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A new smile with only 4 zirconia crowns

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.

 

10 years KATANA™ Zirconia multi-layered series

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.

 

Unilateral bite elevation with a zirconia bridge and a lithium disilicate onlay

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.

 

Clinical case with KATANA™ Zirconia YML

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.

 

Universal adhesives: rationalizing clinical procedures

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.

 

Vereenvoudigde procedures voor directe restauraties

Om hun producten te verbeteren en nieuwe producten te introduceren, maken sommige bedrijven voornamelijk gebruik van basistechnologieën die zijn ontwikkeld door anderen; andere ondernemingen voeren fundamenteel onderzoek uit en ontwikkelen technologie in eigen huis. Is dat verschil relevant voor de professionals die de betreffende producten dagelijks gebruiken in tandarts- of tandtechnische praktijken? Dat is inderdaad relevant; bedrijven die alles vanaf het eerste begin ontwikkelen, hebben doorgaans namelijk een diepgaander begrip van de producten en hun productieprocedures. Zij kunnen dan ook gemakkelijker specifieke producteigenschappen aanpassen, bestaande problemen oplossen en inspelen op de behoeften van de markt. In dit artikel wordt ingegaan op de impact die verschillende door Kuraray Noritake Dental Inc. ontwikkelde basistechnologieën hebben op de workflow voor de vervaardiging van directe composietrestauraties.

 

Directe restauraties - van complex tot eenvoudig

Adhesieve restauratieve tandheelkunde met gebruikmaking van hoogwaardige tandheelkundige adhesieven en harscomposieten is momenteel een van de meest populaire methoden voor de behandeling van cariëslaesies.
Tegenwoordig zijn een single-bottle universeel adhesief plus één of twee kleuren en opaciteiten van een universele composiet meestal voldoende - mits de juiste materialen worden gekozen - om prachtige en duurzame resultaten te realiseren. Dat is echter niet altijd het geval geweest. De ingezette technieken voor de vervaardiging van directe restauraties waren lange tijd behoorlijk complex; de adhesieven bestonden uit technisch gevoelige multibottle- en meerstapssystemen met lange verwerkingstijden. Anderzijds werden met composietvulmaterialen alleen natuurgetrouwe resultaten bereikt als verschillende kleuren en opaciteiten op de juiste manier werden gecombineerd. En zelfs als de complexe procedures correct werden uitgevoerd, was er een relatief hoog risico van microlekkage, verkleuring en - uiteindelijk - secundaire cariës. Kuraray Noritake Dental Inc. heeft zich al in een vroeg stadium geconcentreerd op een oplossing voor deze problemen, te beginnen met de toepassing van het in 1981 ontwikkelde originele MDP-monomeer.

 

Optimalisatie van de hechtsterkte

Het originele MDP-monomeer loste het probleem op van de beperkte levensduur van de hechtsterkte van adhesieve systemen. De hydrofiele MDP-groep (fosfaat) vormt een uitzonderlijk sterke en duurzame en chemische hechting aan calcium, dat voorkomt in hydroxyapatiet, de basiscomponent van glazuur en dentine. Het gevormde MDP-Ca-zout biedt de basis voor een stabiele, sterke en duurzame hybridelaag. In combinatie met de hars van het hechtmiddel resulteert dit in een solide sealing van de caviteit na lichtuitharding. Tot op de dag van vandaag is MDP een essentiële component van alle adhesieve producten van Kuraray Noritake Dental Inc. en dankzij dit cruciale bestanddeel is CLEARFIL™ SE Bond het zelfetsende adhesieve systeem met de Gouden Standaard geworden.

Het originele MDP-monomeer zorgt voor een sterke chemische bevestiging aan glazuur, dentine, metaallegeringen en zirkonium.

Kuraray Noritake Dental Inc. was er echter van overtuigd dat tandheelkundige adhesieven méér dienden te bieden dan alleen een sterke en duurzame bevestiging en ging zich daarom richten op de oplossing van een ander probleem: het risico van demineralisatie en cavitatie, veroorzaakt door bacteriën die achterblijven in de caviteit. Op basis van ervaring in de ontwikkeling van andere adhesieve monomeren vond Kuraray Noritake Dental Inc. het MDPB-monomeer uit, met een antibacterieel reinigend effect voor de caviteit. Anders dan antibacteriële producten die de hechtsterkte van een opvolgend adhesief zouden kunnen aantasten, doodt het MDPB-monomeer de achterblijvende bacteriën zonder afbreuk te doen aan de hechtsterkte. Het monomeer is verwerkt in de primer van het two-bottle zelfetsende adhesief CLEARFIL™ SE Protect en wordt via polymerisatie geïmmobiliseerd.

 

Het bacteriologische mechanisme van MDPB wordt verondersteld gelijk te zijn aan de welbekende antibacteriële agens CPC (CetylPyridiniumChloride), die voorkomt in vele tandpasta‘s en mondspoelproducten.

 

Hoewel de adhesieve procedure al is vereenvoudigd door two-bottle zelfetsende adhesieven, gaan universele singlebottle adhesieven net nog een stapje verder. Het is een uitdaging om de ingrediënten die worden gedistribueerd binnen multi-stepsystemen samen te brengen in één flacon, zonder afbreuk te doen aan de stabiliteit van het product. Dankzij de huidige technologie is dit nu mogelijk. Om het oppervlak zo snel mogelijk na het aanbrengen te sealen, dienen de monomeren snel en efficiënt door te dringen in het tandweefsel. Die penetratie wordt doorgaans echter vertraagd door monomeren die tijd nodig hebben om door te dringen tot de tandstructuur - in het bijzonder vochtig dentine - en soms zelfs moeten worden ingewreven. Om die reden heeft Kuraray Noritake Dental Inc. zich geconcentreerd op de ontwikkeling van de Rapid Bond Technology. Deze technologie omvat het originele MDP-monomeer dat, in combinatie met nieuw ontwikkelde hydrofiele, gecrosslinkte amidemonomeren, is verwerkt in CLEARFIL™ Universal Bond Quick. De hydrofiele amidemonomeren zorgen voor een snelle, diepe en volledige penetratie in het dentine en vormen na lichtuitharding een dicht gecrosslinkt polymeernetwerk, dat garant staat voor een sterke en duurzame hechting. Zodoende gaat er geen tijd meer verloren met wachten en masseren; na lichtuitharding is de caviteit solide en langdurig geseald.

 

GEPREPAREERD DENTINE MET SMEERLAAG.
Vanwege de hydrofiliciteit hebben we behoefte aan een zeer hydrofiele bevestiging, zodat het dentine optimaal wordt gepenetreerd.

DENTINE BEVESTIGD MET CLEARFIL™ UNIVERSAL BOND QUICK.

Tijdens het uitharden zorgt CLEARFIL™ Universal Bond Quick voor een hoog-gecrosslinkt polymeernetwerk. Dankzij dat netwerk heeft de bonding een bijzonder lage waterabsorptie, zodat een duurzame restauratie is gewaarborgd.

 

Vanwege hun hydrofiliciteit (wateraffiniteit) dringen de amidemonomeren van de Rapid Bond Technology goed door in het dentine. Na lichtuitharding heeft de bonding een lage waterabsorptie en daarmee een hoge verouderingsbestendigheid.

 

Optimalisatie van directe restauraties

Combineren van meerdere lagen, kleuren en opaciteiten; het gebruik van uiterst complexe layeringtechnieken voor de vervaardiging van natuurgetrouwe composietrestauraties behoort in vele klinische situaties gelukkig tot het verleden. Dat is te danken aan hoogwaardige harscomposieten die zich naadloos voegen naar de omliggende tandstructuur. Om deze gunstige producteigenschap te realiseren, heeft Kuraray Noritake Dental Inc. haar Light Diffusion Technology (LDT) ontwikkeld. Deze technologie is verwerkt in speciale geprepolymeriseerde vuldeeltjes die werken als miljoenen microprisma‘s, die licht en kleur van de omliggende tandstructuur overdragen en afbuigen. De vuldeeltjes zijngeoptimaliseerd qua afmeting, verdeling en refractie-index en bieden dan ook een ongeëvenaarde natuurlijke vermenging. Deze propriëtaire vultechnologie is verwerkt in het volledige composietaanbod CLEARFIL MAJESTY™ in het nieuwste product - CLEARFIL MAJESTY™ ES-2 Universal - maakt Kuraray Noritake Dental Inc. gebruik van geavanceerd LDT voor een monochrome techniek met vereenvoudigde kleurselectie; dit product is beschikbaar in twee kleuren voor het anterieure gebied en één kleur voor het posterieure gebied. Het harmonieert echter zo fraai dat vrijwel alle kleuren van de klassieke VITA A1-D4 kleurenkaart worden afgedekt.

 

Juiste refractie en transmissie van licht voor een geweldige optische integratie; de lichtdiffusievuldeeltjes van CLEARFIL MAJESTY™ ES-2 van Kuraray Noritake Dental Inc.

 

Een fantastische optische uitstraling hangt niet alleen samen met optische integratie en onzichtbare restauratieranden. Daarom heeft Kuraray Noritake Dental Inc. ook vuldeeltjes ontwikkeld die voor de rest zorgen: een natuurlijke oppervlakglans en langdurig behoud van glans. De oplossing die is verwerkt in CLEARFIL MAJESTY™ ES Flow met drie niveaus van vloeibaarheid, is genaamd Submicron Filler Technology en bestaat uit glanzende vuldeeltjes van submicronformaat. Deze vuldeeltjes zijn zo nietig dat lichtreflectie - zelfs na slijtage - een natuurlijk effect oplevert. De uitzonderlijke silaantechnologie van Kuraray Noritake Dental Inc. wordt gebruikt om miljoenen van die submicronvuldeeltjes bij elkaar te brengen en - door de tijd heen - te houden. Daardoor is de lading met vuldeeltjes in de laagviscose composieten hoger en wordt de wateropname beperkt die de kwaliteit van de uitgeharde composiet anders zou aantasten. De perfecte balans tussen de glanzende submicronvuldeeltjes, lichtdiffusievuldeeltjes, harsmatrix en propriëtaire silaantechnologie is verantwoordelijk voor een uitgebalanceerde combinatie van mechanische en optische eigenschappen.

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

 

Conclusie

Adhesieve monomeren en vuldeeltjes- en silaantechnologie staan garant voor een solide combinatie van vuldeeltjes, clusters en harsmatrix; Kuraray Noritake Dental Inc. is overduidelijk een erkende expert op het gebied van adhesieve restauraties. De propriëtaire technologieën die in de afgelopen decennia zijn ontwikkeld, hebben absoluut bijgedragen aan betere prestaties (op lange termijn) van directe restauraties, en aan een gemakkelijker weg naar betrouwbare en esthetische resultaten.

 

Achieving maximum quality in a minimum amount of time

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.

Interview with Alexander Aronin

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!

 

PANAVIA™: 40 years of success in adhesive luting

DID YOU EVER WONDER WHY THE PRODUCTS OF THE PANAVIA™ BRAND OFFER SUCH OUTSTANDING PERFORMANCE?

 

You probably know that they all contain the original MDP monomer developed in the early 1980s. It has attracted much attention because it is such an excellent adhesive monomer. This phosphate ester monomer forms a very strong bond to tooth structure, zirconia, and dental metals. It has been used in every PANAVIA™ product. In reality, however, other catalytic technologies and ingredients alongside MDP are important technological contributors supporting the performance of our cementation solutions.

 

INGREDIENTS AFFECTING THE POLYMERISATION REACTION

 

One of these decisive additional technologies and ingredients is the polymerization catalyst triggering the curing process. Different from the MDP monomer used in every PANAVIA™ product, the polymerization catalyst has been continuously improved since the introduction of PANAVIA™ EX in 1983. New versions have been developed for PANAVIA™ 21, PANAVIA™ Fluoro Cement and PANAVIA™ V5, for example. Another important component also affecting the curing process is the Touch Cure Technology used in two of the three major products of the current PANAVIA™ Portfolio: PANAVIA™ V5 and PANAVIA™ Veneer LC. This technology was first used in PANAVIA™ 21, which was launched in 1993. The contact of the chemical polymerization activator contained in the self-etching primer with the resin cement paste accelerates the polymerization of the cement from the adhesive interface, thus providing better adhesion of the resin cement. In developing PANAVIA™ V5, we reviewed the chemical composition of the existing PANAVIA™ products and updated it substantially. The Touch Cure technology has also been adopted for use in the case of PANAVIA™ V5 Tooth Primer and the concomitantly used PANAVIA™ V5 Paste. When cementing veneers with PANAVIA™ Veneer LC, we also use PANAVIA™ V5 Tooth Primer for conditioning teeth. This also involves the application of Touch Cure technology for achieving an adhesive connection with the tooth without compromising the working time of the cement paste.

 

 

ADDITIONAL ADHESIVE MONOMERS

 

Even in the field of adhesive monomers, we did not stand still: We developed the LCSi monomer, a long carbon chain silane-coupling agent which made possible to integrate the function of a ceramic primer in our universal self-adhesive resin cement PANAVIA™ SA Cement Universal. With its high level of hydrophobicity, this monomer provides stable, long-term bond strength. Generally speaking, it may be said that the reason bond durability may drop is a hydrolytic reaction damaging the chemical bond between the silica contained in the glass ceramics and the silane-coupling agent.

 

THREE PRODUCTS COVERING VIRTUALLY EVERY NEED

 

By combining these technologies and ingredients smartly, we have succeeded in developing a resin cement portfolio that covers virtually every need. With PANAVIA™ V5, PANAVIA™ SA Cement Universal and PANAVIA™ Veneer LC, it is possible to treat a wide variety of cases. The products allow for the luting of various types of restorations, prosthetic appliances and for the placement of posts and produce great outcomes if used properly according to the instructions for use.

 

PANAVIA™ V5 is the resin cement that has the widest range of uses among the three cement systems just mentioned. It covers almost all the intended uses of the other two cements. Therefore, it is possible for the dental practitioner to choose the right cement system for treatment, according to the cases arriving at the clinic and patient needs, from among these three major resin cement products: PANAVIA™ V5, a resin cement with a wide range of applications; PANAVIA™ SA Cement Universal, a simple and easy-handling self-adhesive resin cement; and PANAVIA™ Veneer LC when there is a need to bond laminate veneers.

EXPLORING NEW OPPORTUNITIES

 

The good thing about developing technologies in a company like Kuraray Noritake Dental is that their application is not limited to a certain product or product group. The R&D Department always carries out research on how to leverage the benefits of the technologies in other applications. Take, for example, KATANA™ Cleaner, which was released in 2019. This cleaning agent can be used to remove saliva, blood, temporary cement, or other contaminants that can adhere to the surfaces of teeth or prosthetic devices during trial fitting and temporary cementation of a prosthetic device. This unique product has been developed by taking advantage of the surfactant function of the MDP monomer.

 

CONCLUSION

 

Hence, it is mainly our long-standing knowledge and experience in the development of dental resin cements and adhesive solutions that provides for the excellence of the current PANAVIA™ Portfolio. We know how to improve on existing technologies, to never stop developing new ones and to continuously look for the best way to combine proven and new components to obtain the best possible outcomes. In the steps of the product development procedure, clinical tests are conducted and feedback from dental practitioners is gathered in order to take into account the extreme conditions found in the oral environment. In the past 40 years, this strategy has proven successful, and we are sure it will help us to develop many other innovative products that offer ideal support in striving to improve the oral health of patients.

 

Cementeren van indirecte restauraties

 

Er zijn bedrijven die voornamelijk gebruikmaken van basistechnologieën die door anderen zijn ontwikkeld om hun producten te verbeteren en nieuwe producten te introduceren, terwijl andere bedrijven fundamenteel onderzoek doen en zelf technologieën ontwikkelen. Is dat verschil relevant voor de professionals die de betreffende producten dagelijks gebruiken in tandarts- of tandtechnische praktijken? Zeker wel. Bedrijven die een diepgaande kennis hebben van de onderliggende componenten, chemie en technologieën kunnen bestaande problemen effectief oplossen en snel en flexibel reageren op de behoeften van de markt. In dit artikel wordt ingegaan op de impact die verschillende, door Kuraray Noritake Dental Inc. ontwikkelde, basistechnologieën hebben op het cementeren van indirecte restauraties

 

Adhesief cementeren, vroeger en nu

 

Het gebruik van diverse soorten keramiek voor het frezen van tandheelkundige restauraties opent nieuwe mogelijkheden in de tandprothetiek, waardoor het nu gemakkelijker is om hoogesthetische restauraties te creëren en te plaatsen. Wat vaak onderschat wordt in deze context, is de rol van adhesieve cementeersystemen; deze ondersteunen niet alleen de esthetische uitstraling van de translucente, restauraties, maar bieden ook mogelijkheden voor minder invasieve preparaties en restauratieontwerpen. De eerste systemen die zorgden voor de chemische hechting tussen de elementen en indirecte restauraties, vertoonden verminderde prestaties op de lange termijn en met een hoge gevoeligheid voor techniek. Bovendien was de procedure uitzonderlijk complex. De technologische ontwikkeling bij Kuraray Noritake Dental Inc. leverde een belangrijke bijdrage aan een verbeterde hechtprestatie op lange termijn, terwijl de verwerking ook eenvoudiger werd.

 

Optimalisering van de hechtsterkte op lange termijn

 

Om een duurzame hechting van de eerste cementeersystemen aan tandstructuren (vooral dentine) te realiseren, besloot, Kuraray, de moederbedrijf van Kuraray Noritake Dental Inc., in de jaren zeventig zich te richten op de ontwikkeling van een sterker adhesief monomeer. Als eerste stap op weg naar succes introduceerde het bedrijf in 1976 het fosfaatmonomeer Phenyl-P. Vijf jaar later leidden voortdurende inspanningen om de moleculaire structuur te verbeteren en te verfijnen tot de lancering van het populaire MDP-monomeer, dat zorgt voor een bijzonder sterke en duurzame hechting aan glazuur, dentine, metaal en zirkonium.

 

 

Het inventiviteit van deze uitvinding wordt benadrukt doordat het nog steeds een essentieel onderdeel is van elk adhesief product en adhesief cementeersysteem van Kuraray Noritake Dental Inc., en inmiddels ook wordt gebruikt door andere fabrikanten om de sterkte en duurzaamheid van hun bevestigingen te optimaliseren. In vergelijking met elders gesynthetiseerd MDP, onderscheidt het Originele MDP-monomer van Kuraray Noritake Dental Inc. zich door een ongeëvenaard niveau van zuiverheid. Onafhankelijke onderzoeken tonen aan dat dit niveau van zuiverheid een positief effect heeft op de hechtingseigenschappen*. Het MDP-monomeer biedt stabiliteit binnen een vochtige omgeving en draagt zo bij aan meer consistente prestaties van het product waarin het is verwerkt.

 


Het niveau van zuiverheid en de hechtsterkte verschillen per MDP-monomeer.


Er werden drie experimentele zelfetsende primers geprepareerd, die bestonden uit 15 wt.% 10-MDP en afkomstig waren uit verschillende bronnen: KN (Kuraray Noritake Dental), PCM (Duitsland) of DMI (Designer molecules Inc., VS). Met dank aan Dr. Kumiko Yoshihara voor de gegevens.

 

Voor adhesieve cementsystemen die moeten zorgen voor een sterke hechting met een uitstekende marginale afdichting is het niet voldoende als ze simpelweg een adhesieve monomeer bevatten. Een efficiënte uitharding van dat monomeer is ook een vereiste en die laat zich niet altijd gemakkelijk realiseren. Om te zorgen voor een effectieve uitharding, zowel chemische als onder licht, van PANAVIA™ V5, heeft Kuraray Noritake Dental Inc. de Touch-Cure Technology ontwikkeld. De kern van deze technologie is een nieuw ontwikkelde, zeer actieve polymerisatieversneller in de PANAVIA™ V5 Tooth Primer. Deze werkt samen met het acidische MDP-monomeer en bevordert de polymerisatie vanaf de interface tussen element en cement zodra PANAVIA™ V5 Paste wordt aangebracht op het al geprimede tandoppervlak. In PANAVIA™ Veneer LC - een lichtuithardend cementsysteem met dezelfde primers worden gebruikt - werkt de polymerisatieversneller van PANAVIA™ V5 Tooth Primer volgens hetzelfde mechanisme. Deze draagt bij aan de uitharding van de adhesieve interface; PANAVIA™ Veneer LC Paste biedt een uitstekende stabiliteit in omgevingslicht en wordt door lichtuitharding gepolymeriseerd.

 

Bijvoorbeeld, dit verschijnsel werd geëvalueerd voor PANAVIA™ F2.0, de voorganger van PANAVIA™ V5. De uitkomst van de studie was dat de eigenschappen ten aanzien van marginale afdichting van PANAVIA™ F2.0 veel beter waren dan die van andere getoetste cementsystemen**. Deze gedocumenteerde, betrouwbare afdichting van de interface komt marginale lekkage minder voor en wordt een hoge graad van polymerisatie bereikt, zelfs in de zelfuithardende modus (zonder lichtuitharding of bij blokkering van het licht door het restauratieve materiaal); het eindresultaat is dus een bijzonder krachtige hechting.

 

Een bijkomend voordeel van de integratie van de polymerisatieversneller is dat deze functioneert als een sterke reductor. Het natriumhypochloriet, dat bij endodontische behandelingen vaak wordt gebruikt als irrigatieoplossing, wordt geneutraliseerd; op die manier wordt het negatieve effect op de hechtsterkte van de naderhand aangebrachte cementpasta opgeheven.

 

 

 

Cementeren van glaskeramiek vereenvoudigen

 

Minder flesjes, minder stappen en gestroomlijnde cementeerprocedures: dat is de reden waarom zelfhechtende composietcementen zijn ontwikkeld en geïntroduceerd in het begin van de jaren 2000. De meeste van die producten hebben echter een beperkt indicatiegebied. Ze presteren goed bij het hechten aan zirkonium, metaal, glazuur en dentine, maar worden niet aanbevolen voor hechten aan glaskeramiek, of hebben in dat geval een extra silaanprimer nodig. PANAVIA™ SA Cement Universal, dat MDP bevat, onderscheidt zicht vanwege een andere gepatenteerde technologie van Kuraray Noritake Dental Inc.: het LCSi-monomeer, Long Carbon-chain Silane Coupling agent. Dit monomeer vormt een sterke chemische hechting aan composiet, en glaskeramiek zoals; porselein, lithiumdisilicaat, etc.. Een aparte primer of voorbehandling is niet meer nodig. Dankzij de voordelen van deze technologie onderscheidt PANAVIA™ SA Cement Universal zich duidelijk van andere zelfhechtende composietcementen als een zelfhechtend eenstapscomposietcement, zelfs voor restauraties die van glaskeramiek worden vervaardigd.

 

 

De hechtsterkte van dit product aan de tandstructuur kan, indien gewenst, nog worden vergroot door gebruik van het universele adhesief CLEARFIL™ Universal Bond Quick met de Rapid Bond Technology. Deze innovatieve technologie is door Kuraray Noritake Dental Inc. ontwikkeld om problemen - specifiek voor universele adhesieven - op te lossen rondom de trage penetratie in tandstructuren, vooral vochtig dentine. Om een goede penetratie te garanderen, moeten deze adhesieven een lange tijd en actief in de tandstructuur worden gewreven of moeten gebruikers even wachten voordat de laag kan worden uitgehard met licht. De Rapid Bond Technology, samengesteld uit het originele MDP-monomeer en de hydrofiele amidemonomeren, zorgt voor een hoge wateraffiniteit, die leidt tot een snelle en diepe penetratie van vochtig dentine. Dankzij deze technologie kan er bij CLEARFIL™ Universal Bond Quick direct na aanbrengen worden verder gewerkt, zonder negatieve invloed op de hechtsterkte.

 

Tandheelkundige transformatie dankzij baanbrekende technologieën 

 

De door Kuraray Noritake Dental Inc. ontwikkelde technologieën hebben een grote bijdrage geleverd aan de verbeterde hechtkracht van adhesieve cementeersystemen en aan een werkelijk universeel gebruik van zelfhechtende composietcementen. Het bedrijf biedt dan ook een gestroomlijnde portfolio van hoogwaardige composietcementen voor elke gebruiker en voor verschillende klinische situaties. Er zijn minder componenten en minder stappen nodig en de procedures zijn vereenvoudigd; dus: minder fouten en duurzame restauraties. De genoemde producten bieden, nog afgezien van de technologiegerelateerde pluspunten, veel bijkomende productvoordelen. Meer informatie via kuraraynoritake.eu.   

 

 

Referenties


*) 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

 

BOND Magazine, 10th edition

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 10th 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