429 Too Many Requests

Case by CDT Mathias Berger, France

Every patient is unique. Their specific backgrounds, functional needs and aesthetic demands need to be respected in any prosthodontic treatment plan. However, the importance of an individual treatment approach increases with the number of teeth to be replaced: After all, the impact of the restorations on facial aesthetics and on the patient’s quality of life is never greater than when all teeth are missing. Fortunately, adequate dental materials and techniques are available for a patient-centered, individual approach, no matter what challenges need to be overcome.

A patient with bruxism

In the present case, an elderly male patient with bruxism was in need of a new maxillary denture. Since the placement of five implants in the maxilla, he had no proprioception in this jaw. This lack of sensation had an impact on the overdenture to be produced: material and design needed to be carefully selected in a way that it would withstand uncontrolled chewing forces. As technical complications are easier to repair than biological complications, the overdenture should not be unbreakable – instead, the replacement of single units should be easily manageable.

Two-part denture design

The solution was a two-part design with a milled bar consisting of the gum area and tooth abutments (fig. 1) combined with single crowns. The material of choice for the bar was KATANA™ Zirconia HTML Plus (Kuraray Noritake Dental Inc.) with a uniform flexural strength of 1,150 MPa throughout the disc, while the single crowns were milled from KATANA™ Zirconia YML that offers natural translucency and strength gradation. While a monolithic design was selected for the posterior crowns, the six crowns for the anterior region received a micro-cutback for aesthetic micro-layering with CERABIEN™ ZR Porcelain. The shade scheme for individualization of the anterior crowns is shown in fig. 2. In a nutshell, customization was performed with the Internal Stains Cervical 1, Grayish Blue, Dark Grey and A+. The finishing layer on the incisors was created mainly using LT0 materials with some CCV-3 on the cervical and LT Natural on the mesial and distal lobes. On the canines, LT1 was used instead of LT0. The posterior crowns were merely finished with liquid ceramics (CERABIEN™ ZR FC Paste Stain, Kuraray Noritake Dental Inc.).

Fig. 1. Sintered bar milled from KATANA™ Zirconia HTML Plus.

Fig. 2. Chroma map for micro-layering in the anterior region.

Fig. 3 shows the finished single crowns with their individual, age-appropriate shade effects on the sintered bar. After checking the fit of the crowns, the gum areas of the bar were individualized using CERABIEN™ ZR Tissue Porcelain (fig. 4). Subsequently, the crowns were luted to the zirconia abutments (fig. 5), leaving screw access holes in aesthetically uncritical positions (fig. 6). The final overdenture ready for try-in is shown in fig. 7. Due to an excellent fit on the implants (fig. 8), it was possible to immediately fix the overdenture with the screws, close the access holes with composite and discharge the patient. The final appearance is shown in fig. 9.

Fig. 3. Finished crowns on the sintered bar.

Fig. 4. Bar with individualized gum areas.

Fig. 5. Placement of the central incisor crowns on the bar.

Fig. 6. Occlusal screw access hole in the finished overdenture.

Fig. 7. Overdenture ready for try-in.

Fig. 8. Intraoral try-in of the aesthetic overdenture.

FINAL SITUATION

Fig. 9. Treatment outcome.

CONCLUSION

This patient case is a good example of how important it is to respect the patient’s background, age and specific demands when producing dental restorations. Thanks to the great variety of restorative materials with different mechanical and optical properties available, it is possible to create suitable prosthetics for virtually every patient. However, for this purpose, it is important to stay up to date regarding new products launched and techniques developed. This way, it is often even possible to create beautiful and durable solutions in a simplified and efficient procedure such as micro-layering on innovative zirconia with a high aesthetic potential.

Dentist:

CDT MATHIAS BERGER

Satoshi Yamaguchi, President, Kuraray Noritake Dental Inc.

KURARAY NORITAKE DENTAL INC. EXCELS IN DENTAL TECHNOLOGY, FOCUSING ON STRENGTH, AESTHETICS AND GLOBAL ADAPTABILITY

Kuraray Noritake Dental Inc., a leader in dental materials and technology, blends innovation with a deep commitment to oral health. Established from the merger of Kuraray Medical Inc. and Noritake Dental Supply Co., Limited, the company excels in providing dental bonding agents, fillings, cements, porcelains, zirconia and CAD/CAM blocks. This synergy has allowed the company to push the boundaries of dental science.

“We aim to enhance global oral health and wellness.”

President Satoshi Yamaguchi highlights the company's approach: "We focus on strength, aesthetics and speed in our products. By developing our own zirconia powder and partnering with CAD/CAM system manufacturers, we achieve high-quality, durable and efficient dental solutions." This commitment is evident in the firm's flagship product, KATANA™ Zirconia Block, renowned for its durability and aesthetic appeal.

Kuraray Noritake Dental is also striving to develop new products for more longterm predictable dental treatment with bioactive properties. The company is not just focused on developed markets like the U.S. and Europe. Mr. Yamaguchi explains: "Understanding local treatment situations is key. In addition to the U.S. and Europe, having sales offices in places like Brazil and China helps us tailor our products to regional demands." This global presence ensures the company remains at the forefront of dental technology, adapting to diverse market needs.

Tooth crown made from KATANA™ Zirconia

Looking ahead, Mr. Yamaguchi envisions Kuraray Noritake Dental as more than just a technological innovator. "In five years, I hope we are seen not only as a tech company but as a holistic provider of oral care solutions," he says. With a commitment to reducing "invisible stress" for dental professionals and patients, the company aims to enhance global oral health and wellness.Original article published in Newsweek Magazine on September 20th, 2024 Written by The Worldfolio

Article by Dr. Florian Zwiener

Modern multi-layered zirconia such as KATANA™ Zirconia STML (Kuraray Noritake Dental Inc.) already meets high aesthetic demands due to its natural colour gradient and high translucency. To achieve further characterisation and optical adjustment to the adjacent teeth, there are essentially two options: veneering with feldspathic ceramic or glazing and individualisation with ceramic stains.

While there are still many indications for veneering, especially in the anterior area, more and more cases can now be solved with monolithic restorations. This allows for a time-efficient chairside workflow with same-day treatment, eliminating the need for temporary restorations. Additionally, the absence of a porcelain layer reduces the wall thickness of the restoration and thus the space required, allowing for less invasive preparation. This also reduces the risk of endodontic complications induced by tooth preparation (grinding trauma). Another advantage is a significant reduction in the chipping risk.

Below are the essential steps for individualisation using ceramic stains, demonstrated through the example of a molar crown.

PREPARATION

The restoration is designed in full contour as usual, ideally dry-milled, and then sintered. After sintering, the restoration is first sandblasted (aluminium oxide 50 μm, 1 to 1.5 bar pressure). This microscopic roughening of the ceramic surface enables an optimal bond with the glaze. Subsequently, the restoration should be cleaned using a steam cleaner or an ultrasonic cleaner to remove all blasting residue.

The functional restoration surfaces must then be polished to avoid the risk of excessive abrasion on the enamel of the opposing dentition, as zirconia is harder than enamel. Following this, optional glazing and characterization with ceramic stains can be performed. However, for areas not in the aesthetic zone, such as the palatal surfaces of maxillary anterior teeth, this is not necessarily required.

PREPARATION: STEPS AT A GLANCE

1. Sandblasting of the sintered restoration (Al2O3 50 μm, 1-1.5 bar)
2. Cleaning (steam cleaner or ultrasonic cleaner)
3. Polishing the occlusal/palatal contact areas

Fig. 1. Sintered and sandblasted zirconia crown.

Fig. 2. Occlusal high-gloss polish.

Fig. 3. TWIST™ DIA for Zirconia (Kuraray Noritake Dental Inc.) enables efficient polishing of zirconia in three steps.

STAINING AND GLAZING

The shades A+, B+, C+, and D+ of the paste-like ceramic stain CERABIEN™ ZR FC Paste Stain (Kuraray Noritake Dental Inc.) enhance the chroma in the cervical area when applied in the respective tooth shade. They are used to strengthen the multicolour effect of the zirconia or to darken the restoration overall. By mixing the stains with glaze or clear glaze in different ratios, the intensity can be adjusted.

Cervical 1 and 2 are suitable for replicating exposed cervical areas or discolouration. Cervical 1 is also useful for marking fissures, as it gives the crown depth and structure without appearing overly dark. Patients typically reject excessively pronounced fissure effects. Since fissure areas in multi-layered materials generally lie in the lightest part of the block (in the enamel layer), it may make sense to darken them slightly with A+, while white hypermineralisations can be replicated on the cusp tips. A narrow band of Grayish Blue below the cusp tips creates an optical translucency effect. In cases where this translucency appears too dark blue or greyish, mixing Grayish Blue with Dark Grey can modify the appearance.

By mixing various colours, numerous different tones can be created. For instance, by adding Yellow to A+, its slightly brownish colour can be adjusted to a warmer, more yellowish tooth shade. It is generally advisable to capture the patient‘s tooth shade with a photo and a custom-made colour ring of the corresponding material before preparation. This can serve as a reference during production, especially in the laboratory, where lighting conditions may differ.

For pronounced characterisations or fine details, it may be necessary to carry out multiple firings to avoid unwanted running effects between the colours and the glaze. This is particularly recommended when replicating anatomical details with high sharpness, such as enamel cracks or local discolourations. For this, a glaze and base shade are first applied and fired, and finer structures are added in a second firing. Alternatively, a fixative firing of the stains without glaze can be performed first, with only a glaze layer fired in the second step. A benefit of CERABIEN™ ZR FC Paste Stain is that its appearance during application closely matches the final firing result. In thick consistency, glaze can also be used to easily rebuild missing proximal contacts.

STAINING AND GLAZING: STEPS AT A GLANCE

1. Glaze with Glaze/Clear Glaze
2. Increase chroma (in the cervical area or over large areas) with A+, B+, C+, or D+
   - Adjust intensity by mixing with Glaze/Clear Glaze
   - Create a warmer tone by mixing with Yellow
3. Replicate discolouration/exposed cervical areas: Cervical 1 and 2
4. Customise fissure areas
   - Darken with A+, B+, C+, or D+
   - Accentuate fissures with Cervical 1
5. Customise cusp tips
   - Replicate hypermineralisations with White
   - Create a band below with Grayish Blue (translucency effect)
   - Adjust translucency effect below cusp tips by mixing with Dark Grey
6. Firing

Alternatives:

1. First firing: Glaze plus base shade, second firing: Finer structures
2. First firing: Fixative stain firing without glaze, second firing: Glaze firing

Fig. 4. CERABIEN™ ZR FC Paste Stain assortment for the practice laboratory.

Fig. 5. Discoloured fissures can be accurately replicated with an ISO10 endodontic file.

Fig. 6 and 7. Glazing and staining in one firing.

Fig. 8. Shade determination using a custom-made KATANA™ Zirconia STML colour ring (A3.5).

Fig. 9. Bridge made from KATANA™ Zirconia STML, sandblasted and occlusally polished.

Fig. 10. Finished glazed and characterised restoration.

Fig. 11. Bridge 14-16 in place.

FINAL SITUATION

Fig. 11. Bridge 14-16 in place.

Dentist:

FLORIAN ZWIENER

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

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

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

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

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

IMPLICATIONS FOR CLINICAL USE

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


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

GREAT AESTHETICS AND HANDLING

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

Fig. 3. Overview of shades available per flowability.

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

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

Case by Dr. Enzo Attanasio

The selection of the restorative material is a crucial step in prosthodontics. Hybrid ceramics offer a range of properties well-suited for various therapeutic situations, both in the presence of vital teeth and of endodontically treated teeth. Using the example of a clinical case, this article will explore the advantages associated with the use of hybrid ceramics in a cracked tooth syndrome scenario.

INITIAL SITUATION

The affected tooth in this case was a mandibular right second premolar (45 according to the FDI notation) with an old amalgam restoration (Figs. 1 and 2). The patient experienced pain upon chewing (specifically upon release). Clinically, there were visible horizontal and vertical crack lines. The tooth was vital and showed no signs of pulpal pathology. It was decided to replace the amalgam restoration and restore the tooth with an overlay made of the hybrid ceramic KATANA™ AVENCIA™ Block. There were two main reasons for this decision. First, whenever root canal treatment would be necessary in the future, the hybrid ceramic material would facilitate endodontic access cavity preparation (compared to any other ceramic material) and subsequent restoration with composite filling material. Second, hybrid ceramics offer greater resistance and improved mechanical properties compared to composite filling materials applied in an incremental layering technique.

Fig. 1. Initial situation: Occlusal view.

Fig. 2. Initial situation: Buccal view.

PREPARATION AND IMMEDIATE DENTIN SEALING

To remove the amalgam restoration and weakened surrounding tooth structure, the occlusal surface of the tooth was reduced by approximately 2 mm. For a smooth colour transition between the tooth and the restoration, the preparation outline was created at the level of interproximal boxes with a vestibular inclined plane (Fig. 3). Subsequently, Immediate Dentinal Sealing (IDS) was carried out (Figs. 4 to 10). This technique involves the use of a universal adhesive like CLEARFIL™ Universal Bond Quick, which is applied to the preparation without prior etching of the peripheral enamel. In the second step, a highly filled flowable composite is applied. In the present case, the material of choice was CLEARFIL MAJESTY™ ES Flow Super Low, applied in a thickness of just 0.5 mm. The preparation was refined using ultrasonic instrumentation: Sonic tips SFM7 and SFD7 (Komet Dental) for refining the boxes; SFD1F and SFM1F (Komet Dental) for margins and steps. Sharp edges were rounded with abrasive discs and then polished with fine polishers. It is crucial that the residual occlusal thickness (prosthetic space) is 1.5 mm, as required by the selected material.

Fig. 3. Prepared tooth structure prior to immediate dentin sealing.

Fig. 4. IDS: Application of the universal adhesive.

Fig. 5. IDS: Light curing of the adhesive layer.

Fig. 6. Thin layer of flowable composite applied to the preparation.

Fig. 7. Contouring, …

Fig. 8. … rounding off sharp edges …

Fig. 9. … and polishing of the sealed surface with dedicated instruments.

Fig. 10. Sealed tooth preparation ready for impression taking.

FROM SCANNING TO TRY-IN

Following digital scanning with the intraoral scanner Primescan™ (Dentsply Sirona), MDT Daniele Rondoni produced the restoration (Figs. 11 and 12). The cementation process involves an initial try in phase to assess the marginal fit of the overlay and the contact areas. Testing occlusion at this stage could be risky as it may lead to fracture of the restoration in case of excessive premature contacts. After try-in (when carried out without rubber dam), the restoration may be contaminated by blood, saliva, or glycerin gel used for the evaluation of fit and aesthetics. Therefore, it is necessary to clean the restoration before proceeding with adhesive phases. The use of a cotton pellet soaked in alcohol is an option, a cleaning agent like KATANA™ Cleaner may be even better as it chemically cleans the restoration and eliminates the contaminants.

Fig. 11. Hybrid ceramic overlay on the printed model.

Fig. 12. Separate overlay.

CONDITIONING OF THE TOOTH AND THE RESTORATION

Afterwards, the restoration was sandblasted (as recommended for most hybrid ceramics) with 50 μm aluminum oxide using AquaCare (Akura Medical) (Fig. 13), and then immersed in distilled water in an ultrasonic bath for 5 minutes. Meanwhile, rubber dam was placed over the entire sextant, the build-up was sandblasted like the intaglio of the overlay and a phosphoric acid etchant (Ultra Etch, Ultradent) was applied to the enamel, rinsed off and the area dried (Figs. 14 to 17). The clean restoration was subsequently conditioned with a silane containing 10-MDP (CLEARFIL™ Ceramic Primer Plus, Kuraray Noritake Dental Inc.) according to the manufacturer’s instructions (Fig. 18). What followed was the application of the universal adhesive (CLEARFIL™ Universal Bond Quick) to the intaglio of the overlay and to the preparation and light curing on both sites (Figs. 19 and 20). One of the advantages of universal adhesives compared to three-step adhesive systems is their minimal film thickness, which does not compromise the fit of the restoration.

It is important to protect adjacent teeth with metal matrix strips during adhesive phases to provide for proper fitting. These elements do not create operational difficulties, but serve their purpose: After restoration placement, the composite or cement used for placement will be easily removable from the mesial and distal surfaces of the adjacent teeth, as they are free of adhesive.

Fig. 13. Sandblasting of the overlay …

Fig. 14. … and the tooth structure.

Fig. 15. Selective etching of the enamel, …

Fig. 16. … followed by thorough rinsing. Adjacent teeth are protected by a metal matrix strip.

Fig. 17. Tooth structure after selective etching, rinsing and drying.

Fig. 18. Silane application.

Fig. 19. Application of the universal adhesive into the overlay.

Fig. 20. Treatment of the tooth structure with the universal adhesive.

DEFINITIVE PLACEMENT

In the present case, a heated composite paste (heated to a temperature of 55 °C) was extruded into the restoration, which was then placed by applying slow, gradual, and strong pressure (Figs. 21 and 22). Excess composite was removed with a scaler in the buccal and lingual areas and floss (e.g. SuperFloss®, Oral-B) in the interproximal areas. Several pressurization phases were performed until no more composite was observed at the tooth-restoration interface.

Fig. 21. Heated composite paste used for definitive placement.

Fig. 22. Restoration placed under rubber dam isolation.

Then, the composite was polymerized for 30 seconds from the buccal and lingual sides with two curing lights, before applying glycerin gel to the margins and polymerizing from occlusal for another minute (Fig. 23). If thorough attention is given to removing excess composite during placement phases, subsequent finishing steps will be quick and easy (Figs. 24 to 27). Finishing and polishing of the interproximal areas was accomplished with an EVA handpiece and 3M™ Sof-Lex™ Finishing Strips (3M). For finishing of the buccal and lingual areas, a medium-grit, flame-shaped diamond bur (diameter 14/16) was used. Finally, the margins should be polished using composite polishers like TWIST™ DIA for Composite (Kuraray Noritake Dental Inc.). After the local anesthesia wears off, one should observe the cessation of pain symptoms, as seen in the present case. The treatment outcome is displayed in Figures 28 and 29.

Fig. 23. Light curing through a layer of glycerin gel blocking the oxygen.

Fig. 24. Finishing of the buccal and lingual margin with a medium-grid, flame-shaped diamond bur.

Fig. 25. Finishing of the interproximal areas with EVA handpiece (fine grain).

Fig. 26. Checking the occlusal contacts.

Fig. 27. Occlusal polishing.

FINAL SITUATION

Fig. 28. Treatment outcome – buccal view.

Fig. 29. Treatment outcome – occlusal view.

CONCLUSION

For posterior teeth restored with amalgam and a significant level of destruction, restoration replacement with hybrid ceramic overlays can be a great option. Mechanical material properties are usually superior to those of layered composites, processing is possible chairside or labside and comparatively quick (no firing required), while the clinical placement procedure is similar to that involved in placing glass ceramics – with the major difference of sandblasting instead of etching the intaglio of the restoration. One of the most important benefits of hybrid ceramics over glass ceramics, however, is the ability to modify the restoration whenever desired. Endodontic access cavities are easily prepared and closed with composite, contact points are quickly adjusted and the surface is polished or re-polished in next to no time. Moreover, the wear properties are similar to those of tooth structure and patients are happy about a natural touch and feel. The aesthetic properties are quite impressive, too.

Dentist:

ENZO ATTANASIO

Enzo Attanasio graduated in 2008 in Dentistry and Dental Prosthetics from the Magna Graecia University of Catanzaro. In 2009, he went on to specialize in the use of laser and new technologies in the treatment of oral and perioral tissues at the University of Florence. That year he also attended Prof. Arnaldo Castellucci’s course in Clinical Endodontics at the Teaching Center of Microendodontics in Florence where, in 2012, he went on to complete his training in Surgical Microendodontics. In 2017 he attended a course on Direct and indirect Adhesive Restorations at Prof. Riccardo Becciani’s Think Adhesive training center in Florence where he later become a tutor. Today, as a member of the Italian AIC and based in Lamezia Terme, Italy, Dr Attanasio has a special interest in Endodontics and Aesthetic Conservative.

En beskrivning av den här nya tekniken och vetenskapligt stöd för uppnådd effekt tillhandahålls i den artikeln av prof. Breschi och hans kollegor på universitetet i Bologna. Titel; “Selective adhesive luting: A novel technique for improving adhesion achieved by universal resin cements”. 

PANAVIA™ SA Cement Universal är ett universalresincement som kan användas utan andra komponenter som självhärdande cement i många kliniska situationer. Cementet ger till och med en god bindning till litiumdisilikat utan att man tillför ytterligare silan. In-vitrostudier har påvisat att resincementet är mycket fukttolerant och mångsidigt och att det ger starka och hållbara bindningar till praktiskt taget alla restaurativa material liksom till emalj och dentin. 

Till tandsubstans har dock de bästa resultaten uppnåtts genom applicering av CLEARFIL™ Universal Bond Quick som separat primer. Därför vill du kanske anamma den här tvåkomponentstekniken för adhesiv cementering som redskap i särskilt utmanande situationer. Tekniken är fortfarande mindre komplicerad än traditionella adhesiva tekniker och ger utomordentliga resultat. 

Medan självhärdande cement är mindre känsliga för fukt kräver universaladhesiver fullständig torrläggning av arbetsområdet för att de ska fungera som tänkt. Därför undrar du säkert vilken teknik som ska användas i fall där du behöver starkast möjliga kemiska bindning till emalj och dentin, men där tillräcklig torrläggning med kofferdam är utmanande eller omöjligt att åstadkomma – till exempel i fall där stödtanden är väldigt kort eller preparationsgränsen ligger subgingivalt. Lösningen i dessa fall heter selektiv adhesivcementering. 

Selektiv applicering av en universaladhesiv i de områden av etsad emalj som inte riskerar att kontamineras av fukt. 

Enkel arbetsgång, pålitligt resultat: det är vad de flesta tandläkare eftersträvar när de cementerar en indirekt ersättning. Följande kliniska fall visar på ett enkelt, men mycket framgångsrikt protokoll för cementering av litiumdisilikatkrona.

Fig 1. Litiumdisilikatkrona efter inprovning och fluorvätesyraetsning av innerytan.

Fig 2a. KATANA™ Cleaner appliceras inuti kronan för komplett avlägsanande av föroreningar; proteiner från blod och saliv, som kan kompromettera kvaliteten hos alla resincement. 

ELLER

Fig 2b. Alternativt kan KATANA™ Cleaner appliceras på en blandningsbricka.

Fig 3. KATANA™ Cleaner appliceras sedan på kronans inneryta.

Fig 4. KATANA™ Cleaner appliceras på den preparerade tanden på samma sätt (gnugga under 10 sekunder, skölj sedan rent och torka).

Fig 5.  Applicering av PANAVIA™ SA Cement Universal i den rengjorda kronan.

Fig 6. Cementet innehåller ett unikt silankopplingsmedel - LCSi-monomeren - för en stark och pålitlig bindning till litiumdisilikater och andra restorativa material, som glaskeramer och hybridkeramer. I blandningspetsen aktiveras silanet av Original MDP

I blandningspetsen aktiveras silanet av Original MDP.

Fig. 7.  Cementöverskottet är enkelt att avlägsna efter två till fem sekunders punkthärdning.

Fig 8. Cementöverskottet, som är i gelstadiet, avlägsnas med hjälp av en sond.

SLUTRESULTAT

Fig 9. Behandlingsresultat direkt efter cementering.

Dentist:

RICHARD YOUNG DDS

KLINISKT FALL OCH BILDER MED TILLSTÅND AV RICHARD YOUNG DDS, SAN BERNADINO, CA

Clinical case by Dr. Frank Heldenbergh

The advancements in zirconia in contemporary dentistry nowadays allow for a wider range of applications, including in the anterior sector, and for chairside production using dedicated CAD/CAM systems. Even without a cutback, KATANA™ Zirconia Block (STML), combined with CERABIEN™ ZR FC Paste Stain (both Kuraray Noritake Dental Inc.), offer an extremely satisfactory aesthetic solution.

In the present patient case, the materials were chosen to replace old PFM crowns on the maxillary central incisors. The planned treatment was in accordance with the patient's wishes, and carried out in a single appointment.

CASE DESCRIPTION

The patient asked for a replacement of the existing crowns on the two maxillary central incisors (teeth 11 and 21, FDI notation). The porcelain-fused-to-metal (PFM) restorations had been in place for about thirty years (Figure 1). She desired aesthetic improvements and slight repositioning of these two teeth.

TREATMENT PLAN

In agreement with the patient, it was decided to perform the entire procedure in one appointment: removal of the existing crowns, digital impressions, production, and bonding of new restorations. The periodontium was healthy with no bleeding. The only uncertainty was whether the existing crowns were cemented onto inlay-cores or if they were Richmond crowns. A preliminary silicone impression was taken as a precautious measure: in case something unexpected prevented the new crowns from being bonded during the session, it would be easily possible to produce temporary crowns.

Fig. 1. Initial clinical situation.

TREATMENT

Using a diamond bur followed by a tungsten carbide bur, the existing crowns were removed, revealing that they indeed were Richmond crowns. Because the anatomy of the intra-radicular posts clearly contraindicates an attempt to remove these posts, it was decided to trim the crowns to transform them into inlay cores rather than risk further damage. The corono-peripheral preparations were reworked at the same time. One of the major challenges was related to the necessity of masking the metal of the transformed coronal-radicular reconstructions. Luckily, the space available was sufficient for the production of full zirconia crowns with a significant thickness (Figure 2). The target shade of the crowns was chosen in consultation with the patient (Figure 3).

Fig. 2. Situation after removal of the existing restorations.

Fig. 3. Shade determination using a shade tab: A2 was the appropriate shade.

Subsequently, impressions were taken using and intraoral scanner, the virtual models were checked and the crowns designed, considering the patient's request to have her two incisors slightly retracted (Figures 4 and 5).

Fig. 4. Virtual models of the patient’s teeth with the newly designed crowns, revealing the space available for a slight retraction.

Fig. 5. Designing of the two crowns.

The two crowns were milled from KATANA™ Zirconia Block 14Z A2 (Figure 6). A quick reminder: unlike lithium disilicate, zirconia prosthetic parts cannot be tried in immediately after milling, as they are around 20 percent larger than their final size after sintering. Final sintering was performed within about 18 minutes using the furnace SINTRA CS (ShenPaz Dental Ltd). After this process, the crowns may be tried on to check their fit, shape, shade and optical integration.

Fig. 6. Milled crowns in the CAD/CAM blocks.

For finishing of the restorations, different options are available. In this case, we decided not to limit ourselves to mechanical polishing of the prosthetic parts, as zirconia does not fluoresce like natural teeth. To add fluorescence as an optical feature, the surface was lightly stained and glazed with CERABIEN™ ZR FC Paste Stain (Figure 7).

Fig. 7. Crowns in the furnace after staining and glazing with liquid ceramics.

After firing, the two incisor crowns were tried in again using a try-in paste corresponding to the chosen resin cement system (PANAVIA™ V5, Kuraray Noritake Dental). In this way, the final appearance was simulated to validate the shade of the cement. The intaglio surfaces of the crowns were then sandblasted before applying CLEARFIL™ CERAMIC PRIMER PLUS as the restoration primer. The prepared teeth were treated with KATANA™ Cleaner (Kuraray Noritake Dental Inc.) to decontaminate the surface from proteins in saliva and possibly blood. Those clean surfaces are ideal for bonding. After thorough rinsing and drying, PANAVIA™ V5 Tooth Primer (containing MDP monomer for bonding with the hydroxyapatite and metal of the preparation) was applied according to the manufacturer’s instructions (Figure 8).

Fig. 8. Selected cementation system and try-in.

Subsequently, PANAVIA™ V5 Paste was applied into the first crown, which was then seated, followed by tack curing (brief photopolymerization for three to five seconds), excess removal and final light curing from all sides.

The procedure was then repeated for the second maxillary central incisor. The result instantly satisfied the patient, both in terms of aesthetics (adaptation, position of the new crowns, mimicry) and the comfort provided (Figures 9 and 10).

Fig. 9. Crowns immediately after placement.

Fig. 10. Aesthetically pleasing and comfortable result.

At a recall after four months, soft tissue conditions were ideal and the patient was happy with the outcome (Figures 11 to 13). The selected zirconia had nice optical properties, masking of the metal posts was successful and the natural surface texture contributed its share to a nice overall picture. The retracted position of the teeth was also perceived positively by the patient, while comfort and function were excellent.

DISCUSSION

Although lithium disilicate has so far been considered the material of choice for prosthetic work in the anterior region, zirconia is nowadays proving to be an extremely satisfactory alternative from every point of view: milling, strength, aesthetics, assembly (among other things, no hydrofluoric acid is required for bonding). KATANA™ Zirconia Blocks (STML) with a multi-layered colour structure in a single 4Y-TZP zirconia block, combined with CERABIEN™ ZR FC Paste Stain, offer a remarkable solution. This applies to treatments around the replacement of existing crowns as well as first-line treatments with less invasive preparations (verti-prep) than those required by other types of ceramics.

Fig. 11. The patient’s smile at a recall after four months.

Fig. 12. Great optical integration.

Fig. 13. Natural surface texture contributing to success Control pictures after four months taken by Emmanuel Charleux.

Dentist:

FRANK HELDENBERGH

Dr. Frank Heldenbergh graduated with a Doctor of Dental Surgery degree from the University of Reims in 1988.Driven by a passion for prosthetics, he pursued further specialization as a Prosthetic Resident at the UFR Odontology of Reims from 1990 to 1992. Dr. Heldenbergh’s dedication to advancing dental practices led him to join the Board of the Academy of Adhesive Dentistry in 1999. His commitment to this field has been unwavering, and he currently serves as the Vice President of A.D.D.A.-R.C.A.

Recognized for his expertise in ceramic veneers, inlays and onlays, Dr. Heldenbergh supervised practical work for the Paris Odontological Society from 2000 to 2018, shaping the skills of many aspiring dentists. His influence extended to the A.D.F. Congress, where he supervised practical work on ceramic veneers from 2000 to 2016. In 2017, he was the Head of Practical Work at A.D.F., a role that allowed him to further contribute to the advancement of dental education and practices. In 2018, he was the Head of Practical Work for ceramic veneers at the Paris Odontological Society.

Recognizing the importance of technology in modern dentistry, Dr. Heldenbergh pursued a University Degree in CAD/CAM from Toulouse in 2022. This addition to his qualifications highlights his dedication to staying at the forefront of dental innovation.

Kompositersättningens hållbarhet är beroende av många faktorer. En del av dem är relaterade till patienten; använder hen hård eller mjuk tandborste, vilken tandkäm använder hen, borstteknik, kost, alkohol, te, kaffe och tobak samt hygienvanor. Men att följa det bästa putsprotokollet är dock helt upp till tandläkaren.

Syftet med korrekt putsning är att avlägsna det syreinihiberade ytskiktet och att skapa en slät yta. En korrekt polerad ersättning förhindrar missfärgning som orsakas av mat, dryck, tobak, te, kaffe eller alkohol och garanterar en långvarig estetik.

Att putsa komposit är en process som kräver extra uppmärksamhet och det består av flera arbetsmoment och principer:

• Att använda polerdiskar ger en jämn och slät yta, avverkar överskott och ger den slutgiltiga formen. Det är viktigt att putsen sker på fuktad yta och med ett 1:1-handtycke på maxhastigheten 5,000 - 10,000 rpm.

• Gummitrissor finns i många typer och former. En av de mest användbara är TWIST™ DIA for Composite. Kitet består av två gummitrssor med olika abrasionsgrad. Den första (mörkblå) används för grovavverkning, den andra (ljusblå) används för f inputs. Puts med dessa trissor ska ske på torr yta utan vattenkylning. Att arbeta utan vattenkylning kan irritera pulpan och därför ska hastigheten begränsas till mellan 5000 och 10000 rpm och det är viktigt att undvika hårt tryck.

• TI nästa steg använder man en diamantpasta med kornstorlekar mellan 1 och 5 micron. Rekommendationen är att använda en putstrissa av gethår tillsammans med diamantpastan. Det viktigaste är att inte använda en hård borste eftersom en sådan kan repa kompositen. Med putstrissa  och polerpasta kommer man åt svåråtkomliga skrymslen som det cervikala området och approximalytor. För att slutföra detta steg används en diamantremsa för mera exakt puts av approximalytorna. För att inte förstöra kontaktpunkterna ska lågabrasiva (Super Fine) remsor användas.

• Ett ytterligare steg för att öka ytglansen och därigenom skydda ytan från att missfärgas är puts med aluminiumoxidpasta och bomullstrissa. Resultatet av att använda en sådan pasta, som ursprungligen är avsedd för puts av keramer, är en exceptionellt slät yta och hög glans. Detta moment utförs på torr yta och med en maxhastighet på 5,000 - 10,000 rpm.

Vid injektionstekniken, precis som vid alla andra tekniker, påverkar putsgraden hållbarheten, såväl som optiska och estetiska egenskaper. Därför ska detta nyckelmoment ägnas tillräckligt med tid. Olika sorters komposit karaktäriseras av både sin sammansättning och fyllnadsgrad, faktorer som inte bara påverkar egenskaperna utan också avgör deras polerbarhet. I vissa fall måste putsprocessen upprepas flera gånger för att man ska uppnå ett högglansigt resultat. Trots sin höga halt av fillers är CLEARFIL MAJESTY™ ES Flow är en komposit som är mycket enkel att putsa till hög glans. Särskilt anpassade gummihjul, putstrissor och pastor gör det enkelt att åstadkomma en jämn och slät yta som i sin tur avgör det långvariga resultatet.

Före

Efter

3 års återkontroll

LÅT DEM SKINA, LÅT DEM LE!

Dentist:

MICHAL JACZEWSKI

Michał Jaczewski tog examen från Wroclaw Medical Universtity 2006 och idag driver han sin privatklinik i Legnica, Polen. Han har specialiserat sig på minimalinvasiv tandvård och digital tandvård och är grundare till Biofunctional School Of Occlusion där han föreläser och ger workshops med fokus på heltäckande patientbehandlingar.

Slipp frustrationen: Finns det en flytande komposit som håller vad den lovar? Vissa kompositer som finns på marknaden har lägre hållfasthet och estetiken är svårbemästrad. Det skapar uppfattningen att flytande kompositer på något sätt är sämre än pastakompositer. Låt oss förklara hur CLEARFIL MAJESTY™ ES Flow skiljer sig från andra f lytande kompositer och att visa hur fackmannamässig silanisering öppnar upp för en ny era av flytande komposit.

Huvudingredienserna i dentala kompositer är resin och f illerpartiklar, komponenter som noggrant kombineras till ett hanterbart och polymeriserbart material för framställning av en solid ersättning. Det är avgörande att f illerpartiklarna blir kvar i matrisen. För att åstadkomma detta måste fillerpartiklarna kunna fästa till matrisen. Ett kopplingsmedel (silan) möjliggör kemisk adhesion mellan kompositens båda beståndsdelar. Silan är ett dubbelverkande, ytaktivt ämne som binder till f illerpatriklarna och som under polymerisation reagerar med momomeren i matrisen. 

KORREKT SILANISERING 

Det låter enkelt, men är i själva verket något helt annat. När man blandar fillerpartiklar och resin uppstår ett problem. Mängden fillerpartiklar som kan tillföras resinblandningen är mycket begränsad. Konsistensen tjocknar väldigt fort och skapar en knappt hanterbar mixtur. Dagens kompositer innehåller, till storleken, allt mindre f illerpartiklar. Ju mindre fillerpartiklarna är desto fler partiklar i en given volym. Detta resulterar i att blandningen ännu fortare blir opraktisk att använda. För att framställa en högkvalitativ komposit behövs därför högkvalitativa silaner som maximerar fillerpartiklarnas vätbarhet. 

DET OSYNLIGA MÄSTERVERKET

Alla silaner och silaniseringstekniker är inte likadana. Kuraray Noritake Dental visar ett av sina mästerverk på detta område. Vi, som är marknadsledande inom silanteknologi, använder enbart högstabila, specialanpassade silaner. Ett av silanerna som används är ett specialtillverkat, långkedjigt silan; Long Carbon Chain Silane (LCSi). Det är detta silan som används i våra flytande kompositer i serien  CLEARFIL MAJESTY™ ES FLOW. 

Resultatet av vår fackmannamässiga silanisering är:

• Högt fillerinnehåll utan att kompromissa handhavandet
• Högstabila ersättningar, också efter materialutmattning
• Hög fuktresistens
• Hög styrka
• Hållbara, naturliga ersättningar
• Väldigt liten vattenupptagning
• Optimalt handhavande

Figur 1: Blandningar med samma mängd resin och fillers, men med olika typ av silanbehandling. Vänster: ingen behandling. Mitten: konventionell behandling. Höger: Kurarays behandling

Ju högre kvalitet på silanet desto bättre blir fillerpartiklarnas vätbarhet, vilket möjliggör ett högre fillerinnehåll utan att handhavandet påverkas negativt. En annan fördel av användningen av våra högkvalitativa silaner är att de i hög grad bidrar till att fillerpartiklarna kvarstannar i den härdade kompositen. Våra kompositer visar också en väldigt liten grad av vattenabsorbtion, vilket också kan hänföras till den fackmannamässiga silaniseringen.

Kombinationen av fillerpartiklar, det ovan nämnda silanet och en lågviskös resinblandning gör att vi kan framställa en flytande komposit med högt fillerinnehåll, som kan användas som universalkomposit. Det garanterar både tixotropa egenskaper och handhavande och kompositen förblir mycket hållbar och stark.

Figur 2: Ju mer sofistikerad silanteknologi, desto fler fillerpartiklar kan tillföras till en given mängd resin.

Flytbarhet

CLEARFIL MAJESTY™ ES Flow tooteperes on kolme erinevat voolavust, mis sobivad teie eelistuse ja restauratsiooni tüübiga: suur, vähene või väga vähene. 

3 nivåer av flytbarhet

STYRKA

CLEARFIL MAJESTY™ ES Flow har ett fillerinnehåll på upp till 75 wt%, 59 vol%, som ger överlägsna (mekaniska) egenskaper och gör den lämplig att använda till och med för posteriora ersättningar.

VAD INNEBÄR DET FÖR DIG?

Hur kan du som tandläkare dra nytta av vår expertis?

Tack vare det höga fillerinnehåller är ersättningar som framställts av CLEARFIL MAJESTY™ ES Flow mycket hållbara och starka. De är starka nog även för posterior användning. CLEARFIL MAJESTY™ ES Flow är starkare än de flesta universalkompositerna i pastaform (se diagrammet nedan). Upprepad belastning har ingen negativ påverkan på vare sig styrka och hållbarhet. Den höga fuktresistensen bidrar samtidigt till lågvarig styrka och långlivad estetik. Fillerpartiklarna i CLEARFIL MAJESTY™ ES Flow består av både submikrona partiklar och partiklar i kluster (0.18 μm till 3.5 μm). De högt uppskattade egenskaperna kontrollerbart handhavande, formstabilitet och att materialet är klibbfritt beror i hög grad på de välbalanserade fillerpartiklarna.

Fillerpartiklarnas utformning och sammansättning är också i hög grad orsaken till den beständiga ytglansen hos ersättningar som är gjorda av CLEARFIL MAJESTY™ ES Flow. Putsen tar inte lång tid; bara några sekunder. Till och med att enbart torka ytan med en gasbinda eller bomullsrulle dränkt i etanol ger hög glans. Ljusspridningsteknologin i CLEARFIL MAJESTY™ ES Flow härleds till stor del till fillerpartiklarna, som bildar nanokluster och ger utmärkta färgmatchande egenskaper som tillåter ersättningen att omärkligt smälta in bland omgivande tandvävnad.

SAMMANFATTNING

Vi kan med säkerhet säga att vår expertis inom silanisering och andra teknologier (som, till exempel, the Light Diffusion Technology) har en mycket positiv inverkan på kvaliteten på våra kompositer, inklusive CLEARFIL MAJESTY™ ES Flow. Då kompositen finns i tre olika flytförmågor erbjuder CLEARFIL MAJESTY™ ES Flow ett väldigt mångsidigt produktutbud med mycket goda handhavandeegenskaper, hög styrka, enkelt putsningsförfarande och enastående ythållbarhet. Oavsett om du vill göra en ersättning, laga cement, arbeta anteriort eller posteriort, med Stamp-tekniken, med injektionsteknik eller nästan vad som helst - det här är den enda komposit du behöver!