as desired, hence avoiding additional appointments and wasting time in the practice and laboratory.

 

INFORMATION IMPORTANT FOR TARGETED ADJUSTMENTS AFTER TRY-IN INCLUDES:

  • Shade
  • Shape, contour and morphology
  • Proportions
  • Pink and white aesthetics
  • Facial appearance, lips and teeth
  • Phonation and mastication

 

“Digitalization has made physical distance irrelevant, and we are able to deliver high-quality restorations even if the patient is hundreds of miles away”
- Dr Efe Celebi -

 

Placement recommendations are a basis for long-term success

Type of restorative material, flexural strength and restoration geometry: Many factors have an impact on how to pre-treat and cement an indirect restoration. While (self-)adhesive luting is usually the preferred placement method for highly-aesthetic restorations, the ones produced from high-translucency zirconia need to be treated differently from those made of lithium disilicate. Knowing the details about the selected restorative material, the dental technician should inform the practitioner about the measures to be taken in the dental office.

 

INFORMATION IMPORTANT FOR THE CEMENTATION OF THE RESTORATION INCLUDES:

  • Type of restorative material in use
  • Restoration already pre-treated in dental laboratory
  • Recommended pre-treatment in the office (sandblasting / HF etching + time)
  • Recommended cementation procedure / cementation system
  • Required cleaning measures after try-in

 

How to standardize

There are many possible ways to standardize the flow of information between the dental practice and laboratory. Depending on the individual preferences and established workflows, a personal or digital approach may be selected. Those preferring a personal approach will possibly want to develop paper forms for some steps, while relying on personal interaction for others. The digital approach uses a combination of digital imaging technologies, case management software and communication platforms to exchange relevant information.

 

A personal approach

At the Laboratorio odontotecnico Castellano in Bologna, Italy, the team around Vincenzo Castellano pursues the approach of personally seeing almost every patient prior to treatment planning. The laboratory technicians’ opinion is determinant for the treatment plan to be developed. Their partner practitioners value their expertise in restorative materials and digital technologies, which are evolving very quickly. The team is simply able to tell which material to choose in a specific situation to best manage the expectations of the patient and the functional needs. “Determining the restorative material in this early phase is very important, as its mechanical parameters (minimum wall thickness etc.) have an impact on the preparation design and depth. In fact, patients are always happy if they are able to meet the dental technician who produces their restorations, and – already well-informed by their dentist and the internet – often seize the opportunity to gather additional information about their planned treatment”, Vincenzo Castellano states.

 

Also, during subsequent appointments like try-in, the responsible dental technician is present to evaluate the situation and gather feedback from the patient directly. In his laboratory, online meetings conducted with patients substitute personal meetings only when this is the only way to enable personal interaction, as – in his opinion – personal meetings always deliver more details important for a great outcome. He says: “The most important approach to the patient is the human one. When using advanced digital technologies, we risk standardizing protocols to the extent that we forget there is an individual in front of us, with their own unique characteristics and wishes, entrusting us with their most precious asset: their smile.”

 

A digital approach

A perfect example of a laboratory with a purely digital approach is DentLab, a Turkish dental laboratory founded in 2015 by Dentgroup, Turkey’s largest Dental Service Organization (DSO). Its founder Dr Efe Celebi and his team have developed a special lab module for the group’s own practice management software, DentSoft. The module allows dental professionals to submit their orders electronically by using online forms and adding digital image data such as X-rays, intraoral scans, face scans and photographs. Users are able to see at a glance which data and information is strictly required. If desired, a user even receives procedural guidance: Specific devices like intraoral scanners, procedures and materials are recommended.

 

Once an order is submitted, the software sends a delivery date notification, so that the next appointment can be scheduled right away. Then, the incoming order is checked. Whenever some details are missing, the practice is contacted via a chat function in the software. Orders with incomplete or inaccurate data are rejected. A feedback function allows the technician to specify what needs to be repeated, improved or modified. Once accepted, the ordered items are produced and shipped to the office in a trackable box. It arrives with pre-treatment and cementation recommendations. Whenever necessary, patient feedback at try-in can be recorded on video or discussed live in a virtual meeting. “Digitalization has made physical distance irrelevant, and we are able to deliver high-quality restorations even if the patient is hundreds of miles away,” says Dr Efe Celebi. To facilitate improvement in the dental laboratory, the software has a case evaluation function that allows dental practitioners to evaluate the fit, function and look of every restoration.

 

“The most important approach to the patient is the human one. When using advanced digital technologies, we risk standardizing protocols to the extent that we forget there is an individual in front of us, with their own unique characteristics and wishes, entrusting us with their most precious asset: their smile.”
- MDT Vincenzo Castellano -

 

Conclusion

By establishing a well-structured, standardized and bidirectional flow of information between the dental office and laboratory, it is possible to improve the overall quality of prosthodontic treatments. It can be implemented with the aid of existing workflow management software, or set up according to individual demands using paper forms and personal meetings.

 

Anyway, sitting down together to discuss the topic of communication in a personal or virtual meeting has additional advantages, as it will help everyone involved develop a better understanding of the procedures carried out and challenges faced by their respective partner in the busy work environment. With this knowledge, it becomes easier to build a strong relationship that grows from mutual feedback and advice promoting common strategies for improvement. The result will be more streamlined work processes with less stress, higher-quality outcomes and happier patients.

 

We would like to express our gratitude to MDT Vincenzo Castellano and Dr Efe Celebi for sharing their individual approaches and the thinking behind them.

 

MDT Vincenzo Castellano Dr Efe Celebi

 

IDS 2025 – an event worth visiting!

This year, the Kuraray Noritake Dental stand will be packed with news from the world of dentistry, so we offer not just one reason to visit, but a whole range: new chairside products, new labside products, inspiring lectures, enlightening hands-on demonstrations… And the best thing? You don´t have to choose just one thing, come and see them all at the Kuraray Noritake Dental booth in Hall 11.3 | Stand E010!

 

Chairside – smart streamlined solutions

When it comes to a dental practice, our vision is clear: a world where your materials and tools work seamlessly in your hands, where complexity is minimized, and where you are given enough time to focus on what matters most: the individual desires and needs of every single patient. This is the future of dentistry - and we are leading the way. Come discover our new additions to the UNIVERSAL EXCELLENCE family: a flowable universal composite and a new generation of a universal bond!

 

Labside – speed and aesthetics hand in hand

No matter whether a minimally invasive procedure or the best aesthetic outcomes are desired: Kuraray Noritake Dental has the products for you. New in the portfolio: CERABIEN™ MiLai - low-fusing porcelains and internal stains. Come and see for yourself its ultra-thin layering, exceptional mechanical properties and consistent handling for both zirconia and lithium disilicate. And while you're there, have a coffee while speed-sintering with our KATANA™ Zirconia discs takes place in real time.

 

Get inspired by 12 expert speakers on 2 stages

Are you a user of or interested in one of Kuraray Noritake Dental’s products or solutions, but eager to learn more about their practical use from proven experts in your field? From Wednesday until Saturday, we offer a programme of exciting lectures and live demonstrations - this time simultaneously on two stages: one dedicated to chairside and the other one to labside topics!

 

Warm welcome

Everyone, from sales person to scientific marketeer, looks forward to giving you a warm welcome, answering your questions and introducing you to the world of innovative Kuraray Noritake Dental products, solutions and workflows. And while you are already in Cologne anyway, why not enjoy the breathtaking beauty of the old town? Have you ever seen its famous Gothic Cathedral? Or its Old Town inviting you to stroll through its narrow alleys, finding traces of history around every corner? This year's IDS offers so many reasons to attend that it's hard not to accept the invitation.

 

Additional information and the full programme of lectures and hands-on courses at the IDS is available online.

 

Mastering Ceramics: A Comprehensive Guide for Dental Ceramists

Discover a detailed walkthrough of an advanced shade reproduction technique with this comprehensive guide by DT Tomáš Forejtek. Tailored for professionals working with CERABIEN™ ZR ceramics (Kuraray Noritake Dental Inc.) and the eLAB protocol, this case study provides step-by-step insights into achieving exceptional results, from documentation to shade selection and framework design to final polish. Whether you are refining your craft or exploring new methods, this resource is a valuable addition to your toolkit.

 

 

Case report by Vasilis Vasiliou

THE ART OF RESTORING SMILES: MASTERING THE CHALLENGE OF A SINGLE CENTRAL INCISOR

Restoring a single maxillary central incisor is possibly the biggest challenge a dental technician can face in everyday work. Especially when a patient is young, it is extremely important to restore her or his smile to its original beauty. Any restoration that is perceivable as such might have a negative impact on their self-confidence and quality of life even in the long term.

 

A STORY OF JOY AND DESPERATION

Take Ioanna, a 14-year-old girl who presented in her dental office in a state of desperation. In the hours before, she had been floating on cloud nine: Her favourite band performed in Cyprus for the first time and she had managed to buy tickets for herself and her best friend. Thrilled, they had arrived at the concert, the band started playing and the crowd danced to the music. It felt like this was going to be the best day of her life. At the time the band played its most popular song, people were delirious, jumping up and down in ecstasy. Between all the exuberant dancing and laughing, however, Ioanna suddenly was hit by a strong push. She fell, her face hitting something hard – a seat in front of her. Pain froze time and it took a few seconds before she understood what had happened: Tasting blood in her mouth, she explored her teeth with her tongue and realized that one of her central incisors had fractured.

 

AFFECTING THE QUALITY OF LIFE

This is one of the many touching stories we listen to every day. A fall during a concert, a push at somebody’s birthday party, a car accident: There are many incidences that can ruin a young, beautiful smile. By paying attention to the involved patients and their stories, one will come to realize how strongly some of them are affected by all this. They cover their mouths when they laugh or hold back their smiles.

 

Any dental technician who is committed to restoring their lost smile in the best possible way is probably aware of the impact his or her work can have and the responsibility coming with it: A Beautiful result will restore not only their smile, but also their self-confidence, will let them start laughing happily, expressing themselves comfortably and simply enjoying social interaction again (Figs. 1 to 5). Compromised outcomes, on the other hand, might have the opposite effect. Being aware of this role should be every technician’s motivation to become better day by day. Evolve for these moments, when our work brings tears of joy to our patients.

 

Fig. 1. Layering sketch for the restoration of a fractured central incisor in three layers: Layer one.

 

Fig. 2. Layering sketch for the restoration of a fractured central incisor in three layers: Layer two.

 

Fig. 3. Layering sketch for the restoration of a fractured central incisor in three layers: Layer three. After the first bake, small details were integrated, followed by a second bake. Finally, the restoration was finished with CERABIEN™ ZR FC Paste Stain and Glaze.

 

Fig. 4. Treatment outcome able to restore not only the smile, but also the self-confidence of the young girl.

 

Fig. 5. Immediately after cementation of the restoration, the restoration is barely identifiable, only the soft tissue needs some time for recovery.

 

ASPECTS TO BE CONSIDERED

But how to proceed in restoring single central incisors in the best possible way? The success of this type of restoration is hidden in the shape, which is the most difficult part. Managing to create a natural morphology is more than half the battle. The other important part is colour. The key to reproducing colour is in understanding how the utilized porcelains work. It is all about light reflection, absorption, translucency and opalescence, value and characteristic details. The more you gain experience and understand the optical properties of teeth and ceramics, the better your outcomes will be. Support is offered by a camera, a macro lens and a twin flash, which are used to capture and analyse the intraoral situation. For an initial analysis and understanding of shape and colour, I like to see the patients in my dental laboratory. Feeling the colour helps to develop the most realistic picture of what needs to be created. The key to successful realisation of the plan just developed is the use of reliable, easy-to-handle materials – in my case KATANA™ Zirconia and CERABIEN™ ZR Porcelains (both Kuraray Noritake Dental Inc.).

 

POSSIBLE STEPS

The first thing to focus on when starting to produce an anterior restoration – like in the case presented in figures 6 to 14 – is the correct value of the tooth. As soon as the framework or base is produced in the right value, you need to place what you see. Does the adjacent tooth show mamelons, traces of blue and orange? Those characteristics simply need to be observed and copied. There is no need to create something fancy. The tricky part is to use the available space reasonably. When there is plenty of space for the porcelain, it may be challenging to keep the value of the framework and avoid a greyish appearance. Depending on the die colour, age of the patient, natural surface texture and space available, an appropriate layering approach and finishing technique may be selected.

 

Fig. 6. Replacement of an anterior crown: Prepared tooth with severe discolouration. The adjacent central incisor has a special shape and vivid inner colour structure.

 

Fig. 7. Framework made of KATANA™ Zirconia ML in the shade A3. The target shade being A3.5, a quite opaque material was selected in a slightly brighter shade to achieve the required masking effect.

 

Fig. 8. Single-bake layering procedure: Application of CERABIEN™ ZR Opacious Body, …

 

Fig. 9. … Cervical Body, …

 

Fig. 10. … Body and Transitional Body.

 

Fig. 11. Incisal cut-back …

 

Fig. 12. … and creation of the mamelon structure.

 

Fig. 13. Application of Aqua Blue 1 …

 

Fig. 14. … followed by T Blue …

 

Fig. 15. … and Luster Porcelains.

 

Fig. 16. Halo effect created with Body.

 

Fig. 17. Treatment outcome. (After a first bake followed by minor adjustments, a second bake, surface texturing and glazing with CERABIEN™ ZR FC Paste Stain Clear Glaze.)

 

CONCLUSION

Creating a single central takes us out of our comfort zone. By paying attention, observing the adjacent teeth carefully and using materials we really understand, it is possible to meet or exceed our patients’ expectations. While specific tools like cameras and experience with the utilized materials offer support in producing predictable outcomes, my main credo is “If you want things around you to change, you must first change yourself”. For continued improvement, it is thus necessary to focus on professional growth and advancement. With the right mentors who will teach us the secrets of stratification and inspire and motivate us to continue advancing, it becomes easier to restore the smiles and self-confidence of our patients every time they need us to.

 

Acknowledgements

Special thanks go to the dental practitioners who treated the patients presented above – Andreas Skyllouriotis DDS, MSD, Surgically-Trained Prosthodontist, and Theo Odysseos, DDS, Diplomate, American Board of Oral Implantology / Implant Dentistry.

 

Dental Technician:

VASILIS VASILIOU

 

Vasilis Vasiliou was born in Nicosia, Cyprus, and graduated from the Technical School for Dental Technicians in Athens in 2004. He has furthered his education by attending several advanced seminars led by mentors and experts in the field, such as Ilias Psarris and Nondas Vlachopoulos.

 

Throughout his career, Vasilis has made significant contributions to the dental community, including presenting at various conferences in Greece and publishing articles in Greek dental magazines. Since 2020, he has been a key opinion leader for MPF Brush Company and, since 2022, a HASS Ambassador. Vasilis has been an active member of the International Team for Implantology (ITI) since 2019.

 

Together with his father, Vasilis runs a successful dental laboratory in Nicosia, specializing in all-ceramic and implant restorations. His extensive experience and commitment to excellence have established him as a respected professional in his field.

 

Kuraray Noritake Dental at the IDS 2025

INTRODUCING BRAND NEW PRODUCTS FOR SUCCESS WITH STREAMLINED, SMART SOLUTIONS

Kuraray Noritake Dental is pleased to announce that at IDS 2025 it will present a number of innovations that fundamentally improve dental procedures without compromising the quality of the result. Additionally, a number of internationally recognized experts will present their lectures and hands-on demonstrations on two separate stages: one dedicated to chair-side and the other one to lab-side topics. All of this represents not one, but a whole host of reasons to visit the stand (repeatedly).

 

CHAIR-SIDE NOVELTIES: UNIVERSAL EXCELLENCE

Development of the new products is rooted in a deep understanding of the demands of modern dental practice. Balancing complex procedures, tight schedules and patient needs is no easy task. That is why Kuraray Noritake´s team has been on a relentless journey to streamline, enhance and refine every step of work for decades. The vision is clear: a world where materials and tools work seamlessly in the dentist´s hands, where complexity is minimized, and where professionals are given enough time to focus on what matters most: the individual desires and needs of every single patient. Discover new additions to the UNIVERSAL EXCELLENCE family: a flowable universal composite and a new iteration of a universal bond.

 

CLEARFIL MAJESTY™ ES Flow Universal represents a fundamental shift in the idea of what universal composites can achieve. By integrating high filler loading and achieving high flexural strength, CLEARFIL MAJESTY™ ES Flow Universal challenges the traditional view of flowable composites as merely temporary fixes. Instead, it positions itself as a permanent solution capable of delivering both aesthetic excellence and structural reliability. Its unique light diffusion technology allows working with just two shades, and, in addition to that, offers a choice of two flowability options for easy handling.

 

CLEARFIL™ Universal Bond Quick 2 is the latest evolution in dental bonding technology, offering a streamlined, efficient solution for dental practitioners. Following the success of its predecessor CLEARFIL™ Universal Bond Quick, the new version “2” offers a redefined monomer technology that delivers exceptional bonding performance with minimal effort. Kuraray Noritake´s proprietary Advanced Rapid Bond Technology combines three key monomers – the original MDP, Amide and Urethane Tetra Methacrylate. Designed to enhance workflows, this adhesive provides robust performance across a wide variety of clinical situations.

 

LAB-SIDE NOVELTIES

Patient-centered prosthodontic approaches are enabled by innovative restorative materials and their correct processing in the dental laboratory. No matter whether a minimally invasive procedure or the best aesthetic outcomes are desired: Kuraray Noritake Dental has the solutions. In 2025, a new “smart” finishing material is being launched, delivering both on efficiency and aesthetics.

 

CERABIEN™ MiLai is a set of porcelains and internal stains specifically designed for the micro-layering technique. The name “MiLai” is derived from the term “micro-layering” and the Japanese word “mirai” (which means future). The innovative product based on synthetic feldspar enables dental technicians to add the final touch to their restorations in a simple and time-saving procedure – for outstanding aesthetics right from the start. The low firing temperature of CERABIEN™ MiLai (740°C) makes it the go-to solution for the finishing of both oxide ceramic (e.g. zirconia) and silicate ceramic (e.g. lithium disilicate) restorations. With fewer lines of porcelain needed, the porcelain inventory is reduced further and fewer decisions need to be taken.

 

Additional information and the full programme of lectures and hands-on courses at the IDS is available online.

 

Kuraray Noritake leads dental innovation

Satoshi Yamaguchi, President, Kuraray Noritake Dental Inc.

 

KURARAY NORITAKE DENTAL INC. EXCELS IN DENTAL TECHNOLOGY, FOCUSING ON STRENGTH, AESTHETICS AND GLOBAL ADAPTABILITY

Kuraray Noritake Dental Inc., a leader in dental materials and technology, blends innovation with a deep commitment to oral health. Established from the merger of Kuraray Medical Inc. and Noritake Dental Supply Co., Limited, the company excels in providing dental bonding agents, fillings, cements, porcelains, zirconia and CAD/CAM blocks. This synergy has allowed the company to push the boundaries of dental science.

 

“We aim to enhance global oral health and wellness.”

 

President Satoshi Yamaguchi highlights the company's approach: "We focus on strength, aesthetics and speed in our products. By developing our own zirconia powder and partnering with CAD/CAM system manufacturers, we achieve high-quality, durable and efficient dental solutions." This commitment is evident in the firm's flagship product, KATANA™ Zirconia Block, renowned for its durability and aesthetic appeal.

 

 

Kuraray Noritake Dental is also striving to develop new products for more longterm predictable dental treatment with bioactive properties. The company is not just focused on developed markets like the U.S. and Europe. Mr. Yamaguchi explains: "Understanding local treatment situations is key. In addition to the U.S. and Europe, having sales offices in places like Brazil and China helps us tailor our products to regional demands." This global presence ensures the company remains at the forefront of dental technology, adapting to diverse market needs.

 

Tooth crown made from KATANA™ Zirconia

 

Looking ahead, Mr. Yamaguchi envisions Kuraray Noritake Dental as more than just a technological innovator. "In five years, I hope we are seen not only as a tech company but as a holistic provider of oral care solutions," he says. With a commitment to reducing "invisible stress" for dental professionals and patients, the company aims to enhance global oral health and wellness.Original article published in Newsweek Magazine on September 20th, 2024 Written by The Worldfolio

 

Individualisation of monolithic zirconia restorations

Article by Dr. Florian Zwiener

 

Modern multi-layered zirconia such as KATANA™ Zirconia STML (Kuraray Noritake Dental Inc.) already meets high aesthetic demands due to its natural colour gradient and high translucency. To achieve further characterisation and optical adjustment to the adjacent teeth, there are essentially two options: veneering with feldspathic ceramic or glazing and individualisation with ceramic stains.

 

While there are still many indications for veneering, especially in the anterior area, more and more cases can now be solved with monolithic restorations. This allows for a time-efficient chairside workflow with same-day treatment, eliminating the need for temporary restorations. Additionally, the absence of a porcelain layer reduces the wall thickness of the restoration and thus the space required, allowing for less invasive preparation. This also reduces the risk of endodontic complications induced by tooth preparation (grinding trauma). Another advantage is a significant reduction in the chipping risk.

 

Below are the essential steps for individualisation using ceramic stains, demonstrated through the example of a molar crown.

 

PREPARATION

The restoration is designed in full contour as usual, ideally dry-milled, and then sintered. After sintering, the restoration is first sandblasted (aluminium oxide 50 μm, 1 to 1.5 bar pressure). This microscopic roughening of the ceramic surface enables an optimal bond with the glaze. Subsequently, the restoration should be cleaned using a steam cleaner or an ultrasonic cleaner to remove all blasting residue.

 

The functional restoration surfaces must then be polished to avoid the risk of excessive abrasion on the enamel of the opposing dentition, as zirconia is harder than enamel. Following this, optional glazing and characterization with ceramic stains can be performed. However, for areas not in the aesthetic zone, such as the palatal surfaces of maxillary anterior teeth, this is not necessarily required.

 

PREPARATION: STEPS AT A GLANCE

  1. Sandblasting of the sintered restoration (Al2O3 50 μm, 1-1.5 bar)
  2. Cleaning (steam cleaner or ultrasonic cleaner)
  3. Polishing the occlusal/palatal contact areas

 

Fig. 1. Sintered and sandblasted zirconia crown.

 

Fig. 2. Occlusal high-gloss polish.

 

Fig. 3. TWIST™ DIA for Zirconia (Kuraray Noritake Dental Inc.) enables efficient polishing of zirconia in three steps.

 

STAINING AND GLAZING

The shades A+, B+, C+, and D+ of the paste-like ceramic stain CERABIEN™ ZR FC Paste Stain (Kuraray Noritake Dental Inc.) enhance the chroma in the cervical area when applied in the respective tooth shade. They are used to strengthen the multicolour effect of the zirconia or to darken the restoration overall. By mixing the stains with glaze or clear glaze in different ratios, the intensity can be adjusted.

 

Cervical 1 and 2 are suitable for replicating exposed cervical areas or discolouration. Cervical 1 is also useful for marking fissures, as it gives the crown depth and structure without appearing overly dark. Patients typically reject excessively pronounced fissure effects. Since fissure areas in multi-layered materials generally lie in the lightest part of the block (in the enamel layer), it may make sense to darken them slightly with A+, while white hypermineralisations can be replicated on the cusp tips. A narrow band of Grayish Blue below the cusp tips creates an optical translucency effect. In cases where this translucency appears too dark blue or greyish, mixing Grayish Blue with Dark Grey can modify the appearance.

 

By mixing various colours, numerous different tones can be created. For instance, by adding Yellow to A+, its slightly brownish colour can be adjusted to a warmer, more yellowish tooth shade. It is generally advisable to capture the patient‘s tooth shade with a photo and a custom-made colour ring of the corresponding material before preparation. This can serve as a reference during production, especially in the laboratory, where lighting conditions may differ.

 

For pronounced characterisations or fine details, it may be necessary to carry out multiple firings to avoid unwanted running effects between the colours and the glaze. This is particularly recommended when replicating anatomical details with high sharpness, such as enamel cracks or local discolourations. For this, a glaze and base shade are first applied and fired, and finer structures are added in a second firing. Alternatively, a fixative firing of the stains without glaze can be performed first, with only a glaze layer fired in the second step. A benefit of CERABIEN™ ZR FC Paste Stain is that its appearance during application closely matches the final firing result. In thick consistency, glaze can also be used to easily rebuild missing proximal contacts.

 

STAINING AND GLAZING: STEPS AT A GLANCE

  1. Glaze with Glaze/Clear Glaze
  2. Increase chroma (in the cervical area or over large areas) with A+, B+, C+, or D+
    - Adjust intensity by mixing with Glaze/Clear Glaze
    - Create a warmer tone by mixing with Yellow
  3. Replicate discolouration/exposed cervical areas: Cervical 1 and 2
  4. Customise fissure areas
    - Darken with A+, B+, C+, or D+
    - Accentuate fissures with Cervical 1
  5. Customise cusp tips
    - Replicate hypermineralisations with White
    - Create a band below with Grayish Blue (translucency effect)
    - Adjust translucency effect below cusp tips by mixing with Dark Grey
  6. Firing

 

Alternatives:

  1. First firing: Glaze plus base shade, second firing: Finer structures
  2. First firing: Fixative stain firing without glaze, second firing: Glaze firing

 

Fig. 4. CERABIEN™ ZR FC Paste Stain assortment for the practice laboratory.

 

Fig. 5. Discoloured fissures can be accurately replicated with an ISO10 endodontic file.

 

 

Fig. 6 and 7. Glazing and staining in one firing.

 

Fig. 8. Shade determination using a custom-made KATANA™ Zirconia STML colour ring (A3.5).

 

Fig. 9. Bridge made from KATANA™ Zirconia STML, sandblasted and occlusally polished.

 

Fig. 10. Finished glazed and characterised restoration.

 

Fig. 11. Bridge 14-16 in place.

 

FINAL SITUATION

Fig. 11. Bridge 14-16 in place.

 

Dentist:

FLORIAN ZWIENER

 

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