High-quality treatment is probably the most important element on the road to patient satisfaction. During every single appointment, the patient wants to feel well cared for by a skilled professional, while chair time and the number of appointments should be reduced to the necessary minimum. This implies that, in the context of prosthodontic treatment, a restoration needs to fit perfectly straight away and be stable over time to avoid remakes and extra appointments.

As explained in the first part of this series of articles, the quality of the selected prosthetic material – e.g. zirconia – has a decisive impact on the design, overall quality and long-term performance of definitive restoration. That is why you as a dental practitioner should

• order restorations that are produced domestically or in a region with the same standards as your own,
• know about the source of the zirconia your laboratory partner uses, and
• avoid deals that are too good to be true.

WHY ASK YOUR LABORATORY TO USE KATANA™ Zirconia

When quality matters, and you want to be sure that the zirconia restorations from your dental laboratory partner offer the desired mechanical and optical properties, requesting KATANA™ Zirconia can be a wise choice. This family of high-quality dental materials provides laboratories with everything they need to deliver restorations that you and your patients will appreciate, regardless of indication and no matter how unique the requirement. This is largely thanks to two factors: sophisticated multi-layered technology and a meticulous blank production process.

THE KEYS TO BRILLIANT AESTHETICS

Early zirconia materials often had a whitish, opaque appearance and were used mainly as framework materials. On the other hand, the dental zirconia used by dental laboratories today is typically pre-shaded and available in various levels of translucency. Some blanks even offer multi-layered technology: Recognising the importance of varying chroma and translucency in different areas of a natural tooth, Kuraray Noritake Dental Inc. has pioneered this trend. In 2013, the company became the first to introduce a blank with a polychromatic structure (KATANA™ Zirconia ML), featuring a natural gradient in chroma and a seamless transition between layers for a tooth-like appearance.

Initially developed for monolithic restorations, which are just polished or characterized with external stains and glazed, this new type of zirconia also inspired the micro-layering technique. Here, restorations are designed in full contour with only a slight cutback in the vestibular area, allowing for subtle porcelain effects that replicate the optical properties of enamel.

Continuous improvements of this first multi-layered zirconia generation ultimately resulted in the current zirconia portfolio offered by Kuraray Noritake Dental Inc. It consists of a multi-layered block for chairside milling machines, a classical framework material, and the KATANA™ Zirconia Multi-Layered discs series – even including a blank with flexural strength gradation:

Fig. 1. Four-layer colour structure of the KATANA™ Zirconia Multi-Layered series

KATANA™ Zirconia Block – Multi-layered block for chairside milling (available for CEREC and other chairside milling machines), with an 18-minute speed-sintering option* for natural tooth-coloured single restorations and short-span bridges.

^{*Speed-sintering option available only with compatible furnaces.}

KATANA™ Zirconia HT – High-strength zirconia for single-unit copings and long-span bridge frameworks, available in five different disc thicknesses.

KATANA™ Zirconia UTML – Ultra-translucent zirconia with a multilayered colour structure, ideal for monolithic anterior restorations including veneers.

KATANA™ Zirconia STML – Balanced translucency and strength for beautiful monolithic restorations, with natural colour gradation. This variant is ideal for crowns and up to three-unit bridges.

KATANA™ Zirconia HTML PLUS – High-translucency option with the strength needed for long-span bridges, offering vivid, natural colour.

KATANA™ Zirconia YML – Advanced zirconia with colour, translucency and strength gradation, featuring a strong body and highly translucent enamel layer for a virtually unlimited indication range.

THE KEYS TO HIGH-QUALITY RESTORATIONS

Zirconia quality depends on factors such as raw material purity, chemical composition, grain size and particle distribution. Every stage of production – from powder preparation to pressing and pre-sintering – affects the final mechanical and optical properties. Kuraray Noritake Dental Inc. optimises each of these steps to achieve consistently high quality.

1. RAW MATERIALS

Unlike most manufacturers who purchase pre-fabricated powders (from partners like Tosoh Corporation), Kuraray Noritake Dental Inc. produces all components in-house, including zirconium oxide, yttrium oxide, aluminium oxide, and those elements forming the company’s proprietary multilayer technology. This innovative technology is used to form a polychromatic blank structure and – in the case of KATANA™ Zirconia YML – additional translucency and flexural strength gradation.

Fig. 2. Powder for KATANA™ Zirconia

BENEFITS

• Natural translucency
• Shades matching VITA classical A1-D4™ shade guide concept
• Well-balanced flexural strength
• Precise millability for outstanding fit
• High ageing resistance
• Predictable sintering performance

2. PRESSING

A uniform density distribution throughout the blank and homogeneous material structure are essential for predictable processing outcomes and accurate fit. Kuraray Noritake Dental Inc. uses a unique pressing process that is designed to create even pressure distribution, minimise airborne particle contamination and reduce gravitation forces. This results in the desired purity and density of the zirconia blanks.

BENEFITS

• Uniform mechanical and optical properties
• Outstanding edge stability
• High surface quality
• Controlled sintering deformation

3. PRE-SINTERING

Pre-sintering gives pressed blanks the stability needed for milling. The selected temperature profile and duration of the pre-sintering cycle determine the material’s strength and hardness and processing properties, and have an impact on the final sintering process. The procedure used by Kuraray Noritake Dental Inc. results in blanks that are stable yet easily machinable with standard diamond-coated tools, without increased breakage risk or excessive tool wear.

Fig. 3. Restoration margins have been milled to a very thin profile, and yet they still show smooth margins without any chipping

BENEFITS

• High surface quality after milling
• Shorter sintering times possible (54 minutes for single tooth restorations and bridges with up to three units made of KATANA™ Zirconia UTML, STML, HTML PLUS or YML; 18 minutes in the case of KATANA™ Zirconia Block)

EVERYTHING YOUR LABORATORY PARTNERS NEED

Whether your partners in the laboratory prefer to work with different zirconia variants tailored to specific needs or a single material for all indications, whether they prefer full porcelain layering or simplified finishing techniques: KATANA™ Zirconia delivers the versatility needed – with a consistently high quality aimed at exceeding expectations.

Knowing this – and knowing how to distinguish high from poor quality zirconia materials – allows you to contribute significantly to the high quality of the prosthetic work produced in the dental laboratory. If you then also establish a well-structured, standardized and bidirectional flow of information maintaining records between practice and laboratory (e.g. by using checklists or a digital platform), all members of the restorative team are able to perform at their best for predictable treatment outcomes and long-term success.

COMPLEMENTARY PRODUCTS FOR THE DENTAL PRACTICE

Regarding the remaining clinical steps like the successful cementation of the delivered zirconia restorations, Kuraray Noritake Dental Inc. is a trustworthy partner, too: As well as offering complementary products for polishing, staining, glazing and veneering of zirconia restorations, the company is also a leading provider of clinical products such as resin cements, adhesives and cleaning agents. KATANA™ Cleaner, for example, can be applied both intra-orally and extra-orally, removing contamination from the bonding surfaces (tooth and restoration) after try-in. Applied to the pre-treated surface directly after cleaning, high-performance resin cement systems like PANAVIA™ V5 establish a strong bond to tooth structure and zirconia (as well as other restorative materials), so that high success rates are achieved even with partial restorations that offer minimal macro-mechanical retention1,2. Finally, if modifications are needed, TWIST™ DIA for Zirconia is a great option. It is suitable for polishing intra-orally and delivers a natural surface gloss. The products are well aligned and designed to complement each other for smooth workflows and outstanding results.

Literature

1. Blatz MB, Alvarez M, Sawyer K, Brindis M. How to Bond Zirconia: The APC Concept. Compend Contin Educ Dent. 2016 Oct;37(9):611-617; quiz 618. PMID: 27700128.
2. Alqutaibi AY, Alghauli MA, Almuzaini SA, Alharbi AF, Alsani AA, Mubarak AM, Alhajj MN. Failure and complication rates of different materials, designs, and bonding techniques of ceramic cantilever resin-bonded fixed dental prostheses for restoring missing anterior teeth: A systematic review and meta-analysis. J Esthet Restor Dent. 2024 Oct;36(10):1396-1411.

Article by doctors Tom Boujenah and Olivier Boujenah.

KEEP IT SIMPLE WHILE MEETING THE PATIENT’S INDIVIDUAL DEMANDS

Every day in our practices, we are faced with a choice between different treatment options. Experience, scientific literature, and patient preferences all help guide us toward one direction or another.

The case presented below could have been managed using a different approach, but the chosen solution aligned with our philosophy: keep it simple while meeting the patient’s individual demands.

A PATIENT WITH HIGH AESTHETIC DEMANDS

A young patient, in his early twenties, presented for consultation with a purely aesthetic concern. He had been wearing a double-retainer resin-bonded fixed dental prosthesis (Maryland bridge) (Figure 1) for several years, placed due to the congenital absence of the mandibular central incisors. Although the bridge had served him well functionally, the patient now wished to replace it with a more aesthetic solution, better matching the current shade of his natural teeth. After clinical and radiographic assessment, several treatment options were considered, taking into account the patient’s age, bone volume, and aesthetic expectations.

The final decision was to fabricate a new resin-bonded bridge, optimized in terms of both design and shade, using a multilayered zirconia to achieve a natural-looking result.

Fig. 1. Initial situation

Fig. 2. iTero 5D+ optical scan

PRELIMINARY STEPS IN THE DENTAL OFFICE

A pre-treatment impression of the bridge was taken before removal, using the iTero 5D+ scanner (Align Technology; Figure 2). These pre-treatment scans, which are performed almost systematically for our prosthetic reconstructions, allow the laboratory to capture the volume of the existing prosthesis, replicate the previous shape (if suitable), and often visualize wear facets. This helps minimize or even eliminate the need for subsequent adjustments. Then, the existing resin-bonded bridge was removed, and the abutment teeth were prepared as minimally invasive as possible. Once again, the intraoral scanner was used to take an impression of the situation (Figure 3).

Fig. 3. Impression after bridge removal and minimal preparation of the lingual surfaces

PRODUCTION OF THE RESIN-BONDED BRIDGE

The scan was sent directly from the intraoral scanner to the Design4me platform (a 3D design platform) to carry out the digital design of the planned bridge (Figures 4 and 5). A repositioning key was also designed by the dental technicians to provide for accurate seating of the bridge during cementation (Figure 6). The material of choice was KATANA™ Zirconia YML, a multi-layered zirconia from Kuraray Noritake Dental Inc., shade B1. It seemed most appropriate due to its outstanding physical and aesthetic properties—specifically its gradient in shade translucency and flexural strength (Figure 7).

Fig. 4. Design of the new bridge using exocad software (Design4me platform)

Fig. 5. View of the soft tissue underneath the bridge showing slight gingival compression

Fig. 6. Repositioning key designed using exocad software (Design4me platform)

Fig. 7. KATANA™ Zirconia YML disc (shade shown not representative of the case presented)

The production centre, DIGISMILE, subsequently received the STL files of the bridge and the positioning key, modeled by the dental technicians on the Design4me platform, ready for milling and printing. We also provided the laboratory with intraoral photos to replicate the surface texture, possible characterizations, and shades. The laboratory performed the milling of the bridge using a DWX-52D milling machine (Roland DG). Polishing, surface finishing, and staining were carried out using Komet burs and Miyo liquid porcelain (Jensen). The repositioning key, meanwhile, was 3D printed with a NextDent 5100 3D Printer (3D Systems) using surgical guide resin (Figure 8).

Fig. 8. Milled bridge and 3D-printed key after polishing and staining

DEFINITIVE PLACEMENT IN THE DENTAL OFFICE

The adhesive cementation procedure is one of the most critical steps of the whole workflow. Once the bridge had arrived in the dental office and try-in was successfully completed, the focus was on moisture control and the establishment of ideal bonding conditions. In this context, strict working field isolation with saliva ejectors, cotton rolls, and ideally a rubber dam is essential, followed by the pre-treatment of the abutment teeth and the retainer wings of the zirconia bridge.

PRE-TREATMENT OF THE TOOTH STRUCTURE

Since the tooth preparations are strictly limited to enamel, the following conservative bonding protocol was adopted:

• Etching with phosphoric acid for 30 seconds on the enamel surfaces.
• Thorough rinsing with water, followed by gentle drying without desiccating the enamel.
• Application of PANAVIA™ V5 Tooth Primer (Kuraray Noritake Dental Inc.), followed by thorough drying with mild air after a 20-second waiting time. This primer contains MDP, which is essential for reliable enamel/zirconia adhesion.

PRE-TREATMENT OF THE ZIRCONIA WINGS OF THE BRIDGE

Even though the intaglio surface was sandblasted in the laboratory, it is crucial to repeat this step in the clinic:

• Cleaning with KATANA™ Cleaner (Kuraray Noritake Dental Inc.) for 10 seconds or ultrasonic cleaning for 5 minutes, followed by rinsing with water.
• Sandblasting with 50 μm aluminum oxide (Al2O3) at 2 bar.
• Application of CLEARFIL™ Ceramic Primer Plus (Kuraray Noritake Dental Inc.) to the intaglio surface without rinsing, followed by gentle drying. This primer also contains MDP, providing for a proper chemical bond to zirconia.

ADHESIVE CEMENTATION

With all surfaces pre-treated appropriately, adhesive cementation proceeded as follows:

• Application of PANAVIA™ V5 Paste (universal shade A2) to the intaglio of the bridge.
• Insertion of the bridge using the repositioning key.
• Light curing (“tack” cure) for 3 to 5 seconds to stabilize the restoration.
• Removal of excess resin cement with a dental explorer. Alternatively, excess may be removed immediately with a soft brush before applying to light cure for the margins.
• Final complete light curing according to the manufacturer’s instructions (Figures 9 and 10).

Fig. 9. Clinical situation captured immediately after cementation

Fig. 10. Lateral view of the restoration immediately after cementation

TREATMENT OUTCOME

Thanks to the pre-treatment scan and the overlay of the old bridge with the new one, no adjustments were necessary, although occlusion control remained essential. At a recall after 18 months, gingival integration was satisfactory: The patient was able to use interdental brushes and maintain the prosthesis properly (Figures 11 and 12).

Fig. 11. Clinical situation 18 months after definitive placement

Fig. 12. Lateral view at 18 months

CONCLUSION

In this clinical case, the choice to produce a double retainer resin-bonded bridge, almost identical in design to the previous one, may seem conservative. However, this decision is supported by several factors: The patient’s good tolerance of the previous prosthesis, the tissue integrity of the abutment teeth, and, most importantly, the opportunity to significantly improve aesthetics thanks to advances in materials and bonding techniques, which allowed us to keep preparations minimal and minimally invasive.

This new bridge, designed with highly aesthetic multilayer zirconia and bonded using a strict protocol, achieved a perfectly integrated and natural result without resorting to more invasive options (therapeutic gradient). Furthermore, this approach invites the restorative team to consider emerging trends in resin-bonded bridge design, notably the option of two single-retainer cantilever bridges, which might be considered in similar cases in the future.

This case highlights the importance of individualized treatment planning, which does not rely solely on innovation, but on precise clinical assessment, attentive listening to patient needs and expectations, careful implementation of available tools, and the use of high-quality materials and protocols.

Dentists:

OLIVIER BOUJENAH

Dr. Olivier Boujenah earned his Doctorate in Dental Surgery from Paris V in 1994 and a University Diploma in Maxillofacial Surgical Rehabilitation from Paris VII in 2008. A pioneer in digital dentistry, he founded DIGISMILE, a training center and fully digital laboratory, and DIGISMILE LAB, dedicated to prostheses and surgical guides. He teaches in the Master’s program in Digital Dentistry at the University of Geneva and has pursued advanced training at Harvard University in digital workflows and guided surgery.

TOM BOUJENAH

Dr. Tom Boujenah graduated from the European University of Madrid in 2023 and completed a University Diploma in Oral Implant Rehabilitation at the Pitié-Salpêtrière Hospital in Paris. Based in private practice in the 16th district of Paris, he focuses on aesthetic and functional oral rehabilitation with a particular interest in implant dentistry and digital workflows. Passionate about innovation, he integrates the latest advances in implantology, prosthodontics, and digital dentistry to deliver personalized and long-lasting treatments.

ACHIEVE CONSISTENT, NATURAL-LOOKING RESTORATIONS WITH CONFIDENCE

Shade selection is one of the most critical steps in restorative dentistry — and one of the most challenging. The KATANA™ Zirconia Shade Selection Guide provides practical, evidence-based recommendations to help clinicians and technicians achieve predictable, lifelike results every time.

Inside, you’ll find clear guidance on how abutment color, restoration thickness, milling and sintering conditions, and finishing methods influence the final shade outcome. Backed by Kuraray Noritake Dental’s expertise, this guide is designed to simplify your decision-making, minimize remakes, and support optimal aesthetics across different workflows.

Download now and equip your practice or lab with proven strategies for shade selection success.

High-quality dental zirconia is crucial in prosthodontic treatments to ensure patient satisfaction and long-term success. The use of high-quality zirconia helps in achieving perfectly fitting restorations that are both aesthetically pleasing and durable, minimizing the need for remakes and extra appointments. Low-quality zirconia, however, can lead to various issues such as poor optical properties, improper fit, and inferior biocompatibility, which may go undetected until they cause clinical problems like gingival recession or early restoration failure. Therefore, selecting high-quality zirconia with the right composition, followed by correct processing, is essential for optimal outcomes in dental restorations.

THE DEVELOPMENT OF DENTAL ZIRCONIA

In the late 1990s, the first CAD/CAM-fabricated Zirconia coping was launched as an alternative to the non-aesthetic metal substructure, providing a strong and more aesthetic framework for porcelain-fused restorations. More recent developments in zirconium oxide have led to a shift from full-baked to monolithic use. This has largely overcome mechanical complications such as chipping and delamination and at the same time avoiding the need for the preparation of much of the tooth structure. Leading to prosthetic restorations that retain as much of the structure as possible.

Dental zirconia has traditionally been manufactured mainly from the tetragonal zirconia crystals with a minor proportion of approximately 3 mol% yttria stabilizer (3Y-TZP); this type is extremely strong but has low translucency.¹ By increasing the amount of yttria added to zirconia to around 5 mol%, the translucency is significantly improved because of the presence of a higher amount of zirconia crystals in the cubic form. This zirconia material is often referred at as 5Y-partially stabilized zirconia (5Y-PSZ). However, this increase in translucency comes at the cost of a decrease in mechanical strength.² The introduction of multi-layered zirconia by Kuraray Noritake Dental Inc. marked a significant advancement in zirconia technology, paving the way for highly aesthetic monolithic restorations. The development of a more aesthetic zirconia resulted in a steep decline of metal-ceramic usage in favour of ceramic prostheses. Nevertheless, there are still concerns about the quality of zirconium oxide prostheses. Not only about adhesiveness, but also about fit and processing. Several clinical reports show outcomes with high success rates up to 97% over more than 15 years.² However, there are also reports showing catastrophic failures of zirconia dental restorations. Let’s look at a very important root cause of these failures; the processing procedure.

ALTHOUGH ALL ZIRCONIA BLANKS MAY LOOK SIMILAR, QUALITY AND PROPERTIES CAN DIFFER WIDELY AS THEY ARE AFFECTED BY:

✓ The quality of the raw materials

✓ Raw material processing

✓ Blank pressing

✓ Pre-sintering

OVERVIEW OF POTENTIAL PROBLEMS AND CLINICAL CONSEQUENCES FOR PATIENTS

ROOT CAUSES OF ZIRCONIA FAILURES

Failures in zirconia restorations can often be traced back to the processing procedures used before the materials reach dental clinics. Most dental manufacturers source their zirconia powder from third-party suppliers, giving them limited control over the quality of the material they receive. Zirconia milling blank manufacturers typically press the raw powders, into disks around 100 mm in diameter, which are then pre-sintered to add mechanical stability. The exact formulations of these blanks are often proprietary and not disclosed. Variations during the disc pressing process can introduce air voids and impurities, negatively impacting the quality of the final restorations.² Dental laboratories further process these blanks by milling them into final shapes based on the 3D profiles provided and then sinter them at temperatures above 1,400°C to achieve the desired final phase. Each blank is designed with an enlargement factor to account for shrinkage during sintering. However, detailed processing procedures, such as milling and finishing, are often typically unavailable. As a result, the exact chemical composition, microstructure, and processing of zirconia materials for dental applications varies significantly depending on the manufacturer and laboratory involved. These variations make the production of zirconia restorations a complex and often unpredictable process.

Kuraray Noritake Dental Inc. is one of the few manufacturers handling the entire dental zirconia production process, including raw material processing, in-house. This end-to-end control allows us to ensure exceptional product quality across all materials. A core principle of Kuraray Noritake is the of a higher amount of zirconia crystals in the cubic form. This zirconia material is often referred at as 5Y-partially stabilized zirconia (5Y-PSZ). However, this increase in translucency comes at the cost of a decrease in mechanical strength.² The introduction of multi-layered zirconia by Kuraray Noritake Dental Inc. marked a significant advancement in zirconia technology, paving the way for highly aesthetic monolithic restorations. The development of a more aesthetic zirconia resulted in a steep decline of metal-ceramic usage in favour of ceramic prostheses. Nevertheless, there are still concerns about the quality of zirconium oxide prostheses. Not only about adhesiveness, but also about fit and processing. Several clinical reports show outcomes with high success rates up to 97% over more than 15 years.² However, there are also reports showing catastrophic failures of zirconia dental restorations. Let’s look at a very important root cause of these failures; the processing procedure. seamless integration of quality performance and ease of use, backed by a strong commitment to providing the right materials and support. As the producer of KATANA™ Zirconia, Kuraray Noritake’s meticulous oversight at every stage of production guarantees consistent quality, enabling us to confidently stand behind the excellence of our products.

KATANA™ PRODUCTION

All our zirconia offerings begin their journey to the dental lab in our Japanese facility where raw zirconia ore is processed to a high quality raw powder. Several delicate treatments are done as next steps, including the addition of several fine-tuned essential components like stabilisers and binders. Kuraray Noritake Dental Inc. benefits from in-house production of the raw materials required for dental zirconia. This provides the perfect base on which to use our multi-layering technology and add any other elements needed to create superior quality and purity of the formulation as well as a precise alignment of the desired properties.

From powder to blank pressing, Kuraray Noritake Dental Inc. uses a unique and highly meticulous pressing process that provides for absolute uniform pressing distributions. Every detail is carefully calculated, managed, and controlled. This phase of the process takes several days, underscoring our goal to achieve the most aesthetic product. The results are uniform mechanical and optical properties, outstanding margin stability, high surface quality and a very controlled sintering deformation. By removing the variables for the dental lab, KATANA™ Zirconia provides a reliable material that will give you the same result, every single time.

In the final stage of production, as our KATANA™ Zirconia blanks are prepared for packaging, each disc undergoes a meticulous manual quality check. This last, hands-on inspection ensures that every KATANA™ Zirconia disc meets the highest standards of excellence that we promise. By giving each disc this personal  attention, we guarantee that the quality and performance of our products consistently exceed expectations, reflecting our unwavering commitment to perfection in every detail.

Kuraray Noritake Dental Inc’s state-of-the-art production facilities enable us to create highly stable pre-sintered blanks with precisely the right rigidity to withstand all kinds of milling. This stability makes KATANA™ Zirconia a product that can be fully used without braking in situations where a large part of the disc already has been milled. Something that frequently occurs with lower quality products that are less strong in green-state. This highly stable quality also makes it possible to shorten the sinter time on KATANA™ Zirconia discs up to 54 minutes for single tooth restorations and bridges with up to three units.

NATURAL COLOUR GRADIENT

Kuraray Noritake is well aware of the importance of varying levels of chroma and translucency in various parts of a natural tooth. Our aim has been to mimic this effect even without the use of porcelain layering. In areas where the dentin core is revealed, a tooth is highly chromatic and rather opaque. In contrast, those parts of a tooth mainly composed of enamel – such as the incisal edge - are highly translucent and have a low chroma. Our patented KATANA™ Zirconia multi-layered technology has been developed to precisely imitate this gradient in chroma and translucency and shows a virtually seamless transition between layers, resulting in a tooth-like appearance without the need for porcelain layering. The four types of multi-layered KATANA™ Zirconia (UTML, STML, YML* and HTML PLUS) have a four-layer colour grading structure. The optical outcome is revealed immediately after sintering.

THE LATEST DEVELOPMENT IN ZIRCONIA

Our commitment to quality performance and ease of use is at the heart of everything we do. In line with these core values, we have pushed the boundaries of dental zirconia technology with our latest innovation: KATANA™ Zirconia YML for flawless aesthetics combined with high strength. In this revolutionary design we developed a multi-layered zirconia with additional flexural-strength and smooth translucency gradation; KATANA™ Zirconia YML.

Furthermore, all KATANA™ Zirconia YML discs are designed using ratios rather than fixed measurements of different layers in the multi-layered structure, this means that regardless of the disc’s thickness, there is always a consistent ratio of 35% of raw material that constitutes the translucent enamel zone. Hence, discs with an increased height, which are typically used to produce larger restorations, will always offer sufficient space in the enamel zone, while smaller discs are optimized for smaller restorations.

THE DESIGN CHOICES MADE ON KATANA™ ZIRCONIA YML GREATLY ENHANCES THE ADVANTAGES FOR THE LAB TECHNICIAN

✓ The ratio design offers design flexibility due to strategic layering.

✓ The accurate reflection of colour and translucency reduce the need for extensive finishing.

✓ Stable CTE throughout the disc allowing to produce high precision full arch restorations.

✓ Uniform, void free and high green-state stability for higher nesting flexibility thus higher output.

✓ Relatively high hardness in the green state, for easy green-state modification and fine tuning without the risk of fracturing or chipping.

✓ The hardness also allows for milling thinner restorations including sharp margins, thereby improving marginal fit.

✓ The part of a prosthesis from the body layer of KATANA™ Zirconia YML can be adjusted thinner than that of other high translucency zirconia, resulting in higher translucency in the body part.

MARGINAL STABILITY AND ENHANCED FITTING ACCURACY

KATANA™ Zirconia YML shows sharp margins and less chipping , thereby leading to better marginal fit. Thinner restorations show that this good result in sharp margin supports the use of KATANA™ Zirconia YML.

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

EVERYTHING THE LAB NEEDS

Kuraray Noritake offers four different types of multi-layered dental zirconia to cover every indication as well as a single-layer HT option to produce frameworks and long-span bridges. In the below chart you can view the range of recommended applications for all KATANA™ Zirconia Multi-layer discs.

CONCLUSION

The choice of dental zirconia significantly impacts the success of dental restorations, translating directly into daily practice for the lab technician. High-quality zirconia, such as that produced by Kuraray Noritake Dental Inc., ensures less cracking and chipping during the manufacturing process, reducing the likelihood of costly redoes due to fit or colour deviations. Superior quality of the zirconia powder, like those in KATANA™ Zirconia, allows for speed sintering, accelerating production without compromising the integrity of the restorations. Additionally, the advanced multi-layered zirconia designs, like Kuraray Noritake’s, reduce the need for extensive porcelain layering to achieve aesthetic results, streamlining the process, and enhancing efficiency.

Kuraray Noritake’s stringent quality control, with its end-to-end in-house production, guarantees consistent and reliable zirconia products. The all-rounder KATANA™ Zirconia YML, designed using precise ratios rather than fixed measurements, offers greater flexibility in design and nesting, ensuring consistent quality across varying restoration sizes. By selecting high-quality zirconia with meticulous quality control, dental labs can achieve optimal outcomes in both performance and aesthetics, ultimately benefiting both technicians, dentists, and patients.

REFERENCES

1. Yarahmadi M., Roa J.J., Zhang J., Cabezas L., Ortiz-Membrado L., Llanes L., Fargas G.; Micromechanical properties of Yttria-doped zirconia ceramics. Journal of the European Ceramic Society, Volume 43, Issue 7, July 2023, Pages 2884-2893.
2. Liao, Y., PhDa, Gruber, M. BSEa ; Lukic H., BSEa; McLees J., CDTb ; Chen S., PhDc ; Boghosian A., DDSd ; Megremis S., MS, PhDa; Survey of the mechanical and physical behaviors of yttria-stabilized zirconia from multiple dental laboratories. Journal Reprint Line (2023) 2, 100018

TEETHMATE™ DESENSITIZER RECOGNIZED AS TOP PRODUCT YET AGAIN

Dental Advisor has recognized TEETHMATE™ DESENSITIZER as a Top Product in the category of Hygiene – Desensitizer yet again. This year’s recognition – the eleventh in a row (2015 – 2025) – was announced in the January/February 2025 issue of the publication. TEETHMATE™ DESENSITIZER allows an effective non-invasive approach to the treatment of hypersensitivity – a painful condition that generally occurs when dentinal tubules are exposed – when used as directed by dental professionals.

HOW IT WORKS

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

BENEFITS IN A NUTSHELL

TEETHMATE™ DESENSITIZER is a versatile solution providing hypersensitivity relief independent of the cause. It is perfectly suited for

• Treatment of dentin exposed by toothbrush abrasion, gingival recession, periodontal disease and/or acid erosion.
• Treatment of dentin after mechanical tooth cleaning, scaling and/or root planing.
• Treatment of the tooth surface before and after bleaching.
• Treatment of prepared dentin for fillings and/or prosthetic restorations.

The use of the product is also beneficial as it is

• Easy to mix and apply.
• Proven to be effective.
• Tissue-friendly and highly biocompatible.

OUTSTANDING CLINICAL PERFORMANCE RATING: 96 PERCENT

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

Among the consultants’ comments were

• “TEETHMATE DESENSITIZER is easy to apply and seems to provide consistent relief.”
• "At six months, the majority of patients continue to experience marked improvement from their preoperative sensitivity or no sensitivity at all."

As a result, the product received a clinical performance rating of 96 percent.

ABOUT DENTAL ADVISOR

The Top Product and Preferred Product Awards from Dental Advisor, a US-based organization, were initiated to help busy practitioners navigate the variety of new dental solutions available, particularly for less invasive techniques and standardized procedures. These awards aim to identify products that improve outcomes consistently. Dental Advisor conducts clinical evaluations and product performance tests shortly after a product’s launch and publishes annual results online to help practitioners identify high-quality dental materials suited to their specific needs.

For more information, visit Dental Advisor at: www.dentaladvisor.com

Interview with Dr. Ludivine Facon

Individual prophylaxis, early defect detection and treatment, minimally invasive restorative techniques: In her joint dental practice in Anstaing, France, Dr. Ludivine Facon does everything in  her power to keep her patients’ teeth healthy for their lifetime. When we met her at the International Dental Show in Cologne, where she was a speaker for Kuraray Noritake Dental Inc., we asked her to share information about her treatment philosophy and how flowable injection fits into her overall approach.

Your treatment philosophy seems to be minimally invasive. Would you please tell us a bit more about it?

Ever since I started treating patients, my priority has always been to preserve the dental tissues and to be as minimally invasive as possible when restoration is required. My interest in prevention started with my thesis in 2000, which focused on oral health prevention in Quebec, Canada, a country where prophylactic care is an integral part of dental treatment. I have always been highly interested in individual prophylaxis, which naturally led me to focus on minimally invasive treatments. My goal is to stay as low as possible on the therapeutic gradient, always thinking about the long-term benefits for the patient.

What are the benefits of this approach for your practice?

Integrating prophylaxis for every patient into my practice allows me to work with excellent surface conditions for bonding. The oral environment is sanitized before applying conservative restorations, and carious lesion removal is kept to a minimum.

When defects – be it a carious lesion or severe tooth wear – are present, I use the following instruments and materials that allow for truly minimally invasive interventions:

• Rondoflex 50-micron sandblaster to roughen the surface,
• Micro diamond burs to remove what is necessary,
• Layered composites for single-tooth restorations,
• Injected composites when multiple teeth are involved.

Case predestined for composite injection, as multiple teeth in the maxilla need to be treated (smile makeover).

What dental materials do you use for your restorative procedures?

I am a hands-on dentist, and in my daily practice, I strictly follow surface preparation and bonding protocols recommended for CLEARFIL™ Universal Bond Quick 2 (Kuraray Noritake Dental Inc.). In addition, I use high-quality composites from Kuraray Noritake Dental Inc. For layering, CLEARFIL MAJESTY™ ES-2 Premium Enamel and Dentin are my got-to solution, while I use CLEARFIL MAJESTY™ ES Flow Low for injection.

What are the benefits of a conservative approach for your patients?

Patients appreciate the fact that my treatment approach is as conservative as possible while still allowing for easy reintervention if necessary, preserving as much healthy dental tissue as possible. Another significant advantage is the moderate cost, which makes the treatment more accessible.

How does composite injection fit into this philosophy?

This technique allows for an easy reconstruction of multiple teeth by transferring a wax-up designed in the lab into the mouth via an injection of modern flowable composite into a transparent silicone index. Patients like this technique because it is aesthetic, reliable, reproducible and minimally invasive. A major advantage is that it allows for touch-ups and repairs, making it a reassuring solution. In some cases, no tooth preparation is needed at all—we simply add material, making the whole treatment truly non-invasive.

Why do you think this technique is promising?

It is a trendy and promising technique because:

• It is non-invasive --> preserves tissues --> aligns with minimally invasive dentistry.
• It is predictable --> due to the index, the technique is reproducible.
• It is easier than traditional layering --> saves chair time and improves patient comfort.
• It is cost-effective --> a cheaper alternative to ceramic veneers.
• It allows for repairs at any time, making it a reassuring option.

How did you proceed before knowing this technique?

In the anterior region, I used traditional composite layering with a wax-up and a palatal silicone index. It allowed me to rebuild the palatal wall and provide for precise incisal edge placement. In the posterior region, I used inlays, onlays, or overlays made of lab-processed reinforced composite or lithium disilicate.

Transparent silicone index with injection hole used to inject the flowable composite and restore the tooth to its planned shape.

What made you start using the new technique?

There has been an explosion in demand for smile enhancements, especially among young adults. The composite injection technique is an appealing alternative for reshaping smiles in young patients with intact teeth but unsatisfactory size or shape. It is less invasive than veneers, which have gained popularity due to social media trends, but often require significant tooth preparation.

How did you proceed in the beginning?

I first discovered the technique in a specialized journal in 2019, then trained myself using online tutorials. Of course, there were some trial-and-error moments, but it is a very accessible technique—even for beginners. To achieve optimal results, I believe that proper case selection and treatment planning are key. One of the most important preconditions for aesthetic outcomes is that the patient’s teeth have a simple shade structure. If the shade structure of the teeth is complex or the required restoration is large, it is better to layer the dentin before injecting the enamel. Moreover, it is essential to produce two models in the wax-up phase, not just one: An “intermediate wax-up model” with every other tooth featuring the wax-up, while the remaining teeth remain unmodified. The second is a “full wax-up model” with all teeth reshaped.

Considering these aspects, it is possible to obtain great outcomes quite quickly. The learning curve is steep, however – as with every new technique to be implemented – you need to step out of your comfort zone.

Apart from CLEARFIL™ Universal Bond Quick 2 and CLEARFIL MAJESTY™ ES Flow Low you already mentioned, what instruments and materials do you use?

For treatment planning including the wax-up, I use digital technology via Smilecloud, but a traditional wax-up works just as well. The production of the silicone index is the most delicate part when doing it in-house. I recommend using EXACLEAR (GC), the only truly effective transparent silicone currently available. Adjacent teeth are isolated with PTFE tape. Finishing instruments that have proven their worth are:

• Scalpel Blade No. 12,
• 3M™ Sof-Lex™ Contouring and Polishing Discs (Solventum),
• Red-ring fine diamond burs,
• TWIST™ DIA for Composite polishers (Kuraray Noritake Dental Inc.).

Intermediate wax-up model: One tooth with wax-up followed by one tooth without.

Full wax-up model.

Do you believe that the quality of the outcome is affected by the composite material you use?

Absolutely! New high-filled flowable composites, like CLEARFIL MAJESTY™ ES Flow Low, offer excellent mechanical properties and polishability, making them very promising.

Highly aesthetic treatment outcome after injection of CLEARFIL MAJESTY™ ES Flow Low.

What material characteristics impact overall quality?

First of all, the optical properties or shade matching ability of the material are crucial. I like the fact that I can select from a variety of shades when using CLEARFIL MAJESTY™ ES Flow. Once the right shade is selected and the thickness of the injected layer does not exceed 1 mm, the optical properties of the restorations may be expected to be exceptional.

Moreover, we need a material with great flow properties (fluid, but not too runny), which is virtually void-free. I prefer using low viscosity flowable composites like CLEARFIL MAJESTY™ ES Flow Low (two other flowabilities – HIGH and SUPER LOW – are also available). The physical properties (mechanical strength) and polishability plus polish retention are also important. They are usually excellent with premium flowable composites.

What are your most important clinical tips and tricks?

For beginners:

• Press firmly on the cervical area of the silicone index to reduce excess material upon removal.
• Finish the proximal area thoroughly before moving to the next injection step. This way, you provide for perfect key positioning for the following teeth.

If you follow the protocol, the technique is very beginner friendly!

What is your opinion about the emerging hybrid "layering & injection" technique?

This hybrid technique complicates the original injection technique, which is meant to simplify composite restorations. However, it is very useful in cases where aesthetic complexity requires layering. For maximum mimicry with this technique, I would love to have injectable composites in an enamel shade at my disposal.

Would you please share your final thoughts with us?

Take your time planning! Observe, document, take photos, use digital tools! Less is more.

Dr. Facon, thank you very much!

Dentist:

LUDIVINE FACON

Dr. Ludivine Facon graduated from the University of Lille, where she developed a solid foundation in dentistry. Passionate about periodontology and dental aesthetics, Dr. Facon pursued specialized training to refine her skills in these fields. In 2007, she completed clinical periodontology training at the Charon Clinic, followed by individual dental prophylaxis training with Michel Blique in 2008. From 2013 to 2014, she attended the long cycle program at the Académie du Sourire in Aix-en-Provence, enhancing her expertise in dental aesthetics. Dr. Facon continued to build on her knowledge with international training, including at the International Institute of Periodontology in Montreal in 2015, and a veneer training course at the GAD Center in Bordeaux the same year. In 2016, she further advanced in mucogingival surgery at the Académie de Parodontologie in Aix-en-Provence. Always keeping up with the latest developments, she participated in the CIDAE training in Brussels in 2022. More recently, in 2024, Dr. Facon completed a course in composite layering and injection, led by Guillaume Piskorski, the French specialist in injected composite technique, in Lille. With extensive expertise, Dr. Facon is also an educator in direct aesthetic composites, having taught at the University of Lille in 2020, 2022, 2023, and 2024.

In part two of this veneer workflow, Roberto Rossi completes the restoration by applying CERABIEN™ MiLai lusters to the pre-stained and sintered KATANA™ Zirconia YML. Watch as he enhances surface texture, gloss, and lifelike detail through precise finishing techniques.

With just a few simple steps, Roberto creates depth, dynamic light effects, and natural contours that rival real enamel. The process is intuitive and efficient, delivering a high-end finish—culminating in a final self-glazing fire for a polished, natural result.

An intelligent solution for dental technicians seeking efficiency without compromising on aesthetics.

In the first part of this aesthetic veneer workflow, dental technician Roberto Rossi demonstrates how to apply internal stains to KATANA™ Zirconia YML. This crucial step enhances the restoration by adding depth, translucency, and natural character from within.

After refining the anatomy and surface texture, Roberto skillfully blends and applies selected shades such as A+, Fluoro, and Incisal Blue. These shades create depth, opalescence, and inner vitality that radiate through the final restoration.

A must-watch for dental technicians looking to elevate their zirconia restorations with advanced, yet straightforward, internal staining techniques.

EUROPEAN KOLS EXPERIENCE INNOVATION AND CRAFTSMANSHIP IN JAPAN

This September, seventeen of Kuraray Noritake Dental’s Key Opinion Leaders (KOLs) from across Europe—representing nine countries—embarked on a remarkable journey to Japan. The program offered a rare opportunity to experience the heart of Kuraray Noritake Dental’s culture of innovation, craftsmanship, and collaboration.

A JOURNEY OF INSIGHT AND INSPIRATION

The tour began in Tokyo, where the group traveled by bullet train to Nagoya to explore some of Japan’s cultural and professional landmarks. Visits to Nagoya Castle and the historic Noritake Garden provided glimpses into the artistry and heritage that continue to inspire our company’s ceramic technologies today.

Nagoya castle.

That evening, an official dinner in Nagoya brought together the European guests and key members of the Kuraray Noritake Dental team, including Ms. Kiyoko Ban, Mr. Yoshihisa Yamada, and Mr. Kazuhiro Yamada. It was an evening filled with rich conversations, meaningful connections, and a shared vision for the future of dental excellence.

FROM CONCEPT TO CREATION: VISITING THE MIYOSHI AND NIIGATA FACTORIES

The following day, the KOLs visited the Miyoshi Factory, where the company’s ceramic products such as KATANA™ Zirconia are manufactured, and  attended insightful presentations by their European peers — including Jorgen Gad, Sophie Dallem, Dumitru Leahu, Marios Georgoulis, Stratos Chatzichristos, and Kamila Krzepkowska — followed by a comprehensive factory tour and in-depth discussions  with R&D experts on zirconia and dental lab materials, providing unique professional insights.

Discussion with Kuraray Noritake Dental team at Miyoshi Factory.

Presentation given by DT Sophie Dallem and DT Dumitru Leahu at Miyoshi Factory.

Presentation given by DT Marios Georgoulis at Miyoshi Factory.

The tour also brought our KOLs to Niigata, where participants experienced firsthand the research and development process behind Kuraray Noritake Dental’s renowned products. A highlight was the hands-on demonstration of CLEARFIL MAJESTY™ ES Flow Universal, allowing each participant to engage directly with the materials and processes that define the company’s quality.

Hands-on course at Niigata plant.

CONNECTING THROUGH COLLABORATION

Between technical sessions, the group visited the Tokyo office and showroom, sharing open discussions with our Japanese colleagues at the headquarters, followed by a sightseeing tour through Tokyo’s landmarks — from the Imperial Palace to Tokyo Tower. These shared experiences strengthened the sense of partnership and mutual respect not only between the European and Japanese teams but also between the KOLs themselves and the company.

“It was an incredible experience meeting exceptional people worldwide, among them top specialists.” 
—    DT Kamila Krezpkowska, Poland

Discussion with Kuraray Noritake Dental team at the Tokyo headquarters.

WORDS FROM OUR KOLS

The feedback from participants was overwhelmingly positive:

“It was truly a lifetime experience — both inspiring and invaluable for me as a dental technician. Witnessing how the materials we use every day are created gave me an even deeper appreciation for the craft behind them.”
— DT Marios Georgoulis, Greece

“I’m so impressed by the organization, the endless friendliness, the openness, and the willingness to answer all my questions. It was a wonderful time, filled with so many experiences.” 
— Dr. Bernhild Stamnitz, Germany

“It was a life experience I will never forget and I am very grateful I got this opportunity to be there.[…] The drive and compassion of all the workers in office, but also at the factory were very impressive to see. The view I had about the quality of your product improved more than it already was.” 
—  Dr. Mark Laske, Netherlands

A SHARED COMMITMENT TO EXCELLENCE

The KOL Japan Tour 2025 was more than a professional visit—it was a bridge between continents, uniting people through shared values of precision, innovation, and artistry. Kuraray Noritake Dental extends heartfelt thanks to all participants and to the teams in Japan who made this unforgettable experience possible.

Group picture at the Kuraray Noritake Dental office in Tokyo.

Arigato!

PANAVIA™ Veneer LC WINS PREFERRED PRODUCT AND RESEARCH AWARDS

PANAVIA™ Veneer LC has been singled out for a Research Award in the category Research – Veneer Cement by Dental Advisor and for a Preferred Product Award in the category Cement: Esthetic Resin. Published in the January/February 2025 issue of the US-based organisation, the annual Top Product, Preferred Product or Research Awards are given to those materials and devices deemed by the publication’s consultants to deliver the best practice-based or lab-based performance in their categories.

BENEFITS IN A NUTSHELL

PANAVIA™ Veneer LC is a specialized veneer cement designed to provide exceptional bond strength to various substrates, along with outstanding gloss retention and wear resistance. The resin cement utilizes smaller-diameter spherical filler particles, facilitating easy dispensing from the syringe and excellent flowability for minimal film thickness. All of these attributes contribute to virtually no change in gloss or surface appearance of veneer margins over time.

EXCELLENT PROPERTIES IN VITRO

To assess the scientific performance of PANAVIA™ Veneer LC, its features and physical properties, specifically its bond strength to various substrates after artificial aging and its wear resistance, were tested in the Dental Advisor Biomaterials Research Center. The investigators’ testing of these attributes reflects the challenges such products must meet – “Ideally, esthetic veneer cements should have a long working time, curing on demand, excellent color stability, and high strength”.

To assess bond strength to dentin, enamel, IPS e.max CAD, and zirconia, the cements were subjected to six months of artificial aging using thermocycling. To test wear resistance after toothbrush abrasion, the testing method involved measuring depth of wear, change in surface roughness, and change in gloss based on a simulation of about 5.5 years of regular toothbrush use.

The investigators reported that PANAVIA™ Veneer LC “had the best gloss retention of the three cements tested and a very even wear pattern,” noting further that “having limited surface roughness after toothbrush abrasion can help lower staining and bacterial adhesion.” Overall, they said, “The PANAVIA™ Veneer LC cement system showed excellent adhesion properties and exceptional gloss retention and wear resistance,” concluding:

OUTSTANDING RATING OF 96 PERCENT

In addition, the product was tested in the clinical setting. 25 clinical evaluators used PANAVIA™ Veneer LC cement system in their dental offices. After a total of 166 uses, the light-curing resin cement received “excellent” to “very good” ratings with regard to completeness of the kit, the shade of the try-in pastes, ease of clean-up of the try-in pastes and excess cement, viscosity, working time and lack of shade shift after curing.

The evaluator’s clinical tips included:

• „Use a micro brush or rubber tip to clean up excess cement before curing.”
• „Apply glycerin gel to the margins after placing the veneer with the cement to eliminate the oxygen inhibition layer and ensure a complete cure before light curing through the gel.”

In their comments, they praised the ease of use of the system, the design of the syringes, the shade options and shade match between try-in and cement shades, e.g.:

• “The white shade of the cement was opaque enough for efficient masking of discolored tooth structure.”
• “Great esthetics, very easy to use, complete system.”

This resulted in an overall clinical rating of 96 percent and an equally high recommendation rate.

ABOUT DENTAL ADVISOR

The Top Product and Preferred Product Awards from Dental Advisor, a US-based organization, were initiated to help busy practitioners navigate the variety of new dental solutions available, particularly for less invasive techniques and standardized procedures. These awards aim to identify products that improve outcomes consistently. Dental Advisor conducts clinical evaluations and product performance tests shortly after a product’s launch and publishes annual results online to help practitioners identify high-quality dental materials suited to their specific needs. Research Awards were initiated to honour those manufacturers of dental products with an ongoing commitment to research, development and advancement of dental materials to enhance treatment quality.

For more information, visit Dental Advisor at: www.dentaladvisor.com