VOUS ÊTES-VOUS DÉJÀ DEMANDÉ POURQUOI LES PRODUITS DE LA MARQUE PANAVIA™ OFFRENT D‘AUSSI BONNES PERFORMANCES?

Vous savez probablement qu‘ils contiennent tous le monomère MDP original développé au début des années 1980. Ce monomère adhésif a beaucoup fait parler de lui pour son excellence. Monomère d‘ester de phosphate, il forme une très forte adhésion à la structure dentaire, à la zircone et aux métaux dentaires. Il a été utilisé dans chaque produit PANAVIA™. Outre le MDP, d‘autres technologies et ingrédients catalytiques sont d‘importants contributeurs qui soutiennent les performances de nos solutions de collage.

INGRÉDIENTS INFLUANÇANT LA RÉACTION DE POLYMÉRISATION

Parmi ces autres technologies et ingrédients déterminants, notons le catalyseur qui provoque le processus de polymérisation. Différent du monomère MDP utilisé dans chaque produit PANAVIA™, le catalyseur de polymérisation a été amélioré en permanence depuis l’introduction de PANAVIA™ EX en 1983. Ainsi, de nouvelles versions ont été développées pour PANAVIA™ 21, PANAVIA™ Fluoro Cement et PANAVIA™ V5, entre autres. Un autre important composant qui influence également le processus de polymérisation est la Touch Cure Technology utilisée dans deux des trois principaux produits de la ligne PANAVIA™ actuelle : PANAVIA™ V5 et PANAVIA™ Veneer LC. Cette technologie est intervenue pour la première fois dans PANAVIA™ 21, qui a été lancé en 1993. Lorsque l’activateur chimique de polymérisation contenu dans l’apprêt à auto-mordançage entre en contact avec la pâte de ciment de résine, la polymérisation de la colle de l’interface adhésive est accélérée, apportant ainsi une meilleure adhésion du ciment de résine. En développant PANAVIA™ V5, nous avons revu et actualisé considérablement la composition chimique des produits PANAVIA™ existants. La Touch Cure Technology a également été adoptée pour le cas d’une utilisation de PANAVIA™ V5 Tooth Primer en concomitance avec PANAVIA™ V5 Paste. Pour coller des facettes avec PANAVIA™ Veneer LC, nous utilisons aussi PANAVIA™ V5 Tooth Primer afin de préparer les dents. Cet apprêt recourt lui aussi à la Touch Cure Technology pour obtenir une connexion adhésive avec la dent sans affecter le temps de travail de la pâte de ciment.

MONOMÈRES ADHÉSIFS ADDITIONNELS

Dans le domaine des monomères adhésifs également, nous n’avons pas ménagé nos efforts : Nous avons développé le monomère LCSi, un agent combinant le silane à longue chaîne carbonée qui a permis d’intégrer la fonction d’un apprêt céramique à notre ciment de résine auto-adhésif universel PANAVIA™ SA Cement Universal. Avec son degré élevé d’hydrophobie, ce monomère apporte une force d’adhésion stable sur le long terme. D’une manière générale, on peut dire que la durabilité d’adhésion peut baisser en raison d’une réaction hydrolytique endommageant l’adhésion chimique entre la silice contenue dans la vitrocéramique et l’agent combinant le silane.

TROIS PRODUITS COUVRANT PRATIQUEMENT TOUS LES BESOINS

En combinant intelligemment ces technologies et ingrédients, nous avons réussi à développer une gamme de ciments de résine qui couvre pratiquement tous les besoins. Avec PANAVIA™ V5, PANAVIA™ SA Cement Universal et PANAVIA™ Veneer LC, il est possible de traiter une grande variété de cas. Ces produits permettent l’assemblage de nombreux types de restaurations, d’appareils prothétiques et la pose de tenons pour offrir d’excellents résultats à condition d’être utilisés conformément aux consignes d’utilisation.

PANAVIA™ V5 est le ciment de résine offrant le champ d’utilisation le plus vaste parmi les trois systèmes de collage que nous venons d’évoquer. Il couvre pratiquement toutes les utilisations visées par les deux autres ciments. C’est pourquoi le praticien dentaire peut, en fonction des cas se présentant à la clinique et des besoins des patients, trouver le bon système de collage pour le traitement en choisissant parmi ces trois principaux produits de ciment de résine : PANAVIA™ V5, un ciment de résine avec un vaste champ d’applications, PANAVIA™ SA Cement Universal, un ciment de résine auto-adhésif simple et facile à manipuler et PANAVIA™ Veneer LC quand il s’agit d’adhésion de facettes stratifiées.

EXPLORER DE NOUVELLES OPPORTUNITÉS

L’avantage du développement de technologies au sein d’une société telle Kuraray Noritake Dental est que leur application ne se limite pas à un certain produit ou groupe de produits. Le département R&D étudie toujours comment tirer profit des bénéfices de ces technologies pour d’autres applications. C’est le cas par exemple pour KATANA™ Cleaner, qui a été mis sur le marché en 2019. Ce nettoyant peut être utilisé pour éliminer la salive, le sang, la colle provisoire et d’autres contaminants qui peuvent adhérer aux surfaces des dents ou des appareils prothétiques pendant les essayages et le collage provisoire d’une prothèse. Ce produit unique a été développé en exploitant la fonction tensioactive du monomère MDP.

CONCLUSION

L’excellence de la gamme PANAVIA™ actuelle découle principalement de nos connaissances et de notre expérience de longue date dans le développement de ciments de résine et solutions adhésives dentaires. Nous savons comment améliorer nos technologies existantes, ne cessons jamais d’en développer de nouvelles et recherchons continuellement la meilleure façon de combiner les composants éprouvés avec les nouveaux pour obtenir le meilleur résultat possible. Au fil des étapes de la procédure de développement de produits, des tests cliniques sont réalisés et les retours de praticiens dentaires sont recueillis afin de prendre en compte les conditions extrêmes dans l’environnement bucco dentaire. Cette stratégie a brillamment fait ses preuves tout au long des 40 dernières années, et nous sommes convaincus qu’elle nous aidera à développer de nombreux autres produits innovants qui offrent un soutien idéal dans nos efforts pour améliorer la santé bucco-dentaire des patients.

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

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 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.

Dentist:

KANSTANTSIN VYSHAMIRSKI

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.

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.

Clinical case by Dr. Florian Zwiener

The 85-year-old female patient presented after osteosynthesis of a multiple mandibular fracture she had sustained after a fall. During fixation, a massive nonocclusion had occurred in the left posterior region of the mandible (teeth 34 to 37; FDI notation). The patient desired to be able to chew properly again in this area. After endodontic treatment of the two avulsed central incisors, which had been replanted in the hospital, and periodontal therapy, a bite elevation was planned on the left side.

The idea was to restore the teeth and elevate the bite with three onlays and a crown made of lithium disilicate (IPS e.max CAD, Ivoclar Vivadent). During tooth preparation, however, a longitudinal root fracture was detected on the first molar. Therefore, only the first premolar was restored in this session. For this purpose, an onlay was produced chairside (with the CEREC system, Dentsply Sirona) and adhesively luted with PANAVIA™ V5 (Kuraray Noritake Dental Inc.). The first molar was extracted. One week later, the extraction socket, which was still healing, was modelled for the ovoid pontic using an electrotome loop. The second premolar and molar were prepared as abutment teeth for a bridge. The bridge was then milled from KATANA™ Zirconia Block for Bridge in the shade A3.5 and individualized with CERABIEN™ ZR FC Paste Stain (both Kuraray Noritake Dental inc.). After another week, the bridge was luted with the self-adhesive resin cement PANAVIA™ SA Cement Universal (Kuraray Noritake Dental Inc.) following sandblasting.

Fig. 1. Situation after multiple mandibular fracture on the left side.

Fig. 2. Clinical situation at the initial appointment in the dental practice.

Fig. 3. Open bite in the mandibular left posterior region.

Fig. 4. Bridge design …

Fig. 5. … using the CEREC Software.

Fig. 6. Due to the bright shade of the teeth in the cusp area, the restoration was positioned high in the KATANA™ Zirconia Multi-Layered Block.

Fig. 7. Surface texturing in the pre-sintered state (prior to the final sintering procedure).

Fig. 8. Bridge after a seven-hour sintering cycle.

Fig. 9. Appearance of the bridge after individualization with CERABIEN™ ZR FC Paste Stain …

Fig. 10. … and two glaze firings.

Fig. 11. Clinical situation after restoring the teeth with a lithium disilicate onlay and a zirconia bridge.

FINAL SITUATION

Fig. 12. Onlay and bridge in place (after adhesive luting with PANAVIA™ V5 and self-adhesive luting with PANAVIA™ SA Cement Universal).

Fig. 13. Final X-ray used to check for excess cement around the bridge.

Dentist:

DR. FLORIAN ZWIENER

Dr. Florian Zwiener is a distinguished dental professional known for his expertise in Endodontics, Prosthodontics, and CAD/CAM technology. Born in Cologne, Germany, he developed a passion for dentistry and pursued his education at the University of Cologne, where he obtained his degree in Dentistry. Currently, Dr. Florian Zwiener practices at the Dr. Frank Döring Dental Clinic in Hilden, Germany. Here, he continues to apply his specialized knowledge and skills, ensuring that his patients receive the highest quality of care. Follow Dr. Zwiener on Instagram: @dr.florian_zwiener.

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.

Case report with Dr. José Ignacio Zorzin

Rationalizing clinical workflows: This is the main reason for the use of universal products in adhesive dentistry. They are suitable for a wide range of indications and different application techniques, fulfil their tasks with fewer components than conventional systems and often involve fewer steps in the clinical procedure. Universal adhesives are a prominent example.

How do universal adhesives contribute to a streamlining of workflows?

When restoring teeth with resin composite, the restorative material will undergo volumetric shrinkage upon curing. By bonding the restorative to the tooth structure with an adhesive, the negative consequences of this shrinkage – marginal gap formation, marginal leakage and staining, hypersensitivity issues and the development of secondary caries – are prevented. The first bonding systems available on the dental market were etch-and-rinse adhesives, which typically consisted of three components: an acid etchant, a primer and a separate adhesive. Later generations combined the primer and the adhesive in one bottle, or were two or one-bottle self-etch adhesives. Universal adhesives (also referred to as multi-mode adhesives) may be used with or without a separate phosphoric acid etchant.

Fig. 1. Volumetric shrinkage of resin composite restoratives and its clinical consequences.

Which technique to choose depends on the indication and the clinical situation. In most cases, the best outcomes are obtained after selective etching of the enamel¹. Bonding to enamel is generally found more effective when the enamel is etched with phosphoric acid, while the application of phosphoric acid on large areas of dentin involves the risk of etching deeper than the adhesive is able to hybridize. When the cavity is small, however, selective application of the phosphoric acid etchant to the enamel surface may not be possible, so that a total-etch approach is most appropriate. Finally, in the context of repair, the self-etch approach may be the first choice, as phosphoric acid might impair the bond strength of certain restorative materials by blocking the binding sites. By using a universal adhesive, all these cases may be treated appropriately, as the best suitable etching technique can be selected in every situation.

Apart from the differences related to the use or non-use of phosphoric acid etchant on the enamel or enamel-and-dentin bonding surface, the clinical procedure is always similar with the same universal adhesive. The following clinical case is used to illustrate how to proceed with CLEARFIL™ Universal Bond Quick (Kuraray Noritake Dental Inc.) in the selective enamel etch mode, and it includes some details about the underlying mechanism of adhesion.

How to proceed with selective enamel etching?

A clinical example.

This patient presented with a fractured maxillary lateral incisor, luckily bringing the fragment with him. Hence, it was decided to adhesively lute the fragment to the tooth with an aesthetic flowable resin composite.

Fig. 2. Patient with a fractured maxillary lateral incisor.

Fig. 3. Close-up of the fractured tooth.

Fig. 4. Working field isolated with rubber dam.

As proper isolation of the working field makes the dental practitioner’s life easier, a rubber dam was placed using the split-dam technique. It works well in the anterior region of the maxilla, as the risk of contamination with saliva from the palate is minimal. Once the rubber dam was placed, the bonding surfaces needed to be slightly roughened to refresh the dentin. As the surfaces were also slightly contaminated with blood and it is important to have a completely clean surface for bonding, KATANA™ Cleaner was subsequently applied to the tooth structure, rubbed into the surfaces for ten seconds and then rinsed off. The cleaning agent contains MDP salt with surface-active characteristics that remove all the organic substances from the substrate. The fragment was fixed on a ball-shaped plugger with (polymerised) composite and also cleaned with KATANA™ Cleaner.

Fig. 5. Cleaning of the tooth …

Fig. 6. … and the fragment with KATANA™ Cleaner.

What followed was selective etching of the enamel on the tooth and the fragment for 15 seconds. Whenever selective enamel etching is the aim, it is essential to select an etchant with a stable (non runny) consistency – a property that is offered by K-ETCHANT Syringe (Kuraray Noritake Dental Inc.). Both surfaces were thoroughly rinsed and lightly dried before applying CLEARFIL™ Universal Bond Quick with a rubbing motion. This adhesive is really quick: Study results show that the bond established immediately after application is as strong and durable as after extensive rubbing into the tooth structure for 20 seconds.^2,3 The adhesive layer was carefully air-dried to a very thin layer and finally polymerized on the tooth and on the fragment.

Fig. 7. Selective etching of the enamel of the tooth …

Fig. 8. … and the fragment with phosphoric acid etchant.

Fig. 9. Application …

Fig. 10. … of the universal bonding agent.

Fig. 11. Polymerization of the ultra-thin adhesive layer on the tooth …

Fig. 12. … and the fragment.

What happens to dentin in the selective enamel etch (or self-etch) mode?

After surface preparation or roughening, there is a smear layer on the dentin surface that occludes the dentinal tubules, forms smear plugs that protect the pulp and prevents liquor from affecting the bond. When self-etching the dentin with a universal adhesive, this smear layer is infiltrated and partially dissolved by the mild self-etch formulation (pH > 2) of the universal adhesive. At the same time, the adhesive infiltrates and demineralizes the peritubular dentin. The acid attacks the hydroxyapatite at the collagen fibrils, dissolves calcium and phosphate and hence enlarges the surface. Then, the 10-MDP contained in the formulation reacts with the positively loaded calcium (and phosphate) ions. This ionic interaction is responsible for linking the dentin with the methacrylate and thus for the formation of the hybrid layer.^4,5

In the total-etch mode, the phosphoric acid is responsible for dissolving the smear layer and demineralising the hydroxyapatite. This leads to a collapsing of the collagen fibrils, which need to be rehydrated by the universal adhesive that is applied in the next step. Whenever the acid penetrates deeper into the structures than the adhesive, the collagen fibrils will remain collapsed. This will most likely result in clinical issues including post-operative sensitivity⁶.

When applying the adhesive system, a dental practitioner rarely thinks about what is happening at the interface⁷. However, every user of a universal adhesive should be aware of the fact that a lot is happening there. This is why it is so important to use a high-performance material with well-balanced properties and strictly adhere to the recommended protocols.

Fig. 13. Schematic representation of dentin after tooth preparation: The smear layer on top with its smear plugs occluding the dentinal tubules protects the pulp and prevents liquor from being released into the cavity.

Fig. 14. Schematic representation of dentin after the application of a universal adhesive containing 10-MDP: The mild self-etch formulation partially dissolves and infiltrates the smear layer, while at the same time demineralizing and infiltrating the peritubular dentin5.

In the present case, the tooth and the fragment now needed to be reconnected. For this purpose, CLEARFIL MAJESTY™ ES-Flow (A2 Low) was applied to the tooth structure. The fragment was then repositioned with a silicone index, held in the right position with a plier and light cured. To obtain a smooth margin and glossy surface, the restoration was merely polished. The patient presented after 1.5 years for a recall and the restoration was still in a perfect condition.

Fig. 15. Reconnecting the fragment with the tooth structure.

Fig. 16. Treatment outcome.

Why is it important to adhere to the product-specific protocols?

Universal adhesives contain lots of different technologies in a single bottle. While this fact indeed allows users to rationalize their clinical procedures, it also requires some special attention. As every highly developed material, universal adhesives need to be used according to the protocols recommended by the manufacturer. In general, materials may only be expected to work well on absolutely clean surfaces, while contamination with blood and saliva is likely to decrease the bond strength significantly. Depending on the type of universal adhesive, active application is similarly important, as is proper air-drying and polymerization of the adhesive layer. In addition, care must be taken to use the material in its original state, which means that it needs to be applied directly from the bottle to avoid premature solvent evaporation or chemical reactions. When adhering to these rules, universal adhesives offer several benefits from streamlined procedures to simplified order management and increased sustainability, as fewer bottles are needed and likely to expire before use.

Dentist:

DR. JOSÉ IGNACIO ZORZIN

Dr. José Ignacio Zorzin graduated as dentist at the Friedrich-Alexander University of Erlangen-Nürnberg, Germany, in 2009. He obtained his Doctorate (Dr. med. dent.) in 2011 and 2019 his Habilitation and venia legendi in conservative dentistry, periodontology and pediatric dentistry (“Materials and Techniques in Modern Restorative Dentistry”). Dr. Zorzin works since 2009 at the Dental Clinic 1 for Operative Dentistry and Periodontology, University Hospital Erlangen. He lectures at the Friedrich-Alexander University of Erlangen-Nürnberg in the field of operative dentistry where he leads clinical and pre-clinical courses. His main fields of research are self-adhesive resin luting composites, dentin adhesives, resin composites and ceramics, publishing in international peer-reviewed journals.

References

1. Van Meerbeek, B.; Yoshihara, K.; Van Landuyt, K.; Yoshida, Y.; Peumans, M. From Buonocore‘s Pioneering Acid-Etch Technique to Self-Adhering Restoratives. A Status Perspective of Rapidly Advancing Dental Adhesive Technology. J Adhes Dent 2020, 22, 7-34.
2. Kuno Y, Hosaka K, Nakajima M, Ikeda M, Klein Junior CA, Foxton RM, Tagami J. Incorporation of a hydrophilic amide monomer into a one-step self-etch adhesive to increase dentin bond strength: Effect of application time. Dent Mater J. 2019 Dec 1;38(6):892-899.
3. Nagura Y, Tsujimoto A, Fischer NG, Baruth AG, Barkmeier WW, Takamizawa T, Latta MA, Miyazaki M. Effect of Reduced Universal Adhesive Application Time on Enamel Bond Fatigue and Surface Morphology. Oper Dent. 2019 Jan/Feb;44(1):42-53.
4. Fehrenbach, J., C.P. Isolan, and E.A. Münchow, Is the presence of 10-MDP associated to higher bonding performance for self-etching adhesive systems? A meta-analysis of in vitro studies. Dental Materials, 2021. 37(10): 1463-1485.
5. Van Meerbeek, B., et al., State of the art of self-etch adhesives. Dental Materials, 2011. 27(1): 17-28.
6. Pashley, D.H., et al., State of the art etchand-rinse adhesives. Dent Mater, 2011. 27(1): 1-16.
7. Vermelho, P.M., et al., Adhesion of multimode adhesives to enamel and dentin after one year of water storage. Clinical Oral Investigations, 21(5): 1707-1715.

Certaines entreprises utilisent principalement des technologies de base développées par d‘autres afin d‘améliorer leurs produits et d‘en introduire de nouveaux, alors que d‘autres sociétés mènent des recherches fondamentales et développent la technologie en interne. Cette différence est-elle importante pour ceux qui utilisent les produits en résultant au cabinet ou laboratoire dentaire au quotidien ? C‘est le cas - étant donné que les entreprises qui développent tout à partir de rien disposent généralement d‘une compréhension plus approfondie des produits et de leurs procédures de production, ce qui leur permet de modifier plus facilement certaines caractéristiques, de résoudre certains problèmes et de répondre aux besoins sur le marché. Cet article décrit l‘impact de plusieurs technologies de base développées par Kuraray Noritake Dental Inc. concernant le flux de travail associé à la création de restaurations composite directes.

Les restaurations directes - de la complexité à la simplicité

La dentisterie restaurative adhésive utilisant des adhésifs dentaires et résines composites haute performance est actuellement l‘un des plus populaires traitements des dents avec lésions carieuses. De nos jours, un flacon unique d‘adhésif universel et une ou deux nuances et opacités de composite universel suffisent généralement pour obtenir des résultats esthétiques et durables, à condition de sélectionner les bons matériaux. Toutefois, cela n‘a pas toujours été le cas. Pendant longtemps, les techniques utilisées pour créer des restaurations directes étaient assez complexes : les adhésifs étaient des flacons multiples sensibles à la technique appliquée et des systèmes à étapes multiples avec des temps d‘application longs. D‘un autre côté, les matériaux de charge composites ne produisaient des résultats naturels qu‘à grands renforts de nuances et opacités différentes et combinées correctement. Et, même lorsque les procédures complexes étaient mises en oeuvre correctement, le risque de microfuite, décoloration et caries secondaires au final était relativement élevé. Kuraray Noritake Dental Inc. a misé sur le solutionnement de ces problèmes à un stade relativement précoce, en commençant par l‘utilisation du monomère MDP original développé en 1981.

Optimiser la perfomance d'adhésion

Le monomère MDP original répondait au problème de durabilité limitée de la performance d‘adhésion des systèmes adhésifs. Le groupe hydrophile (phosphate) du MDP forme une liaison chimique particulièrement solide et durable avec le calcium de l‘hydroxyapatite, le principal composant de l‘émail et de la dentine. Le sel MDP-Ca formé procure la base pour une couche hybride stable, solide et durable. En combinaison avec la résine de l‘agent adhésif, le résultat est un scellement hermétique de la cavité après photopolymérisation. Jusqu‘à l‘heure actuelle, le MDP est un composant essentiel de tout produit adhésif de Kuraray Noritake Dental Inc., et c‘est le composant clé qui a fait de CLEARFIL™ SE Bond le système adhésif à auto-mordançage de référence absolue.

Cependant, convaincue que les adhésifs dentaires devaient apporter davantage qu‘une seule adhésion solide et durable, Kuraray Noritake Dental Inc. a commencé à se pencher sur un autre problème : le risque de déminéralisation et de cavitation causé par les bactéries restées dans la cavité. Sur la base de son expérience dans le développement d‘autres monomères adhésifs, Kuraray Noritake Dental Inc. a inventé le monomère MDPB qui a pour une action de nettoyage antibactérien de cavité. Différent d‘autres agents antibactériens qui pourraient nuire à la solidité de l‘adhésion d‘un adhésif appliqué ultérieurement, le monomère MDPB détruit les bactéries persistantes sans affecter la performance d‘adhésion. Il est contenu dans l‘apprêt de l‘adhésif à auto-mordançage en deux flacons CLEARFIL™ SE Protect et est immobilisé par polymérisation.

Le mécanisme bactéricide du MDPB est supposé similaire à celui de l‘agent antibactérien bien connu qu‘est le CCP (chlorure de cétylpyridinium), qui est contenu dans de nombreux dentifrices et bains de bouche.

Si l‘adhésif à auto-mordançage en deux flacons a simplifié la procédure d‘adhésion, la version en flacon unique a permis d‘aller encore plus loin. Réunir les ingrédients des systèmes en étapes multiples dans un seul flacon sans compromettre la stabilité du produit relève du défi. La technologie actuelle permet désormais cela. Pour sceller la surface le plus tôt possible après l‘application, la pénétration des monomères dans le tissu dentaire doit être rapide et efficace. En général, la pénétration est toutefois ralentie par les monomères qui ont besoin de temps pour pénétrer la structure dentaire - en particulièrement la dentine humide - et requièrent parfois même un mouvement de friction à cette fin. C‘est pourquoi Kuraray Noritake Dental Inc. s‘est concentrée sur le développement de la Rapid Bond Technology. Elle consiste dans le monomère MDP original associé aux monomères hydrophiles à réticulation d‘amide nouvellement développés et intégré à CLEARFIL™ Universal Bond Quick. Les monomères amides hydrophiles permettent une pénétration rapide, complète et profonde dans la dentine et forment avec la polymérisation un dense réseau polymère réticulé responsable d‘une adhésion solide et durable. Ainsi, les temps de friction et d‘attente sont supprimés et un scellement hermétique et durable de la cavité est réalisé après photopolymérisation.

En raison de leur hydrophilie (affinité avec l‘eau), les monomères amide de la Rapide Bond Technology pénètrent très bien la dentine. Après photopolymérisation, l‘adhésion présente une faible absorption d‘eau et donc une grande résistance dans le temps.

Optimiliser les restaurations directs

Combiner plusieurs couches, nuances et opacités : Heureusement, l‘utilisation de techniques de stratification très complexes pour créer des restaurations composite naturelles appartient au passé dans de nombreuses situations cliniques. En effet, les résines composites hautement développées se mélangent parfaitement à la structure dentaire adjacente. Pour fournir cette caractéristique favorable, Kuraray Noritake Dental Inc. a développé sa propre technologie de diffusion de la lumière (« Light Diffusion Technology », LDT). Cette technologie est incorporée dans des charges spécialement pré-polymérisées qui agissent comme des millions de micro-prismes transmettant et réfractant la lumière et la couleur depuis la structure dentaire alentour. Optimisés en taille, distribution et indice de réfraction par rapport à la matrice, les charges offrent un mélange naturel incomparable. L‘ensemble de la gamme de composites CLEARFIL MAJESTY™ contient cette technologie de charge maison. CLEARFIL MAJESTY™ ES-2 Universal, le dernier produit dans lequel Kuraray Noritake Dental Inc. fait usage du niveau supérieur de LDT permet une technique à nuance unique avec simplification de la sélection de nuance : il est disponible en deux nuances pour la zone antérieure et en une nuance unique pour la zone postérieure, mais se mélange si bien qu‘une couverture de quasiment chaque nuance du nuancier VITA classique A1-D4 est obtenue.

La réfraction et la transmission de la lumière sont le moyen d‘obtenir une excellente intégration optique : les charges de diffusion de la lumière de CLEARFIL MAJESTY™ ES-2 de Kuraray Noritake Dental Inc.

Étant donné qu‘un excellent aspect ne dépend pas seulement de l‘intégration optique et de marges de restauration indétectables, Kuraray Noritake Dental Inc. a également développé des charges qui assurent le reste, à savoir une brillance de surface naturelle et une rétention de polissage durable. La solution intégrée dans CLEARFIL MAJESTY™ ES Flow avec ses trois niveaux de fluidité est appelée « Submicron Filler Technology », consistant en des charges brillantes de taille submicronique. Ces charges sont si petites que les réflexions lumineuses offrent un effet naturel, même après usure. L‘exceptionnelle technologie silane de Kuraray Noritake Dental Inc. est utilisée pour rassembler des millions de ces charges submicroniques et les maintenir ensemble dans la durée. Elle permet des charges élevées dans les composites de faible viscosité et limite l‘absorption d‘eau qui entraînerait autrement une dégradation du composite polymérisé. L‘équilibre parfait entre les charges submicroniques brillantes, les charges de diffusion de la lumière, la matrice de résine et la propre technologie silane offre une combinaison équilibrée de propriétés mécaniqueset optiques.

Exemple d‘une restauration « single-shade » avec CLEARFIL MAJESTY™ ES-2 Universal.

Conclusion

Monomères adhésifs, technologies de charge et technologie silane procurent une solide combinaison de charges, clusters et matrice résine : Clairement, Kuraray Noritake Dental Inc. est un expert de confiance dans le domaine des restaurations adhésives. Ses propres technologies développées au cours des dernières décennies ont incontestablement contribué à améliorer (à long terme) la performance des restaurations directes et à faciliter l‘obtention de résultats fiables et esthétiques.

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!