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

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

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

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

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

Where did the name PANAVIA™ come from?

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

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

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

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

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

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

What about the surface-cure characteristics of the cement?

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

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

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

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

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

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

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

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

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

How did production change?

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

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

When did external researchers start showing interest in PANAVIA™?

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

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

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

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

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

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

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

MITSUNOBU KAWASHIMA

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

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

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

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

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

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

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

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

Article by Dr. Adham Elsayed

High-performance adhesive resin cements are often the enablers of minimally invasive prosthodontic treatments. When the main aim is to save as much healthy tooth structure as possible, preparation designs that offer sufficient macro-mechanical retention for conventional cements are usually abandoned. The designs chosen instead need to rely on a strong and durable chemical adhesion established between the tooth structure and the restorative material – a task successfully accomplished by modern adhesive resin cement systems.

An excellent example of a minimally invasive, non-retentive preparation and restoration design is the single-retainer resin-bonded fixed dental prosthesis (RBFDPs), nowadays usually made of 3Y-TZP zirconia. With its single cantilever bonded to the oral and proximal enamel surface of an adjacent tooth, it requires minimal to no healthy tooth structure removal. The RBFDP is often used to replace a congenitally missing tooth – in many cases a maxillary lateral incisor – in young patients with incomplete dentoalveolar development and narrow edentulous spaces unsuitable for conventional implant placement¹ (Fig. 1 and 2). Additional factors hindering implant therapy – like an insufficient bone volume or angulated roots – are also not an issue for this type of restoration. And compared to orthodontic gap closure, the treatment approach with a RBFDP is less risky, as it does not affect the vertical jaw relationship, prevent canine guidance or compromise the aesthetic appearance². Finally, it is much less invasive than conventional FDPs, which is usually not a treatment option for young patients in the anterior region. The level of patient satisfaction and the success rates of this treatment approach are impressive^3-7.

Fig. 1-2. Replacement of both congenitally missing maxillary lateral incisors with single-retainer zirconia RBFDPs after soft tissue augmentation and gingival margin correction.

Despite the numerous advantages and excellent clinical performance – single-retainer RBFDP made of zirconia showed a survival of 98.2 percent and a success rate of 92.0 percent after ten years⁴ – many dental practitioners still opt for alternative treatment options. The reason may be a lack of trust in the bond strength and durability to zirconia. However, this bond can be very strong and durable – provided that a few rules are respected.

HOW TO ESTABLISH A STRONG BOND TO THE TOOTH STRUCTURE

In order to decide whether a missing tooth may be successfully replaced by a single-retainer RBFDP made of zirconia, the abutment tooth should be examined carefully. It needs to be vital and largely free of caries or direct restorations, while the oral enamel surface must be large enough for resin bonding¹. In addition, the space required for the placement of a retainer wing (thickness: about 0.7 mm) needs to be available, as a non-contact design is important for the success of the restoration. Among the preparation designs described in the literature is a lingual veneer and small proximal box preparation with retentive elements located in the enamel only¹, or no preparation at all⁷. For restoration placement, the abutment tooth is treated as usual: after cleaning e.g., with fluoride-free prophylaxis paste, phosphoric acid etchant is applied to the bonding surface, which is then thoroughly rinsed and dried.

HOW TO ESTABLISH A STRONG BOND TO THE RESTORATION

The recommended pre-treatment for the bonding surface of the retainer wing made of zirconia is small-particle (50 μm) aluminium oxide air-abrasion at a low pressure (approx. 1 bar)^8,9, followed by ultrasonic cleaning. Figures 3 (A-E) shows the sequence of surface treatment of zirconia restorations. As a visual aid for a controlled air-abrasion treatment, the marking of the surface with a pen has proven its worth. The whole air-abrasion procedure should be carried out after try-in, during which the tooth surface and the restoration usually becomes contaminated through contact with saliva and sometimes blood. Proteins present in saliva and blood that contaminate the bonding surface are safely removed in this way, while the required surface modification necessary to establish a strong and durable bond to the selected resin cement system is achieved¹⁰.

FIGURE 3: SEQUENCE OF SURFACE TREATMENT OF ZIRCONIA RESTORATION.

Fig. 3A. Cleaning of the restoration prior to luting with water steam cleaner.

Fig. 3B. Marking of the bonding surface as an visual aid for the air-abrasion.

Fig. 3C. Air-abrasion with 50-μm Al₂O₃ particles with 1 bar pressure.

Fig. 3D. Application of a primer containing 10-MDP.

Fig. 3E. Application of the composite resin cement.

WHICH RESIN CEMENT SYSTEM TO CHOOSE

Subsequently, the components of the resin cement system are applied. Regarding the selection of the system, it is generally recommended to use a restoration primer or resin cement that contains 10-Methacryloyloxydecyl dihydrogen phosphate (10-MDP)¹¹. In this way, a high-quality chemical bond is established. Among the resin cement systems used in the available long-term clinical studies is PANAVIA™ 21 (Kuraray Noritake Dental Inc.)^4-6. Launched in 1993, this anaerobic-curing adhesive resin cement contains several important technologies like the MDP monomer and the Touch Cure Technology found in PANAVIA™ V5, the state-of-the art dual-cure multi-bottle adhesive resin cement system of the company. In order to further improve the bonding performance of this present product, however, the team of developers reviewed the basic composition, updated existing technologies and combined them with completely new ingredients.

Even with PANAVIA™ 21 introduced 30 years ago, high success rates were obtained^4-6. The few observed failures were mainly due to chipping of the veneering ceramic or debonding. Sometimes caused by traumatic incidents, the debondings resulted in no further damage and the restorations were simply rebonded using the same cementation system and procedure.

One might expect that with its improved formulation, PANAVIA™ V5 will offer an even stronger and more durable bond than predecessor products, so that it is even better suited for such demanding applications as the resin-bonded fixed dental prosthesis. In a pilot study, this assumption was confirmed⁷. Without any preparation of the abutment tooth, but a defined size of the bonding surface of at least 35 mm², the team of researchers placed 24 monolithic zirconia resin-bonded bridges (made of KATANA™ Zirconia HT) to replace congenitally missing lateral incisors. The palatal sides of the central incisors were cleaned with pumice paste and treated with phosphoric acid, while the bonding surfaces of the restorations were sandblasted with aluminum oxide particles (50 μm, 2.5 bar pressure). Afterwards, twelve restorations were luted with PANAVIA™ V5, the other twelve with PANAVIA™ F2.0 (another earlier-version resin cement from Kuraray Noritake Dental Inc.). After an observation period of 32 to 50.47 months, the success and survival rates in the PANAVIA™ V5 group were 100 percent. In the other group, a connector fracture, a chipping and two debondings occurred. Based on these results, the authors of the publication concluded that “it has been seen that the new generation cement (PANAVIA™ V5) is more successful”⁷.

CONCLUSION

For many years, minimally invasive indirect restorative approaches like the replacement of missing incisors with resin-bonded fixed dental prostheses have been performed successfully by some dental practitioners. Many others, however, still seem to be hesitant whether these approaches will lead to the desired results in their hands. The available clinical study results, however, have confirmed that the procedure is highly advantageous and successful, while ongoing development efforts in the field of adhesive resin cements have led to products further decreasing the failure rates related to debonding. Even if a debonding occurs, however, no damage is usually done, so that the restoration can be rebonded again with little effort. These findings – together with the well-known benefits of minimally invasive dentistry in general – should encourage dental practitioners to start exploring the full potential of adhesive dentistry for themselves. In this context, PANAVIA™ V5 is definitely an excellent choice.

References

1. Sasse M, Kern M. All-ceramic resin-bonded fixed dental prostheses: treatment planning, clinical procedures, and outcome. Quintessence Int. 2014 Apr;45(4):291-7. doi: 10.3290/j.qi.a31328. PMID: 24570997.
2. Tetsch J, Spilker L, Mohrhardt S, Terheyden H (2020) Implant Therapy for Solitary and Multiple Dental Ageneses. Int J Dent Oral Health 6(6): dx.doi. org/10.16966/2378-7090.332.
3. Wei YR, Wang XD, Zhang Q, Li XX, Blatz MB, Jian YT, Zhao K. Clinical performance of anterior resin-bonded fixed dental prostheses with different framework designs: A systematic review and meta-analysis. J Dent. 2016 Apr;47:1-7. doi: 10.1016/j.jdent.2016.02.003. Epub 2016 Feb 11. PMID: 26875611.
4. Kern M, Passia N, Sasse M, Yazigi C. Ten-year outcome of zirconia ceramic cantilever resin-bonded fixed dental prostheses and the influence of the reasons for missing incisors. J Dent. 2017 Oct;65:51-55. doi: 10.1016/j.jdent.2017.07.003. Epub 2017 Jul 5. PMID: 28688950.
5. Kern M. Fifteen-year survival of anterior all-ceramic cantilever resin-bonded fixed dental prostheses. J Dent. 2017 Jan;56:133-135.
6. Sasse M, Kern M. Survival of anterior cantilevered all-ceramic resin-bonded fixed dental prostheses made from zirconia ceramic. J Dent. 2014 Jun;42(6):660-3. doi: 10.1016/j.jdent.2014.02.021. Epub 2014 Mar 5. PMID: 24613605.
7. Bilir H, Yuzbasioglu E, Sayar G, Kilinc DD, Bag HGG, Özcan M. CAD/CAM single-retainer monolithic zirconia ceramic resin-bonded fixed partial dentures bonded with two different resin cements: Up to 40 months clinical results of a randomized-controlled pilot study. J Esthet Restor Dent. 2022 Oct;34(7):1122-1131. doi: 10.1111/jerd.12945. Epub 2022 Aug 3. PMID: 35920051.
8. Kern M. Bonding to oxide ceramics—laboratory testing versus clinical outcome. Dent Mater. 2015 Jan;31(1):8-14. doi: 10.1016/j.dental.2014.06.007. Epub 2014 Jul 21. PMID: 25059831.
9. Kern M, Beuer F, Frankenberger R, Kohal RJ, Kunzelmann KH, Mehl A, Pospiech P, Reis B. All-ceramics at a glance. An introduction to the indications, material selection, preparation and insertion techniques for all-ceramic restorations. Arbeitsgemeinschaft für Keramik in der Zahnheilkunde. 3rd English edition, January 2017.
10. Comino-Garayoa R, Peláez J, Tobar C, Rodríguez V, Suárez MJ. Adhesion to Zirconia: A Systematic Review of Surface Pretreatments and Resin Cements. Materials (Basel). 2021 May 22;14(11):2751.
11. Al-Bermani ASA, Quigley NP, Ha WN. Do zirconia single-retainer resin-bonded fixed dental prostheses present a viable treatment option for the replacement of missing anterior teeth? A systematic review and meta-analysis. J Prosthet Dent. 2021 Dec 7:S0022-3913(21)00588-6. doi: 10.1016/j.prosdent.2021.10.015. Epub ahead of print. PMID: 34893319.

Interview with Dr. Michał Jaczewski

The flowable injection technique is becoming a popular technique used to aesthetically restore multiple teeth with flowable composite. A renowned instructor who teaches dental practitioners the skills needed to use the technique successfully is Michał Jaczewski. He graduated from Wroclaw Medical University (Poland) in 2006 and runs his own private practice in the city of Legnica since 2011. He is the founder of the Biofunctional School of Occlusion, which conducts trainings in the field of comprehensive dental treatments, and is passionate about aesthetic digital dentistry. At the International Dental Show 2023 in Cologne, he showed us when, why and how he uses flowable injection in his dental office.

Could you please describe the technique in a few words?

The flowable injection technique is a simple, predictable, repeatable way to restore teeth using flowable composite. It is based on a wax-up, over which a silicone index is produced. This index then serves as the key for the injection of the flowable composite, which is light-cured through the transparent silicone. The most important benefit is that this technique works without or in some cases with a very minimal tooth preparation. It is a minimally invasive technique that can be used by beginners and by experienced dentists. Using a composite with a well-balanced opacity in a thickness of 0.3 mm and a special polishing protocol, it is possible to achieve excellent morphological and optical outcomes.

When did you start using the flowable injection technique and what are its major indications?

I started using the technique in 2018. It was originally invented to restore anterior teeth, but nowadays, it is successfully used in the posterior region as well. To my mind, it is particularly useful whenever the shape of multiple teeth needs to be corrected to improve a patient’s smile, no matter whether young or old. This may be the case after orthodontic treatment. The teeth are simply aligned and then restored to the perfect shape using this non-invasive technique. I also use flowable injection for a smile makeover, to restore worn teeth and to change the vertical dimension of occlusion in the context of full-mouth reconstructions. In the latter case, the restoration may be temporary and used for a mid- to long-term “test drive”. However, it can also serve as the final restoration.

How do you start when planning to restore a patient’s teeth with the flowable injection technique?

The most important phase heavily influencing the success of this technique is the planning phase. It consists of documentation, impression taking and the creation of a wax-up and mock-up as well as the production of the silicone index. You can of course work in the traditional way with a silicone impression and conventional wax-up, but the use of digital technologies in this phase will improve your workflow significantly. I usually start with photo and video documentation and a digital impression. Records of the centric relation and occlusion are needed as well. Then, a virtual wax-up is created using digital smile design software. In this step, it is important to take into account the facial characteristics of the patient, a task that is best accomplished using the facial flow concept. Based on the resulting design, a virtual treatment outcome can be displayed and discussed with the patient. Once approved, the model with wax-up is printed in different versions: the full wax-up model and an “interlip model” with an alternating design – one tooth with wax-up followed by one tooth without. These models are used to produce the required indexes made of transparent silicone.

Digital Smile Design: Patient with severe tooth wear.

Virtual wax-up displayed in the patient’s mouth.

Models printed on the basis of the virtual mock-up.

Silicone index produced on the alternating (interlip) model.

When and why do you produce more than one silicone index?

It is particularly useful to work with the complete and the alternating (partial) silicone index when planning to restore all teeth in the maxilla. Starting with the alternating index gives me additional stability and lays the foundation for a precise outcome especially with regard to the planned occlusal height. In the lower jaw, where the handling of the index and the composite is more difficult due to the presence of saliva and moving soft tissues, I always recommend to divide the working field into three sections – one anterior and two posterior regions – and work on them separately.

How do you prepare the teeth and inject the flowable composite?

In most cases, all we need is a roughening of the enamel surfaces for the bonding procedure, which is usually possible by air abrasion with aluminum oxide (50 μm at low pressure). Then, the enamel is etched with phosphoric acid etchant and a universal bonding agent is applied. The silicone index is equipped with an injection hole on the incisal edge. This is easily accomplished with the cannula of the flowable composite syringe pressed through the material from the inside to the outside. In the posterior region, it may be useful to utilize a harder material and integrate two holes for each tooth on separate cusps – one for the injection and one for the outward flow. On a hard index, a diamond bur is needed for this procedure. I place the index, inject the flowable composite from the bottom to the top, light-cure the material shortly and remove the index. Final polymerization is carried out after index removal and the application of a layer of glycerin gel. Once the excess material is removed and the proximal part of the restoration is finished perfectly, the procedure is repeated for the other teeth before the restorations are polished.

Do you have any favourite products for the technique?

For the silicone index, I use EXACLEAR (GC), as it is the most transparent silicone available on the market. My favourite composite for the flowable injection technique is CLEARFIL MAJESTY™ ES Flow of low viscosity (Kuraray Noritake Dental Inc.). In my dental office and during my courses, I had the chance to test a lot of different products. In this context, I found that the material from Kuraray Noritake Dental offers a few advantages. It is a modern type of nano composite with a wide range of indications and a large shade offering. With its three viscosities, it can be used in many different clinical situations. I started using it five years ago and for the flowable injection technique, the Low variant is my first choice, as it is the most universal one suitable for anterior and posterior teeth. The most decisive advantages that influenced my decision to use it are its natural aesthetics and superior polishability. You can achieve a spectacular effect without any special skills. As a bonding agent, I prefer to use CLEARFIL™ Universal Bond Quick, which makes my workflow even easier, faster and more predictable. For polishing, I have developed my own protocol.

How do you finish and polish your restorations?

I start in the proximal area with polishing strips and sometimes a proximal saw. For shape adjustments, three different diamond and carbide burs have proven their worth. Subsequently, I proceed with fine or extra fine Sof-Lex™ Finishing and Polishing Discs (3M) used for contouring and finishing and rubber polishers TWIST DIA™ for Composite (Kuraray Noritake Dental Inc.), which already create a nice, natural surface gloss with low effort. Then, a wheel brush made of goat hair is used with diamond polishing paste (Diamond excel, FGM) and finally, I use a cotton wheel along with an aluminum oxide polishing paste (Pasta Grigia II, anaxDENT). In this way, it is possible to create a mirror finish.

Etching of the enamel with phosphoric acid etchant.

Complete silicone index in place.

Application of CLEARFIL™ Universal Bond Quick.

Situation immediately after the injection of CLEARFIL MAJESTY™ ES Flow (Low), light curing and removal of the silicone index.

Proximal adjustments with rotating instruments.

What are the biggest benefits of the flowable injection technique?

For patients and dental practitioners, the biggest advantages are savings in time and money. Many patients cannot afford ceramic veneers, and they are extremely happy to be offered a high-quality alternative that can be delivered in a single appointment. The procedure is prepless and the restorations can easily be repaired or the colour changed if they wish, so that there is virtually no risk involved in the treatment. Dental practitioners are usually able to start treating patients after they have attended a single course. While practicing makes them perfect, the first results are often already quite impressive, so that there is no huge investment involved for beginners – neither in time nor in new materials. Of course, you can invest lots of time in the finishing and polishing procedure, but I am sure you will find the right balance between effort and outcome.

Set of instruments for the flowable injection technique.

Do you have any recommendation of how to start using the technique?

First of all, I would like to encourage everyone to leave their comfort zone and try something new on a regular basis. For me, starting to work with the flowable injection technique was a real gamechanger, and I would never want to work without it again. Before starting to use the technique, I would definitely attend a course that teaches you all the theoretical knowledge needed for a successful first case, and maybe even a practical workshop.

Michał Jaczewski during his presentation at the Kuraray Noritake Dental booth in Cologne.

For further insights and resources on the Flowable Injection Technique, we invite you to explore additional materials available. Dive deeper into this innovative approach, check out another clinical case using Flowable Injection Technique, as demonstrated by Dr. Michał Jaczewski. Additionally, read the expert advise on how to avoid air bubbles in the composite restorations! These valuable tips will enhance your understanding and application of the technique.

Article by Dr. Bassem Jaidane

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

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

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

CASE OBSERVATION

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

Fig. 1. Initial clinical situation.

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

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

TREATMENT PLAN

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

TREATMENT

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

Fig. 3. Preoperative picture.

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

Fig. 4. Virtual model.

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

DISCUSSION

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

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

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

Fig. 6. Cutback design of the restorations.

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

Fig. 8. Immediate post-operative picture.

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

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

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

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

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

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

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

Fig. 9. Treatment outcome.

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

CONCLUSION

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

Dentist:

DR. BASSEM JAIDANE

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

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

References

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

DENTAL ADVISOR Editor’s Choice and 2023 Preferred Product award recipient, quickly provides durable bond in a single procedure

CLEARFIL™ Universal Bond Quick has been named a 2023 Editor’s Choice by DENTAL ADVISOR, which evaluates dental products and equipment and publishes its findings annually. It has also received recognition as DENTAL ADVISOR’s Preferred Product this year in the category of Universal Bonding Agents. The 31 consultants who evaluated its application during 1,065 usages gave it the excellent overall rating of 98%.

CLEARFIL™ Universal Bond Quick is a single-bottle fluoride-releasing, universal adhesive with MDP monomer and amide monomer chemistry called rapid bond technology. This combination of the MDP monomer, which creates a strong chemical bond to hydroxyapatite, and newly developed hydrophilic amide monomer, which is highly hydrophilic, is responsible for fast chemical bonding and quick penetration into dental tissue. Because the amide monomer rapidly permeates dentin and enamel, it eliminates the need for long rubbing application of the adhesive into the dentin and reduces the wait time after application. After curing, the innovative amide monomer forms a moisture-resistant cross-linked polymer network.

As a result, the bonding is moisture-resistant and stable, with durable results. This method, which reduces application time without compromising bond strengths, sealing, or desensitizing, also reduces technique sensitivity.

A fast and versatile agent that bonds directly to dentin, enamel, metals, zirconia and lithium disilicate restorative materials, CLEARFIL™ Universal Bond Quick is suitable for bonding direct and indirect restoration and can be used for total-etch, selective-etch, or self-etch methods. When mixed with CLEARFIL™ DC Activator, CLEARFIL™ Universal Bond Quick becomes dual-cure and has universal use with both self- and dual-cured resin cements and core build-up resins. 

The practitioners evaluating the product commented on its ease in dispensing and placement, viscosity, suitability for all bonding procedures, and convenience. Among their remarks were: “Perfect viscosity. Ease of use and speed were great.” and “Great for replacement of silane to prime crowns for cementation with resin cement - will self-cure with the dual-cured resin.”

Honors such as Editor’s Choice that are conferred by US-based DENTAL ADVISOR were introduced to help busy practitioners make sense of the numerous new solutions indicated for less invasive techniques, standardized or simplified procedures, and better outcomes on a regular basis. DENTAL ADVISOR conducts its practice-based clinical evaluations and product performance tests shortly after product launch, and publishes results annually online to help potential users identify high-quality new dental materials and determine which among them are best suited to fulfill their individual requirements.

A pioneer in digital dental photography, the editor-in-chief of the “International Journal of Esthetic Dentistry” and a supporter of universal products: We are talking about Dr Alessandro Devigus, the owner of a private practice in Bülach, Switzerland. At the International Dental Show 2023 in Cologne, we had a conversation with him about his favourite products from Kuraray Noritake Dental Inc. and the concept of universal excellence.

Dr Adham Elsayed, Clinical and Scientific Manager at Kuraray Noritake Dental Inc., interviewing Dr Alessandro Devigus.

Dr Devigus, why did universal products attract your attention?

We all would like to reduce the number of products and components used in our dental offices to make our lives easier and more predictable. Several years ago, when the first universal products started entering the dental market, I realized that these products and the concept behind them are able to help me achieve this goal.

For what kinds of treatments do you currently use universal products?

The main field of application is restorative dentistry, in indirect and direct restorative workflows, which often go hand in hand. Whenever possible and in accordance with the needs and desires of the patient, I opt for minimally invasive direct composite restorations, often realized using universal products. Cosmetic corrections or tooth wear treatments in the lower jaw, for example, are often carried out in a prepless procedure with resin composite applied with a single-shade technique. For anterior restorations in the upper jaw of the same patient, however, I might opt for ceramic restorations, luted with a universal resin cement.

What are your favourite indirect restorative materials, for which indications do you use them and when do universal products come into play?

I produce most of my single-tooth restorations chairside with CEREC. In the anterior region, the choice is usually between different types of glass ceramic materials. In some indications, when two central incisors or all four maxillary incisors need to be restored, zirconia is also a suitable option. In these cases and for indirect restorations in the posterior region, KATANA™ Zirconia Block is my preferred material. Having tested many different types of chairside zirconia, I can say that this product simply offers the most natural colour gradation and the desired vitality. Hence, finishing is quick and easy. At the same time, the high flexural strength of the material supports me in my striving for minimally invasive preparations. For definitive placement of the produced overlays and crowns, PANAVIA™ SA Cement Universal from Kuraray Noritake Dental Inc. is my dual-cure resin cement of choice. It bonds to virtually every surface including lithium disilicate without a separate primer and offers a good flowability that facilitates restoration placement. An additional feature contributing to a quick and stress-free clinical procedure is its easy and gingiva-friendly excess removal after tack curing.

What about direct restorations?

One of my favourite resin composites is CLEARFIL MAJESTY™ ES-2 Universal (Kuraray Noritake Dental Inc.). Its single shade for the posterior and two shades for the anterior region offer just the right combination of translucency and intrinsic colour to imitate a large number of tooth shades. The effect is that it blends in nicely with the surrounding tooth structure without appearing grayish. In the posterior region, I was able to observe a certain masking potential, so that discoloured abutment teeth do not cause any problems. With this material, the shade determination step is eliminated. Clinical workflows are also simplified by the use of CLEARFIL™ Universal Bond Quick. The universal adhesive is not only versatile as it is suitable for many indications and all etching techniques, but also extraordinarily quick in its application, as the need for an extensive rubbing into the tooth structure is eliminated. In this way, it is possible to streamline direct restorative procedures.

Why do you use so many products from Kuraray Noritake Dental Inc.?

I simply like products from Japanese companies. They stand for quality, integrity and clinical relevance. Japanese people seem to be deeply committed to the company they work for and to their work, pay attention to every detail and try to deliver the best outcomes possible. This attitude is reflected in Kuraray’s mission “For people and the planet—to achieve what no one else can.”, and it is reflected in the products of the company as well. They offer the properties I need to deliver high-quality dental treatments.

You said that making your life easier and more predictable is the main reason for you to opt for universal materials. Please explain.

In the first place, using fewer products and components that are easy and quick in their application allows me to get a grip on costs. With fewer steps and fewer bottles, shortened application times and standardized workflows, the time a patient needs to sit in the chair is reduced, which allows me to save the most valuable factor in the office: my time. At the same time, material storage and order management are streamlined, so that it is much easier to keep track of dates of expiry, hence saving material costs as well. And the best thing about it is that all these savings are possible without compromising treatment quality. Provided that the user is able to handle the materials properly – which is facilitated by the minimal number of steps and ease of use – the quality of the outcomes is extremely high!

Dr Devigus, we thank you for sharing your insights with us.

2023 DENTAL ADVISOR Top Product is an everyday cement that eliminates the need for a separate primer

PANAVIA™ SA Cement Universal adheres to virtually all substrates, including lithium disilicate, in a single procedure without the need for a separate primer or silane, and it also offers easy, gingival-friendly removal of excess cement and requires no refrigeration. Therefore it is no wonder that this year DENTAL ADVISOR gave PANAVIA™ SA Cement Universal Top Product award in the category of Indirect Restoratives.

What makes its strong and durable bond possible without the added step of applying a separate substrate is that PANAVIA™ SA Cement Universal combines two innovative technologies in a single product. The silane coupling agent, LCSi monomer, establishes a durable, chemical bond with porcelain, lithium disilicate, and composite resin; and the original MDP monomer provides for chemical reactiveness with zirconia, dentin and enamel.

The result is a convenient, versatile, and efficacious single solution to practitioners’ everyday cementation needs for a wide variety of indications, including cementation of crowns/bridges, inlays/onlays, posts, splints, and even adhesion bridges.

The significant benefits and quality of PANAVIA™ SA Cement Universal are reflected in the study findings and feedback of the 31 DENTAL ADVISOR clinical evaluators who used the cement in 516 applications and gave it an overall clinical rating of 96 percent. Their comments on its ease of use, handling characteristics, and aesthetics included: “Good flow and film thickness;” “Amazing viscosity, tack cure-ability, and very easy cleanup;” and “Great color match, and I liked the universal ability to work with so many substrates.”

The Top Product or Preferred Product Awards conferred by US-based DENTAL ADVISOR were introduced to help busy practitioners make sense of the numerous new solutions indicated for less invasive techniques, standardized or simplified procedures, and better outcomes on a regular basis. DENTAL ADVISOR conducts its practice-based clinical evaluations and product performance tests shortly after product launch, and publishes results annually online to help potential users identify high-quality new dental materials and determine which among them are best suited to fulfill their individual requirements.

For more information visit the website of DENTAL ADVISOR: www.dentaladvisor.com.

Entrevista com Yoshihisa Yamada
Gerente Geral, Divisão de Tecnologia da Kuraray Noritake Dental Inc.

KATANA™ Zirconia ML foi apresentado há dez anos, na IDS 2013 em Colónia, como o primeiro produto de zircónia da indústria odontológica com uma estrutura de cor multicamadas. Desde aquele evento, os blocos KATANA Zirconia ML tornaram-se muito populares. Esforços contínuos de desenvolvimento levaram à linha atual de materiais multicamadas, KATANA Zirconia UTML, STML e HTML PLUS, e o nosso produto mais recente – KATANA Zirconia YML. A nossa nova tecnologia com gradação de cor, translucidez e resistência é encontrada em KATANA Zirconia YML.

Créditos das fotos para MDT Giuliano Moustakis.

Quão importante foi a invenção da tecnologia multicamada original da Kuraray Noritake Dental para o mercado odontológico?

A nossa impressão é que o material teve um impacto significativo no mercado odontológico. Sendo o primeiro material de zircónia com uma estrutura colorida multicamadas, KATANA Zirconia ML foi o nosso primeiro produto da sua classe a oferecer as propriedades necessárias para a produção eficiente de restaurações de zircónia de contorno total com aparência natural. Antes de sua introdução, o conceito de “zircónia de contorno total” não era amplamente aceite devido às propriedades estéticas dos materiais de zircónia disponíveis até então: Muitos deles não tinham o nível de translucidez desejado, enquanto outros precisavam ser tratados com líquidos de tingimento ou stains em um procedimento complexo para obter uma aparência de tonalidade natural. Com o lançamento de blocos de zircónia multicamadas, que adicionaram com sucesso gradação de cor natural à estrutura, as restaurações estéticas de zircónia de contorno total começaram a tornar-se populares entre os técnicos de prótese dentária em todo o mundo. O alto potencial da tecnologia foi confirmado na feira IDS 2013, quando vimos não apenas utilizadores finais, mas também engenheiros de empresas concorrentes virem ver este produto.

Estrutura de cores de 4 camadas dos discos multicamadas KATANA.

Créditos das fotos para MDT Daniele Rondoni.

Que mudanças foram impulsionadas pela introdução do KATANA Zirconia ML?

Após a introdução do KATANA Zirconia ML, muitas empresas começaram a desenvolver discos de zircónia multicamadas, criando uma nova categoria de produtos odontológicos com valor técnico e clínico agregado. Estamos convencidos de que a invenção da Kuraray Noritake Dental desempenhou um papel importante na mudança da zircónia usada exclusivamente como material de estrutura para abordagens alternativas, incluindo restaurações de zircónia de contorno total. Se apenas discos de zircónia monocromáticos estivessem disponíveis, imaginamos que um número cada vez maior de técnicos dentários teria adotado o conceito de usar corantes líquidos para obter uma aparência natural de coroas e pontes de contorno total. Isso teria impedido que as restaurações monolíticas de zircónia se tornassem tão populares quanto são hoje.

Como a tecnologia KATANA Zirconia ML evoluiu nos últimos dez anos?

Com base em nossa tecnologia central exclusiva desenvolvida para inventar o KATANA Zirconia ML, continuamosa fazer esforços para criar produtos ainda melhores. Um dos grandes pontos fortes da Kuraray Noritake Dental é sua capacidade de desenvolver internamente todas as matérias-primas para os seus produtos de zircónia. Isso permitiu-nos ajustar os limites entre as camadas o mais discretamente possível, mesmo quando os discos consistem em várias camadas. Isso nos permitiu fornecer discos multicamadas com as qualidades estéticas e de resistência necessárias e com uma taxa de contração estável e previsível. Nos últimos dez anos, concentrámo-nos em adicionar novos materiais com diferentes níveis de translucidez e resistência para oferecer um portfólio que atenda às demandas de praticamente todos os técnicos de prótese dentária, profissionais e pacientes.

Por exemplo, o advento do KATANA Zirconia STML, que possui qualidades estéticas ainda melhores do que o KATANA Zirconia ML, tornou possível usá-lo sozinho para criar restaurações altamente estéticas, sem a necessidade de caracterizar ou individualizar as restaurações. Claro que, se usar discos multicamadas KATANA Zirconia e tratar as restaurações com um agente de coloração de superfície, como CERABIEN™ ZR FC Paste Stain, pode criar restaurações ainda mais estéticas em um tempo mais curto.

Quais são os benefícios da tecnologia multicamadas da Kuraray Noritake Dental, em comparação com as soluções de outros fabricantes?

Os discos multicamadas KATANA Zirconia oferecem a vantagem de fornecer a cor adequada mesmo quando são sinterizados em alta velocidade. Há duas razões para isso. Primeiro, desenvolvemos matérias-primas exclusivas com características adequadas para queima de alta velocidade. Isso permite a criação de restaurações com a mesma resistência, estabilidade e estética a serem alcançadas após a queima de curta e longa duração. A segunda razão é que possuímos o know-how técnico em matéria de excelente coloração que a Noritake Dental Supply, uma das predecessoras da Kuraray Noritake Dental, cultivou durante seus muitos anos desenvolvendo materiais cerâmicos. A Noritake Co., Ltd., empresa-mãe da Noritake Dental Supply, é um fabricante de cerâmica de longa data, famoso pela sua loiça de mesa e outros produtos excelentes. É esse histórico que nos permite controlar adequadamente a coloração do pigmento usando nosso know-how em pigmentos inorgânicos e fornecer programações de queima únicas. Esses dois pontos fortes permitem-nos trazer vantagens únicas aos nossos produtos. Ou seja, eles permanecem estáveis ​​e retêm a coloração apropriada mesmo em programas de queima rápida.

CERABIEN™ ZR FC Paste Stain sendo aplicado à restauração KATANA Zirconia.

Créditos das fotos para MDT Roberto Rossi.

Como conseguiu encurtar os tempos de sinterização de forma tão significativa, resultando em sua sinterização rápida com protocolos uniformes?

Quando tempos de sinterização mais curtos se tornaram possíveis, a Kuraray Noritake Dental recomendou que a KATANA Zirconia ML fosse sinterizada por sete horas. Depois disso, quando foi lançado um novo forno que afirmava ser capaz de queima rápida, utilizámo-lo para queimar o KATANA™ Zirconia ML numa base experimental. Descobrimos, felizmente, que o nosso material de zircónia era especialmente compatível com a queima rápida. Este foi o início da nosso estudo totalda queima de curta duração do nosso material de zircónia. Pode-se dizer que começamos a investigara queima de curta duração quase por acidente. Então, enquanto desenvolvíamos KATANA Zirconia STML e KATANA Zirconia UTML, sucessores de KATANA Zirconia ML, concentrámo-nos em incorporar a queima de curta duração nas suas características e fizemos vários ajustes, alcançando finalmente a combinação ideal de fatores para a queima de curta duração bem sucedida de zircónia.

Quais são os benefícios da tecnologia multicamadas de segunda geração da Kuraray Noritake Dental, em comparação com as soluções de outros fabricantes?

Uma vantagem do KATANA Zirconia YML é que ele pode ser aplicado para tratar uma ampla gama de casos sem limitações complexas de posição dentro do disco. O motivo: ele oferece esse alto nível de estética, mantendo grande resistência. Essa vantagem de ser adequado para uma gama maior de casos também simplifica a gestão de stocks. Além disso, os utilizadores beneficiam da nossa experiência no desenvolvimento de matérias-primas e na reprodução de cores com cerâmica. Essa experiência permitiu-nos desenvolver um produto de zircónia em que cada camada tem um nível diferente de translucidez, mantendo grande resistência e estética admirável em todo o bloco.

A recomendação de sinterização é apenas uma diretriz; alguns ajustes podem ser necessários dependendo de cada forno individual. Se o forno não puder ser ajustado de acordo com a programação de sinterização de 54 ou 90 minutos, a sinterização rápida não pode ser usada.

* As restaurações podem ser removidas a 800°C ou menos dependendo das circunstâncias.

** Para o cronograma de sinterização do KATANA™ Zirconia HT, consulte a tabela prática na embalagem do produto.

É realmente possível resolver todos os casos usando apenas KATANA™ Zirconia YML?

Para todos os casos que podem ser tratados com KATANA Zirconia STML, KATANA Zirconia UTML ou KATANA Zirconia HTML PLUS, KATANA Zirconia YML também é uma opção. Portanto, é possível usar apenas KATANA Zirconia YML para todos os seus casos de zircónia – o que provavelmente é uma das razões da sua grande popularidade. Possui grande resistência e excelente estética e, sendo tão versátil, ajuda a simplificar o a gestão de stocks. Obviamente, os outros materiais multicamadas da Kuraray Noritake Dental também apresentam propriedades excelentes. Dependendo dos recursos de que precisa, também seria uma opção selecionar entre esses produtos - KATANA Zirconia STML, KATANA Zirconia UTML ou KATANA Zirconia HTML PLUS – para realizar suas restaurações ideais.

KATANA Zirconia YML, finalizada com CERABIEN ZR.

Créditos das fotos para MDT Giuliano Moustakis.

Por que a marca KATANA em geral é tão popular entre os técnicos de prótese dentária em todo o mundo?

Acreditamos que os técnicos de prótese dentária escolhem o KATANA porque descobrem que podem criar restaurações altamente estéticas usando etapas simples e diretas.

Existe algum potencial de desenvolvimento adicional na tecnologia multicamada?

Com base em nosso know-how técnico, há sempre espaço para melhorias. É por isso que nunca paramos de inovar e ouvir a voz dos nossos clientes. Desenvolver o que os ajuda na melhoria de seus resultados, proporcionando procedimentos mais previsíveis e menos stressantes é o nosso objetivo final. No momento, esperamos desenvolver produtos com resistência ainda maior, maior translucidez e estética excepcional que tenham uma aparência natural semelhante a dentes reais, mesmo quando o material usado for zircónia de contorno total.

YOSHIHISA YAMADA

Pouco antes do KATANA™ Zirconia ML ser lançado no IDS em Colónia há dez anos, tive o prazer de ser convidado para o Japão. Nós visitamos as instalações de produção da KATANA Zirconia e aprendemos com Kazunobu Yamada e Takuro Nagura como o novo material funcionava. Até o momento, todas as zircónias dentais que usei eram brancas e bastante opacas.

Fiquei imediatamente impressionado com a complexidade do procedimento de produção, incluindo todas as medidas tomadas pela Kuraray Noritake Dental para fornecer um material extremamente alto e qualidade em branco. Os blanks pareciam ter uma estrutura multicamada extremamente homogênea e uma alta densidade responsável por bordas estáveis ​​e superfícies lisas. O que nos foi dito na fábrica foi confirmado por Kazunobu Yamada, que compartilhou sua experiência e nos mostrou vários casos full-contour. Fiquei agradavelmente surpreso com o fato de ele ser capaz de produzir resultados impressionantes sem adicionar nenhuma cor. Além disso, Kazunobu Yamada foi obviamente capaz de polir a superfície de suas restaurações em segundos. A superfície perfeitamente lisa nos permitiria evitar o uso de esmalte, que costuma desgastar muito rapidamente, deixando uma superfície potencialmente áspera que pode prejudicar o antagonista.

Com base no que aprendi no Japão, voltei para a Itália e comecei a experimentar o novo material incrível. Enquanto Kazunobu Yamada identificou o KATANA Zirconia ML como a solução para restaurações monolíticas na área posterior, comecei a usá-lo em todas as regiões da boca - com diferentes conceitos de design, desde contorno total até microcorte com microcamadas na vestibular área. A área de contato oclusal foi sempre mantida em zircónia lisa e polida.

Fig. 1. Exemplo inicial de restaurações anteriores feitas de KATANA Zirconia ML individualizadas com CERABIEN™ ZR usando a nova técnica de microcamadas.

Fig. 2. Projeto de redução possível.

Durante o período de testes, aprendi muito sobre a nova zircônia, tão diferente das gerações anteriores. O insight mais importante foi que as condições de processamento têm um grande impacto no resultado final. A Kuraray Noritake Dental forneceu suporte valioso, por ex. na forma de protocolos de sinterização e recomendações de processamento e acabamento. Isso me ajudou a desenvolver meu próprio fluxo de trabalho e conceito com base em um design de contorno completo na região posterior e diferentes opções de microcutback com microcamadas na região anterior. Para mim, esta é uma combinação perfeita do novo tipo de zircónia (KATANA) e o material de porcelana tradicional (CERABIEN ZR Luster Porcelain e Internal Stain).

Em maio de 2013, em uma reunião do Noritake Study Club em Florença, Itália, apresentei a nova abordagem pela primeira vez. Muitos colegas ficaram entusiasmados e começaram a adotá-lo. Enquanto outros desenvolvimentos como variantes de materiais mais translúcidos (cúbicos) e uma nova geração de zircónia multicamada com resistência à flexão e gradiente de translucidez aumentaram as opções de aplicação e o potencial estético, a microcamada tornou-se uma abordagem verdadeiramente popular usada por técnicos de prótese dentária em todo o mundo . Em 2016, foi reconhecido como um fluxo de trabalho relevante durante uma reunião fechada da European Academy of Aesthetic Dentistry.

Fig. 3. Superfícies de zircónia palatina perfeitamente polidas de restaurações anteriores.

Fig. 4. Caso mais recente mostrando um paciente que recebeu restaurações feitas de KATANA Zirconia STML …

Fig. 5. … finalizado com CERABIEN ZR Internal Stains e uma microcamada de CERABIEN Luster Porcelain LT1.

Mas qual é a principal razão para o sucesso do conceito e da zircónia multicamada com a KATANA Zirconia ML como pioneira? Na minha opinião, não deve ser implementado por maior simplicidade ou razões económicas, como se poderia supor à primeira vista. O tempo economizado no procedimento de estratificação deve ser gasto em outras tarefas, como texturização da superfície e um ajuste fino do procedimento de processamento. O benefício real é que o KATANAZirconia ML e seus sucessores permitem melhores soluções adaptadas às necessidades do paciente. Em primeiro lugar, eles nos permitem salvar a estrutura natural do dente, pois a espessura necessária da parede é reduzida. Eles também oferecem vantagens mecânicas, pois o lascamento é evitado e a área de contato oclusal permanece lisa ao longo do tempo. Em meu laboratório dentário, mudamos completamente nossos fluxos de trabalho e – preferindo uma abordagem mais conservadora sempre que indicado para o caso em questão – muitas vezes abandonamos a estratificação completa.

A KATANA Zirconia pode ser considerada uma grande contribuição para o fluxo de trabalho digital no laboratório e consultório odontológico, o que aumenta a eficiência dos procedimentos protéticos. Com a série KATANA Zirconia Multi-Layered, é fácil cumprir nossa promessa de oferecer a melhor qualidade e estética possíveis. A razão é que os materiais nos apoiam de maneira ideal, oferecendo a combinação perfeita de tradição e inovação.