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ADHESIVE LUTING: A DRIVER OF INNOVATION

What would modern restorative treatments be like without the availability of high-performance (self-)adhesive resin cements? Tooth preparations would still be much more invasive due to the need for sufficient mechanical retention between the tooth and the restoration. At the same time, it would be impossible to restore teeth with many innovative, tooth-coloured materials such as low-strength ceramics and composite. In short, restorative dentistry would be much less developed than it is today.

When the first resin cements were introduced several decades ago, however, the achieved progress came at the expense of simplicity: Adhesive luting procedures were highly complex and the many different components quite technique sensitive. Luckily, this has changed over the years due to continued development efforts ultimately resulting in the products that are currently available. The resin cement line-up of Kuraray Noritake Dental Inc. consists of three main products: the dual-cure three-component system PANAVIA™ V5, the single-component dual-cure universal resin cement PANAVIA™ SA Cement Universal and the light-curing PANAVIA™ Veneer LC.

For those who would like to learn more about the three systems, this 10^th issue of the BOND Magazine is definitely worth reading. It reveals important details about the 40-year history of the PANAVIA™ brand, sheds light on the strengths of each resin cement to facilitate indication-specific cement selection and provides in-depth information about their clinical use. In addition, two articles are dedicated to hot topics around the luting of restorations made of zirconia, a popular restorative material that some still consider to be unsuitable for adhesive luting procedures. For everyone wondering how it is possible to successfully lute minimally invasive restorations made of zirconia, the article titled “Innovative resin cements forming the basis of minimally invasive prosthodontics” is highly recommended. Those unsure about how to proceed with 5Y-TZP should read the article “How to cement restorations made of high-translucency zirconia”. Interesting information about cleaning options prior to adhesive luting rounds out the content of this magazine.

Click here to read. Enjoy reading!

Start Reading: BOND | VOLUME 10 | 10/2023

Previous versions:

BOND | VOLUME 9 | 08/2022

BOND | VOLUME 8 | 12/2021

BOND | VOLUME 7 | 10/2020

Photo credits to Giuliano Moustakis

Can you imagine a world without multi-layered zirconia? The invention of a zirconia material with natural colour gradation and well-balanced translucency and strength led to fundamental changes in the way zirconia-based restorations are produced. When the first product of its kind – KATANA™ Zirconia ML – was introduced to the dental market exactly ten years ago, dental technicians all over the world suddenly started rethinking their manufacturing concepts.

Since then, the trend towards a decreased thickness of the porcelain layer, a limiting of this layer to the vestibular area and the production of monolithic restorations is clearly perceivable. Technicians have developed their own concepts of micro-layering, which allow for more patient-centred approaches. This is also due to the fact that the total wall thicknesses of the restorations may be decreased without compromising the aesthetics. The line-up of multi-layered zirconia currently available from Kuraray Noritake Dental Inc. (KATANA™ Zirconia UTML, STML, HTML Plus and KATANA™ Zirconia YML with additional translucency and strength gradation) enables users to make indication-related material choices for the production of restorations that are precisely aligned to the individual demands of each case.

The reasons to choose KATANA™ quality

But why choose KATANA™ Zirconia instead of any other multi-layered zirconia disc? According to experienced users of the KATANA™ Zirconia Multi-Layered series, there are many reasons to opt for KATANA™.

For Jean Chiha, owner at North Star Dental Laboratories and Milling Center in Santa Ana, California, it is the combination of optical and mechanical properties that makes the difference: 

“KATANA™ Zirconia is the game changing material with well-balanced esthetics and strength!”. 

Naoki Hayashi, president of Ultimate Styles Dental Laboratory in Irvine, California, aesthetics is the most decisive argument to opt for the discs from Kuraray Noritake Dental Inc. He states:

“KATANA™ Zirconia discs offer trusted esthetics which gives me confidence in my clinical cases”.

Naoto Yuasa, chief ceramist at Otani Dental Clinic in Tokyo, adds predictability as an important factor:

“KATANA™ sustains my passions for aesthetic restorations and those of a predictable future in the long run”, whereas dependability is the key element.

For Hiroki Goto, the laboratory manager at Sheets and Paquette Dental Practice in Newport Beach, California reports:

“Without KATANA™ there is no pride. Haven’t experienced it yet? You have to see how reliable it is!”

Finally, we have asked Kazunobu Yamada, a pioneer in making porcelain laminate veneers using complementary color techniques and a first-hour user of KATANA™ Zirconia, what comes to his mind when thinking about KATANA™ Zirconia. According to the president of CUSP Dental Laboratory in Nagoya City, there is a clear link between the product name and its characteristics:

“Did you know that the word "KATANA" also means "protection against misfortune and evil"? Katana zirconia, the culmination of many years of research and development by Kuraray Noritake, has an unparalleled quality. KATANA™, for me, is truly "Protection for all technicians".”

The origin of well-balanced properties

It seems that the KATANA™ Zirconia Multi-Layered line-up stands out due to set of valuable properties enabling a dental technician to produce beautiful, high-quality restorations every time. The secret of success lies in meticulous raw material selection and controlled processing from the powder to the pre- sintered blank carried out at the production facilities of Kuraray Noritake Dental Inc. in Japan. They provide for the high product quality that is responsible for the materials’ outstanding behaviour supporting the best possible outcomes.

Case by Kanstantsin Vyshamirski

A male patient (47 years of age) presented to his dentist with severe damage to his teeth. His main request was to increase aesthetics, to achieve a more pleasing envisaged aesthetic area. A side request was to achieve a ‘whitening but natural look’. This was achieved by using a lighter colour palette of zirconia and porcelain materials. The final result was achieved through the creation of a wax-up, followed by a mock-up, provisional restoration and finally adhesive bonding of the zirconia crowns.

Initial situation

Fig. 1. Initial situation. Male patient (47 years of age)

Fig. 2. Planning the new smile according to patient’s aesthetic and functional parameters.

Fig. 3. Mock-up in place to check the new look in the patient’s mouth.

Fig. 4. KATANA™ Zirconia YML shade A1 crowns with labial cutback after milling.

Fig. 5. Crowns after sintering on on the plaster model.

Fig. 6. Noritake CERABIEN™ ZR porcelain layering map.

Fig. 7. Finishing the labial surface using both polishing and selfglaze. On the palatal side of the crowns only CERABIEN™ FC Paste Stain stains and glaze were used for finishing. To aid in optimisation of the soft tissue condition the palato-cervical and near proximal areas were polished.

Fig. 8. Finished crowns on the plaster model.

Fig. 9. Try-in using PANAVIA™ V5 White try-in paste, to confirm the proper appearance. For the final adhesive cementation PANAVIA™ V5 White has been used.

Final situation

Fig. 10. Situation after seven months. The result is aesthetically pleasing and the gingival condition excellent.

Fig. 11. Recall after 1.5 years

Click here for the product page for more details

What can you expect to find online

- General information about:
- KATANA™ Zirconia YML
- CERABIEN™ ZR porcelains
- FC Paste Stain
- PANAVIA™ V5
- Full Product Assortment
- Safety Data Sheets
- Instructions For Use
- Technical Information

Kanstantsin started his dental technician career in 2014. His speciality is aesthetic prosthetic porcelain works. Kanstantsin is an experienced user of KATANA™ Zirconia and Noritake porcelains. He owns his lab in Riga, Latvia.

Nogle virksomheder bruger hovedsageligt grundlæggende teknologier, som andre har udviklet, til at forbedre deres produkter og indføre nye produkter, mens andre virksomheder udfører grundlæggende forskning og teknologiudvikling internt. Er denne forskel relevant for en person, som til dagligt bruger de heraf følgende produkter i en tandlægepraksis eller på et laboratorium? Det er den, fordi virksomheder med en dyb forståelse for de underliggende komponenter, kemi og teknologier er i stand til at løse eksisterende problemer og reagere fleksibelt og hurtigt på markedets behov. Denne artikel beskriver virkningen af flere grundlæggende teknologier, der er udviklet af Kuraray Noritake Dental Inc. til cementering af indirekte restaureringer.

Adhæsive cementer før og nu

Fræsning af forskellige typer keramiske tandrestaureringer har åbnet op for nye muligheder inden for protetik. Man kan producere og placere meget æstetiske restaureringer. Det, der ofte undervurderes i denne sammenhæng, er den rolle adhæsive cementer spiller, da de ikke kun understøtter de gennemsigtige, tandfarvede restaureringers æstetiske udseende, men også baner vejen for mindre invasive præparations- og restaureringsdesign. Tidlige produkter, der sikrede kemisk adhæsion mellem tænder og indirekte restaureringer, havde desværre en tvivlsom adfærd og en høj teknisk følsomhed på lang sigt, samtidig med at appliceringsproceduren var ekstremt kompleks. Teknologiudviklingen hos Kuraray Noritake Dental Inc. har bidraget væsentligt til en forbedret, langtidsholdbar bindingsevne og en forenklet applicering.

Optimering af den langtidsholdbare bindingsevne

For at opnå en langtidsholdbar binding af tidlige cementeringssystemer til tandstrukturen (især dentin) besluttede Kuraray, et moderselskab til Kuraray Noritake Dental Inc., i 1970‘erne at fokusere på udviklingen af en mere kraftig adhæsiv monomer. Det første skridt på vejen mod ”excellence” var at indføre fosfatmonomeren Phenyl-P i 1976. Fem år senere førte fortsatte bestræbelser på at forbedre og forfine dens molekylære struktur til indførslen af den populære
MDP-monomer, der er i stand til at skabe en særlig kraftig og langtidsholdbar binding til emalje, dentin, metal og zirkonia.

Det, at den stadig er en del af alle Kuraray Noritake Dental Inc.’s adhæsiver og adhæsive cementer og samtidig også bruges af andre producenter til at optimere deres produkters bindingsstyrke og -holdbarhed, understreger opfindelsens genialitet. Sammenlignet med MDP, der er syntetiseret andre steder, skiller Kuraray Noritake Dental Inc.’s originale MDP-monomer sig ud for sit uovertrufne renhedsniveau. Uafhængige undersøgelser viser, at dette renhedsniveau har en positiv effekt på bindingsadfærden1. MDP-monomeren har, ved at tilbyde stabilitet i et fugtigt miljø, bidraget til en mere ensartet ydeevne for de produkter, der indeholder den.

Forskellige MDP-monomerer tilbyder forskellige renhedsniveauer og forskellige bindingsevner.

Der blev klargjort tre eksperimentelle, selvætsende primere bestående af 15 wt % 10-MDP fra forskellige kilder: KN (Kuraray Noritake Dental), PCM (Tyskland) eller DMI (Designer molecules Inc., USA). Data venligst udlånt af Dr. Kumiko Yoshihara.

For at adhæsive resincementer skal kunne give en kraftig binding med en enestående marginal forsegling, er det dog ikke nok at indeholde en adhæsiv monomer. En effektiv polymerisering af denne monomer er ligeledes nødvendig - men det er ikke altid så let at opnå. For at kunne sikre en effektiv lys- og mørkhærdning af PANAVIA™ V5 har Kuraray Noritake Dental Inc. udviklet sin Touch-Cure Technology. Denne teknologis vigtigste del er en nyudviklet, meget aktiv polymeriseringsaccelerator i PANAVIA™ V5 Tooth Primer, som kan eksistere sammen med den sure MDP-monomer, der fremmer polymerisering ved grænsefladen mellem tanden og cementen, så snart PANAVIA™ V5 Paste påføres på den forbehandlede tandoverflade. I PANAVIA™ Veneer LC - en lyshærdende resincement, der fungerer med de samme primere - viser polymeriseringsacceleratoren i PANAVIA™ V5 Tooth Primer den samme virkningsmekanisme. Det bidrager til polymeriseringen af den adhæsive grænseflade, mens PANAVIA™ Veneer LC Paste har en fremragende omgivende lysstabilitet og polymeriseres ved lyshærdning.

Dette eksempel blev for eksempel evalueret for PANAVIA™ F2.0, forgængeren til PANAVIA™ V5. Resultatet af forsøget: PANAVIA™ F2.0 viste meget bedre marginale forseglingsegenskaber end de andre evaluerede cementer2. Denne dokumenterede sikre forsegling af grænsefladen giver en lavere forekomst af marginal lækage, en meget høj polymeriseringsratio, selv i selvhærdende tilstand (uden lyshærdning eller hvor lyset måtte være blokeret af restaureringsmaterialet) og dermed en særlig kraftig binding.

En ekstra fordel ved indføjelsen af polymeriseringsacceleratoren er, at den fungerer som et kraftigt reduktionsmiddel. Den neutraliserer natriumhypochlorit, som ofte bruges som skylleopløsning under endodontisk behandling, og eliminerer dermed dens negative effekt på bindingsstyrken af den efterfølgende cementpasta.

Forenkling af glaskeramisk cementering

Færre flasker, færre trin og strømlinede cementeringsprocedurer. Det er derfor de selv-adhæsive resincementer blev udviklet og indført i starten af 00’erne. De fleste af disse produkter har dog et begrænset indikationsområde. De fungerer godt på zirkonia, metal, emalje og dentin, men anbefales enten ikke eller kræver en ekstra silanprimer til glaskeramisk binding. PANAVIA™ SA Cement Universal med MDP er anderledes, fordi det er en anden patentbeskyttet teknologi fra Kuraray Noritake Dental Inc.: LCSi-monomer er et silankoblingsmiddel med en lang kulstofkæde. Denne monomer danner en kraftig kemisk binding med resinkomposit, porcelæn og silica-keramik (såsom lithiumdisilikat), hvilket fjerner behovet for en separat silankomponent (en primer eller et adhæsiv). PANAVIA™ SA Cement Universal skiller sig klart ud fra andre selv-adhæsive resincementer som en ægte enkomponentscement, ved at udnytte fordelene ved denne teknologi, selv til restaureringer af glaskeramik.

Hvis det ønskes, kan produktets bindingsstyrke til tandstrukturen øges ved at bruge det populære universaladhæsiv CLEARFIL™ Universal Bond Quick med Rapid Bond Technology. Denne teknologi er udviklet af Kuraray Noritake Dental Inc. for at løse problemer med langsom indtrængning af tandstrukturen, især våd dentin, som er typisk for universaladhæsiver. For at sikre korrekt indtrængning skal disse adhæsiver gnides aktivt ind i tandstrukturen i lang tid, eller brugerne skal vente i et stykke tid, før produktet er lyshærdet. Den patenterede Rapid Bond Technology, der består af den originale MDP-monomer, kombineret med hydrofile amidmonomerer, giver en høj affinitet til vand, hvilket giver en hurtig og dyb indtrængen af våd dentin. Som følge heraf forkortes appliceringstiden, og håndteringen forenkles, uden at det påvirker bindingens ydeevne negativt.

Konklusion

Teknologier, der er udviklet af Kuraray Noritake Dental Inc., har i høj grad bidraget til en forbedret bindingsevne for adhæsive cementer og en meget universel brug af selv-adhæsive resincementer. Som følge heraf tilbyder virksomheden en strømlinet portefølje af højtydende resincementer til alle brugere og til typiske kliniske situationer. Der er behov for færre komponenter og færre trin og procedurerne forenkles - hvilket giver færre fejl og æstetiske restaureringer, der holder. Udover de teknologirelaterede fordele tilbyder de nævnte produkter mange andre fordelagtige funktioner. En detaljeret beskrivelse findes online på kuraraynoritake.eu.   

Referencer

*) 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.
**) 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

Nogle virksomheder bruger hovedsageligt grundlæggende teknologier, som andre har udviklet, til at forbedre deres produkter og indføre nye produkter, mens andre virksomheder udfører grundlæggende forskning og teknologiudvikling internt. Er denne forskel relevant for en person, som til dagligt bruger de heraf følgende produkter i en tandlægepraksis eller på et laboratorium? Det er den, fordi virksomheder, der udvikler alt fra bunden, som regel kender produkterne og fremstillingsprocedurerne bedre, hvilket gør det lettere for dem at ændre specifikke funktioner, løse eksisterende problemer og reagere på markedets behov. Denne artikel beskriver virkningen af flere grundlæggende teknologier, der er udviklet af Kuraray Noritake Dental Inc., på arbejdsprocessen med at skabe direkte restaureringer i komposit.

Direkte restaureringer - fra komplekst til simpelt

Adhæsiv genopbyggende tandpleje, der anvender højtydende dentaladhæsiver og resinkompositter er lige nu en af de mest populære måder at behandle tænder med kariesangreb på. I dag er en enkelt flaske universaladhæsiv og en eller to nuancer og opaciteter af universalkomposit normalt nok til at skabe smukke og holdbare resultater, forudsat at de rigtige materialer er valgt. Dette har dog ikke altid været tilfældet. De teknikker, der blev brugt til at lave direkte restaureringer, har i lang tid været ret komplekse: Adhæsiver var teknisk krævende og krævede flere flasker og flere trin med lange appliceringstider. Omvendt giver kompositfillere kun naturtro resultater, når mange forskellige nuancer og opaciteter kombineres på den rigtige måde. Og selvom de komplekse procedurer blev udført korrekt, var risikoen for mikrolækage, misfarvning og i sidste ende sekundær caries forholdsvis høj. Kuraray Noritake Dental Inc. fokuserede ret tidligt på at løse disse problemer og startede med at bruge den originale MDP-monomer, der blev udviklet i 1981.

Optimer af bindingsevnen

Den originale MDP-monomer var i stand til at løse problemet med adhæsivernes begrænsede langtidsholdbare bindingsevne. MDPs hydrofile (fosfat) gruppe danner en særlig kraftig og holdbar kemisk binding med calcium, der findes i hydroxyapatit, som er hovedbestanddelen i emaljeog dentin. Det MDP-Ca-salt, der dannes, danner grundlaget for et stabilt, kraftigt og holdbart hybridlag. Sammen med resin i bindemidlet opnås en tæt forsegling af kaviteten efter lyshærdning. MDP har hidtil været en vigtig komponent i enhver adhæsiv fra Kuraray Noritake Dental Inc. og det er den nøglekomponent, der har gjort CLEARFIL™ SE Bond til den gyldne standard for selvætsende adhæsivsystemer.

Kuraray Noritake Dental Inc. var dog overbevist om, at dentale adhæsiver burde give mere end blot en kraftig og langvarig binding, og begyndte derfor at fokusere på at løse et andet problem: risikoen for demineralisering og kavitation forårsaget af resterende bakterier i kaviteten. På baggrund af sin erfaring med at udvikle andre adhæsive monomerer opfandt Kuraray Noritake Dental Inc. MDPB-monomeren, der har en antibakteriel kavitetsudrensende effekt. I modsætning til antibakterielle midler, der kan forringe bindingsstyrken af et efterfølgende appliceret adhæsiv, dræber MDPB-monomeren de resterende bakterier uden at påvirke bindingsevnen. Den følger med primeren til det 2-trins selvætsende adhæsiv CLEARFIL™ SE Protect og immobiliseres ved polymerisering.

MDPBs bakteriedræbende mekanisme formodes at være den samme som det velkendte antibakterielle stof CPC (Cetylpyridiniumchlorid), der findes i mange typer tandpasta og mundskyl.

Selvom de 2-trins selvætsende adhæsiver allerede har forenklet klæbeproceduren, går 1-trins universaladhæsiver lige skridtet videre. Det er en udfordring at samle ingredienser, fordelt på flere trin, i én flaske uden at gå på kompromis med produktets stabilitet. Takket være moderne teknologi er dette nu muligt. For hurtigst muligt at forsegle overfladen efter appliceringen skal gennemtrængningen af monomererne i tandvævet være hurtig og effektiv. Men gennemtrængningen bremses normalt af monomerer, der har brug for tid til at trænge ind i tandstrukturen - især våd dentin - og sommetider endda skal gnides ind. Derfor fokuserede Kuraray Noritake Dental Inc. på at udvikle Rapid Bond Technology. Den går ud på kombinere den originale MDP-monomer med nyudviklede hydrofile tværbindende amid-monomerer og er integreret i CLEARFIL™ Universal Bond Quick. De hydrofile amid-monomerer giver en hurtig, dyb og fuldstændig gennemtrængning af dentinen og danner ved hærdning et tæt tværbundet polymernetværk, der er ansvarligt for en kraftig og holdbar binding. Tiden der går med at vente og gnide fjernes derfor, og der skabes en tæt og langvarig forsegling af kaviteten efter lyshærdning.

Deres hydrofilicitet (evnen til at blande sig med vand) betyder, at Rapid Bond-teknologiens amidmonomerer trænger meget godt gennem dentinen. Efter lyshærdning har bindingen en lav vandoptagelse og derfor en høj
modstandsdygtighed over for aldring.

Optimering af direkte restaurering

Kombination af flere lag, nuancer og opaciteter: Brugen af meget komplekse layeringteknikker til at skabe naturtro kompositrestaureringer hører heldigvis fortiden til i mange kliniske situationer. Dette skyldes højt udviklede resinkompositter, der blender perfekt sammen med den omkringliggende tandstruktur. For at opnå denne gode egenskab har Kuraray Noritake Dental Inc. udviklet sin egen Light Diffusion Technology (LDT). Denne teknologi bruges i særlige præpolymeriserede fillers, der fungerer som millioner af mikroprismer, der transmitterer og bryder lys og farve fra den omkringliggende tandstruktur. Fillerne er optimeret i størrelse, fordeling og brydningsindeks i forhold til matrixen og giver en uovertruffen naturlig blending. Hele CLEARFIL MAJESTY™ kompositdelen indeholder den patenterede fillerteknologi. Det nyeste produkt – CLEARFIL
MAJESTY™ ES-2 Universal – hvor Kuraray Noritake Dental Inc. gør brug af den næste generation af LDT, giver mulighed for at benytte en enfarvet teknik med et forenklet farvevalg. Produktet fås i to nuancer til den forreste del og i én nuance til den bagerste del, men blender så godt ind at det dækker stort set alle nuancer i VITA classical A1-D4-farveguiden.

Korrekt brydning og transmission af lys for at opnå en god optiskintegration: lysdiffusionsfillere i CLEARFIL MAJESTY™ ES-2 fra Kuraray Noritake Dental Inc.

Da en smuk optisk fremtoning ikke kun afhænger af optisk integration og usynlige restaureringsmarginer, har Kuraray Noritake Dental Inc. også udviklet fillers, der sørger for resten - en naturlig overfladeglans og holdbar polering. Løsningen, der er integreret i CLEARFIL MAJESTY™ ES Flow med dens tre flydeevnegrader, kaldes Submicron Filler Technology, som består af blanke submikrone fillers. Disse fillers er så små, at lysets refleksion virker naturlig også efter nogen tid. Kuraray Noritake Dental Inc.’s exceptionelle silanteknologi bruges til at samle millioner af disse submikrone fillers og sørge for at holde dem sammen over tid. Det giver mulighed for høje fillermængder i kompositter med lav viskositet og begrænser vandoptagelsen, som ellers ville føre til nedbrydning af den hærdede komposit. Den perfekte balance mellem de blanke submikrone fillers, lysdiffusionsfillers, resinmatrix og patenteret silanteknologi sikrer en balanceret kombination af mekaniske og optiske egenskaber.

Voorbeeld van een eenkleurige restauratie, vervaardigd van CLEARFIL MAJESTY™ ES-2 Universal.

Konklusion

Adhæsive monomerer, fillerteknologier og silanteknologi, der giver en solid kombination af fillers, clusters og resinmatrix: Kuraray Noritake Dental Inc. er uden tvivl en pålidelig ekspert inden for adhæsive restaureringer. De patenterede teknologier, der er udviklet inden for de seneste årtier, har i høj grad bidraget til at skabe en bedre (og mere holdbar) ydeevne af direkte restaureringer, hvor pålidelige og æstetiske resultater er meget nemmere at opnå.

Interview with Andreas Chatzimpatzakis

Fewer bakes, fewer ceramic powders - there is clearly a trend toward simplification in the production of zirconia-based prosthetic work. This is also true for implant-based restorations, which often involve gum parts. DT Andreas Chatzimpatzakis, international trainer for Kuraray Noritake Dental Inc., and the owner of ACH Dental Laboratory in Athens, Greece, shares his approach to high aesthetics in implant prosthodontics in the following conversation.

You are a user of the CERABIEN™ ZR portfolio from the outset. When did you test the products for the first time and why?

Well, it was many years ago when I finished my very first zirconia-based restoration. The reason to test CERABIEN™ ZR was that when I asked the dental technician who had milled the framework which porcelain system to use. He suggested to use CERABIEN™ ZR, which I did. I was immediately impressed by the system and by the outcome I was able to achieve on the first attempt.

Did you ever test any other porcelain systems for ceramic layering?

Yes. Before I becoming an international trainer for Kuraray Noritake Dental Inc., I had the opportunity to test many other porcelain systems for layering on zirconia. Based on this experience, I can say that CERABIEN™ ZR is unique and the best system I have ever used. The reason is that its translucency and chroma are extremely close to natural teeth. In addition, due to a controlled firing shrinkage, a One-Bake Technique may be employed even in long-span restorations.

Your hands-on demonstration at the Kuraray Noritake Dental booth during the IDS 2023 in Cologne focused on White and Pink Aesthetics achieved with CERABIEN™ ZR. Is there a specific concept you use?

Nowadays, everyone producing dental restorations – no matter whether based on natural teeth or on implants – is confronted with increasing aesthetic demands of patients and dental practitioners. The high demands are developed because life-like restorations and cosmetic dental treatment outcomes are presented everywhere in the web and on social media. The showcased quality of outcomes is simply expected, even if the financial budget is limited. To be able to fulfil these demands in the field of implant-based prosthodontics, I have developed an approach that allows me to achieve high aesthetics with little effort. My concept is based on using not too many ceramic powders. For extra chroma and special characterization, I rely on the power of the internal live stain technique, first introduced by Hitoshi Aoshima-sensei.

Please summarize the most important details of your presentation.

The first important detail is the design and characterization of the framework. Before sintering, I apply Esthetic Colorant for KATANA™ Zirconia. After the sintering process, shade base stain and internal stains are mixed and applied. In this way, I create a nice canvas that helps me to achieve a life-like result with only a few selected ceramic powders. In most cases, three to five powders are enough to produce a great result. Among the powders used most frequently are Opacious Body, Body, LTX, Mamelon and CCV. After the first bake and a little grinding, I make use of internal stains again. They offer support in the controlling of the chroma and the integration of special characteristics. When this step is completed, the final build-up is done with one or two ceramic powders, most of the times LT1 and Enamel or LT0. Pink aesthetics are usually created with Tissue 1, 3 and 5. For the free gingiva, LT Coral is my go-to solution. The major goal is always to obtain maximum quality in a minimum of time. To achieve this, a good knowledge of the materials and of course practicing – on both, porcelain build-up and morphology – are strictly required.

Fig. 1. Complex implant-based restoration: Framework design.

Fig. 2. Esthetic Colorant …

Fig. 3.  … applied prior to the final sintering procedure.

Fig. 4. Appearance after sintering.

Fig. 5. Final outcome.

Are there any concrete tips and tricks you would like to share?

For the characterization of the framework, I mix the internal stains with shade base stain powders; mostly with SS Fluoro. For the first bake, especially when the restoration is large and the amount of ceramic to be applied huge, I reduce the heating rate up to 38 degrees per minute. I also increase the drying process up to 17 or even 20 minutes depending to the restoration. Experience shows that these measures optimize the aesthetic outcomes.

You often mention that it is extraordinarily important to understand the morphology of natural teeth to be able to produce beautiful restorations. Why is this the case?

A successful prosthetic restoration needs to offer proper function and aesthetics. Function means a precise fit, perfect contact points and occlusion, a proper emergence profile and interproximal embrasures for self-cleaning etc. All this is described by the term morphology. Aesthetics, on the other hand, is guided by shape and colour. The effort required to establish a proper morphology is much higher (about 70 percent of the total work) than the effort involved in obtaining the right translucency, opalescence and chroma.

What instruments do you use to imitate the morphology of natural teeth and how do you do it?

I usually make use of the Optimum™ Spring Ceramic Brush Size 8 (MPF Brush Co.), stones and diamond burs for detailed grinding and carving after the final bake. I studied morphology at the Osaka Ceramic Training Centre in Japan with Shigeo Kataoka-sensei. According to him, a key factor in creating a perfect macro and micro morphology lies in the shadows. To be able to take into account the interference of light and shadow during grinding, a light source is placed on one side of the restoration.

How many bakes do you need to produce highly aesthetic restorations?

It depends on the case, although in many situations, I nowadays opt for some kind of micro-layering. Lately, I have used micro-layering a lot with internal stain directly on the zirconia framework. In other cases, I do a quick first bake, then the internal staining, a final bake and glazing. For small or single-unit restorations in the posterior region, a One-Bake Technique is often sufficient. Even a Zero-Bake approach using Esthetic Colorant on a monolithic zirconia restoration may be appropriate here, and it is very convenient. If there is a restoration with high aesthetic demands – these are typically single anterior restorations – the technique I select depends on the shade. In some cases, using only the internal stain technique is enough to reach a high aesthetic level, while in other cases, additional steps need to be taken. To my mind, there is no single technique that fits all cases. As mentioned before, I try to achieve high aesthetics in a minimum of time.

Fig. 6. Clinical example of achieving high aesthetics in a minimum of time: Before …

Fig. 7. … and after crown placement.

Fig. 8. High aesthetics …

Fig. 9. … achieved in a minimum of time.

Did your approach change due to the availability of high-translucency zirconia materials with colour (and flexural strength) gradation?

Well, yes! My overall approach changed more to micro-layering. Several years ago, we needed to consider how to mask the framework and how to achieve translucency in areas with limited space. The problem was solved for single-unit and small anterior bridge restorations with the availability of KATANA™ Zirconia UTML and STML. With the introduction of KATANA™ Zirconia YML, a high-translucency material became available for long-span or implant-based restorations as well. We have strength and translucency all in one disc. In most of my cases, the framework material replaces the dentin with regard to morphology and shade. Hence, I need to focus on adding the enamel by applying the transparent and translucent powders. The powders of the internal stain technique are used to characterize the framework, and with a micro-layer of porcelain, the goal of creating an aesthetic restoration in the minimum of time is achieved. This is exactly why I am sure that micro-layering is the future.

What drives you to share your knowledge with others?

My passion! I love my work! And I love to see technicians become better and better. Dental technology is an exciting journey, a journey that begins when the first impression arrives in the dental laboratory, and it ends when the final restoration is cemented into the patient’s mouth. And this journey is so exciting because we change lives. We change people’s personalities, we give them back their smile, we give them back their self-respect. Consider that every day, every single moment working on our bench trying to imitate nature… there is nothing more exciting than that!!!

My approach as an instructor is to lead dental technicians to master the art of observing natural teeth. This is the way every individual will understand morphology and shade. You need no special talent to be a very good dental technician. You need to observe! Your eyes see, your mind understands, and your hands will follow.

Alexander (Alek) Aronin is a master dental technician who dedicated himself to the creation of high-end, handmade porcelain restorations. He runs a dental laboratory and morphology school in Spain, and travels the world as a lecturer and teacher.

The greatest source of inspiration in his professional life is the book Collection of Ceramic Works by Hitoshi Aoshima. Through reading it in 1996, he discovered superb outcomes of working with dental ceramics. Moreover, the book’s content made him realize that the creation of handmade porcelain work is a result of special education and manual skills. Those who want to become masters need a lot of commitment and a striving for continuous improvement, which Alek shows in his work and his classes. We talked to him about his philosophy and his enthusiasm for the creation of lifelike restorations. He shared with us his perspective on the future of dental technology and gave some practical tips on how to achieve a high level of professional satisfaction.

Photo courtesy of Dennis Debiase

Alek, many dental technicians decide to focus on CAD/CAM technology and automated processing of dental ceramics. Due to improvements on the material side, a handmade porcelain layer is no longer necessary in many clinical cases. In this context, the manual refinement process is reduced to a minimum. Why did you decide to take a completely different path and focus on fully manual dental craftsmanship?

The shift towards automated processing is not a matter of choice for dental technicians rather, it is a natural response to the evolution of technology. The high-end manual refinement process remains unchanged. The human element, from communication to hand crafting among skilled individuals and demanding clients, has been a constant so far throughout history. This traditional connection remains stable for centuries.

Digitalisation is not the revolution in the dental industry, and I do not see the benefit of it in our narrow specialization yet. In the area we are working, we do all steps of our case faster, incomparably more precise and more profitable. But we are keeping eye on machines and waiting for a suitable one.

Machines and automated processes widely serve mass production businesses focused on fast, affordable and uniform results in a highly competitive field. Our goal and workflow are different - we provide individual work and personal attention to each of our partners and patients.

So, we do not compete with the production labs and do not interrupt each other, we coexist in parallel worlds as always. A small number of dentists and their patients will always demand personal attention and valued restorations and service of the highest quality.

Many dental technicians admire your work. Yet, you continue to strive for improvement. Why is this the case?

On one side, we are limited by static ceramic material used to mimic dynamic natural teeth that keep changing for a lifetime. On the other side, we are limited by our manual skills. I am still far away from my teachers and Japanese colleagues. My target is to improve the fabrication process. My goal is to achieve the simplicity and imperfectness like Aoshima-sensei.

Alek lecturing at the IDS 2023 in Cologne.
Photo courtesy of Dennis Debiase

We are enjoying the outcome, but prefer to focusing on the improvement of the process, and move on to create a better one. This is what I am learning in Japan, and this is what I teach my students.

Talking about learning: What are the most important aspects a dental technician who wants to improve his skills should have in mind when looking for a good teacher?

Manual skills are very important, but not the only aspect that should be taken into account. Every individual should be motivated and guided and this is a teacher’s job.

I love the traditional Japanese way of teaching and learning: The teachers are passionate, leading the way by evoking emotions and manual skills to bring the best out of every single student. My personal advice for dental technicians who want to become masters in the creation of lifelike high-end dental restorations is to select their teachers carefully and go to a private school or courses whenever they have the chance.

What are the most important tools a dental technician needs to use when trying to create high-end lifelike restorations?

I suggest to focus on four aspects:

1. Documentary dental photography - required for documentation and communication with the dental office and patients using constant (once set and never changed) parameters of the photo equipment.
2. Focus to the biomimetic additive dentistry. This is a minimum machine invasive field. Dental technicians and dentists should be able to develop a deep knowledge about clinical and lab-side procedures to be able communicate with each other.
3. Mastering morphology and function (shape carving), and anatomy (internal staining), which comes with value control and mimicking fine tooth details for best integration in the mouth.
4. Written communication (stop phone calls) is very important, this is the way how to exchange the information between the patient, clinic and lab by strict protocols.

I teach these complex skills in my morphology school and in many of my trainings worldwide. Focusing on the four aspects, a dental technician has a great chance to become a good specialist in a relatively short period of time in a narrow field.

Is material selection important for achieving great results?

I’ve been using Noritake ceramic for most of my life, and the reason is simple: Noritake created their EX-3 porcelain over 40 years ago, and it was so well-made that it has not needed any changes since.

This is showing their consistently high quality and creates unbroken succession in the valuable tradition of passing on techniques and knowledge.

Today, among different generations of dental technicians, we can use and share the same methods, vocabulary and abbreviations, powders, and temperature charts developed by our skilled teachers 30 to 40 years ago. This unique feature sets Noritake and Creation porcelains apart from all other brands and systems in the world.

The other Noritake porcelain I use quite frequently is CERABIEN™ ZR, which is also well-tried and tested and has even some more advantages than EX3.

Is there any final advice you would like to give?

To become a good professional, I suggest to developing in four parallel directions:

1. Practicing on phantoms - fabricating cases and ceramic samples. It helps to experiment and practice with varied materials and techniques.
2. Implementing the achieved techniques in clinical cases.
3. Working with case presentation PowerPoint or Keynote: documenting the working steps in pictures and videos from beginning to end.
4. Mastering the communication using e-mails. Constantly calibrate and adjust the information exchange process between the clinic and lab. Acquire deeper knowledge about the work of each other.

Good luck!

Interview with Mitsunobu Kawashima
Manager, Technology Division of Kuraray Noritake Dental Inc.

In 1983 – exactly 40 years ago – PANAVIA™ EX was introduced in Japan as the first product of the PANAVIA™ family and the first product containing the original MDP monomer. Since then, the PANAVIA™ family of resin cements has been continuously expanded by developing new resin-cement materials that are precisely adjusted to the contemporary demands of dental practitioners. The current line-up of easy-to-use, high-performance adhesive luting materials is globally available and used by dental practitioners with high quality standards.

We had a conversation with Mr. Mitsunobu Kawashima about PANAVIA™ EX as a ground-breaking innovation in the field of dental resin cements and subsequent steps toward the current well-balanced resin cement portfolio. He is currently responsible for the development of chair-side materials in the Technology Division of Kuraray Noritake Dental Inc. (Kuraray Noritake Dental) and has been part of the team developing the many products of the PANAVIA™ family for more than 30 years.

The resin cements developed by the company before the introduction of PANAVIA™ EX contained the adhesive monomer Phenyl-P. Why did you decide not to use Phenyl-P in the new formulation?

At the time we decided to develop PANAVIA™ EX, we were engaged in the development of new adhesive monomers to replace Phenyl-P. The main aim of this project was an improvement of our products’ bond strength to metal alloys and dentin. Among the new adhesive monomers being developed, we decided to use the MDP monomer, because it features excellent bonding to tooth structure and metal alloys used in dentistry, as well as superb resistance to water. Incidentally, our first products to contain the original MDP monomer were the resin cement PANAVIA™ EX and the bonding agent CLEARFIL™ NEW BOND.

Where did the name PANAVIA™ come from?

The name “PANAVIA™” is a compound word consisting of “PAN” and “VIA”. The former is of Greek origin, and the latter is of Latin origin. “PAN” means “everything” and “VIA” means “way” or “method”. Consequently, the name “PANAVIA” describes a “method for bonding everything”; it represents our desire to have products launched under the umbrella of the PANAVIA™ brand recognized as dental materials that can bond to all types of restoration and tooth structure.

Would you please tell us the story behind the development of PANAVIA™ EX?

Back in the early 1980s, it was indispensable for us to develop new adhesive monomers as a part of our project to develop a new resin cement with unprecedented adhesive properties. In this context, we conducted a comprehensive literature search for compounds thought to be involved in adhesion. At the same time, we carried out a variety of R&D activities, including basic research to quantitatively clarify the relationship between the molecular structures of monomers and their adhesive qualities, synthesis trials of various monomers and bond strength tests. Consequently, we succeeded in developing the MDP monomer that had the physical properties we were working to obtain. Following the development of that MDP adhesive monomer, we were finally able to create PANAVIA™ EX in our laboratory. In early 1982, we completed the first prototype of PANAVIA™ EX for external evaluation and asked a dental college in Japan to evaluate it. He found that the prototype cement might cure too quickly in clinical use. This was due to the fact that we had not taken into account the difference between room temperature and intraoral temperature, which has a huge impact on the curing time. This error led us to recognize how important clinical evaluations are during the development of dental materials. To this day, we continue to place great importance on the opinions of clinicians whenever a new material is being developed.

The name “PANAVIA™” is a compound word consisting of “PAN” and “VIA”. The former is of Greek origin, and the latter is of Latin origin. “PAN” means “everything” and “VIA” means “way” or “method”.

What were the key technological features of this new PANAVIA™ EX cementation system?

The system had five key features: Appropriate film thickness, appropriate flow properties of the paste, radiopacity, improved bond strength and improved surface-cure characteristics. At the time that PANAVIA™ EX was developed, a film thickness of 30 μm or less was desired for luting cements. The largest components we wanted to use in the formulation – the silica filler particles present in our composite resin – had a maximum particle diameter of 50 μm. We were able to achieve a film thickness of 30 μm or less by significantly extending the silica grinding time, which made the filler particles much finer. An appropriate paste consistency – a low level of viscosity and good flowability – was achieved by using low-viscosity monomers for PANAVIA™ EX. In order to make the cement radiopaque, we dispersed radiopaque filler within the powder component. In fact, we were convinced that it was essential to be able to check for the presence of excess cement under the gingival margins after a restoration was placed. The increase in bond strength was achieved by blending the MDP monomer into the liquid component.

What about the surface-cure characteristics of the cement?

Every dental practitioner knows that the surface of resin cements must be protected from oxygen in the air in order to cure properly. For this purpose, we developed OXYGUARD, a water-soluble gel material. It is applied to the restoration margins to cover the unpolymerized resin cement surface and protect it from exposure to oxygen. In this way, the formation of an oxygen inhibition layer – a layer of uncured resin on the surface that compromises the marginal integrity of the restoration – is prevented and an intact, fully polymerized cement surface can develop. In this way, the use of OXYGUARD has contributed greatly to improving the cure characteristics of cements.

What do today’s PANAVIA™ products and PANAVIA™ EX have in common?

The PANAVIA™ family of products, including PANAVIA™ EX, share the concept of “being a resin cement product that opens new dimensions in dentistry”. PANAVIA™ EX was our first resin cement, and it was conceived as a cement for a new era. It can bond to tooth structure and dental metals very well, thanks to the use of the MDP monomer. This important adhesive monomer is still used today in many of our products. Ever since the launch of PANAVIA™ EX, Kuraray Noritake Dental has continued to take on new challenges and has developed many new products in the growing PANAVIA™ family. These include PANAVIA™ 21, a cement in paste form that has a self-etching primer as an accessory; PANAVIA™ Fluoro Cement, a dual-cure cement paste that releases fluoride; and PANAVIA™ F2.0, which can be used with an LED curing unit. The current portfolio consists of PANAVIA™ V5, which features the substantially improved bonding performance that was achieved after a major review of the basic composition of the series, PANAVIA™ SA Cement Universal, which works as a standalone product without separate primers, and PANAVIA™ Veneer LC, PANAVIA™ family’s latest product. The latter is a light-curing resin cement with the specialized purpose of bonding laminate veneers.

In retrospect, what did the introduction of PANAVIA™ EX mean to Kuraray Noritake Dental?

In the development of new resin cements, it is important to quickly respond to the rapidly changing trends in the market. Whenever new prosthodontic treatment concepts appear – like adhesive bridges as a minimally invasive treatment option replacing a single tooth – or new restorative materials are introduced, such as different types of ceramics – we need to check if our resin cement systems are compatible with the tasks that come with these changes, as well as possibly developing new ones. Following the launch of PANAVIA™ EX, we received a wide range of feedback from experts working at dental clinics and laboratories. We leveraged this feedback in subsequent development projects, always striving to stick close to the clinical setting. After Kuraray Medical Inc. merged with Noritake Dental Supply Co., Limited, this ethos was embedded in the work ethic of all employees of Kuraray Noritake Dental.

Can you give us a brief history of the PANAVIA™ EX journey to the currently available PANAVIA™ family portfolio?

Since the launch of PANAVIA™ EX 40 years ago, six different PANAVIA™ products have been released. Each of them has received high acclaim for their unique features, both in the Japanese resin cement market and abroad. For 40 years, we have been improving PANAVIA™ in response to the demands of the times. We developed a product with increased adhesion when non-retentive preparation designs (adhesive bridges) and smaller bonding surfaces (due to less invasive preparations) became popular. And for users concerned about secondary caries, we developed a material with fluoride-releasing properties. At the same time, we focused strongly on making dental cementation easier by finding ways to make our resin cements bond well to various types of crown-restoration materials, including precious metals and ceramics. During these drives towards improvement, “achieving reliable general luting” has always been at the forefront of our goals. We believe that the successful evolution of the PANAVIA™ brand owes a great deal to our incessant efforts to obtain a high level of bond strength to dentin after chemical polymerisation”.

How did the R&D department evolve over the years?

Initially, our efforts in the development of dental materials had focused on bonding agents and restorative composite resins. PANAVIA™ EX was just one of our new development projects and only a few staff members were assigned to that product. After PANAVIA™ EX was launched in 1983 and it was accepted worldwide, our product line-up of resin cements was expanded considerably. Consequently, we have increased the number of development staff assigned to resin cements and set up a special development team responsible for the self-adhesive resin cement product line that includes PANAVIA™ SA Cement Universal. As a result, the size of the team assigned to resin cements has expanded substantially.

How did production change?

When PANAVIA™ EX was launched in 1983, the product was manufactured exclusively for the Japanese market in a relatively small facility. Today, in order to produce all products of the PANAVIA™ family for the global market, we have automated our production facilities and increased the production equipment and systems dedicated to producing the resin cement paste. To support our product quality, we have also set up a quality control system that assures we turn out safe and high-quality products, drawing on over 40 years of technical knowhow and experience in the production of resin cements.

For 40 years, we have been improving PANAVIA™ in response to the demands of the times.

When did external researchers start showing interest in PANAVIA™?

The development of PANAVIA™ EX was carried out with the active participation of researchers at a dental college in Japan, involving such activities as performing basic adhesion tests and experimenting with clinical applications using adhesive bridges. At that time, resin cements that provided a strong bond to tooth structure or metal alloys were not widely used. I believe that overseas researchers were interested in the development of PANAVIA™ EX at a relatively early stage, for this reason.

What current concept do you have in mind as you continue developing your adhesive cements?

We have two basic central concepts: “Achieving greater bond strength” and “Delivering easier handling characteristics”. I think that the shades of resin cements are also devised in each product in order to get the most of the characteristics of aesthetic restorative materials. At our company, we have embodied “achieving greater bond strength” in PANAVIA™ V5, and “delivering easier handling characteristics” in PANAVIA™ SA Cement Universal. We will continue to explore the development and introduction of various new technological applications, to bring even higher performance products to market.

What do you think is the strength of Kuraray Noritake Dental’s R&D team?

We conduct R&D activities continuously, focusing on the development of luting materials. In our product development department, the same person is often responsible for one product category over long period of time. For example, I have been engaged in the development of PANAVIA™ products for much of my time with the company. The result is that each person in the development department can be said to be an expert in a certain category of products. They leverage the technical knowledge acquired in the past for the development of new products, resulting in entirely new discoveries.

Do you have any ideas about what the future of PANAVIA™ will be?

We will continue to focus on the development of even simpler, easier-to-use resin cements suitable for a wide range of applications – products based on the concept of universality. This should allow users to focus more on the actual treatment than ever before, while of course delivering a strong and durable bond between the tooth structure and the restoration.

MITSUNOBU KAWASHIMA

Eight-time DENTAL ADVISOR Top Product selection provides effective relief for a painful condition

Dentine hypersensitivity is a painful condition that affects millions of people worldwide. It generally occurs when tubules are exposed for any number of reasons, including gingival recession, dental erosion or excessive tooth brushing. It can also be a side effect of professional tooth cleaning, scaling and root planning, tooth whitening, or restorative procedures.

TEETHMATE™ DESENSITIZER, which was honored by DENTAL ADVISOR every year from 2015 to 2022 as a Top Product selection, allows an effective non-invasive approach to the treatment of hypersensitivity when used as directed by dental professionals.

TEETHMATE™ DESENSITIZER is designed to crystalize hydroxyapatite (HAp), a mineral that is naturally found in enamel and dentin, and is the human body’s strongest material. When applied to exposed, mechanically treated, or freshly prepared dentin, the calcium phosphate based mixture blocks the exposed tubules and provides immediate pain relief. During setting, HAp is formed, providing for long-term prevention of hypersensitivity. Further, when used in the context of restorative treatment, TEETHMATE™ DESENSITIZER does not have a negative effect on the bond strength of subsequently utilized dental adhesives or cements.

DENTAL ADVISOR clinical study found TEETHMATE™ DESENSITIZER effective in providing hypersensitivity relief immediately following and for up to six months after application. The study evaluated 27 patients diagnosed with gingival recession-related hypersensitivity, which was diagnosed using thermal testing with cold air. For the initial assessment, patients were asked to evaluate their level and frequency of hypersensitivity per tooth on a five-point scale. They were questioned about their level of sensitivity immediately after TEETHMATE™ DESENSITIZER was applied, according to the instructions for use, and again six months later. At baseline, 91 percent of the patients stated that they had no or only mild, sporadic sensitivity, which was still the case for 85 percent after six months.

This natural, tissue-friendly product is highly biocompatible and is free of gum irritants such as glutaraldehyde or methacrylates. It is indicated for use by dental professionals for all  sensitivity challenges in everyday practice, including prevention of cervical hypersensitivity before/after bleaching, scaling or root planning, and underneath restorations.

The Top Product or Preferred Product Awards conferred by US-based DENTAL ADVISOR were introduced to support potential users in identifying high-quality dental materials and determining which among them are best suited to fulfill their individual requirements. Awards are based on results of its practice-based clinical evaluations and product performance tests, which are conducted shortly after product launch.

Among products honored this year are five from Kuraray Noritake Dental Inc.: CLEARFIL™ SE Protect, CLEARFIL MAJESTY™ ES Flow (Low), and PANAVIA™ SA Cement Universal were selected as Top Products; and CLEARFIL™ Universal Bond Quick and CLEARFIL™ CERAMIC PRIMER PLUS were chosen as Preferred Products.

KATANA™ Zirconia STML and PANAVIA™ SA Cement Universal

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

KATANA™ Zirconia STML er et meget populært materiale, der anvendes i mange tandlaboratorier rundt omkring i verden. Sammenlignet med de traditionelle stelmaterialer af zirkonia, som hovedsageligt har en tetragonal polykrystallinsk struktur, har dette materiale et højere yttriaindhold, hvilket fører til en anderledes materialestruktur,som har indflydelse på de optiske og fysiske egenskaber (translucensen øges, bøjestyrken nedsættes). Som følge heraf er indikationsområdet begrænset til restaureringer med en enkelt tand og broer med to til tre enheder i de anteriore og posteriore regioner. Den største fordel ligger i det kraftigt forbedrede æstetisk potentiale, som er gør, at materialet overvejende kan anvendes til fremstilling af monolitiske restaureringer eller restaureringer med mikrocut-back-teknik, hvor de tilpasses personligt med mikrolag af porcelæn.

Mens indikationerne og den tekniske procedure er velkendte, synes der at være nogle uklarheder vedrørende håndtering på tandklinikken. Er konventionel cementering mulig og anbefales den, eller er en adhæsionsprocedure at foretrække? Skal overfladen præpareres på samme måde som tetragonal zirkonia, eller er der behov for en anden procedure? Og hvilken langsigtet holdbarhed kan man forvente af KATANA™ Zirconia STML-restaureringer? Et nærmere kig ind i den tilgængelige videnskabelige litteratur giver nogle retningslinjer.

Endelig anbringelse af restaureringer KATANA™ Zirconia STML

Konventionel cementering eller adhæsion? I princippet er begge procedurer mulige, når restaureringen, der skal placeres, har et retentivt design. Det er almindeligt accepteret, at en fuldt dækkende krone opnår tilstrækkelig retention ved den konventionelle cementering, når blot abutmenttanden er mindst 4 mm høj, og konvergensvinklen for de aksiale vægge ligger mellem 6 og 12 eller maksimalt 15 grader1,2.

Årsagen er, at materialets bøjestyrke er højere end 350 MPa3, den afgørende værdi for konventionel cementering. Da konventionelle cementer er uigennemsigtige og kun fås i en enkelt farve, kan anvendelsen af en (selvbindende) resincement af æstetiske grunde være at foretrække sammen med alle højtranslucente restaureringsmaterialer. Under alle omstændigheder er disse produkter et must, hvor en makro-retentiv præparering ikke er muligt eller ønsket. Kort sagt er brugen af en selvbindende eller bindende resincement at foretrække i mange situationer. Et argument der taler for de selvbindende resincementer, er den mindre arbejdsindsats forbundet med deres brug.

Men hvad med forbehandlingen af zirkonia? Uanset hvilken type dental zirkonia der anvendes, er ætsning med flussyre ineffektiv på grund af den manglede glasmatrice i materialet. Det er imidlertid klart, at overflademodifikation er nødvendig for at etablere en stærk og holdbar binding til ethvert resincement-system4,5.

Den metode, der generelt anbefales til højstyrkezirkonia, er sandblæsning med aluminiumoxidpartikler eller tribokemisk siliciumdioxid-belægning4. Partikelstørrelsen skal være lille (≤ 50 μm) og trykket lavt (ca. 1 bar) for at undgå en svækkelse af materialets mekaniske egenskaber3,4. For materialevarianter
med en lavere styrke, er der en højere risiko for at materialet svækkes5, og det er derfor endnu mere vigtigt at arbejde med et lavt tryk og lille partikelstørrelse5-8. For KATANA™ Zirconia er det imidlertid blevet rapporteret, at  “aluminiumoxid-sandblæsning øgede den biaksiale bøjestyrke for KATANA™ STML i betydelig grad”.9 Dette betyder, at korrekt udført sandblæsning af restaureringer fremstillet af KATANA™ Zirconia STML ikke påvirker materialets bøjestyrke, og endda er forbedrer den på grund af de specifikke egenskaber ved zirkonia fra Kuraray Noritake Dental.

På baggrund af disse fund kan følgende procedurer anbefales for højtranslucent zirkonia:

Mulighed 1
Luftslibning med aluminiumoxid efterfulgt af anvendelse af selvbindende resincement, der indeholder 10-MDP6

Mulighed 2
Tribokemisk siliciumdioxid-belægning efterfulgt af silanisering af bindingsoverfladen6

Da den dobbelthærdende selvbindende resin PANAVIA™ SA Cement Universal indeholder den originale MDP-monomer og det lange kulstofkædede silankoblingsmiddel (LCSi Monomer), er den således velegnet til begge procedurer.

PANAVIA™ SA Cement Universal fås i en automix-sprøjte og et håndmix-system, der består af en pasta-til-pastaformulering. Den ene pasta indeholder den oprindelige MDP-monomer i et hydrofilt monomermiljø, og den anden indeholder den inaktive LCSi-monomer i et miljø af hydrofobe monomerer. Når pastaerne trykkes ud, blandes de enten i sprøjtens blandespids (automix) eller dispenseres ud på en blandeblok og blandes med hånden (håndmix). Bagefter appliceres materialet gang på restaureringens intaglio-flade, og restaureringen anbringes. Fjernelse af overskydende cement udføres nemmest efter punkthærdning (2 til 5
sekunder).

Hvor godt fungerer dette på klinikken?

Den bedste måde at kontrollere, om den beskrevne procedure reelt fungerer i det kliniske miljø, er ved at gennemføre et klinisk forsøg. Det er præcis, hvad en gruppe forskere fra University Complutense i Madrid, Spanien, har gjort med materialekombinationen KATANA™ Zirconia STML og PANAVIA™ SA Cement Universal10. Inden for rammerne af det prospektive kliniske forsøg blev 30 posteriore kroner KATANA™ Zirconia STML anbragt i 24 personer med behov for posteriore tandrestaureringer. Tænderne blev præpareret som anbefalet for helkeramiske restaureringer til hvilke der anbefales en vægtykkelse på ca. 1 mm (anbefalet minimum vægtykkelse af KATANA™ Zirconia STML for kroner i det posteriore område: 1,0 mm). Restaureringerne blev sintret, karakteriseret og glaseret som anbefalet af materialeproducenten og efterfølgende indprøvet. Inden cementering blev intaglio-fladen på restaureringerne forbehandlet med aluminiumoxidpartikler (50 μm, 1 bar tryk) efterfulgt af ultralydsrensning. Brugen af PANAVIA™ SA Cement Universal skete også i overensstemmelse med producentens anbefalinger.

En klinisk evaluering af kroner blev udført efter 6, 12 og 24 måneder ved hjælp af California Dental Association (CDA) kvalitetsevalueringssystem. De parametre, der evalueres i dette system, er overfladen og farven på restaureringerne, deres anatomiske form og kronernes marginale integritet. Efter 24 måneder var succes- og overlevelsesraten 100 procent. Med hensyn til alle tre parametre blev kronerne vurderet som „tilfredsstillende“ (score 3 eller 4), marginintegritet (nøgleparameteren for vurdering af resincementens ydeevne) blev vurderet som „fremragende“ (den højest mulige score 4) i alle 30 tilfælde.

Konklusion

Forskerne konkluderede, at „de fremragende resultater, der blev opnået i dette forsøg, tyder på, at den tredje generation af tandunderstøttede monolitiske zirkonia-kroner i posteriore regioner synes at være et godt alternativ til metalkeramiske kroner, anden generation af monolitiske kroner og facadekroner af zirkonia. En langsigtet forsøg er nødvendig for at bekræfte resultaterne af dette kortvarige forsøg.“ Derfor ser det ud til, at KATANA™ Zirconia STML OG PANAVIA™ SA Cement Universal udgør et lovende team, og at de, i det omfang de anbefalede protokoller overholdes, sandsynligvis vil producere fremragende resultater, der er holdbare i mange år fremefter.

References

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

Article by Dr. Bassem Jaidane

Among the most common problems in modern dentistry is that of restoring a patient‘s lost aesthetic dental appearance. To do this, new technologies are available to practitioners. For anterior teeth where aesthetics are paramount, dentists prefer the least invasive treatments possible, such as layered dental veneers (cut-back). In cosmetic dentistry, practitioners are often faced with cases requiring a multidisciplinary treatment plan or different types of restorative materials to be used at the same time. For cases of prosthetic restoration combining dental veneers, dental crowns and dental bridges, dentists are often faced with situations where the difference in shade is noticeable in the final result, this is explained by the difference in restorative material, product, adhesion technique, the thickness of the prosthetic element and the colour of the abutment, whether it is a living natural tooth, devitalized, or even an implant abutment^1-2.

In the presence of a treatment plan requiring dental veneers, crowns and dental bridges, choosing zirconia as the only restorative material is no longer an option but an obligation. The is due to the limited mechanical properties of lithium disilicate and feldspar porcelain restorations, which contraindicate their use as dental bridges. There are different factors explaining the reluctance of practitioners to use the zirconia dental veneer technique³: One is the absence of the vitreous phase. It makes impossible to create an optimal adhesion surface with hydrofluoric acid at the level of the intaglio of the zirconia veneers. Another is the lack of translucency of the first zirconia generations.

Modern zirconia materials, however, are particularly well-suited for cases requiring a combination of veneers, crowns and dental bridges of the same optical appearance. This is due to their increased translucency and excellent mechanical properties. The following article describes and discusses the realization of a clinical case treated with dental veneers and a crown using KATANA™ Zirconia UTML (Kuraray Noritake Dental Inc.). the veneers were placed with PANAVIA™ Veneer LC (Kuraray Noritake Dental Inc.). The patient presented an aesthetic problem at the level of an anterior implant-supported crown.

CASE OBSERVATION

Patient S, from the Tunisian Sahel, engineer in France, with no significant pathological history and aged 29, presented in January 2023 due to an aesthetic problem negatively affecting her smile. The extraoral examination was without abnormalities, while the intraoral examination showed good oral hygiene, healthy gums, a thin free gingiva and a protruded zirconia crown on an implant in the region of the maxillary right central incisor (figs 1 and 2).

Fig. 1. Initial clinical situation.

Fig. 2. Occlusal view revealing the volume and position of the crown on the central incisor.

During the preliminary interview, it turned out that the implant in the region of the right central incisor had been placed in 2020. The patient’s former dentist had left Tunisian territory. The patient does not have any document or reference on the dental implant, and she wishes to “straighten” the crown and improve the aesthetics of her smile before her planned wedding ten days after her first consultation.

TREATMENT PLAN

After having had the informed consent of the patient and after having asked the indication of dental veneers for aesthetic reasons, the treatment was initiated. According to the treatment plan, seven maxillary anterior teeth (from first premolar to first premolar) should receive an incisal overlap preparation (depth: 0.1 to 0.3 mm) for the placement of veneers made of KATANA™ Zirconia UTML. For the implant in the region of the right central incisor, it was planned to replace the existing crown by a crown made of KATANA™ Zirconia UTML without replacing the abutment. This was due to the lack of information about the implant type and the lack of time.

TREATMENT

After taking the preoperative photos (fig 3), choosing the color of the veneers and anesthetizing the maxillary anterior region, the incisal overlap preparation was carried out on the seven maxillary teeth and the zirconia crown was removed from the implant. A cylindrical diamond bur was used to separate the zirconia part from the abutment. Subsequently, a bite record and impressions were taken using the wash technique. In addition, a temporary crown was produced and placed on the abutment.

Fig. 3. Preoperative picture.

In the dental laboratory, virtual models were created based on the conventional impressions (fig. 4). Then, the zirconia restorations were designed in full contour, cut back for the veneering porcelain and finished by layering with CERABIEN™ ZR porcelain (Kuraray Noritake Dental Inc.). At try-in during the second session, we checked the insertion, the gingival margins, and the contact points between the veneers and the crown on the implant. Given the superior mechanical properties of the zirconia veneer, the shape and thickness of the veneers were modified chairside to have a harmonious anterior curve and a better aesthetic rendering. After determining the colour of the resin cement, the temporary crown was put back in place.

Fig. 4. Virtual model.

After glazing and preparation of the bonding surfaces in the dental laboratory, the upper veneers were cemented according to the PANAVIA™ Veneer LC protocol. We ended the session by removing excess cement. An occlusion check and postoperative photos were taken after three days.

DISCUSSION

In this case, the dental veneers and the crown on the implant were produced using a KATANA™ Zirconia UTML disc. This type of zirconia has an yttrium oxide proportion of 5 mol%, leading to about 70 % cubic zirconia phase, and therefore a higher translucency than earlier generations of zirconia. With a translucency of 51 % (light transmission, illuminant: D65, specimen thickness: 1.0 mm. Source: Kuraray Noritake Dental Inc); this zirconia allows us to have remarkable optical properties (fig 5).

Fig. 5. Remarkable optical properties of the final restorations.

The patient chose color BL1 and requested a transparent incisal edge. For this reason, a cutback design of the zirconia (fig. 6) and porcelain layering was the technique of choice. Figure 7 shows the slight transparency in the incisal edge region of the new restorations. The zirconia veneers technique was chosen to avoid the color difference between the crown on the implant and the veneers. The pleasant aesthetic appearance and a harmonious smile are confirmed by the post-operative picture (fig 8). According to the manufacturer, the flexural strength of KATANA™ Zirconia UTML is 557 MPa, which is higher than that of lithium disilicate and feldspathic porcelains. As zirconia veneers will be more resistant to shear forces, it is possible to eliminate contact points that interfere during try-in or even safely modify the shape of the restorations in vivo. This is done with specific burs adapted to zirconia during different stages of the fittings according to the wishes of the patient⁴.

Fig. 6. Cutback design of the restorations.

Fig. 7. Slight transparency at the incisal edges of the restorations.

Fig. 8. Immediate post-operative picture.

In the present case, we were able to adjust the crown until we had a perfect anterior line. It was thus possible to optimize the inclination of the crown without replacing the dental implant, in just one week.

Given the significant shear resistance, the dental laboratory technician made zirconia dental veneers with an average thickness of 0.3 mm. Such a thin veneer requires less preparation of the dental tissue, which will be limited to enamel instead of extending into the dentin, where the adhesion value is lower due to its low chemical composition in minerals⁵.

The expected difficulty in bonding zirconia veneers is explained by the absence of a vitreous phase given the poor adhesion of the crystalline phase to the bonding cement. However, the desired surface modification can be achieved with a different procedure: tribochemical silica coating. It was used in the present case to improve the adhesion of the zirconia veneers to the resin cement system. Indeed, it was found in an in-vitro evaluation that the tribochemical preparation technique and the application of MDP provide an optimized adhesive interface⁶. In this study, dual-beam focused ion-beam technology followed by scanning electron microscopy were used to compare the resin/zirconia bonding interface with tribochemical preparation/MDP and the bonding interface between resin/zirconia without this preparation.

The tribochemical process consists of an aero-abrasion of the zirconia surface with particles coated with silica combined with a silane primer containing MDP. The phosphate ester groups of this silane bind to the surface oxides of the zirconia, and the methacrylate group makes covalent bonds with the resin matrix of the PANAVIA™ Veneer LC cement⁷.

In the present clinical cases, the KATANA™ Zirconia UTML veneers were abraded with silicon dioxide with the formula SiO2. As a primer, we chose CLEARFIL™ CERAMIC PRIMER PLUS (Kuraray Noritake Dental Inc.), because it contains the original MDP monomer, developed Kuraray Co., Ltd.⁸.

To clean the veneers before applying CLEARFIL™ CERAMIC PRIMER PLUS, KATANA™ Cleaner (Kuraray Noritake Dental Inc.) was used. The presence of saliva and residues from fittings can alter the interface with the resin cement, which presents a risk of bonding failure of Zirconia veneers⁹.

One of the most important challenges in this case was to be able to hide the greyish color of the implant abutment which was visible through the zirconia crown. To hide the gray of the abutment, a resin opaker was applied. These techniques combined with the PANAVIA™ Veneer LC white gave us an optimal result (figs. 9 and 10)¹⁰.

Fig. 9. Treatment outcome.

Fig. 10. New smile designed according to the individual desires of the patient.

CONCLUSION

KATANA™ Zirconia UTML veneers have better mechanical properties than conventional veneers, so that the zirconia veneers technique allows users to combine bridges, crowns and dental veneers without a noticeable difference in shade. It offers acceptable translucency and aesthetics according to our observation. The technique of bonding the zirconia veneers with PANAVIA™ Veneer LC combined with a tribochemical treatment and the application of MDP on the adhesion surfaces allowed for a secure bonding, while the dyschromia caused by the implant abutment was effectively concealed.

Dentist:

DR. BASSEM JAIDANE

Born in Sousse, Tunisia, on June 12, 1983, Dr. Bassem Jaidane obtained his Doctorate in Dental Medicine in 2010 at the Faculty of Monastir. He opened his own clinic in 2010, specializing in aesthetics and dental implants, as well as dental veneers. Omni-patrician and passionate about all areas of dentistry, he has also developed advanced knowledge in dental prosthetics: 3D design, ceramic layering, finishing and glazing of crowns, bridges and veneers…

Dr. Bassem Jaidane has therefore acquired a certain expertise on the different types of dental veneers, whether pressed ceramic veneers, machined veneers, layereded veneers with the cut-back technique and lumineers veneers, after having carried out numerous cases. in feldspathic and lithium disilicate veneers, Dr. Bassem Jaidane has become one of the pioneers of the technique of dental veneers on zirconia.

References

1. Restaurations esthétiques grâce à la technique du cut-back Par Fleur Nadal, Geoffrey Di Bacco, Julien Chesnot Publié le 01.06.2019. Paru dans L‘Information Dentaire n°23 – 12 juin 2019 (page 28-29).
2. Effects of ceramic layer thickness, cement color, and abutment tooth color on color reproduction of feldspathic veneers Christopher Igiel, Michael Weyhrauch, Barbara Mayer, Herbert Scheller, Karl Martin Lehmann PMID: 29379907 Int J Esthet Dent 2018;13(1):110-119.
3. Influence of Air-Particle Deposition Protocols on the Surface Topography and Adhesion of Resin Cement to Zirconia. Acta Odontol: Sarmento, H.R.; Campos, F.; Sousa, R.S.; Machado, J.P.B.; Souza, R.O.A.; Bottino, M.A.; Ozcan, M: Acta Odontol Scand . 2014 Jul;72(5):346-53.doi: 10.3109/00016357.2013.837958. Epub 2013 Oct 31.
4. Comparison of the Mechanical Properties of Translucent Zirconia and Lithium Disilicate:Kwon, S.J.; Lawson, N.C.; McLaren, E.E.; Nejat, A.H.; Burgess, J.O. J.Prosthet:: J Prosthet Dent . 2018 Jul;120(1):132-137. doi: 10.1016/j.prosdent.2017.08.004. Epub 2018 Jan 6.
5. The Success of Dental Veneers According To Preparation Design and Material Type:Yousef Alothman, Maryam Saleh Bamasoud: Open Access Maced J Med Sci. 2018 Dec 14;6(12):2402-408.doi:10.3889/oamjms.2018.353. eCollection 2018 Dec 20.
6. The Effect of Resin Bonding on Long-Term Success of High-Strength Ceramics: Blatz, M.B.; Vonderheide, M.; Conejo, J: J Dent Res 2018 Feb;97(2):132-139. doi: 10.1177/0022034517729134. Epub 2017 Sep 6.
7. Ultra-thin monolithic zirconia veneers: reality or future? Report of a clinical case and one-year follow-up: Rodrigo Othávio Assunção Souza, Fernanda Pinheiro Barbosa, Gabriela Monteiro de Araújo, Eduardo Miyashita, Marco Antonio Bottino, Renata Marques de Melo, and Yu Zhang :Oper Dent :2018 ;43(1) :3_11.doi :10.234/16-350-T.
8. Functional monomer impurity affects adhesive performance :Kumiko Yoshihara 1 , Noriyuki Nagaoka, Takumi Okihara , Manabu Kuroboshi, Satoshi Hayakawa, Yukinori Maruo, Goro Nishigawa, Jan De Munck, Yasuhiro Yoshida, Bart Van Meerbeek : Dent Mater : 2015 Dec;31(12):1493-501.doi: 10.1016/j.dental.2015.09.019. Epub 2015 Oct 28.
9. Effect of decontamination materials on bond strength of saliva-contaminated CAD/CAM resin block and dentin Kei Takahashi, Tomohiro Yoshiyama, Akihito Yokoyama, Yasushi Shimada, Masahiro Yoshiyama : Dent Mater J 2022 Jul 30;41(4):601-607. doi: 10.4012/dmj.2021-268. Epub 2022 Apr 13.
10. Masking ability of implant abutment substrates by using different ceramic restorative systems Pablo Machado Soares , Ana Carolina Cadore-Rodrigues , Maria Gabriela Packaeser , Atais Bacchi , Luiz Felipe Valandro , Gabriel Kalil Rocha Pereira , Marília Pivetta Rippe J Prosthet Dent 2022 Sep;128(3):496.e1-496.e8. doi: 10.1016/j.prosdent.2022.05.010. Epub 2022 Aug 16. Affiliations PMID: 35985853 DOI: 10.1016/j.prosdent.2022.05.010.

CLEARFIL MAJESTY™ ES FLOW RECEIVES “NIOM TESTED” QUALITY SEAL

Before being allowed to market a dental composite filling material, it must, among other things, meet the set standards within ISO 4049:2019 Dentistry - Polymer-based restorative materials. Prompted by the tremendous positive response Kuraray Noritake Dental Inc. received from users of the CLEARFIL MAJESTY™ ES Flow series, we asked the Nordic Institute of Dental Materials (NIOM), an independent research institute, to test this product line on key aspects within the said ISO standard.

While it was not mandatory for us to have the CLEARFIL MAJESTY™ ES Flow series tested, our confidence in the quality of our product prompted us to do so. NIOM thoroughly evaluated CLEARFIL MAJESTY™ ES Flow in all three different levels of flowability: High, Low, and Super Low (Fig. 1). Among the properties assessed were depth of cure, flexural strength, water sorption and solubility, and colour stability after irradiation and water sorption. NIOM found that regarding all properties, the three flowabilities and different shades proved to comply with the requirements.

We are pleased to have gone the extra mile and proud that an independent party verified that our product meets the stringent ISO standards.

Fig. 1. CLEARFIL MAJESTY™ ES Flow in its three different levels of flowability.

IMPLICATIONS FOR CLINICAL USE

These test results are an external proof for users of the popular flowable composite series that they safely can be used as specified by Kuraray Noritake Dental Inc. in the product’s instructions for use. The NIOM test results obtained regarding the depth of cure imply that, when applied to the recommended layer thickness, the composite will polymerise adequately – which is essential for a great long-term performance. In addition, all three flowabilities offer sufficient strength and water sorption/solubility behaviour even to be suitable for restorations, including the occlusal surface of molars and pre-molars. This means that the materials are very well suited for a wide range of indications, including restoring all cavity classes and repairing existing restorations and cementing (Fig. 2).


Fig. 2. Three variants of CLEARFIL MAJESTY™ ES Flow and the suggested use areas.

GREAT AESTHETICS AND HANDLING

On top of these well-balanced mechanical properties, CLEARFIL MAJESTY™ ES Flow in its innovative syringe handles well due to an easy dispensing, bubble-free application, easy sculpting facilitated by its non-sticky formulation, and easy polishing behaviour. Coming in a variety of shades (Fig. 3) and equipped with proprietary Light Diffusion Technology, the material in its three different levels of flowability blends nicely and effortlessly with the surrounding tooth structure, creating a natural overall look. Both handling and aesthetics have been rated very good to excellent by dental advisor consultants in the context of a clinical evaluation.

Fig. 3. Overview of shades available per flowability.

NIOM also provides proof of the positive aesthetic properties: the institute's tests to evaluate colour stability after irradiation and water sorption reveal that CLEARFIL MAJESTY™ ES Flow is expected to remain stable over time. This feature is important for the long-term aesthetics of the restorations created with the materials.

Choose a reliable, high-quality, flowable, direct restorative material that withstands rigorous testing.