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Steve Meeze definitely has it: a passion for dentistry. Yet, there was a time when he was unhappy in his job as a dental practitioner. Fundamental changes were necessary to lay the foundations for finding personal fulfillment in his work. We spoke to him about his motivation to do things differently and about the path he has chosen and is following down to the present day.

Many students of dentistry would like to run their own dental office one day. For you, this dream came true, but you ultimately decided to take a different path. Why did this change seem necessary?

After graduation in 1983, running my own dental office seemed to be a great plan: I wanted to be independent, grow my patient base, and become successful, which went very smoothly in the beginning. This economic success, however, did not protect me against starting to feel unhappy and burned-out after several years. Once I began to take my negative emotions seriously and to search for the underlying causes, I realized that is was not merely the workload that troubled me. The truth was that I was missing a sense of purpose in many of my daily tasks. This seemed to be the reason for my lack of energy and motivation to proceed with what I had started. Luckily, I was able to find my personal “why” after some time.

Where did you find your own fulfillment or sense of purpose?

I ultimately found it in the field of conservative dentistry. The reason is that direct restorative treatments with composite allow me to do amazing things in a non-invasive or minimally invasive way. Doing no harm and always being able to go back simply feels good, and my patients are incredibly grateful for what I do. Their gratitude is my reward. This is why I decided to dedicate myself exclusively to treating patients with composite.

How do you do this?

In 2009, I sold my own dental office and started working in different practices in Flanders. In this process, I established some highly valuable partnerships with colleagues, who appreciate my skills and refer their patients to me mainly in the course of interdisciplinary treatment. These orthodontists or surgeons need someone who puts the finishing touches to their work. And this is exactly what I do: I create a beautiful smile at the end of an often complex treatment. Other patients approach me on their own accord with fractured or misshaped teeth and the desire for esthetic improvement. In any case, I listen to them carefully before I start planning. Knowing what is on their minds, I can treat them with confidence. The most precious moment for me is when I hand over the mirror and let them evaluate my work. Their positive reaction, the glint in their eyes is what motivates me every day.

Is there a specific technique you use in your daily work?

Yes, I use the Light Facing Concept I developed to solve esthetic issues in the anterior region. This technique focuses of creating a harmony without the need to sacrifice large amounts of healthy tooth structure. With this concept, a fractured anterior tooth, for example, is restored in three steps: Initially, a single dentin shade of composite of the same color as the fractured tooth is used to create the desired tooth shape and make the fracture line disappear. In this step, shade selection is independent of the final color I would like to reach. Subsequently, I correct the color with an opaque material and try to match the shade of the adjacent teeth as exactly as possible. If necessary, I create mamelons and other individual characteristics in this layer. The final step is carried out on all anterior teeth whenever the appearance of the treated tooth differs from the others: A light facing – i.e. a very thin layer of more or less translucent composite – is added to mask the differences. In cases with minimal shade differences, a composite with a high translucency is used, while a more opaque material is preferable whenever the differences are more apparent.

What is your preferred material for the Light Facing Concept?

My personal experience shows that the best results are obtained with CLEARFIL MAJESTY ES-2 Premium composite from Kuraray Noritake. It simply offers the best mimetic (chameleon) effect of all composite materials I have tested so far, and I have tested many of them. The material tends to blend in with the surrounding tooth structure, and only four shade combinations are usually sufficient to cover the whole range of my patients’ tooth shades. I love this virtually magical effect!

What is your personal conclusion?

When I made the decision to start doing what really makes me happy, I could not be sure that I had chosen the right path. Retrospectively, I know that giving up my present career and taking steps towards personal fulfillment has been exactly the right thing to do. I love the fact that I can satisfy my patients’ desires without sacrificing healthy tissue, and my Light Facing Concept implemented with MAJESTY ES-2 make it easy for me to obtain the results they have been dreaming of.

CASE EXAMPLES

Fig. 1 : Case example: Color change with composite – initial clinical situation.

Fig. 2.: Case example: Color change with composite – treatment outcome.

Fig. 3: Case example: Shape correction with composite – initial clinical situation.

Fig. 4:  Case example: Shape correction with composite – immediate treatment outcome.

Combining ease of use and excellent viscosity, CLEARFIL™ CERAMIC PRIMER PLUS is a stable and universal prosthetic primer designed for all restorations. By incorporating Kuraray Noritake Dental’s original MDP monomer and a silane monomer, it is able to provide an enhanced adhesive surface for ceramics, hybrid ceramics, composites and even metals. CLEARFIL™ CERAMIC PRIMER PLUS is best used in conjunction with the adhesive resin cement PANAVIA™ V5 to ensure durable restorations.

The key to CLEARFIL™ CERAMIC PRIMER PLUS’s performance is in the monomers it possesses. The MDP monomer strongly bonds to metals and zirconia, while the silane coupling agent MPS efficiently adheres to composites and all silica-based ceramics. “What makes CLEARFIL™ CERAMIC PRIMER PLUS different to other primers is its stability,” says Peter Schouten, Technical Manager at Kuraray Noritake Benelux. “Normally, activated silanes are very unstable. However, the well-balanced formula of CLEARFIL™ CERAMIC PRIMER PLUS provides it with a shelf life of three years after production, making it easy and predictable to use.”

Procedural simplicity

Every element of CLEARFIL™ CERAMIC PRIMER PLUS is designed to deliver maximal procedural simplicity. It is packaged in an easy-to-squeeze bottle that dispenses the solution easily and accurately. Whereas other similar products need to be left in place for one minute or more, this primer is immediately effective upon application. “CLEARFIL™ CERAMIC PRIMER PLUS benefits the dentists by offering a reliable primer for all materials, without being difficult to apply or use,” says Schouten. “From titanium to zirconia, from lithium disilicate to composite—simply apply and dry, and you're done.”

PANAVIA™ V5

A resin cement with unrivalled procedural simplicity and predictability, PANAVIA™ V5 is a member of Kuraray Noritake Dental’s PANAVIA family. It sets a new standard for adhesion, 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 amine-based cements.

CLEARFIL™ CERAMIC PRIMER PLUS and PANAVIA™ V5

Providing strong bonding to not just hydroxyapatite, but to metals and zirconia as well, PANAVIA™ V5 is designed for use in conjunction with CLEARFIL™ CERAMIC PRIMER PLUS. The cementation procedure is efficient and effective: use PANAVIA V5 Tooth Primer for the pretreatment of the tooth, CLEARFIL™ CERAMIC PRIMER PLUS for the priming of the restoration, and PANAVIA™ V5 for the cementation.

NOW 18 Minutes Sintering using the CEREC SpeedFire

KATANA™ Zirconia Block, the innovative multi-layered zirconia block^*1, can be used with Dentsply Sirona's CEREC system^*2. Now the 18 minutes sintering program^*3 is developed and installed into CEREC SpeedFire. New sintering technology makes it possible to fabricate full zirconia restoration in approx. 35 minutes.

An ideal composite material should satisfy three basic requirements: function, aesthetics and biocompatibility. A member of the CLEARFIL MAJESTY family, Kuraray Noritake Dental’s CLEARFIL MAJESTY™ ES Flow combines excellent handling, polishability and mechanical strength to provide a solution for all cavity classes. This universal flowable composite employs silane and filler technologies to maximise both its procedural and aesthetic outcomes, allowing dentists to create long-lasting restorations with reduced chairside time.

A new standard for flowable composites

Traditionally, a composite’s flowability has been inversely related to its filler content. When flowable composites were first introduced in the mid-1990s, their lower viscosity was enabled by a filler level much lower than that of conventional composites. This, however, meant that these flowables fared poorly in a clinical setting, demonstrating inferior mechanical properties when compared to traditional hybrid composites.

With CLEARFIL MAJESTY™ ES Flow, dentists can now use a flowable composite with mechanical properties comparable to those of conventional alternatives. Thanks to Kuraray Noritake Dental’s silane technology, millions of submicron filler particles fit into the composite, reliably adhering to the resin and maintaining long-term stability. CLEARFIL MAJESTY™ ES Flow possesses a scientifically tested flexural strength of over 150 MPa, similar to that of a universal nano hybrid composite, making it suitable for use in Class I and II restorations.

Aesthetic restorations

However, the small, durable particles of CLEARFIL MAJESTY™ ES Flow provide more than just mechanical reliability. Special cluster fillers provide a light diffusion effect that is similar to that of natural teeth, meaning that the material blends effortlessly with the existing tooth structure. Unlike other flowables, CLEARFIL MAJESTY™ ES Flow is glossy immediately after curing. This gloss can be improved with remarkable simplicity—simply wipe the cured resin with an ethanol-moistened gauze or cotton roll to produce a smooth surface that is proven to maintain its gloss over time.

Ideal handling

CLEARFIL MAJESTY™ ES Flow’s low viscosity monomers ensure that it has excellent handling characteristics, promising better sculpting for the dentist. The flowable composite does not stick to the needle tip or to any instruments, only adhering to the area to which it is applied, while the proprietary design of the syringe itself minimises air bubbles when dispensing. Once dispensed, the paste possesses great consistency with its non-slumping formula, ensuring that it can maintain its shape. A truly universal composite, CLEARFIL MAJESTY™ ES Flow allows dentists to create highly aesthetic restorations with ease.

Obtain results in four simple steps

Creating aesthetic and durable restorations has never been more achievable. Simply prepare the cavity and apply bonding, dispense and sculpt the CLEARFIL MAJESTY™ ES Flow, light-cure and, finally, polish. It’s as easy as that.

PANAVIA and KATANA: The perfect combination

Scientific research has demonstrated that, when bonding zirconia, optimal bond values can only be achieved with resin cements—specifically, MDP monomer-based resin cements. With PANAVIA V5, we offer a dual-cure resin cement with dentine bond strengths equal to our gold standard light-cure bonding agent CLEARFIL SE BOND, even when used in self-cure mode. Through our KATANA Zirconia range, Kuraray Noritake Dental presents a ceramic material for restorative procedures that has excellent translucency and shade options. Together, PANAVIA V5 and KATANA Zirconia make an ideal team for durable and reliable indirect restorations.

PANAVIA V5

In 1983, Kuraray introduced its patented MDP monomer in PANAVIA EX cement. With its clinically proven adhesion, our PANAVIA family has set the industry standard for adhesion for over 30 years. As the newest addition to the PANAVIA cement line, PANAVIA V5 provides strong bonding not just to zirconia but to hydroxyapatite and metals as well. Unlike other dual-cure resin cements, PANAVIA V5 offers improved bond strength to all tooth structures. Simple to use and with predictable results, PANAVIA V5 is unique in its user friendliness and procedural consistency. 

KATANA Zirconia

Our KATANA Zirconia discs are processed using a proprietary zirconia powder, allowing it to have as natural a translucency and colour as possible. The KATANA range consists of several options designed for full-contour zirconia prostheses, from single crown to full arch: KATANA Zirconia UTML (Ultra Translucent Multi Layered), STML (Super Translucent Multi Layered), ML (Multi Layered) and HT (High Translucent). The multilayered build-up of KATANA Zirconia STML provides a translucency and chroma that gradually decrease from the cervical to incisal regions, just like natural dentition. KATANA Zirconia UTML is perfect for anterior restorations, such as veneers, owing to its natural translucency and colour gradient. With a flexural strength considerably higher than that of lithium disilicate, KATANA Zirconia has the mechanical and aesthetic properties to achieve well-balanced restorations between natural teeth in the anterior zone.

An ideal team

PANAVIA V5 provides a strong and durable bond between KATANA Zirconia-based restorations and the tooth structure. PANAVIA V5 resin cement offers optimal margins and predictable restorations. Always use PANAVIA V5 Tooth Primer for the pretreatment of the tooth and CLEARFIL CERAMIC PRIMER PLUS for the priming of the restoration.

“We’re thrilled by the possibilities presented from the combination of PANAVIA V5 and KATANA Zirconia,” said Mitsuru Takei, Head of Technical Services at Kuraray Europe. “Together, they make achieving natural-looking restorations easier than ever.”

Shining a light on our lesser-known stars

Founded in 1926, Kuraray has a long and storied history of providing high-quality solutions in a number of fields. Since 1978, we have produced dental materials, such as the CLEARFIL and PANAVIA families of products, that have given our company a deserved reputation as an industry leader in excellence and innovation. However, there are many more products manufactured by Kuraray Noritake Dental that play a pivotal role in the daily work of dental practices worldwide, albeit without the same level of name recognition. With that in mind, we would like to highlight just a few of them.

CARIES DETECTOR

Kuraray Noritake Dental’s CARIES DETECTOR is the ideal tool for practitioners of conservative dentistry. A caries-disclosing agent, it assists in identifying carious lesions and plays a pivotal role in the maintenance and preservation of teeth. Fast and easy to use, CARIES DETECTOR provides support in the excavation of the demineralised and caries-affected outer tooth layers by staining the damaged parts red. This ensures that as little as possible healthy dentine is removed, aiding in the preservation of the tooth structure and maintaining pulp vitality. Dentists can excavate with precision and confidence thanks to our CARIES DETECTOR.

K-ETCHANT Syringe

The K-ETCHANT Syringe comes with an etching gel that is indicated for etching tooth enamel and dentine, as well as cleaning the surface of ceramics, hybrid ceramics, composite resins and metal restorations. Being thixotropic, it can be applied in a controlled manner and stays where you want it. Thanks to this nifty property, the K-ETCHANT Syringe treats only those areas that need to be etched.

CLEARFIL™ CERAMIC PRIMER PLUS

A stable, universal primer for all cement and repair indications, CLEARFIL™ CERAMIC PRIMER PLUS incorporates both Kuraray Noritake Dental’s original MDP monomer and a silane monomer. This allows for excellent bond strength to all silica-based ceramics, zirconia, composites and even metals, all at a high level of procedural simplicity. CLEARFIL™ CERAMIC PRIMER PLUS pairs perfectly with the adhesive resin cement PANAVIA™ V5 for reliable restorations.

Of course, this is only a glimpse into the variety of solutions that Kuraray Noritake Dental delivers. To find out more about our wide range of dental products, visit https://www.kuraraynoritake.eu/en/.

At Kuraray Noritake Dental, we understand that the most important factors for successful prostheses are strength and aesthetic appearance. With our KATANA Zirconia multi-layered series, we are proud to provide a range of materials with the translucency, colour gradient and durability to make every prosthesis as natural as possible, from veneers to full-contour restorations.

Launched in 2015, KATANA Zirconia UTML (Ultra Translucent Multi Layered) is the most translucent series at 43 per cent, a level equal to that of lithium disilicate or glass. This optimal translucency, combined with its natural colour gradient, allows the material to be used with confidence for veneers and crowns between natural teeth in the anterior region. KATANA Zirconia UTML is available in 20 shades in two shade groups (standard and enamel), with the reduced chroma of the enamel shades allowing for an enhancement of the translucency of the incisal area. As the flexural strength of KATANA Zirconia UTML—557 MPa—is 30 per cent higher than that of lithium disilicate, it can be reliably used to produce durable and aesthetic single restorations. 

KATANA Zirconia STML (Super Translucent Multi Layered) likewise has a natural colour and translucency gradient that transmits light in the incisal area while blocking it in the cervical area. This provides clinicians with the basis for beautiful full-contour prostheses, regardless of the abutment colour. With a translucency of 38 per cent and a flexural strength of 748 MPa—even higher than that of UTML, this series is recommended for up to three-unit posterior bridges, as well as crowns in the anterior and posterior regions.

The KATANA Zirconia ML (Multi Layered) and HT (High Translucent) series possess a flexural strength of 1,125 MPa, providing the highest level of mechanical strength in the KATANA line. Ideal for frameworks and long-span bridges, this series has a translucency of 31 per cent and ensures the aesthetic appearance of zirconia required by Kuraray Noritake Dental.

Give your brush a break

Often, the only way to ensure a prosthesis’s natural appearance is by dipping. With the KATANA Zirconia series, prostheses simply need to be milled and sintered to create natural aesthetics. To give them an even more natural look, the buccal surface can be stained with FC Paste Stain (Cerabien ZR).

Cementation with PANAVIA

Built upon the foundation of our original MDP monomer, PANAVIA cements are the best option for cementing prostheses or bonding to zirconia in a dental practice or laboratory. Both PANAVIA V5, developed for all indications, and PANAVIA SA Cement Plus, designed for ease of use, utilise the MDP monomer and have high bond strength to zirconia and durability. With PANAVIA cements, restorations can be cemented adhesively, expanding the options for use with zirconia.

No other resin cement offers such ease of use and consistency in procedure. Indeed, the unrivalled simplicity and predictability of PANAVIA V5 is nothing less than astonishing.

Always the same cementation procedure. Always the special PANAVIA V5 Tooth Primer for the pretreatment of the tooth. And always CLEARFIL CERAMIC PRIMER PLUS to prime the restoration. 

In 1983, Kuraray introduced the PANAVIA EX resin cement and, with it, our patented MDP adhesive monomer. Since then, the MDP monomer has repeatedly been clinically proved and has set the industry’s adhesive standard for over 30 years. PANAVIA V5 is the newest addition to the PANAVIA cement line and sets a new adhesive benchmark for resin cements by providing self-cure dentine bond strengths equal to our gold standard light-cure bonding agent CLEARFIL SE BOND.

PANAVIA V5 is able to provide strong bonding not just to hydroxyapatite but to metals and zirconia as well. It can be used for all clinical cementation indications, including on crowns, veneers, inlays/onlays, bridges, crowns/abutments on implants, and posts. With PANAVIA V5, you always follow the same procedures prior to prosthetic cementation: roughen and prime the prosthesis, prime the tooth, and apply the cement to the prosthesis.

Aesthetic stability in shading 

When it comes to maintaining shade in aesthetic cementation, conventional composite cements tend to discolour over time. With PANAVIA V5, Kuraray Noritake Dental presents an amine-free paste in five different shades—Universal (A2), Clear, Brown (A4), White and Opaque (only in self-cure mode)—that has been scientifically proved to demonstrate a lower level of post-curing colour variance than amine-based cements do. In addition, the new PANAVIA V5 try-in paste allows you to accurately simulate the shading of your cementation before it has been performed. As part of Kuraray Noritake Dental’s continued commitment to excellence in adhesion, this combination aims to enable the continued stability and natural appearance of the cement shading after curing.

PANAVIA V5 Tooth Primer

Almost all dual-cure resin cements available have been scientifically demonstrated to require light curing to achieve an acceptable bond strength. Thanks to Kuraray Noritake Dental’s focus on research and development, the MDP monomer-based PANAVIA V5 Tooth Primer contains a new catalyst that solves this issue. It provides an accelerated curing process from the moment the cement touches the primer, which, in turn, leads to a high degree of conversion from monomer to polymer. PANAVIA V5 presents a milestone in adhesion, as it offers improved bond strength for all tooth structures, even when used in the self-cure mode.

Prime with CLEARFIL CERAMIC PRIMER PLUS

PANAVIA V5 is designed for use in conjunction with CLEARFIL CERAMIC PRIMER PLUS, a stable universal primer that contains both Kuraray Noritake Dental’s original MDP monomer and a silane monomer. This allows it to bond to all silica-based ceramics (including lithium disilicate), zirconia, composites and metals. It provides excellent bond strengths to all of these materials, as well as procedural simplicity.

To find out more about integrating PANAVIA V5 into your restorative workflow, visit www.kuraraynoritake.eu/en/panavia-v5.html

Reliable adhesive cementation of zirconia

10-Methacryloyloxydecyl Dihydrogen Phosphate is a bit of a tongue-twister for anyone who is not a chemist by profession, so in everyday communication, this adhesive monomer is referred to by the three initial letters: MDP. MDP is indispensable in the dentistry business. For example, reliable adhesive cementation of zirconia restorations would not be possible without MDP. This adhesive monomer was developed by Kuraray Noritake Dental in 1981.

Requirements
Indirect restorations in modern dentistry must fulfil at least three requirements. First of all, they must be tissue-saving. This implies that a full crown is not the first choice, because approximately 70% of the tooth tissue has to be sacrificed for such a restoration. Nevertheless, full crowns are often still indicated by virtue of their mechanical retention. But given that the retention which can be achieved by adhesive cementation is now sufficiently reliable, a less invasive restoration than a crown should be chosen more often. And this choice may very well be for a zirconia restoration. Combined with the preliminary sandblasting of such an adhesive restoration, this choice is now an appropriate one thanks to MDP.

Durability is the second requirement for an indirect restoration. This quality of a restoration is largely associated with the flexural strength of the restoration material. While it has become clear that zirconia achieves the best durability scores, it should be pointed out that the cementation method also contributes significantly to the durability of a facing, inlay, onlay, etching bridge etc., which can nowadays all be realised in zirconia.

KATANA Zirconia UTML

KATANA Zirconia STML

KATANA Zirconia ML

AESTHETICS
Aesthetic acceptability is the third requirement for a modern indirect restoration. This means that porcelain baked on metal has become a thing of the past; full-ceramic materials are now the standard. Zirconia still has a relatively poor reputation in terms of aesthetics due to the extreme whiteness of the earliest examples from the turn of the century. Types of zirconia are now available with varying translucencies, and there are even so-called multi-layer varieties (KATANA Zirconia ML, STML and UTML by Kuraray Noritake), and these new zirconia no longer have to be porcelain-baked. Obviously, baking is still possible, and partial baking is a choice that is frequently made. One of the results of a multi-layer build-up is that the transparency is higher incisally than cervically, as it is in natural elements; the light falls through the incisal margin, but is blocked at the cingulum of the restoration. With a modern zirconia material such as KATANA Zirconia ML, this variable transparency goes hand in hand with a natural colour gradient from cervical to incisal. In a given colour, A1 for example, the cingulum has the corresponding dentine shade body and it passes to incisal in the appropriate enamel colour via two transition shades.

These veneers were made from KATANA Zirconia UTML and coloured using CERABIEN ZR External Stain

SURFACE
The new zirconia materials are changing the way dental technicians operate, as illustrated by the experience of Daniele Rondoni, a renowned dental technician. This professional, from Savona in Italy, has specialised in the use of Multi-Layering technology for ceramic materials (Tecnica della Multistratificazione in Ceramica). According to his philosophy, the choice of restoration materials should be so wide that customised solutions can be realised. Among other things, he believes that there will still be room for baked porcelain on a core of lithium disilicate or zirconia. Using baked porcelain, the dental technician can modify the surface texture of an aesthetic restoration to lend, as it were, a certain age to the restoration.

As for surface structure, the fact that the material allows for the smooth polishing of the occlusal plane is crucial to counteract abrasion by the antagonist and to maintain the occlusal balance. In this respect, the hardness of the material selected is not the main factor; the smoothness and resistance of the surface are far more important.

FLEXURAL STRENGTH
When selecting material for restorations, the dental technician also has the option to choose KATANA Zirconia Ultra Translucent Multi-Layered for veneers or anterior crowns; a zirconia with a translucence comparable to that of glass. This translucence is especially important with anterior restoration which is to be fitted between flawless natural elements, a situation that often occurs after anterior traumas. Such a restoration effected using KATANA Zirconia UTML harmonises with the neighbouring natural teeth, not least because this type of zirconia does not cause the frequently-occurring white appearance common in anterior crown. The modern aesthetic zirconia materials of the second generation are sintered at a temperature of 1,550°. This temperature is maintained for two hours. The dental technician needs to be aware that this temperature differs from the sintering temperature for KATANA Zirconia High Translucent Multi-Layered (1,500 °C). Wide-span bridges can be realised with the latter product, whereas the size of bridges made from KATANA Zirconia Super Translucent Multi-Layer remains limited to a maximum of four elements. KATANA Zirconia UTML can be used for small anterior bridges, but is more suitable for anterior crowns and veneers. The reason for this is that the flexural strength of these highly aesthetic zirconia materials is lower than the flexural strength of the standard zirconia, in which the flexural strength – 1,125 MPa – is sufficient for the production of durable widespan bridges. The flexural strength of the highly aesthetic zirconia varieties (approximately 750 MPa (STML) and 550 MPa (UTML)) is amply sufficient to ensure the durability of solitary aesthetic restorations and limited-span bridges.

Minimum wall thickness of KATANA*

* Maintain 0.8 mm thickness of pressed ceramic in all areas. When trimming of the zirconia framework the framework should be at least 0.4 mm.

PREPARATION
Flexural strength is not the only decisive factor for durability; the method of preparation is also crucial to properties of this material. Chamfer preparation is the required form of preparation,
with no knife-edge outline, no deep shoulder and, obviously, no undercuts. Since the restorations are fixed adhesively, parallel walls or grooves in the preparation are undesirable, and sharp
edges and transitions must be rounded off. If a preparation for a full crown has nevertheless been made, a substantial height difference between the vestibular and palatal/lingual outline is
contra-indicated.
 

Using the new zirconia materials means that a thickness of only 0.4 to 0.8mm need be removed for a veneer in the incisal and cervical area, and only 0.5mm is required in the labial plane,
which corresponds with the requirement to save tissue. For inlays, too, only 1mm is sufficient to achieve a durable result. If the inlay is extended to an onlay, 1mm is also sufficient for the
area where the cusps are capped. For a full crown in the lateral parts, a 1mm space must be kept as a minimum, which thickness must also be maintained for the upright walls of the preparation.

FIXATION
A wide range of possibilities have already been suggested for the durable fixation of zirconia-based restorations. All of these options have also been researched, but according to Prof. Matthias
Kern, there is no point in conducting further research into the best cementation procedure. This scientist and practitioner, who currently works at Kiel University, in Germany, has been involved
in the adhesive cementation of zirconia for nearly twenty years.Based on his wide experience, Kern is convinced that three requirements have to be met to achieve the reliable cementation
of zirconia. First of all, a rubber dam must be applied for the operation, which is obviously easier for partial restorations than for total restorations. It is not only from the perspective of tissuesaving that it is useful to keep the preparation limited for this reason. The second condition is that micro-mechanical adhesion needs to be achieved. For zirconia restorations, the necessary adhesion is obtained by sandblasting the surface. Obtaining chemical adhesion is the third condition. Based on extensive research, Kern is fully convinced that chemical adhesion can only be achieved by using MDP. His first publication on this subject dates back to 1998. It was the use of Kuraray Noritake’s PANAVIA, which did indeed contain MDP, which made it possible to achieve durable synthetic resin bonding to zirconia
after sandblasting.
 

SANDBLASTING
Dentists and dental technicians are apparently somewhat averse to sandblasting*, as evidenced by the extensive research conducted in an attempt to find an alternative. No such alternative has yet
been found. Efforts have been made to fuse a silica layer onto the zirconia to improve bonding, but according to Kern, the results of this procedure – the Rocatec method, for example – have been
disappointing. Nor is the silanisation of a zirconia restoration effective, because zirconia does not react to silan. Dentists who want to achieve the durable cementation of their zirconia restorations therefore have no other option than the purchase of a sandblasting device. Sandblasting can be carried out in a small cabin to prevent the surrounding area of the practice from being
affected. Soft air abrasion is carried out at 0.5 bar, while tight air abrasion is performed at 2.5 bar. The exact pressure is not all that crucial to the adhesion of the zirconia, providing that it is between
0.5 and 2.5 bar**. Kern advises sandblasting at a pressure of 1 bar, so that the surface to be bonded becomes somewhat rougher without this being visible to the naked eye. Obviously, the part of
the restoration that does not require bonding, such as the outside
of a veneer or the dummy of an etching bridge, has to be protected from the effect of the abrasive grains. It is also advisable to apply a colorant (waterproof marker pen) to the area to be sandblasted
prior to the operation. The colour disappears during sandblasting, making it easy to check that the entire adhesive surface has actually been abraded.

SANDBLASTING
Sandblasting of zirconia oxide at a lower pressure is a requirement for an effective adhesion. The
combination of sandblasting and MDP ensures both mechanical adhesion in the micro-roughness and
chemical adhesion between zirconia dioxide and MDP. There is extensive research material to corroborate the effectiveness of this method.

* It had long been assumed that the tetragonal and/or cubic structure would relapse into a
monoclinic state due to sandblasting, as a result of which fracturing would occur because
of the associated expansion. Sandblasting with aluminium oxide particles of 50 micron as a
maximum and a maximum air pressure of 2.5 bar does not, however, cause any damage.
** Airpressure is different from manufacturer‘s recommendation.

Adhesive monomer
The restoration surface can be cleaned using alcohol after the
sandblasting process. This step is optional. If the alcohol becomes
contaminated, for example, by saliva residues, the effect will be
negated, because the sandblasted surface would be contaminated
as well. The choice of the fixation procedure is relatively simple
provided MDP is used. This adhesive monomer was developed in
1981 by Kuraray Noritake Dental to improve the adhesive strength
to hydroxyapatite, and has proved its strength ever since. MDP is
not present in the glass ionomer cements (GIC’s), which, because
of their ease of use, are also sometimes used for the cementation
of zirconia restorations. ‘Don’t!’ warns Kern. It is clear from all the
studies that the composite cements containing MDP provide the
most durable results. The oldest known cement from this category
is PANAVIA EX, which was introduced in 1983. The optimised
PANAVIA V5 was presented recently as the single cement for
all cementation indications guaranteed to work according to a
predictable procedure. All the cements and bondings produced by
Kuraray Noritake contain MDP.

Possibly because Kern conducted his research in Maryland for
two years, he has recorded remarkable results with adhesively
cemented Maryland bridges (etching bridges). It has also become
apparent that, most of the time, an adhesion bridge functions best
with only one wing. For example, if a one-wing zirconia adhesion
bridge is cemented using a cement containing MDP instead of
a lateral upper incisive adhesive, such an adhesion bridge may
remain in place for up to 20 years, to the satisfaction of both
dentist and patient. This restoration, with its survival rate of 95.2%
after five years, therefore qualifies as a permanent restoration.

And the same goes for an onlay bridge made from zirconia.
Sandblasting and MDP; the formula for the durable bonding
of zirconia restorations.

So bear in mind: MDP also stands for a Mega Durable Product.

PANAVIA V5 for the adhesive fixation of zirconia
Achieving a reliable bonding to zirconia – it can be done! Read all about it in the preceding article.

PANAVIA V5 is the successful successor to both PANAVIA F2.0 and CLEARFIL ESTHETIC CEMENT. Thanks to its excellent adhesive bond with both dental tissue and all indirect materials, superior aesthetics, and unambiguous processing, PANAVIA V5 is a popular bonding cement. PANAVIA V5
provides a single cement for all cementation indications and features an unambiguous procedure.

CONCISE INSTRUCTIONS FOR USE
1. Sandblast the zirconia surface to be bonded with aluminium oxide powder (30-50 μm) at low pressure, then clean the restoration in an ultrasound bath and allow it to dry.

2. Apply CLEARFIL CERAMIC PRIMER PLUS to the restoration surface, then proceed to Apply & Go. Dry the entire surface using a gentle air flow.

3. Apply PANAVIA V5 Tooth Primer to the element and leave it to take effect for 20 seconds. Dry the surface with air.

4. Apply PANAVIA V5 Paste to the restoration surface and
position the restoration.

Applying the paste.

Positioning
After placement, remove excess cement using a gauze, a small brush, or something similar.

5. Remove surplus cement and light-cure. Always take account of the self-curing time needed for opaque elements and the use of PANAVIA V5 Opaque..

Daniele Rondoni

Owner of a dental laboratory in Savona

Professor Matthias Kern

Christian-Albrechts University