429 Too Many Requests

Mulle esitatakse sageli küsimusi suuõõnesiseste keraamikaikildude parandamise kohta. Taastamise õnnestumiseks on oluline arvestada mitmeid tähtsaid asjaolusid. Võib-olla on kõige olulisem tuvastada, miks murdumine üldse juhtus. Kui näiteks peamiseks põhjuseks on koormuspinge, tuleks seda restaureerimisel arvestada. Muud asjaolud, millega arvestada, on saaste eemaldamine, optimaalne karestamine ja pinna keemiline aktiveerimine
ning saaste ennetamine restaureerimise käigus. Samuti tuleks tööpinna isoleerimiseks kasutada kofferdami.

ADHESIOONI ALUSED

Adhesioon saab olla edukas ainult siis, kui kasutatakse õigeid aineid ja meetodeid. Erinevad pinnad vajavad toimimiseks sageli erinevat töötlemist. Siiski tuleks
arvestada parimate tulemuste saavutamiseks adhesioonil kolme põhialust.

1) Mehaaniline retentsioon tänu karestatud pinnale.
2) Keemiline aktiveerimine keemiliselt aktiivsete ainetega.
3) Kõrge siseenergiaga sidumispind, mis võimaldab optimaalset vastastikust toimet (märgumisvõime) pinna ja kasutatava aine vahel. Saaste vähendab
sidumisvõimet ja seda tuleb igal juhul vältida ning see peab olema eemaldatud.

MURDUDE TÜÜBID

Kõige sagedasemad murrud on sellised, mis on ainult keraamikas, ja need, mis hõlmavad ka substruktuuri paljastumist proteesides PFZ ja PFM.

Paljudel juhtudel on tegemist ainult keraamika piiratud lahtimurdumisega, näiteks lõikeservas. Taolisel juhul vastupidava restauratsiooni saavutamiseks
alustage sidumis-/restauratsiooniala suurendamisest peene teemantlihviga, et luua suur kaldnurk. Peene karedusega puuri tuleb eelistada keskmise või jämeda karedusega puurile, kuna pinnapealsete soonte suur hulk annab optimaalsema sidumispinna kui väiksem arv sügavamaid sooni. Adhesioonipinna täiendav karestamine liivapritsiga (tera suurus 50 μm, surve 2 bar) on soovitatav, et suurendada pinda veelgi.

Kui restaureerite Keraamikakildusid, mille puhul on sisestruktuur paljastatud, on oluline tähele panna, et tegemist on mitmete substraatidega, mis viitab
vajadusele kohandada restauratsiooni vastavalt.

Puhastage karestatud murdunud pind põhjalikult. Selleks on parim toode KATANA™ Cleaner. See on ohutu ja lihtsasti kasutatav toode, millel on
tõhus puhastusvõime. Seda saab kasutada nii suuõõnesiseselt kui ka -väliselt kõigil materjalidega. Pärast loputamist ja põhjalikku kuivatamist on
pind valmis järgmiseks etapiks – keemiliseks aktiveerimiseks.
CLEARFIL™ CERAMIC PRIMER PLUS sisaldab nii silaani kui ka MDP-d ja sellega saab töödelda nii ränisisaldusega keraamikat kui ka metallioksiide
(tsirkoonium) ning metalle. Pärast pealekandmist ja põhjalikku kuivamist saab komposiidi restauratsiooni teha kohe ilma täiendava sidumisetapita. Komposiidi
puhul on hea valik vastupidav ja voolav CLEARFIL MAJESTY™ ES Flow. Sellel on kõrge elastsustugevus, mis on isegi suurem kui paljudel topeldatavatel
komposiitidel. Lisaks kohandub see pinnaga paremini ja lihtsamalt. CLEARFIL MAJESTY™ ES Flow’ hinnatud omadused on ka kiire ja hõlbus poleerimine ning läike säilimine.

NÄPUNÄITED JA NÕUANDED

• Isoleerige tööpind kofferdamiga
• Lihvige killu kaldserv suures ulatuses, kasutades selleks peent teemantlihvi
• Karestage adhesioonpind, eelistatavalt liivapritsiga
• Puhastage parandatav pind KATANA™ Cleaneriga
• Kandke kogu sidustatavale alale CLEARFIL™ CERAMIC PRIMER PLUS-i (sh paljastunud tsirkooniumile või metallile) ning kuivatage põhjalikult
• Katke paljastunud metall õhukese CLEARFIL™ ST OPAQUER-i kihiga ja valguskõvastage
• Restaureerige tugeva voolava komposiidiga, näiteks CLEARFIL MAJESTY™ ES Flow’ga

Peter Schouten
Tehniliste küsimuste juht, Kuraray Europe Benelux
Keemiaanalüütikuna kasutab ta oma keemilist tausta, et esmapilgul keeruline (toode)
teha lihtsaks ja läbipaistvaks. Tema kirg seisneb teabe jagamises toodete ja tehnoloogiate
rakendamise kohta võimalikult lihtsas võtmes.

Innovation and workflow simplification made possible

In this edition of BOND, we're shining a spotlight on the innovation and workflow simplification made possible by high-quality products like our "KATANA™ Zirconia" range.

In an interview with Atsushi Matsumoto and Yuta Tajima about KATANA™ Zirconia YML these experts explain the benefits of this new material possessing different concentrations of yttria in a single blank, and highlight how its multi-layered nature allows practitioners to work with a nearly universal zirconia suitable for all cases.

Mathias Fernandez Lombardi has contributed an excellent article detailing the science behind "KATANA™ Zirconia", Kuraray Noritake Dental's brand new 4.4.1. kit is introduced and last, but certainly not least, Dr Stefano Daniele details his experiences with KATANA™ Cleaner.

Click here to read. Enjoy!

Start Reading: BOND | VOLUME 8 | 12/2021

Previous versions:

BOND | SPECIAL EDITION | 06/2021

BOND | VOLUME 7 | 10/2020

BY PETER SCHOUTEN

ZIRCONIA
CRYSTALLISATION

Zirconia is here to stay in dentistry. Since its introduction some two decades ago, the possibilities for use of zirconia have increased enormously. But how is this compound produced? What happens during sintering, what types are available, and how are the desired shape and shade of the final product achieved?

PSZ or Partially Stabilised Zirconia was the first of the zirconium oxides to be used in dentistry. This type of zirconia was stabilised using yttria, and is currently no longer in use. It consisted of a mix of monoclinic, tetragonal and cubic crystals. For many years, the so-called Y-TZP variety was used (yttria tetragonal stabilised zirconia polycrystal). This has outstanding flexural strength (> 1,000 MPa), however, a non aesthetic opaque white appearance. It consists for mostly of tetragonal crystals with a diameter of some hundreds of nanometres. Approximately 3 mol% yttria is added to keep the material stable at room temperature;
this variety is therefore sometimes described as 3Y zirconia. New varieties, such as cubic zirconia, were developed with the aim of improving the aesthetic
properties of the material. Cubic zirconia is characterised by high translucency but has a lower flexural strength. However, although the flexural strength of this type is considerably lower than that of the tetragonal version, it is nevertheless much higher than that of lithium disilicate. This form also contains a higher amount of yttria, ranging from 4 to more than 5 mol%.

CRYSTAL PHASES

We currently know of zircona crystals in three major shapes.

Monoclinic

Normally, zirconia exists only at room temperature in the monoclinic phase. Monoclinic zirconia has low strength and translucency.

Tetragonal
These zirconia crystals are metastable and only exist at room temperature after stabilisation, mainly by adding yttria.
Although tetragonal zirconia is strong, it has limited aesthetic properties.

Cubic
Cubic crystals are stable and provide improved translucency. Due to the addition of a higher percentage of yttria, cubic
zirconia work pieces are not as strong as tetragonal ones. On the other hand, they are highly aesthetic and therefore
suitable for monolithic restorations, even in the anterior zone.

CRYSTALLISATION PROCESS
Zircona is almost invariably offered as a partially sintered material. In this form it is always opaque white, and the true
colour and translucency is only apparent after sintering. During sintering, the material shrinks to its ultimate size; a
multitude of small crystals merg to form larger crystals, but although the crystals themselves increase in size, the total
volume decreases. This shrink factor is therefore taken into account in the software, so that the end product is not only
colourfast after sintering, but is also sizewise correct.

Small crystals merge into larger ones during the sintering process.

KATANA™ Multilayer HTML before (left) and after sintering.

The KATANA™ Zirconia family of multi-layered CAD/CAM blanks has a new member: KATANA™ Zirconia YML (yttria multi-layered). Based on Kuraray Noritake Dental Inc. (KND) proprietary multi-layer technology, this new material offers multiple layers with different levels of chroma and translucency PLUS different concentrations of yttria in a single blank. We talked to two experts from Kuraray Noritake Dental’s Research & Development Department in Japan, Atsushi Matsumoto and Yuta Tajima, about the new product and its specific features.

Mr. Matsumoto, Mr. Tajima, KND already offers a broad range of zirconia materials covering virtually every indication. Why did you decide to start developing yet another dental zirconia?

The KATANA™ Zirconia series has indeed received high praise and great feedback from the market. Users particularly appreciate the remarkably high strength of HTML, the well-balanced aesthetic and strength properties of STML, and also the high translucency of UTML. Although there has been a large increase of zirconia materials in the dental market recently, we have received many requests from our customers for a more universal material that offers the excellent properties of all variants of KATANA™ Zirconia in one product. This product should allow them to fabricate all kinds of restorations from a single disc, from single crowns to full bridges, while maintaining high aesthetic and mechanical properties for both anterior and posterior restorations. As the developer of the KATANA™ Zirconia series, the invention of KATANA™ Zirconia YML is our response to these desires expressed by our customers.

What is the main difference between KATANA™ Zirconia YML and the other available products of the KATANA™ Zirconia Multi-Layered Series?

All layers of KATANA™ Zirconia UTML, STML and HTML are produced from the same basic powder composition and therefore offer the same strength throughout the whole blank. Depending on the case specific requirements, users need to select the most suitable type of material, either a high-strength zirconia or a highly translucent variant. KATANA™ Zirconia YML is an all-in-one zirconia suitable for all cases: It consists of a high-translucency enamel layer, an intermediate layer offering well-balanced strength, translucency and colour, and a high-strength body layer. The raw materials used for this product are developed and produced by KND exclusively for YML. This is another milestone in advanced product development KATANA™ Zirconia.

We have received many requests from our customers
for a more universal material.

In general, the currently available zirconia materials with an integrated strength gradient do not have a very positive image in the eyes of many dental technicians and specialists, due to the fact that in the incisal area, the materials seem to be insufficiently strengthened. This can lead to fractures when it comes to long-span restorations, especially if they are inadequately positioned within the blank. How carefully did KND focus on these problems and how did they try to solve them in order to stand out from the competition?

The current yttria-based multi-layer products on the market are facing complicated limitations in connector position in large cases, such as full-arch restorations, due to the lack of an ideal combination of aesthetics and strength. To overcome this challenge, KND developed well-balanced raw materials of high strength and high aesthetics, and by including these raw materials in the intermediate layer between the enamel and body layers. The result is that even for long-span restorations, it is very simple to position the connectors thanks to its excellent balance between high strength and high aesthetic properties. Due to these unique attributes incorporated in our new product, the risk of deformation and breakage is avoided.

Another problem is the often clearly visible line between the different layers containing different amounts of yttrium oxide, which can be seen at a more detailed inspection after sintering. How did you address this issue?

At KND, we achieved both, adequate translucency gradation and invisible transition lines, even for zirconia layers with different yttria content. This has been accomplished thanks to our multi-layer zirconia manufacturing technology refined over many years, which includes mixing the appropriate amount of each layer's boundary to intentionally avoid transition lines. In addition, the newly developed interlayer raw materials and a newly designed sintering schedule were the keys to success.

How is it possible to have a sintering protocol that works for different zirconia components within the KATANA™ Zirconia YML blank and allows for the shortest sintering times ever?

The amount of shrinkage during sintering is determined by different factors such as the number and quantity of additives (yttria, alumina etc.) it contains. If the shrinkage ratio of each layer is different, transition lines are likely to appear between the layers, which might produce tensions in the material structure. The newly developed raw material for KATANA™ Zirconia YML enables us to control and unify the shrinkage ratio for all layers, even for raw materials with different yttria contents.

The use of proprietary raw materials produced in-house with excellent properties suitable for high-speed sintering was the main precondition that allowed for the development KND’s high-speed sintering schedule (54 min for restorations up to 3-unit bridges), which is available for all products of the KATANA™ Zirconia multi-layered series. This option improves the efficiency of the dental technician’s work and simplifies the workflow.

Are there any differences in milling and adjusting KATANA™ Zirconia YML compared to competitor products?

All KATANA™ Zirconia products from KND have an appropriate hardness with less chipping during the milling process thanks to the raw materials manufactured and refined in-house. Also, after the sintering procedure, it offers excellent chipping resistance, especially during very challenging marginal adjustments.

Is there anything else that sets KATANA™ Zirconia YML apart from other products with an integrated strength gradient?

Yes, KATANA™ Zirconia YML offers reduced sintering deformation, thanks to in-house developed raw materials, based on proprietary technology to control shrinkage rate. Moreover, we offer a wide range of shades (14), which is another important aspect (apart from the material’s well-balanced aesthetic properties and absence of transition lines) for the creation of lifelike restorations. Finally, since three out of four layers meet the conditions for an ISO class 5 classification, there are few restrictions on the design variation of the prosthesis.

Why should a dental technician consider using KATANA™ Zirconia YML instead of any other dental zirconia (in your opinion)?

Atsushi Matsumoto:

It is now possible for dental technicians to produce strong and aesthetic restorations with just one material, KATANA™ Zirconia YML. This allows for a reduced inventory, while working time is significantly shortened due to the possibility of high-speed sintering.

Yuta Tajima:

To my mind, the most convincing properties are excellent firing accuracy due to well-balanced material properties across all layers, the wide range of shades available and the great design flexibility even when designing long-span bridges. Last but not least, the trusted quality of the KATANA™ brand and the label “Made in Japan” are reasons to opt for this new product.

All blanks from the KATANA™ Zirconia Series stand out from other dental zirconia materials due to their particularly fine-grained, densely pressed microstructure, which is the basis for a superior surface quality, edge stability and the resulting accuracy of fit. What is the secret behind this exceptionally high blank quality?

Since we do not know the correlation between marginal stability properties (chipping, etc.) and material compositions, structures etc., it is very difficult to answer this question. It may depend on the structures of the zirconia crystals, the raw material itself, the correct strength level after pre-sintering or any other minor factor during the manufacturing process of the disc. All these factors together, of course, are important.

We are using pigments developed by KND, which have an excellent colour stability without fading even after the final sintering procedure.

Even if the restoration margins have been milled to a very thin profile, they still show smooth margins without any chipping.

A clear advantage of the KATANA™ Zirconia series, much praised by KND's Key Opinion Leaders, is its colour stability and shade match to the "VITA classical shade guide". Can you explain the importance of an in-house conducted addition of additives and color pigments in form of metal oxides to satisfy the user and distinguish KATANA™ Zirconia from competitors’ products?

We are using pigments developed by KND, which have an excellent colour stability without fading even after the final sintering procedure. The particle size is appropriately controlled. In addition, our professional "colour mixing" staff, reflecting the opinions of clinically experienced dental technicians both inside and outside the company, have achieved a pigment mixture that shows only a slight change in shade even in cases with different thicknesses.

What is your vision with regard to future developments in dental zirconia?

Since the introduction of zirconia on the dental market, many significant material advances have been achieved. Today, there are high-strength, low light-transmitting zirconia materials up to high light- transmitting, low strength zirconia materials available on the market. Furthermore, there are now also high light-transmitting, low strength zirconia materials in mixed systems (YML series) offered. Our foremost goal is to develop the ultimate zirconia in near future, combining both high strength and high light transmission, which breaks the general expectation of a compromise between strength and translucency within zirconia materials.

Interview with Mathias Fernandez Y Lombardi, EU Scientific Manager, Kuraray Europe GmbH

Kuraray Noritake Dental Inc. reinvented its original zirconia multi-layer technology by integrating newly developed raw materials with different yttria content into the proven multi-layer colour structure. The material that is based on this innovative technology, KATANA™ Zirconia YML, offers a well-balanced flexural strength, chroma and translucency gradation throughout the blank.

According to pilot users of the new zirconia discs, the greatest benefit of using KATANA™ Zirconia YML is in the true empowerment of the laboratory. We asked Kuraray Noritake’s EU Scientific Manager Dental Ceramics & CAD/CAM Materials, Mathias Fernandez Lombardi, to explain how the new material is able to positively affect work routines in the dental laboratory.

The greatest benefit of using KATANA™ Zirconia YML is in the true empowerment of the laboratory.

Mathias Fernandez Lombardi, who should consider working with KATANA™ Zirconia YML?

KATANA™ Zirconia YML is designed for laboratories and milling centres with a strong focus on simplification. With its strong body and highly translucent enamel layer, it offers exactly the properties required for an unlimited indication range. Being perfectly suited for the production of durable monolithic long-span posterior bridges and of highly aesthetic anterior crowns or partial restorations, KATANA™ Zirconia YML is a true all-rounder that eliminates the need for another zirconia or even ceramic CAD/CAM material. At the same time, it supports highly automated production procedures and requires minimal hand work.

What are the benefits of using a single material for every indication?

Several benefits are related to the use of a single, all-round material. It leads to a reduced number of blanks to be stored, which simplifies inventory management and minimizes the storage space needed. Moreover, it facilitates standardization of laboratory workflows. Using the same material every time means that there are no differences in the basic design and milling parameters like minimum wall thicknesses and connector strengths, in the sintering protocols and finishing options to be taken into account. Hence, errors are less likely to occur and routines are easily established. Finally, the risk of cross-contamination is eliminated when a single material is processed with the available equipment (milling machine, milling and finishing tools, and sintering furnace). Predictable outcomes and flawless aesthetics are usually the result.

What are the benefits related to the use of KATANA™ Zirconia YML as the only ceramic CAD/CAM material?

I guess that the most important argument is that aesthetic outcomes are easily and efficiently achieved with KATANA™ Zirconia YML for all kinds of restorations, even for long-span bridges. It is usually sufficient to produce monolithic restorations for the posterior region, which are just polished or glazed. Anterior restorations may be designed monolithically or with minimal cut-back, and the user may choose between CERABIEN™ ZR (CZR) FC Paste Stains and CZR Internal Stains plus glaze to obtain a natural look. Another benefit of KATANA™ Zirconia YML is its seamless multi-layer structure combined with an extraordinary blank quality.

Why is this seamless structure and high blank quality important for users?

The seamless multi-layer structure, that is a smooth transition from one layer to the next, is the precondition for structural integrity and flawless aesthetics. It ensures that the material is free of transition lines, offers accurate dimensions after sintering (due to uniform shrinkage) and shows a reliable long-term performance not compromised by internal tensions. In KATANA™ Zirconia YML, a completely homogeneous composition, with carefully aligned CTE-values and shrinkage ratios in all parts of the blank, is responsible for this benefit.

Aesthetic outcomes are easily and efficiently achieved with KATANA™ Zirconia YML for all kinds of restorations, even for long-span bridges.

For its development, Kuraray Noritake Dental leveraged its long-standing expertise in dental ceramics and the advantages of an end-to-end in-house blank production process, without which it would have been impossible to reach the requested quality level. Due to the fact that the material is so well aligned, it was even possible to develop a 54-minute sintering programme that produces equally good results as the proven 90-minute or 7-hour programmes and becomes the go-to option for all rush cases. With this feature, KATANA™ Zirconia YML becomes the “jack of all trades” material: It offers highest comfort and security like an SUV, but when it comes to speed, it is in no way inferior to a sports car.

The above sintering recommendations represent only a guideline; depending on each individual furnace and condition, some adjustments might be necessary. If the 54 or 90-minute sintering program is not programmable in your furnace, it is not possible to set the furnace according to one of these schedules. *The material is removed from the furnace at 8000C. A furnace with a configurable YML sintering program is required.

Users who have already tested ceramic materials with a strength gradient know that positioning of long-span restorations in the blank can be tricky. What are the rules to be respected when positioning a long-span bridge in a YML blank?

Positioning of restorations in KATANA™ Zirconia YML discs is extraordinarily easy. The reason is that the gap between the lowest flexural strength found in the enamel area and the highest flexural strength found in the lowest body layer is comparatively small. Moreover, the Body Layer 1 that is found adjacent to the enamel layer already offers a flexural strength that is higher than the 800 MPa requested for bridges with four or more units. Consequently, users are on the safe side whenever they place their long-span restorations in the middle of the blank. More specifically, half of the connector cross section needs to be in the lower half of the disc, which is quite different from other materials with strength gradation that allow for connector positioning in the body area only. KATANA™ Zirconia YML restorations with a maximum of three units may be positioned in any layer. In this context, the fact that the thickness of each layer increases proportionally with the height of the disc comes as a benefit: The enamel layer is large enough to exploit its aesthetic potential in single-unit or small bridge cases.

Positioning of long-span restorations in the middle of the disc.

What would you recommend dental technicians who would like to empower their laboratory or milling centre?

I can truly recommend testing KATANA™ Zirconia YML in the laboratory environment to see how it handles and to assess its potential. The exceptional blank quality and seamless integration of the different layers, the ease of positioning and processing efficiency are factors potential users need to experience in real life to understand what they mean for their daily work. Similarly, the aesthetic outcomes need to be assessed in the clinical environment for an authentic impression of the natural look and feel obtained. I am sure that KATANA™ Zirconia YML will be able to convince virtually everyone who wants to empower the laboratory with an easy-to-use, efficient universal zirconia solution that fits virtually every patient’s and every dentist’s needs! Kuraray Noritake Dental knows that dental technicians and practitioners are in need of products that support their striving for simplification, standardization and increased efficiency so urgently needed in present times. Therefore, our product innovations are all focused on delivering more performance with less effort. KATANA™ Zirconia YML is the latest addition to a whole series of materials pursuing this goal.

Minimum connector cross-sections are to be respected during the computer-aided design of KATANA™ Zirconia YML restorations.

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

We are pleased to share with you short training videos for CERABIEN™ ZR (CZR) porcelain.

Check out the below working steps and learn more about how to achieve outstanding aesthetics using this tried and proven material.

It is strong, it is pre-shaded like natural teeth, and it is reliable: KATANA™ Zirconia HTML, the highest strength version among KATANA™ multi-layered zirconia series. Now, Kuraray Noritake Dental Inc. has carefully optimized the product to further improve its optical properties and to harmonize the sintering schedules with all other materials of the KATANA™ Zirconia Multi-Layered Series.

The new KATANA™ Zirconia HTML Plus offers all popular properties of its predecessor, including the multi-layered colour structure and uniform strength distribution throughout the blank. It is suitable for a variety of indications including long-span bridges with a minimum wall thickness of just 0.4 mm in the anterior and 0.5 mm in the posterior region. This allows for minimally invasive preparations, while the user may choose between a monolithic, cut-back or framework design combined with the preferred finishing technique.

The PLUS refers to additional benefits like the material’s improved optical properties: KATANA™ Zirconia HTML Plus offers an increased translucency of 45 percent (compared to 43 percent KATANA™ Zirconia HTML) and an even more natural shade appearance of the manufactured restorations. “As the colour of the restorations appears deeper, more vivid and more saturated, and the translucency is closer to that of natural teeth, a great optical integration is achieved straight away. This leads to a reduced finishing effort”, says Mathias Fernandez Y Lombardi, EU Scientific Manager Dental Ceramics & CAD/CAM Materials at Kuraray Noritake Dental. At the same time, the high flexural strength (1,150 MPa) is maintained, providing for an unlimited range of indications.

Like its predecessor and all other materials of the KATANA™ Zirconia Multi-Layered Series, KATANA™ Zirconia HTML Plus is the result of an in-house development, powder compilation and blank production process that is able to control every detail. This enabled our specialists to achieve a precise alignment of the desired properties, while maintaining a high blank quality that leads to the accurate milling results with smooth surfaces and regular edges users of KATANA™ Zirconia HTML are familiar with.

The unique powder composition and specific in-house blank production procedure also allowed us to streamline the sintering protocols. For single-tooth restorations and bridges with up to three units, three different protocols are available: a 54-minute high-speed sintering programme specifically developed for remake and rush cases, a 90-minute schedule and the traditional seven-hour sintering programme. The latter is also suitable for long-span restorations.

These three options and identical schedules are available for KATANA™ Zirconia HTML Plus, KATANA™ Zirconia UTML, KATANA™ Zirconia STML and the new KATANA™ Zirconia YML with additional flexural strength and technical translucency gradation. With this feature, it becomes extraordinarily easy to standardize procedures despite an indication-specific selection of the best-suited KATANA™ Multi-Layered Zirconia.

Mathias Fernandez Y Lombardi concludes: “KATANA™ Zirconia HTML Plus is completely in line with our philosophy of developing products that support their users in streamlining and simplifying procedures without limiting choices. Users may choose from a whole range of highly specialized or universal zirconia solutions, may opt for their preferred design and finishing technique, and can select the sintering protocol that suits their individual needs. At the same time, the manual effort is reduced and the risk of starting the wrong sintering programme is eliminated.”

One for all: With KATANA™ Zirconia YML (yttria multi-layered), Kuraray Noritake Dental Inc. has launched a true allrounder covering traditional and new zirconia indications. At the KATANA™ Zirconia YML Virtual Kick-Off Symposium on July 3, 2021, professionals from the clinical and technical field as well as scientific experts from Kuraray Noritake Inc. provided insights into the properties and benefits of the innovation. We had a conversation with three of them about the specific features of KATANA™ Zirconia YML and its potential role in the dental practice and laboratory. Mathias Fernandez Y Lombardi, EU Scientific Manager Dental Ceramics & CAD/CAM Materials, provided insights from inside the company, while Prof. Dr. Florian Beuer MME, Charité – Universitätsmedizin Berlin and MDT Nondas Vlachopoulos, owner of the dental laboratory AestheticLab in Athens, shared their external perspectives.

Prof. Dr. Florian Beuer MME and Mathias Fernandez Y Lombardi during the conversation at the Kick-Off Symposium in Munich.

MDT Nondas Vlachopoulos virtually attended the meeting.

What are the most important features and benefits of the new KATANA™ Zirconia YML?

Mathias Fernandez Y Lombardi: KATANA™ Zirconia YML is a 5^th generation zirconia featuring next-generation multi-layered technology: it offers colour, translucency and flexural strength gradation in one disc – for a virtually unlimited indication range. As it may be used as the only zirconia or even ceramic CAD/CAM material in a laboratory or milling centre, it is designed for everyone who would like to simplify and standardize laboratory procedures. It may be sintered within 54 minutes, offers a high accuracy of fit and may be finished using time-saving techniques.

The new discs presented at the KATANA™ Zirconia YML Virtual Kick-Off Symposium.

Multi-layered structure of KATANA™ Zirconia YML.

What are the benefits of using a single zirconia for every indication from the dental technician’s perspective?

Nondas Vlachopoulos: The use of a universal zirconia solution with a high aesthetic potential and well-aligned mechanical properties allows dental technicians to reduce their inventory and streamline their procedures – from designing to finishing. Nowadays, we all know that, in order to optimize the outcomes, it is essential that we develop a deep understanding of a material’s properties, respect its design parameters (like minimum wall thicknesses) and adhere to the sintering protocols. It is much easier to accomplish this for a single material than for many different ceramics, and the potential for errors is minimized with a single-material approach. With KATANA™ Zirconia YML, this approach enables us to produce very different outcomes depending on where the restoration is placed in the multi-layered blank.

What are the benefits of using KATANA™ Zirconia YML as the only ceramic material from the dental practitioner’s perspective?

Florian Beuer: To my mind, the most important benefit of using a single zirconia every time lies in a simplified documentation. When different ceramic materials are used in the dental laboratory, we need to keep track of the material selected in every single case. Only in this way, it is possible to make the right cementation decisions (regarding cement selection and the appropriate pre-treatment of the restoration). In addition, when it comes to failure of the restoration, we need to know which material was used to prove that it has been processed correctly and is suitable for the actual indication. This is much easier when a single material is used every time. Zirconia is predestined for this approach as it is forgiving, supports minimally invasive preparations and – in case of KATANA™ Zirconia YML – almost everything can be done with it.

What are the secrets of KATANA™ Zirconia YML that allow for excellent treatment outcomes despite the one-for-all approach?

Mathias Fernandez Y Lombardi: KATANA™ Zirconia YML is based on a completely new, seamless multi-layer technology combining different, newly developed raw materials with varying yttria concentrations in a single blank. The inhouse development of the powders and their precise adjustment of each other in terms of properties like shrinkage and coefficients of thermal expansion are prerequisites for a smooth transition from one layer to the next. Only if the layers are very well integrated, it will be possible to reliably produce even long-span restorations with a delicate design, perfect fit and flawless aesthetics (without transition lines). The aesthetic properties were also optimized by integrating clinical instead of purely technical translucency.

Please explain the term clinical translucency.

Mathias Fernandez Y Lombardi: Usually, translucency of dental materials like zirconia is measured in its white, pre-shaded state. This so-called technical translucency value is increased by adding yttria to the formulation, which makes the zirconia itself appear brighter (increasing the whiteness). The translucency of the final restoration, however, is also affected by pigments and other additives in the formulation. Consequently, monolithic restorations made of different materials with the same technical translucency value may vary widely in terms of their actual, clinical translucency, which affect the overall aesthetic potential. The formulation of KATANA™ Zirconia YML has been optimized by carefully selecting and combining the right additives to obtain a natural, tooth-like translucency.

Translucency and shade appearance of KATANA™ Zirconia YML (left column) compared to various other 5^th generation zirconia materials.

Nondas Vlachopoulos, is this measure of optimizing the clinical translucency a key feature enabling the one-for-all approach of KATANA™ Zirconia YML?

Nondas Vlachopoulos: The positive effect attributed to this measure is noticeable, as KATANA™ Zirconia YML has a particularly warm and natural appearance especially in the body area some other materials with flexural strength gradation are lacking. This leads to an exact colour match with the VITA classical A1-D4 shade guide, and reduces the need for manual shade adjustments. This is important for a one-for-all approach, as the material should be a perfect basis for the production of monolithic restorations, which are not covered by a thick porcelain layer able to mask any imperfections. However, there is another key feature that facilitates the zirconia’s use for virtually every indication: Its exceptional design flexibility. It enables users to control the translucency and overall aesthetics by positioning the restoration quite freely within the blank. For restorations with up to three units, there is a complete freedom of placement. Larger restorations with four or more units need to be positioned in a way that at least 50% of the connector cross-section is in the bottom half of the disc. This is easily accomplished and gives us optimal options to exploit the various properties of each layer depending on the aesthetics and strength needed in each specific case.

Positioning guidelines for KATANA™ Zirconia YML.

What is the recommended finishing procedure?

Mathias Fernandez Y Lombardi: In principle, all designs and finishing options are available for KATANA™ Zirconia YML – from a monolithic design individualized with liquid ceramics to microlayering after a minimal vestibular cutback or even full ceramic layering on frameworks. As the aesthetic potential of the zirconia is already high, however, we believe that in most cases, the first option is absolutely sufficient. In this case, a monolithic restoration is milled and the surface subsequently treated with our liquid ceramic system CERABIEN™ ZR FC Paste Stain. The pastes are easily applied in ultra-thin layers, very well controllable and wear resistant.

Anterior and posterior crown made of KATANA™ Zirconia YML after sintering (left part) and after sintering and finishing with CERABIEN™ ZR FC PASTE STAIN (right part).

Nondas Vlachopoulos, what is your preferred finishing procedure for restorations made of KATANA™ Zirconia YML?

Nondas Vlachopoulos: In the posterior area, I often opt for monolithic restorations individualized with CERABIEN™ ZR FC Paste Stain. The technique leads to beautiful outcomes a large majority of patients would love to see even in the anterior region. However, as orders for the production of anterior restorations coming my way are usually placed by clinicians and patients with the highest possible aesthetic demands, I often go for a framework design and full porcelain layering with CERABIEN ZR Porcelains. The materials (like EX-3 portfolio for metal frameworks) are based on synthetic feldspathic porcelain with a structure and particle distribution very similar to natural dentin and enamel. All in all, I like the fact that I can select the most suitable finishing technique for every individual case, and I believe that it is often possible to reduce the finishing effort to a minimum.

Clinical translucency, design flexibility, mechanical properties: Apparently, the differences between the available zirconia materials – even of the 5^th generation – are huge. How can users ensure that the material they select is of high quality and offers favourable mechanical as well as optical properties?

Florian Beuer: When the first-generation zirconia materials appeared on the dental market, laboratory testing revealed that there are huge differences in quality between materials of different manufacturers. Although independent studies comparing the properties and behaviour of 5^th generation zirconia are still scarce, it may be assumed that differences do exist. My recommendation is to select a several materials from well-known manufacturers supporting clinical studies, compare the study results already available, and test the selected options in the laboratory setting. Directly comparing design concepts, the processing quality and final appearance will most likely reveal which material is a dental technician’s favourite. I am sure that KATANA™ Zirconia YML is among the materials worth being tested.

Thank you for this insightful conversation.

The Function that becomes aesthetics

Italian dental technician, CDT Stefano Lograno, demonstrates how it is possible for the medical-technical prosthetic team to adopt a protocol from diagnostics to cementation, in which aesthetics can be functionally guided in a simple, predictable and standardized workflow following the criteria of the gnathological school of Vienna of Prof. Rudolf Slavicek.

Click here to read. Enjoy!

Start Reading: BOND | SPECIAL EDITION | 6/2021

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BOND | VOLUME 7 | 10/2020

Nii paljude turul saada olevate adhesiivide, tsementide ja taastavate materjalide korral on raske otsustada, milline toode sobib individuaalseteks lahendusteks kõige paremini. Otsene testimine hambaravi praksises on võimatu, sest saada olevaid lahendusi on väga palju. Laboratoorsed uuringud annavad teavet üksikute toote omaduste kohta, kuid ei võimalda tavaliselt luua üldpilti. Lisaks on erinevate analüüside tulemused harva erinevate analüüsitingimuste tõttu võrreldavad. Kliinilised uuringud on tavapäraselt väga kasulikud, sest võimaldavad hinnata valitud materjalide kliinilist (pikaajalist) toimivust, kuid need avaldatakse tavaliselt aastaid pärast toote turuletulekut. Seega ei ole need saadaval varajastes staadiumites. Väga heaks teabe allikaks on praksistes teostatud hinnangud, sest nad toetavad võimalikke kasutajaid kõrge kvaliteediga hambaravi materjalide tuvastamisel.

Üheks institusiooniks, mis viib läbi ja avaldab praktikal põhinevaid kliinilisi hinnanguid ning toote toimivuse analüüse, on Ameerika Ühendriikides paiknev DENTAL ADVISOR. Üks kord aastas saavad parima toimivusega hambaravi materjalid ja seaded auhinnad Top Product ja Preferred Product Award. Võitjate nimekiri avaldatakse veebis (www.dentaladvisor.com) ja jaanuari-veebruari numbris ajakirjas DENTAL ADVISOR. Aastal 2021 olid mitmed ettevõtte Kuraray Noritake Dental Inc. tooted auhinnavõitjate seas.

Auhinnad Top Product Award

CLEARFIL™ SE Protect sai auhinna Top Product kategoorias „Otsesed restauratiivmaterjalid, kinnitusmaterjalid: isesöövitavad materjalid“. Isesöövituva adhesiivi moodustumine põhineb kahe-etapilisel isesöövitava adhesiivi moodustumise kuldstandardil, kuid CLEARFIL™ SE BOND sisaldab lisaks MDPB monomeeri, mis on antibakteriaalse kaviteete puhastavate omadustega, ning fluoriidi pikaajaliseks fluoriidi vabastamiseks. Ajakirja DENTAL ADVISOR auhinna väljaandmine põhines materjalianalüüsil, mida viisid läbi 13 DENTAL ADVISOR-i konsultanti ja toimetajat oma hambaarstipraksistes kuue nädala jooksul. Oma suurepärase toimivuse tõttu sai antibakteriaalne isesöövituv adhesiiv 98 protsendilise kliinilise hinnangu.

Kuuendat aastat järjest sai parima Top Product kategoorias „Otsesed restauratsioonid, komposiit, kõrgelttäidetav modelleeritav“ toode CLEARFIL MAJESTY™ ES Flow.

Universaalne voolav komposiit, mis sai ka auhinna Editor’s Choice, on saadaval kolmes voolavusastmes kõrgest väga madalani*. See võimaldab kasutajal valida sobiva viskoossuse igaks kliiniliseks lahenduseks. Kõrge voolavusega variant on parim kaviteetide laineriks ja vaikkatteks IDS protseduuridel. Väga vähe voolav variant on eriti sobilik laminaatide paigaldamisel ja isegi tagumiste tippude ülesehitamiseks. Universaalset voolavat komposiiti testisid 29 ajakirja DENTAL ADVISOR konsultanti rohkem kui 900 kasutuskorra vältel. Hinnatud omadused - paigaldamine/käitlemine, esteetika, viskoossus ja poleeritavus - hinnati suurepärasteks. Selle tulemusena on soovitati toodet 100 protsenti ja üleüldine kliiniline hinnang oli 98 protsenti.

* DENTAL ADVISOR hindas ainult keskmise voolavusastmega toodet (Low), sest kaks teist versiooni ei ole Ameerika Ühendriikides saadaval.

Toode, mis saavutas tunnustuse ajakirja Dental Advisor kollektiivilt juba seitsmendat korda järjest on TEETHMATE™ DESENSITIZER, mida kasutatakse ülitundlikkuse raviks.

Auhinna Top Product võitnud toode disainiti hüdroksüapatiidi (HAp) tootmiseks, mis täidab avatud dentiini tuubuleid ja emailipragusid. See toob endaga kaasa olulise ülitundlikkuse vähenemise, kui seda kanda paljastatud, mehhaaniliselt töödeldud või värskelt ette valmistatud dentiinile. Kui toodet kasutada restauratiivses hambaravis, ei ole tootel TEETHMATE™ DESENSITIZER negatiivset mõju adhesiivide või tsementide sideme tugevusele. Ajakiri DENTAL ADVISOR viis läbi kuus kuud kestnud kliinilise hinnangu, millesse kaasati 27 igeme taandumisega seonduva ülitundlikkusega patsienti. Toote kasutamine oli väga efektiivne kohese ja isegi pikaajalise (kuus kuud) ülitundlikkuse leevendamisel. Tänu sellele sai toode suurepärase hinnangu skooriga 96 protsenti.

Isekinnituva tsemendi kategoorias sai auhinna Top Product PANAVIA™ SA Cement Plus. See kaksikhooldusega isekinnituv vaiktsement eristub oma kasutusmugavuse, meeldiva viskoossuse ja lihtsa jääkide eraldamise poolest pärast valgusimpulssidega kõvastamist.

Tooted Preferred Product

Aastal 2021 toodete Preferred Product seas, mis pääsesid valikusse Editor’s Choice, on PANAVIA™ SA Cement Universal. See aastal 2020 auhinna Top Product võitnud isekinnituv universaalne vaiktsement sisaldab unikaalset LCSi monomeeri. See monomeer on silaanil põhinev ning sisaldab oma molekulis unikaalset pikka süsinikahelat. Süsinikahel loob kestva keemilise sideme portselaniga, liitiumdisilikaadiga ja vaiktsmendiga ilma lisasilaani sisaldava praimeri vajaduseta. Teine valemis sisalduv võtmetehnoloogia on algne MDP monomeer, mis tagab keemilise reaktiivsuse tsirkooniga, dentiiniga ja emailiga. Koos tagavad tehnoloogiad, et PANAVIA™ SA Cement Universal tekitab tugeva ja kestva ühenduse peaaegu kõikide restauratiivsete materjalidega ilma eraldi praimeri vajaduseta. Toote käsitsemisomadused, esteetika ja igemesõbralikkus said väga head kuni suurepärased hinnangust 31-lt kliiniliselt hindajalt, kes kasutasid tsementi 516 rakenduses. Üleüldine kliiniline hinnang oli 96%.

Lisaks oli toode CLEARFIL™ Universal Bond Quick teist aastat järjest ajakirja Dental Advisor konsultantide eelistatud toode Preferred Product.

Universaalset sidusainet võib peale kanda isesöövitava tehnikaga või koos K-ETCHANT süstlaga emailile söövitamise või täieliku söövitamise tehnikaga. Sidusaine sisaldab kiire sideme loomise tehnoloogiat, milleks on algne MDP monomeer koos innovatiivsete hüdrofiilsete amiidide monomeeridega. Sidusaine töötab koheselt ja ilma lisa-ekspositsiooniaja vajaduseta, mitmete kihtide pealekandmisteta ja ilma liigse hambastruktuuri hõõrumiseta. Kiire ja lihtne pealekandmise protseduur oli üks peamistest põhjusteks, miks ajakirja DENTAL ADVISOR konsultandid valisid toote CLEARFIL™ Universal Bond Quick tooteks Preferred Product ja valikuks Editor’s Choice kliinilise hinnanguga 98 protsenti.

Lõpetuseks valiti toode CLEARFIL™ CERAMIC PRIMER PLUS tooteks Preferred Product aastatel 2019, 2020 ja 2021 ning valikuks Editor’s Choice aastal 2021. Toode sisaldab algset MDP monomeeri ja silaani monomeeri, mis tagavad suurepärase sideme tugevuse igasuguste restauratiivsete materjalidega, nt silikaadipõhistele keraamikatele, tsirkoonile, komposiitidele ja isegi metallidele. Kasutajad võidavad protseduuride lihtsusest, sest toode lihtsalt kantakse aluspinnale ja kuivatatakse pärast soovituslikku eeltöötlust. Kliinilises hinnangus saavutas toode soovitustaseme 96 protsenti ja üleüldise DENTAL ADVISOR konsultantide hinnangu 96 protsenti.

Kokkuvõte

Enamus ettevõtte Kuraray Noritake Dental tooteid, mis võitsid käesoleval aastal auhinna, põhinevad vaigu tehnoloogiatel, mis on üheks meie võtmekompetentsidest. Me arendasime oma algse MDP monomeeri välja 1980-ndate aastate keskel. Tegemist on funktsionaalse monomeeriga, mis on hädavajalik komponent meie kõikides sideainetes, mida me oleme turule toonud tänase päevani, sh auhinnatud CLEARFIL™ SE Protect, PANAVIA™ SA Cement Universal, CLEARFIL™ Universal Bond Quick ja CLEARFIL™ CERAMIC PRIMER PLUS. See on ainult üks meie mitmetest ekspertiisivaldkondadest. Me pakume kasutajatele ka ennetavaid tooteid ja mitmeid restauratiivseid materjale komposiidi täitematerjalidest nagu CLEARFIL MAJESTYTM ES Flow kuni hambakeraamikani nagu KATANA™ Zirconia UTML, STML ja HTML. Me näeme auhindade võitmist positiivse tõestusena usaldusväärsest toote töökindlusest, mis toetab hambaarste nende eesmärkide saavutamisel.