Dr. Adham Elsayed

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.

A guideline with regard to contemporary materials

The retention of the fixed prosthodontic restorations is a critical factor for the long-term success, as the loss of crown retention is one of the main reasons for failure of crowns and fixed dental prosthesis (FDP) ^{(1, 2)}. There are three main elements that need to be considered to achieve proper retention of the restorations; the tooth preparation, the restorative material and the luting agent.

TOOTH PREPARATION

During tooth preparation there are some important features to be considered, such as the height, angle and surface texture of the abutment tooth, in order to achieve an adequate retention and resistance form which provide stability of the restorations to resist dislodgment and subsequent loss ⁽³⁾. Retention form is responsible for counteracting tensile stresses, whereas resistance form counteracts shear stresses ⁽⁴⁾.

In order to achieve a sufficient retention and resistance form for full coverage crowns it is recommended that the height of the abutment tooth should be at least 4 mm and that the optimal convergence angle should range from 6 to 12 degrees with a maximum of 15 degrees ^{(1, 5-8)}.

RESTORATIVE MATERIAL

With the continuous introduction of new restorative materials to the dental market it is important to take into consideration the different mechanical properties of the various materials. The composition and the surface properties of the material have a decisive role in the ability to accomplish mechanical and/or chemical attachment to the restoration and therefore achieving required retention.

LUTING AGENT

The luting agent is the connection between the tooth and the restoration. Proper luting of indirect restoration is critical in achieving long-term success as it highly influences the retention of the restoration as well as tightly sealing the gap between the restoration and the tooth. Although there are several classifications for the definitive luting agents, they can be , however, classified into two main categories based on the ability to achieve chemical connection to different substrates; conventional (e.g. zinc phosphate, glass-ionomer and resin-modified glass-ionomer cements) and adhesives. Most commonly used and best documented adhesive luting agents are the adhesive composite resin cements.

Composite resin cements can be further classified according to the chemical composition into traditional full-adhesive resin cement and self-adhesive resin cements, both also differ in the bonding procedure. The full-adhesive resin cements require pre-treatment of the tooth structure and restorative material using separate adhesive systems. In this combination of the resin cement and the adhesive system, very durable chemical bonding can be reached.

To simplify the luting procedure and eliminate the need of using several components, the self-adhesive resin cements are a good choice for the daily busy practice, in which reliable bonding can be achieved in only one simple step of cement application, mostly without additional primers or bonding agents.

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, in this article, the authors aim 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.

CONVENTIONAL CEMENTATION OR ADHESIVE LUTING?

The choice of whether to use a conventional cement or an adhesive resin cement depends on several factors, the key factors are:

1. Retention and resistance form of the abutment tooth.
2. Mechanical and optical properties of the restorative material (flexural strength and translucency).
3. Simplicity of the workflow and special requirements of the working environment.

1) RETENTION AND RESISTANCE FORM OF THE ABUTMENT TOOTH

Minimal-invasive restorations, such as resin-bonded FDP, labial and occlusal veneers and inlay-retained FDP are based on a non-retentive preparation form. In this case the only possible method to achieve retention is the adhesive luting ^(9-11).

Even though such preparations completely lack a retentive form, long-term success of the restorations is well-documented when using a durable resin cement (e.g. PANAVIA™ 21, Kuraray Noritake Dental Inc., Japan) and proper bonding procedure ^{(10, 11)}.

For full-coverage restorations (e.g. crowns and FDPs), the guidelines for tooth preparation discussed before (minimum height of 4 mm and maximum convergence of 15 degrees) need to be applied in order to achieve the retention and resistance form required to make cementation with a conventional luting agent acceptable.

However, in reality this retention form is hard to realize due to several factors.

In cases of severe loss of tooth substance, achieving a minimum height of the abutment tooth is only possible with building up the tooth using a core build-up material which in some cases can be considered time consuming especially when the required build-up is minor (for example 1-2 mm). Moreover, increasing the height through core build-up is sometimes not possible, as in cases with short clinical crowns and insufficient occlusal clearance that is essential to provide the minimum thickness required for the restorative material. In such cases surgical crown lengthening is necessary to increase the height of the tooth without compromising the occlusal space required, which can be time consuming for the clinician and undesirable for the patient as it involves a surgical procedure and extends the treatment process.

Concerning the convergence angle, several studies showed that in reality and in daily practice of the dentist, the preparation angle is much higher than 15 degrees ^{(5, 6, 12, 13)}. For instance, preparations from general practitioners were evaluated digitally and compared to clinical recommendations and it was found that the mean convergence angle was 26.7 degree with the distopalatal angle being 31.7 degree ⁽¹²⁾.

Based on the previous concerns, it can be concluded that achieving a proper retention form during daily practice is hard to realize and thus conventional cementation in such cases can present clinical problems especially on the long term. Therefore, adhesive luting can be recommended in these cases as an alternative to conventional cementation ^{(6, 14)}. For full-coverage restorations with preparation designs featuring at least some mechanical retention, the use of self-adhesive resin cements can be considerate a good alternative as it provides high clinical success rates ^{(9, 15)}.

Conclusion / Clinical Significance:

• For non-retentive minimal-invasive restorations, traditional full-adhesive luting is a must.
• For full-coverage restorations, full-adhesive or self-adhesive luting is recommended.
• In case a retentive preparation with minimum height of 4mm and convergence angle of 6-12 degrees, adhesive luting as well as conventional cementation can be used.

2) MECHANICAL AND OPTICAL PROPERTIES OF THE RESTORATIVE MATERIAL

Flexural strength and translucency of the restorative material are critical factors that influence the decision which luting agent to use.

a) Flexural strength

As a general guideline for all-ceramic restorations, ceramics with low and medium flexural strength under 350 MPa should be adhesively luted with composite resin cements, as these restorations rely on resin bonding for reinforcement and support ^{(9, 14, 16)}. This includes feldspathic-, glass-, hybrid-ceramics and composite.

Although discussions on conventional cementation versus adhesive luting for high-strength ceramics with flexure strength of more than 350 MPa have been going on for a long time ⁽⁹⁾, there are several studies showing an increased stability and strength of all types of ceramics, even lithium disilicate and zirconia, when they are adhesively luted ^{(9, 17-20)}.

It is also important to consider that the documented success of most conventional cements is mainly combined with restorations made of metal or early generations of zirconia. Nonetheless, the clinical success of new generations of high-translucent zirconia can be significantly influenced by the luting agent as these new generations have notably lower flexural strength ⁽⁹⁾. And therefore, attention has to be paid to minimal material thickness together with adhesive luting to ensure long-term clinical success and prevent fractures ⁽⁹⁾.

Conclusion / Clinical Significance:

• For glass-ceramic, hybrid-ceramics and composites, adhesive luting is a must.
• For lithium disilicate and zirconia restorations, adhesive luting is highly recommended.
• For metal restorations, adhesive luting as well as conventional cementation can be used.

b) Translucency

To meet the increasing esthetic demands of the patients, new materials and techniques are continuously introduced, aiming to provide the perfect esthetic restorations. This includes not only new restorative materials but also new modifications to the luting agents as well. Highly translucent ceramics can deliver superior esthetics and therefore their popularity and clinical applications expanded widely among clinicians. It is nevertheless very important for the clinician to apprehend that the final esthetic result is influenced by the complete restorative complex and not just by the restorative material, as the luting agent is a key factor in achieving the desired high esthetics ^(21-24).

For that reason, the choice of an opaque conventional cement for cementation of high-translucent restoration should not be recommended as it can negatively influence the final esthetic results. Therefore, composite resin cements are the material of choice, as they are available in different shades and translucencies for the clinician to be able to choose the suitable resin cement to achieve the desired esthetics based on the restorative material and thickness as well as the color of the underlying abutment. Some composite resin cements offer try-in paste so that the clinician and the patient can visualize the final results before luting and therefore better choose the appropriate shade of the resin cement.

Conclusion / Clinical Significance:

• For all translucent ceramic restorations, adhesive luting is highly recommended.
• For metal and opaque high-strength zirconia restorations, adhesive luting as well as conventional cementation can be used.

3) SIMPLICITY OF THE WORKFLOW AND SPECIAL REQUIREMENTS OF THE WORKING ENVIRONMENT

The process of adhesive luting with full-adhesive composite resin cements (e.g. PANAVIA™ V5, Kuraray Noritake Dental Inc.) requires separate etching and priming procedures usually using a self-etch adhesive system (e.g. PANAVIA™ V5 Tooth Primer, Kuraray Noritake Dental Inc.) as well as a primer for the restorative material such as a universal primer that can be used for different substrates including metal, ceramics and composites (e.g. CLEARFIL™ CERAMIC PRIMER PLUS, Kuraray Noritake Dental Inc.). These procedures are technique sensitive and intolerant to contaminations, therefore the luting process needs a dry oral environment avoiding any contamination, such as saliva or blood, preferably using rubber dam, as any contamination can compromise the bond strength. Therefore, inability to maintain dry field as in case of subgingival preparation margins is considered a contraindication for traditional full-adhesive luting. However, this method provides very durable bond strength, therefore it is the luting method of choice for minimal invasive non-retentive preparations, such as resin-bonded FDPs, labial and occlusal veneers and inlay-retained FDPs, in which the retention is mainly dependent on the adhesion ^(9-11).

Still, in everyday practice, clinicians seek efficiency and effectivity by using a simple but durable luting agent for the insertion of full-coverage restorations such as tooth-or implant-supported crowns and FDPs. Although the conventional cements are simple and fast in their use, they provide little or no adhesion at all and therefore they are not recommended in several cases ^{(6, 9, 14, 15, 19, 20)}. A simple but reliable method can be well accomplished by the use of self-adhesive resin cements (e.g. PANAVIA™ SA Cement Universal, Kuraray Noritake Dental Inc.) as they can be considered the best alternative for full-adhesive adhesive luting in less critical situations that do not rely entirely on adhesion ^{(9, 15)}. Furthermore, self-adhesive resin cements are not as technique sensitive and intolerant to contaminations as traditional full-adhesive resin cements.

Typically, a MDP phosphate monomer is integrated in the self-adhesive resin cement, which is required to chemically bond to different substrates, making it possible for the resin cement to chemically bond to non-precious metals and zirconia as well as tooth substance. However, regardless of the self-adhesive resin cement, the use of a separate silane coupling agent is still required when bonding to silica-based ceramics (e.g. leucite, lithium silicate and lithium disilicate), hybrid ceramics and composite restorations.

Recently, a unique self-adhesive resin cement (PANAVIA™ SA Cement Universal, Kuraray Noritake Dental Inc.) was introduced: through an innovative and distinctive production technology, a silane-coupling agent (long carbon chain silane (LCSi)) is integrated in the cement, and thus being the real universal adhesive system that completely eliminate the need for any other adhesive or primer when being used for all substrates including glass ceramics. So the luting process can be in this case truly shortened to one step.

Therefore, this unique cement combines several advantages of adhesive luting as well as the straightforward procedure of the conventional cementation without compromising the clinical success, regardless of the type of the restorative material.

As a conclusion, adhesive luting has more benefits over conventional cementation, regarding retention, esthetics, stabilization of the tooth and the restoration as well as preventing micro leakage ^{(6, 9, 14-17, 19, 20, 25, 26)} (Table 1). Moreover, there are no absolute contraindications for adhesive luting other than hypersensitivity to methacrylate monomers, as self-adhesive resin cements can be used in cases where full-adhesive resin cements are contraindicated, such as inability to avoid contamination (Table 2). As a result, adhesive luting can be generally used in every clinical situation, whereas conventional cementation is limited (Table 3).

Dentist(s):

Prof. Dr. Florian Beuer
Professor and Chair, Department of Prosthodontics, Geriatric Dentistry and Craniomandibular Disorders, Charité – Universitätsmedizin Berlin, Germany.

Dr. Adham Elsayed
Clinical and Scientific manager, Kuraray Europe GmbH, Hattersheim, Germany.

References

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5. Edelhoff D, Özcan M. To what extent does the longevity of fixed dental prostheses depend on the function of the cement? Working Group 4 materials: cementation. Clin Oral Implants Res. 2007;18 Suppl 3:193-204.
6. Güth JF, Stawarczyk B, Edelhoff D, Liebermann A. Zirconia and its novel compositions: What do clinicians need to know? Quintessence Int. 2019;50(7):512-20.
7. Smith CT, Gary JJ, Conkin JE, Franks HL. Effective taper criterion for the full veneer crown preparation in preclinical prosthodontics. J Prosthodont. 1999;8(3):196-200.
8. Uy JN, Neo JC, Chan SH. The effect of tooth and foundation restoration heights on the load fatigue performance of cast crowns. J Prosthet Dent. 2010;104(5):318-24.
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11. 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;65:51-5.
12. Guth JF, Wallbach J, Stimmelmayr M, Gernet W, Beuer F, Edelhoff D. Computer-aided evaluation of preparations for CAD/CAM-fabricated all-ceramic crowns. Clin Oral Investig. 2013;17(5):1389-95.
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15. Blatz MB, Phark JH, Ozer F, Mante FK, Saleh N, Bergler M, et al. In vitro comparative bond strength of contemporary self-adhesive resin cements to zirconium oxide ceramic with and without air-particle abrasion. Clin Oral Investig. 2010;14(2):187-92.
16. Kern M, Thompson VP, Beuer F, Edelhoff D, Frankenberger R, Kohal RJ, et al. All ceramics at a glance. 3rd English Edition ed: AG Keramik; 2017.
17. Attia A, Abdelaziz KM, Freitag S, Kern M. Fracture load of composite resin and feldspathic all-ceramic CAD/CAM crowns. J Prosthet Dent. 2006;95(2):117-23.
18. Borges GA, Caldas D, Taskonak B, Yan J, Sobrinho LC, de Oliveira WJ. Fracture loads of all-ceramic crowns under wet and dry fatigue conditions. J Prosthodont. 2009;18(8):649-55.
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21. Calgaro PA, Furuse AY, Correr GM, Ornaghi BP, Gonzaga CC. Post-cementation colorimetric evaluation of the interaction between the thickness of ceramic veneers and the shade of resin cement. Am J Dent. 2014;27(4):191-4.
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In de video toont Dr. Elsayed hoe hij binnen 10 minuten met de stempeltechniek een klasse-I restauratie legt. Clearfil Majesty ES Flow en de stempeltechniek vormen een ideale combinatie om snel tot een prachtig afgewerkt esthetisch eindresultaat te komen.

Translucentie - het vermogen van het materiaal om licht door te laten zonder transparant te worden - is een zwaarwegende factor als het gaat om de esthetische prestaties van restauraties in het anterieure gebied. Tanden zijn van nature translucent en het is vaak zichtbaar als een restauratie is vervaardigd met materiaal met een afwijkende translucentie. Bovendien geeft het materiaal een onnatuurlijke indruk bij een kleurverschil ten opzichte van de omringende elementen. Als ontwikkelaar van de multi-layered zirkoniumtechnologie presenteert Kuraray Noritake Dental met trots het KATANA Zirconia-programma, een keramische oplossing voor restauratieve procedures die garant staat voor een perfecte kleuraansluiting op de omliggende elementen dankzij de uitmuntende translucentie en brede kleurkeuze.

Hoewel zirkonium al sinds eind 20e eeuw wordt toegepast in de restauratieve tandheelkunde, is de populariteit van dit materiaal - als metaalvrij alternatief - door de recente ontwikkeling van hoog-translucente opties enorm toegenomen. Waar de vroegere generaties van dit materiaal nog een onnatuurlijke, krijtachtige witheid hadden, die afbreuk deed aan de esthetiek, combineren de nieuwere versies mechanische prestaties met een visuele superioriteit waarbij de kleurverschillen tussen de glazuur- en dentinelagen realistisch worden nagebootst. Onze KATANA Zirconia-lijn loopt voorop binnen deze nieuwe norm; dankzij de glazuurachtige translucentie, gecombineerd met opaciteit en chroma van dentine en de duurzaamheid is dit materiaal namelijk geschikt voor full-contour zirkonium kronen en bruggen, maar ook voor inlays/onlays en zelfs veneers. De multi-layered technologie van KATANA Zirconia komt voort uit onze gedrevenheid om via R&D een uiterst esthetisch en biocompatibel restauratief materiaal aan te bieden. 

Pioniersdrift

Een groot deel van de vooruitgang in de translucentie van zirkonium is het resultaat van innovatie van het poeder dat de basis van de blokken en schijven vormt. Het overgrote deel van zirkoniumproducenten betrekt dit poeder van één gezamenlijke leverancier; het poeder van Kuraray Noritake Dental daarentegen is eigendom en wordt binnen het eigen bedrijf verwerkt. En dankzij deze pioniersdrift zijn zowel de translucentie als kleur van KATANA Zirconia zo natuurlijk mogelijk. De serie KATANA Zirconia UTML (Ultra Translucent Multi Layered) heeft een translucentie van 43% en is leverbaar in 16 standaardkleuren plus 4 glazuurtinten; daarmee is dit product het ideale en harmonieuze medium voor vrijwel alle anterieure restauraties tussen natuurlijke elementen.

Ons programma van KATANA Zirconia schijven omvat verschillende opties voor full-contour zirkonium voorzieningen, van enkele kronen tot volledige bruggen: KATANA Zirconia UTML, STML (Super Translucent Multi Layered), ML (Multi Layered) en HT (High Translucent).

De multi-layeropbouw van KATANA Zirconia betekent dat de translucentie van met dit materiaal vervaardigde restauraties, net als bij een natuurlijk gebit, hoger is in het incisale gebied dan in het cervicale. Elke KATANA Zirconia reeks heeft een andere translucentie en mechanische eigenschappen, zodat clinici een breed scala aan restauratieve behandelingen in de anterieure en posterieure gebieden kunnen invullen.

"Het KATANA Zirconia programma bewijst onze inzet voor de levering van esthetische en betrouwbare producten aan clinici over de hele wereld," aldus Eileen Tan, Product Manager Europa bij Kuraray Dental Benelux. "Dankzij KATANA Zirconia kunt u uw voorzieningen een werkelijk natuurlijke uitstraling meegeven."