TIPS AND TRICKS

Case by MDT Daniele Rondoni and MDT Roberto Rossi

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

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

WE UTILIZE ESTHETIC COLORANT MAINLY FOR THREE PURPOSES:

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

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

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

PURPOSE 1

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

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

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

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

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

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

FINAL SITUATION

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

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

Fig. 1h. Great incisal translucency.

PURPOSE 2

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

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

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

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

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

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

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

PURPOSE 3

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

HOW TO APPLY ESTHETIC COLORANT?

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

SINTERING PARAMETERS

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

CONCLUSION

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

Dentists:

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

Adhesive cementation then and now

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

Optimizing the long-term bonding performance

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

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

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

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

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

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

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

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

Simplifying glass-ceramic cementation

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

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

Conclusion

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

References

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

Case by Michal Jaczewski

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

INITIAL SITUATION

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

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

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

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

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

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

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

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

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

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

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

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

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

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

*Not a brand name of Kuraray Noritake Dental.

Fig. 15. High-shine results after polishing.

FINAL SITUATION

Fig. 16. Final restoration, immediately after treatment.

Fig. 17. Final restoration after 2 days.

Dentist:

MICHAL JACZEWSKI

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

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

Case by Leonidas Dimitriou, MDT

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

CASE EXAMPLE 1

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

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

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

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

Fig. 4. Restorations after porcelain layering.

FINAL SITUATION

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

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

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

CASE EXAMPLE 2

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

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

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

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

Fig. 11. Restorations after internal staining.

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

FINAL SITUATION

Fig. 13. Final outcome after glazing.

Dentist:

LEONIDAS DIMITRIOU, MDT

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

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

Photo credits to MDT Giuliano Moustakis.

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

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

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

Photo credits to MDT Daniele Rondoni.

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

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

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

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

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

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

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

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

Photo credits to MDT Roberto Rossi.

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

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

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

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

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

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

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

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

KATANA™ Zirconia YML, finished with CERABIEN™ ZR.

Photo credits to MDT Giuliano Moustakis.

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

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

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

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

Dentist:

YOSHIHISA YAMADA

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

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

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

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

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

Case by CDT Daniele Rondoni and MDT Roberto Rossi

Working with high-translucency, multi layered zirconia (KATANA™ Zirconia Multi-Layered series from Kuraray Noritake Dental Inc.) paves the way toward indirect restorations that are closely adapted to our patients’ needs. Reduced wall thicknesses allow for minimally invasive tooth preparations, while polished zirconia in the occlusal contact areas provides for an antagonist-friendly behaviour. All this is possible due to the high aesthetic potential and homogeneous structure of the materials, which work well with a full-contour design or slight vestibular cutback. For individualization or characterization, different options are available. The portfolio of finishing solutions from Kuraray Noritake Dental has just been complemented by Esthetic Colorant for KATANA™ Zirconia, a set of twelve dyeing liquids for the company’s multilayered zirconia. They are applied to the milled restoration surface prior to sintering.

Some readers may wonder why there is a need for effect liquids applied to pre-shaded zirconia with a multi-layered colour structure. Being aware of natural teeth’s unique play of colours stemming from the shape and shade of the dentin core, however, the reason is quite obvious: Esthetic Colorant diffuses into the zirconia structure, hence allowing us to create depth effects even in monolithic restorations. Moreover, it enables the user to pre-treat tissue areas, and even by using the liquids on cutback designs, we are able to reproduce case-specific internal optical characteristics quite easily. Our standard approach for the use of Esthetic Colorant on KATANA™ Zirconia HTML Plus is described by means of the following case example: An implant- and tooth-based twelve-unit bridge with a slight vestibular cutback design, finished with Esthetic Colorant and CERABIEN™ ZR Porcelain.

Fig. 1. Restoration with sintering support removed from the blank.

Fig. 2. Esthetic Colorant for KATANA™ Zirconia: Available shades.

Fig. 3. Frontal view of the milled restoration after the application of Esthetic Colorant. A chromatic map is not needed since the colours of the applied liquids are clearly visible.

Fig. 4. Occlusal view of the milled restoration after the application of Esthetic Colorant. The liquids were applied with the Liquid Brush Pen for Esthetic Colorant.

Fig. 5. Frontal view: Appearance of the restoration after sintering.

Fig. 6. Occlusal view: Appearance of the restoration after sintering.

Fig. 7. Beautiful translucency and mamelon structures in the incisal area.

Fig. 8. Situation after the application of a thin layer of CERABIEN™ ZR Porcelain, which creates an enamellike window effect and reveals the play of colours found underneath.

Fig. 9. Restoration after firing and glazing.

FINAL SITUATION

Fig. 10. Beauty shots…

Fig. 11. … of the final restoration.

Easy handling and application, impressive colour effects: Esthetic Colorant perfectly fits into our micro-layering approach with a cutback design adjusted to the age and needs of every patient. Being applied on the pre-sintered zirconia surface, the liquids do not require any extra heat treatment – the restoration is simply dried and then sintered as usual. Esthetic Colorant may be used instead of or in combination with internal stains, luster porcelains and liquid ceramics – whatever complements a laboratory’s existing approach to highly aesthetic zirconia restorations.

Dentists:

Case by Kokla Thalia, Postgraduate student in Restorative Dentistry program, Faculty of Dentistry, National and Kapodistrian University of Athens, Greece

Restoring Class II cavities can be challenging due to limited access to the posterior area, where the interproximal contact needs to re-established in a proper way. Inadequate contacts tend to result in increased plaque accumulation, food impaction and, as a consequence, the development of caries and irritation of the interproximal gingiva. Therefore, it is essential that the interproximal contact is restored based on the model of nature. A suitable matrix system and a proper clinical protocol can help us succeed in this context. The following clinical case is used to illustrate a possible strategy.

Fig. 1. Initial clinical situation. 23-year-old female patient with caries on the mandibular left second premolar.

Fig. 2. Situation after cavity preparation, isolation of the working field with rubber dam and the placement of a sectional matrix fixed with a ring. It is essential that the matrix imitates the natural shape of the contact area, which is usually rather flat or concave cervically and convex in the middle and occlusal parts.

Fig. 3. Etching of the tooth structure with phosphoric acid etchant. Afterwards, the adhesive needs to be applied (in this case, Universal Bond Quick was used according to the manufacturer’s instructions).

Fig. 4. CLEARFIL MAJESTY™ ES-2 Premium in the shade A3E is applied in the distal box to build up the wall first. In this way, the available space is used to model the most critical part of the restoration before simply filling the cavity in increments with the dentin shade A3D.

FINAL SITUATION

Fig. 5. Final restoration after finishing and polishing. In accordance with the concept behind CLEARFIL MAJESTY™ ES-2 Premium with its pre-defined shade combinations, the final enamel layer was build-up using the shade A3E. However, the use of a single opacity is also possible in the posterior region depending on the aesthetic demands.

CONCLUSION

By elevating deep interproximal margins, it is possible to focus on the critical designing of the contact point when there is still sufficient space available to do so. This simplifies the procedure, while all that is left to do can be managed in a straightforward way like a Class I restoration.

JUST COLOR: ESTHETIC COLORANT FOR KATANA ZIRCONIA

The natural tooth impresses with wonderful light-optical effects - characteristic features that result from the inner structure of the tooth. Imitating these specific effects in zirconia restorations with the staining technique or micro-layering has shown limitations so far. Kuraray Noritake has addressed this problem. Based on solid research and development work, an amazingly simple solution was created - Esthetic Colorant for KATANA Zirconia.

Mr. Stratos Chatzichristos CDT will present Esthetic Colorant in detail in this online webinar. He will show how the aesthetically individual effect of a zirconia restoration can be intensified with the new effect liquids and will showcase practical application and material science basics. Learn how to achieve a zirconia restoration with truly impressive aesthetics.

Topics:

•    basics about Esthetic Colorant for KATANA Zirconia
•    differences to traditional staining and infiltration solutions
•    areas of application of Esthetic Colorant
•    achieving a true color effect
•    masking effect for the zirconia framework (discolored stumps or metallic abutments)
•    economic advantages of using Esthetic Colorant
•    material basics of zirconia

“Very nice handling properties”

PAVANIA™ Veneer LC receives 4.6 rating in REALITY’s Five Star Award

After a FirstLook evaluation published in May 2022, a team of evaluators from REALITY RATINGS & REVIEWS has thoroughly tested PANAVIA™ Veneer LC in the clinical practice environment – with great outcomes. The purely light-cured resin cement received 4.6 out of 5 stars in the Five Star Award, the most convincing features being its handling and viscosity.

While most of the evaluators used PANAVIA™ Veneer LC for the permanent cementation of veneers, some also tested the onlay indication (restricted to high-translucency materials of a material-specific maximum thickness). Those who decided to polish the margins (43 %) found that the resin cement is very well polishable with little effort. Among the handling properties highlighted were easy seating with virtually no drifting, non-stickiness and easy excess removal – both after tack curing and in the cement’s uncured state. In addition, the evaluators praised the minimal film thickness and favourable viscosity, which has a considerable impact on the ease of seating. The working time was sufficient for all evaluators, independent of their way of working (filtering/blocking dental unit light or not, placing multiple veneers simultaneously or one veneer at a time).

The shade offering – PANAVIA™ Veneer LC is available in the four shades Clear, Universal/A2, Brown/A4 and White – was regarded adequate by most evaluators (79 %), the most popular shade being Clear. One evaluator stated that “I think the “clear” shade is my new favorite. It seems to have a brightness to it compared to other clear or translucent cements.”. Being the only shade with a high opacity, White was found to have a decisive impact on the appearance of the final restoration. The try-in pastes were well-received for their handling and easy rinse-off ability.

The PANAVIA™ Veneer LC kit available in Europe consists of PANAVIA™ Veneer LC Paste, PANAVIA™ V5 Tooth Primer and CLEARFIL™ CERAMIC PRIMER PLUS. Hence, it builds confidence by sharing primers with the proven PANAVIA™ V5, while its long working time and specific handling properties add extra benefits that are extremely valuable during veneer cementation. Click here to read the full evaluation!