Conventional Cementation Vs. Adhesive Luting

Proper luting of indirect restoration is critical in achieving long-term success as it highly influences the retention of the restoration.

With the availability of different types of cements, the decision of choosing the suitable luting agent and method can be confusing for the practitioner. Especially with the wide use of contemporary restorative materials such as new generations of highly translucent zirconia as well as reinforced-composites, it is important to take into consideration that the properties of such materials differ highly from metal or earlier generations of zirconia.

Subsequently, the choice of the luting agent must be appropriate to achieve satisfying results and long-term success. Therefore, the aim of this online seminar is to provide insights for the clinicians on choosing the correct luting agent that can help achieve satisfactory results for the dentist as well as the patients.

Dr Adham Elsayed

• PhD degree in Prosthodontics and Implantology from the University of Kiel, Germany
• Certified Specialist in Prosthodontics, German Society for Prosthetic Dentistry and Biomaterials (DGPro)
• Certified Specialist in Implantology, German Society for Implant Dentistry (DGI)
• Clinical & Scientific Manager DACH, Kuraray Europe GmbH

Conventional Cementation Vs. Adhesive Luting

Proper luting of indirect restoration is critical in achieving long-term success as it highly influences the retention of the restoration.

With the availability of different types of cements, the decision of choosing the suitable luting agent and method can be confusing for the practitioner. Especially with the wide use of contemporary restorative materials such as new generations of highly translucent zirconia as well as reinforced-composites, it is important to take into consideration that the properties of such materials differ highly from metal or earlier generations of zirconia.

Subsequently, the choice of the luting agent must be appropriate to achieve satisfying results and long-term success. Therefore, the aim of this online seminar is to provide insights for the clinicians on choosing the correct luting agent that can help achieve satisfactory results for the dentist as well as the patients.

Dr Adham Elsayed

• PhD degree in Prosthodontics and Implantology from the University of Kiel, Germany
• Certified Specialist in Prosthodontics, German Society for Prosthetic Dentistry and Biomaterials (DGPro)
• Certified Specialist in Implantology, German Society for Implant Dentistry (DGI)
• Clinical & Scientific Manager DACH, Kuraray Europe GmbH

Fig. 1. Initial situation: caries lesions and insufficient restorations are detected on the occlusal surface of the second molar.

Fig. 2. Situation after placement of rubber dam for moisture control.

Fig. 3. Appearance of the teeth following caries removal and placement of sectional matrix.

Fig. 4. Etch-and-Rinse technique (Enamel for 30 sec. and Dentin for 15 sec.).

Fig. 5. Situation after rinsing. Etch patterns are visible in the enamel.

Fig. 6. Appearance of the teeth following application of CLEARFIL™ Universal Bond Quick.

Fig. 7. Cavity lining with a layer of flowable composite (CLEARFIL MAJESTY™ ES-Flow Low, A2).

Fig. 8. Occlusal view of the final restorations produced with CLEARFIL MAJESTY™ ES-2 Universal (U shade).

Fig. 9. Situation after rubber dam removal and occlusal adjustments.

FINAL SITUATION

Fig. 10. Follow-up after 7 days.

Sometimes, you need it runny so that it flows into every corner or undercut, and sometimes, you need it to stay put where applied or malleable to create a specific shape. It is difficult to cover every flowable composite indication with a single viscosity. That is why Kuraray Noritake Dental Inc. offers CLEARFIL MAJESTY™ ES Flow with three different levels of flowability: High, Low, and Super Low. The level of flowability is selected depending on the indication, and the geometry and size of the cavity. For example, the high-flowability option is best suited as a cavity liner, while the super low flowability variant is preferable in the context of composite veneering.

However, the material has much more to offer, as confirmed by the consultants of the Dental Advisor who have honored the product with an Editors’ Choice and a Top Product Award for the sixth time in a row (Volume 38, Number 01, January-February 2021).

The 29 Dental Advisor consultants tested the medium flowability variant (Low) of CLEARFIL MAJESTY™ ES Flow in their dental practices. They assessed the product’s performance regarding placement/handling, esthetics, viscosity and polishability. All four properties received an “excellent” rating. CLEARFIL MAJESTY™ ES Flow Low shows no running during placement, while it offers a good adaptation to the cavity walls and even flows into narrow areas. Kuraray Noritake Dental Inc.’s Light Diffusion technology provides that the material integrates seamlessly with the surrounding tooth structure and a glossy surface is obtained simply by wiping with a cotton roll soaked in alcohol.

Due to these properties and a convincing overall performance, the product received a 98 percent rating, and all 29 consultants stated that they would recommend CLEARFIL MAJESTY™ ES Flow to a colleague. Since 2015, the product has won the Top Product Award time and again, and with its three viscosities, it is likely to be the product of choice for an even broader range of indications.

Case by Francesco Ferretti and Marco Nicastro

Aesthetic restoration of anterior teeth using KATANA™ UTML Full anatomical crowns, with vestibular stratification and BOPT*¹.

^{*1 Biologically Oriented Preparation Technique}

Initial situation

Final result

Shows excellent aesthetic properties of KATANA™ UTML and the perfect integration in harmony with pink tissues.

Figure 1. The patient requested a solution for an aesthetic problem due to unnatural look of old restorations and black triangles coming from past history of periodontitis. The resulting retraction of the tissues had left the margins of the prosthesis clearly visible, and the loss of the papilla peaks, together with the numerous black spaces between the crowns, required a complex therapeutic approach.

Figure 2. The treatment plan for the periodontal problems con-sisted of a non-surgical approach, with scaling and root planing, and the replacement of the previously fixed prostheses to recondition the marginal tissues and facilitate the restoration of a new, aesthetically pleasing gingival architecture.

Figure 3. From a functional point of view, we decided to reduce the deep frontal bite to restore a correct overjet-overbite ratio. This reduction was also important from an aesthetic point of view, as it allowed us to shape the various elements correctly.

Figure 4. We usually remove old prostheses before beginning a periodontal treatment, and make a first, provisional restoration to create an environment in which the soft tissues can heal. If we have to work beyond the cement enamel joint (CEJ), we prefer a vertical preparation for posts, and the purpose of the provisional restoration is to condition the marginal tissues using Dr. Loi’s BOPT.

Figure 5. For the BOPT, the vertical preparation of the post has a finish line that extends inside the gingival sulcus. The temporary conditioning of the tissues induced by the provisional prosthesis allows us to modify the level of the gingival parables to a certain extent.

Figure 6. The image on the left shows the clinical healing of the tissues one month after the initial periodontal treatment. The role of the provisional restoration, appropriately realigned, is clear. The conditioning of the tissue has been achieved by means of the provisional restoration, which has modified the level and shape of the marginal tissue. Once filled with correctly fitted crowns, the interproximal spaces will be further reduced after the definitive restoration.

Figure 7. The correct management of the provisional restoration is crucial for the healing of the tissues. The placement of a provisional restoration before the periodontal therapy has allowed us to create the right environment for complete healing. At the same time, the vertical preparation has allowed us to gradually condition the marginal gingival tissue by shortening or lengthening the provisional restoration as necessary.

Figure 8. One of the advantages of a vertical preparation is that taking the final impression is easy, because the absence of a horizontal finish line greatly simplifies the procedure. On the other hand, the BOPT also requires the taking of an impression of the sub-gingival portion of the preparation. The dental technician will have to decide marginal shape of restorations according to the position of the gingival line in consultation of the clinician, and based on the tests conducted with the provisional restoration.

Figure 9. After the casting of the model, we prepared the gingival area to accommodate an ideal configuration of gingival parables.

Figure 10. After making a wax model, we assessed whether the height of the gingival zenith level could be further corrected. This photo shows that gingival level of 21 was not yet ideal, so we stretched it distally.

Figure 11. Once the wax model was complete, we extracted the element from the model and evaluated its protrusion. It was only after joining the gingival protrusion to the arbitrary margin of the preparation that we proceeded to a scan and milled the crowns.

Figure 12. The restoration was carried out with Katana™ UTML zirconia based on the new formulation of cubic zirconium oxide. This ultra tralucent material was chosen because we were working with light and non-discolored posts.

Figure 13. We finished the crowns on a positional impression to help to improve the gingival adaptation; we had some dispersion of the tissues in the first precision impression due to the use of retractors. We finished the crowns with CZR FC Paste Stain colours and glaze.

Figure 14. The surface colours and the slight contrast created are highlighted in this black-and-white image taken with a blue filter.

Figure 15. In this translucent image, we can see the natural translucent effect of KATANA™ UTML and invisible fusion between abutments and crowns.

Figure 16. Clinical image one year after cementation made with PANAVIA V5; this shows the good clinical condition of the marginal tissue, with no signs of inflammation or bleeding. The BOPT allowed us to optimise the level of the gingiva without resorting to periodontal surgery, while the shape of the new crowns has made it possible to close all interproximal spaces for an optimally aesthetic result.

Figure 17. The brightness of the restorations (thanks to the use of a particularly translucent zirconia) combined with the shape of the incisors, has greatly im-proved the aesthetic of the restoration, even though the condition initially appeared to be particularly unfavourable.

Figure 18. Compared to the previous prostheses, the incisal reduction allowed not only for the optimisation of the functional phase by reducing the overbite, but also made it possible to achieve a more natural aesthetic, with the contour of the incisal margins following that of the lower lip.

Dentists:

FRANCESCO FERRETTI

Born in Rome on 15th March 1957, Francesco Ferretti gets his degree as dental technician at the Institute “Edmondo de Amicis”, in Rome. In 1980, he starts working and, from 1987 to 1994, he cooperates with IVOCLAR VIVADENT giving consulting as ceramist. In 1992 he starts working exclusively with Prof. Mario MARTIGNONI.

• After one year cooperation with Prof. Martignoni, he starts working with the ORAL DESIGN CENTER founded in Rome by Mr. Willi Geller, and becomes a partner, improving prosthesis esthetics.
• Is registered outside the course of dentistry at the University of Rome Tor Vergata.
• In 2001, he founds ESTECH DENTAL STUDIOS, in cooperation with Pentron for technical training and consulting.
• He has published articles and studies in Italian and American magazines. He is interested in Metal Free techniques.
• Winner of the 2004 Polcan Aiop.
• He is a member of: ANTLO LAZIO ( National Association of Lab Owners) with the president of the Lazio region 2013-2014.
• National cultural manager ANTLO 2017-2020.
• Teacher of prosthetics perfectioning at the University of Chieti for the year 2002, he has been re-confirmed for the year 2003, 2004, 2005 to deal with Metal Free.
• Teacher of prosthetics perfectioning at the University of Naples 2006.
• He has participated as a speaker at numerous conferences in Italy. ESCD member has participated as a speaker at ten in Florence 2009 and Turin 2013.

MARCO NICASTRO

Marco Nicastro takes a degree in “Odontoiatria e Protesi Dentaria (Dentistry and Dental Prosthesis) at the University of Rome “ La Sapienza in 1989. Since the beginning he is interested in prosthesis restoration dentistry and aesthetic problems.

• From 1990 to 1996 he attends Prof. Martignoni’s studio, where he develops his prosthesis knowledge.
• From 1993 to 1998 he cooperates as lecturer with the Oral Design Centre in Rome, directed by Mr. Ferretti and Mr. Felli, giving lectures and courses about aesthetic restoration either in Italy or in foreign countries. In the same period he enlarges his experience in aesthetics, attending training courses at the University of Geneva, in Switzerland.
• Since 1993 he has been cooperating with Mr. Francesco Ferretti in the organization of Courses and Conferences, paying particular attention to metal free methodology.
• Vice President of the European Society of Cosmetic Dentistry (ESCD).
• Founding member and active member of Gimnasium interdisciplinary CAD-CAM (GICC).
• Active member of the Italian Society of Conservative Dentistry (SIDOC).
• Partner of the Italian Academy of Prosthetic Dentistry (AIOP).
• President of Like Mine Dental Education in Rome since 2001.
• He won, with Francesco Ferretti, the Polcan award of the Italian Accademy of Prosthetic Dentistry in 2004.

With so many different adhesives, cements, and restorative materials available on the dental market, it seems difficult to decide which products are best suited to fulfill the individual requirements. A direct comparison obtained through testing of all products in the dental office is simply impossible due to the great number of available solutions. Laboratory investigations provide information about specific product properties, but usually cannot create the overall picture. Moreover, the results of different tests are barely comparable due to variations in test conditions. Clinical study results are very useful as they shed light on clinical (long-term) performance of selected materials, but they are usually published years after a product’s launch. Hence, they are not available in the early stages. A great source of information are practice-based evaluations, as they support potential users in identifying high-quality dental materials.

One of the institutions conducting and publishing practice-based clinical evaluations and product performance tests is the US-based DENTAL ADVISOR. Once per year, the dental materials and equipment with the best performance receive a Top Product or Preferred Product Award. The list of winners is published online (www.dentaladvisor.com) and in the January-February issue of the DENTAL ADVISOR. In 2021, numerous products from Kuraray Noritake Dental Inc. were among the award winners.

Top Product Awards

CLEARFIL™ SE Protect received a Top Product Award in the category Direct Restoratives, Bonding Agent: Self-Etch. The self-etch adhesive is based on the formulation of the gold standard two-step self-etch adhesive CLEARFIL™ SE BOND but contains an extra MDPB monomer offering an antibacterial cavity-cleansing effect and fluoride for long-term fluoride release. The honoring of the DENTAL ADVISOR is based on a material test carried out by 13 DENTAL ADVISOR consultants and editors in their dental offices for six weeks. Due to its excellent performance, the antibacterial self-etch adhesive received a 98 percent clinical rating.

For the sixth year in a row, the Top Product Award in the category Direct Restoratives, Composite: Highly Filled Flowable went to CLEARFIL MAJESTY™ ES Flow.

The universal flowable composite that also became the Editor’s Choice comes in three different levels of flowability, from high to super low*. This enables the user to choose the right viscosity for every clinical situation – with the high flowability variant being the perfect choice for cavity lining and as a resin coat in IDS procedures, and the super low flowability option being specifically suited for direct veneer procedures and even for build-up of posterior cusps etc. The universal flowable composite was tested by 29 consultants of the DENTAL ADVISOR in more than 900 clinical applications. The evaluated properties – placement/handling, aesthetics, viscosity and polishability – were rated “excellent”. This led to a recommendation rate of 100 percent and a 98 percent overall clinical rating.

^{*DENTAL ADVISOR evaluated only the standard level of flowability (Low), because other two variants are not available in US.}

A product that earned recognition from the Dental Advisor for the seventh time already is TEETHMATE™ DESENSITIZER for hypersensitivity treatment.

The product that won a Top Product Award this year was designed to create hydroxyapatite (HAp), which is able to occlude open dentinal tubules and enamel cracks. This leads to a significant reduction of hypersensitivities when applied to exposed, mechanically treated or freshly prepared dentin. When used in the context of restorative treatment, TEETHMATE™ DESENSITIZER does not have a negative effect on the bond strength of dental adhesives or cements. A six-month clinical evaluation conducted by the DENTAL ADVISOR involving 27 patients with gingival recession-related hypersensitivity revealed that the use of the product is very effective in providing immediate and even long-term (six-months) hypersensitivity relief. This resulted in an excellent rating with a score of 96 percent.

In the category Self-Adhesive Cement, an additional Top Product Award went to PANAVIA™ SA Cement Plus. The dual-cure self-adhesive resin cement stands out due to its ease of use, favorable viscosity and an easy excess removal feature after tack-curing.

Preferred Products

Among the 2021 Preferred Products that also received an Editor’s Choice label is PANAVIA™ SA Cement Universal. The Top Product Award winning self-adhesive universal resin cement from 2020 contains the unique LCSi monomer. This monomer is a silane coupling agent, which has a unique long carbon chain in its molecule. This carbon chain establishes a durable, chemical bond with porcelain, lithium disilicate and composite resin without the need for a separate silane containing primer. The other key technology present in the formulation is the original MDP monomer, which ensures chemical reactiveness with zirconia, dentin and enamel. Together, the technologies ensure that PANAVIA™ SA Cement Universal produces a strong and durable bond with virtually every restorative material without the need for a separate primer. Its handling characteristics, aesthetics and gingival friendliness received very good to excellent ratings from 31 clinical evaluators, who used the cement in 516 applications. The result of the overall clinical rating was 96 percent.

Moreover, CLEARFIL™ Universal Bond Quick was honored as a Preferred Product by the Dental Advisor consultants for the second consecutive year.

The universal bonding agent may be applied using the self-etch technique or – together with K-ETCHANT syringe – in the selective enamel etch or total-etch technique. Containing our rapid bond technology – a combination of the original MDP monomer with innovative hydrophilic amide monomers – the adhesive works instantly and without the need for extended exposure times, application of multiple layers or extensive rubbing into the tooth structure. The fast and easy application procedure was one of the main reasons for the consultants of the DENTAL ADVISOR to select CLEARFIL™ Universal Bond Quick as a Preferred Product and Editor’s Choice with a 98 percent score in a clinical evaluation.

Finally, CLEARFIL™ CERAMIC PRIMER PLUS became a Preferred Product in 2019, 2020 and 2021, and an Editor’s Choice in 2021. It contains the original MDP monomer and a silane monomer, which ensure excellent bond strength to all kinds of restorative materials, i.e., to silica-based ceramics, zirconia, composites and even metals. Users benefit from procedural simplicity as the product is just applied and dried to the bonding surface after the recommended pretreatment. In a clinical evaluation, the product received a recommendation rate of 96 percent and a 96 percent overall score from the DENTAL ADVISOR consultants.

Conclusion

Most of the Kuraray Noritake Dental products that received an award this year are based on resin technologies, one of our key competencies. In the 1980s, we developed the original MDP monomer, a functional monomer, which is an essential component of any adhesive product we introduced down to the present day, including the award-winning CLEARFIL™ SE Protect, PANAVIA™ SA Cement Universal, CLEARFIL™ Universal Bond Quick and CLEARFIL™ CERAMIC PRIMER PLUS. This is only one of our many areas of expertise. We also provide users with preventive products and a whole range of restorative materials – from composite filling materials like CLEARFIL MAJESTY™ ES Flow to dental ceramics like KATANA™ Zirconia UTML, STML and HTML. We see the winning of the awards as a positive proof of a reliable product performance that supports dental practitioners in reaching their own goals.

Interview with Dr Imad Ghandour

In recent years, zirconia has emerged as the preferred choice for dentists who wish to perform restorative procedures with a reliable and metal-free material. With the recent development of multi-layered aesthetic high-translucency options, zirconia’s popularity has further increased. In comparison to the opaque whiteness of older generations of zirconia, these newer versions have an enhanced appearance and functionality that makes them suitable for natural-looking anterior restorations.

Kuraray Noritake Dental’s KATANA Zirconia disc range is made with a proprietary zirconia powder - processed in-house - that gives it its natural appearance. Suitable for zirconia prostheses, from single crown to full arch, it is an ideal option for restorations in both the anterior and posterior regions. We spoke with Dr Imad Ghandour, a prosthodontist with a strong scientific background and a private practice in Le Cannet in France, about his experiences with the KATANA Zirconia range in restorative procedures.

Dr Ghandour, when did you first start using zirconia as a material for your restorations?

In 1998, when I was still sintering manually, I began using zirconia alumina. It was nice to have an alternative to metal alloys that was much more aesthetic. From 2003, however, I started with VITA blocks, but only for frameworks - I would still build up with ceramics. Now, with so much of dentistry being digitally focused, there is a need for a material that can be milled without changing anything in the morphology of the teeth. Why? Because we need to be able to reproduce the treatment plan as accurately as possible. Simply put, the KATANA Zirconia range solves this need for me.

With respect to dentistry being digitally focused, how has this changed the role of the dentist regarding performing restorative procedures?

Well, it is clear that we have entered the age of digital dentistry. Around 80 per cent of restorations are conducted via CAD/CAM systems and without dentists even touching the materials themselves. There are great advances being made in the technologies that are available for everyday use in dental practices worldwide, and many of them can be used to assist dentists performing restorative procedures. It is important, though, to keep in mind that these technological advancements alone will not lead to better results - they should supplement the requisite hands-on skills and techniques that all dentists must first learn. With this base of fundamentals, we can then use digital dentistry to make restorative procedures more predictable and reproducible. Of course, to ensure the best results in restorative procedures, dentists also need to use the materials that have the best aesthetic and mechanical properties.

For how long have you been using Kuraray Noritake Dental’s KATANA Zirconia range, and what has your experience been?

I have been using KATANA Zirconia for a little bit more than one year. In that time, I have primarily used the KATANA Zirconia STML (Super Translucent Multi Layered) line and have been pleasantly surprised by how natural-looking the restorations I have made with the material are. For example, when I sinter a crown made of Katana Zirconia STML, I am amazed at how much the sintered material is reminiscent of a pearl - it truly brings to mind the idea of one’s teeth being one’s pearly whites.

When using KATANA, how do you ensure that you select the correct shade to achieve a natural look?

Firstly, no one - not a dentist nor a dental technician - can be absolutely certain that the shade and chroma of the restoration that is in one’s hand will be the same once it is in position in the oral cavity. This is due to the complexities of the oral environment - the pinkness of the gingivae, for one, can have a large impact on how the restoration appears, often making it seem far duller than it does in the light of a dental laboratory. This can cause dental practitioners to compensate and make prostheses that appear far brighter than they will when they are in place.

With a product like KATANA and its related glazing materials, however, I can create crowns and other restorations that have an optimal fluorescence and translucency and are able to maintain their shading better than any other ceramic material I have used. I am able to select a shade with the confidence that it will look exactly the same once placed inside the mouth, with its chroma remaining unabsorbed by the gingiva. Achieving a natural look, then, depends on choosing a shade that is as close to that of the surrounding dentition as possible. Since KATANA Zirconia UTML (Ultra Translucent Multi Layered) is available in 16 standard shades and a further four enamel shades, there is no shortage of options in this regard.

How does the multi-layered technology of KATANA Zirconia help you to achieve optimal and natural-looking aesthetic results?

Well, firstly, the layering of the material is designed to replicate the colour and translucency progression of natural teeth, which allows for restorations to blend in as much as possible. This multi-layered technology has also proved itself to be very handy when I am sintering crowns made of KATANA Zirconia. Simply put, if one sinters a crown quickly, it will be a little more opaque. If one sinters it at a higher temperature and quite slowly, it will be much more translucent. The multi-layered aspect of KATANA Zirconia is excellent in that it gives me the ability to make restorations more or less translucent depending on what is required.

With 40 years of success in the commercial dental products market, Kuraray Noritake Dental has firmly established its commitment to providing leading-edge solutions for adhesive dentistry. The 1983 introduction of the PANAVIA™ EX resin cement, which utilized Kuraray’s original MDP monomer technology, set the industry standard for adhesion and has continued to do so for over 30 years since. With PANAVIA™ V5, and PANAVIA™ SA Cement Universal which is the latest addition to PANAVIA™ family, Kuraray Noritake Dental presents a pair of resin cements designed for strong, durable bonding for zirconia-based and other restorations.

PANAVIA™ V5

PANAVIA™ V5 is a resin cement with exceptional procedural simplicity and predictability. It sets a new standard for adhesion to the KATANA™ Zirconia Block or other zirconia, allowing for self-cure dentine bond strengths equal to our gold-standard light-cure bonding agent, CLEARFIL™ SE BOND. PANAVIA™ V5 offers natural aesthetic stability in shading through its amine-free paste, which is available in five shades and has been scientifically proven to demonstrate a lower level of post-curing colour variance than other cements.

PANAVIA™ SA Cement Universal

PANAVIA™ SA Cement Universal is a forerunner in self-adhesive resin cements that adheres virtually to all materials including glass ceramics. The original silane coupling agent, LCSi monomer, incorporated in the paste creates a strong chemical bond to porcelain, lithium disilicate and composite resin. Available in an automix or handmix option, its high concentration of MDP monomer allows for increased chemical reactiveness with zirconia, which, combined with mechanical retention created by sandblasting, has been demonstrated as crucial for durable bonding to this material. Building upon the success of our PANAVIA™ SA Cement Plus, it offers a wide range of indications for adhesion and is suitable for crowns/bridges, inlays/onlays, posts, and even adhesion bridges.

By Peter Schouten, Technical Manager Kuraray Europe Benelux

Kuraray Noritake’s self-adhesive cement series, PANAVIA™ SA Cement Universal, has evolved through several stages of development since it was first introduced as “CLEARFIL™ SA Cement”. Over time, various improvements have been implemented, bringing us to our latest product: PANAVIA™ SA Cement Universal. Improvements include: strengthening of the bonding power to dental tissue, increasing the storage temperature to room temperature and extending the shelf life to three years. What remained the same - the easy removal of any excess cement, the moisture tolerance and the integration of the original MDP monomer.

The original MDP enables PANAVIA™ SA Cement Universal to be bonded to dental tissue as well as to metals and zirconia ceramics. Until recently, the chemical bonding of glass-based materials such as porcelain, glass ceramics, including lithium disilicate, and composite, was only possible with an additional silane-based primer.

With the introduction of PANAVIA™ SA Cement Universal the silanisation step has become redundant. Instead, the silane has been incorporated into the PANAVIA™ SA Cement Universal paste. As a result, there is only one single universal procedure, without the need for separate primers.

LCSi

Adding silane to the paste sounds easy. However, there are some limiting factors. For example, keeping silane in the form of γ-MPS (γ-methacryloxypropyltrimethoxysilane) active for a long time is a challenge. This is partly due to γ-MPS’ hydrophilic nature. Contact with water under acidic condition results in hydrolysis of alkoxy groups of silane. Therefore, it is best to use a more hydrophobic and thus stable silane and to avoid bringing it into contact with water and acid prematurely.

We have been using a long-chain silane (LCSi) for some time in a number of our superior composites, such as CLEARFIL™ MAJESTY™ Posterior and CLEARFIL™ MAJESTY™ ES Flow. However it’s the first time we have used it in a cement.

This unique silane has long hydrocarbon spacer (the hydrocarbon chain between the silanol group and the methacrylate group) which makes it more hydrophobic and stable than the small γ-MPS molecule. The reaction with the silica particles in the glass-based materials is expected to be also more orderly and faster. The result is a more optimally bonded surface with a greater resistance to hydrolysis.

A great deal of thought has gone into combatting the degradation of silanes in PANAVIA™ SA Cement Universal. It was decided to separate the more hydrophilic components from the hydrophobic ones so they only come together when the paste is mixed. This is why we are able to achieve a three-year shelf life, even when stored at room temperature.

Research

It’s not only in-house data that show comparable or even better bonding of PANAVIA™ SA Cement Universal to glass-based materials, than with its previous version, PANAVIA™ SA Cement Plus, in combination with CLEARFIL™ CERAMIC PRIMER PLUS. The first results from independent research are also strongly supporting this.

With PANAVIA™ SA Cement Universal, there is now a self-adhesive resin cement on the market that allows virtually all indirect materials to be bonded directly without the intervention of primers or bonding.

Case by Aleksandra Łyżwińska, DMD

This clinical case concerns a patient with a lesion on the occluso-distal aspect of the mandibular left first premolar. We opted for a direct treatment approach with a combination of flowable and high-viscosity composite resin (CLEARFIL MAJESTY™ ES Flow - Super Low A2, CLEARFIL MAJESTY™ ES-2 Classic A2). In order to establish a strong bond between the tooth structure and the restorative material, we decided to selectively etch the enamel and then apply a clinically proven self-etch adhesive (CLEARFIL™ SE BOND 2).

Fig. 1. Initial clinical situation.

Fig. 2. Appearance of the premolar after caries removal.

Fig. 3. Placement of a sectional matrix for anatomical shaping, the establishing of tight interproximal contacts and protection of the adjacent tooth.

Fig. 4. Appearance of the tooth structure after selective enamel etching.

Fig. 5. Interproximal wall built up with CLEARFIL MAJESTY™ ES-2 Classic (A2 shade) and cavity filled with CLEARFIL MAJESTY™ ES Flow - Super Low A2.

Fig. 6. After initial polishing.

FINAL SITUATION

Fig. 7. Occlusal view of the treatment outcome after finishing and polishing.

Fig. 8. Follow up after 1 week.

Dentist:

ALEKSANDRA ŁYŻWIŃSKA
Warsaw, Poland

Aleksandra Łyżwińska, DMD, is a passionate aesthetic and adhesive dentist. Driven by Evidence Based Dentistry, her goal includes using modern composite materials and bonding agents in her clinical practise. In addition to her primary job, she worked as a lecturer and an assistant professor at the Department of Conservative Dentistry and Endodontics of Medical University of Warsaw, her alma mater.