Importance of high-quality prosthodontic treatment

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

But how is it possible to deliver perfectly fitting, high-quality restorations every time? Among the potential sources of problems with the quality of indirect restorations are common mistakes made in the dental office or laboratory, communication issues and – often overlooked – the use of low-quality dental zirconia.

Zirconia restorations – contemporary and aesthetic dental solution

More than 20 years ago, zirconia entered the dental market as a substitute to metal used for the production of crowns and bridges. Both materials – zirconia and metal – were usually combined with a layer of porcelain, forming porcelain-fused-to-metal or porcelain-fused-to-zirconia restorations. In the years to come, several leading manufacturers of dental zirconia (like Kuraray Noritake Dental Inc.) focused on material improvements. These improvements gradually transformed the original white-opaque framework material into a ceramic material with tooth-like optical and excellent mechanical properties. The latest zirconia variants, available with different levels of translucency and strength, are regarded as the best-possible treatment option in a wide variety of patients and indications by many dental professionals around the world. One reason is that they require just a small or no layer of porcelain. Another is that, with low minimum wall thicknesses, they allow for conservative tooth preparations, while they offer a favourable long-term behaviour – that is, if a high-quality material is used.

Quality differences of dental zirconia

Zirconia product quality may vary depending on various factors such as the purity of the raw materials (not only zirconia, but also alumina and yttria as well as colour additives etc.), the exact chemical composition, the grain size and particle distribution. Every step in the blank production process – from powder compilation to blank pressing and pre-sintering – has an impact on the final quality, i.e., the mechanical and optical properties of the zirconia, too.

Common issues resulting from low-quality zirconia

Whenever there is something wrong with the optical properties of a restoration – with its translucency, its overall colour or the transition from one layer to the next in blanks with a multi-layered colour structure – the problem will become apparent after the final sintering procedure in the laboratory. A remake might be necessary and eventually, the blemish might be identified during try-in, which will most likely have a negative impact on patient satisfaction. The same is true for cases with an improper fit resulting from inhomogeneities in the material structure, for example. What is even worse is an inferior biocompatibility, surface quality, edge stability, flexural strength or fracture toughness. These issues are identifiable only with testing equipment that is very expensive and usually not available in dental laboratories. This means that flaws of this kind usually remain undetected until a real clinical problem – like gingival recession, increased plaque accumulation, higher wear or an early failure that might cause pain and discomfort – occurs.

Overview of potential problems and clinical consequences for patients

Certification and standardization of dental zirconia

That is why specialists have developed an ISO standard (ISO 6872:2015), which describes in-vitro tests every manufacturer of dental zirconia used in Europe or the United States needs to conduct in order to pass FDA approval and receive the CE mark. The described tests are used to measure the flexural strength and fracture toughness, the two probably most important properties determining the long-term behaviour of restorations produced from the material. Every material used in Europe or the United States needs to have passed these tests.

How to avoid placing low-quality dental zirconia restorations in your patients’ mouths

Hence, everyone using this certified dental zirconia should be safe and able to minimize material-related risks. However, the increasing popularity of dental zirconia has attracted the attention of companies trying to have their share of the cake without undergoing the necessary efforts needed to safeguard a high product quality and pass certification. Non-certified products that lack CE marking have one thing in common: they definitely put your business and patient at risk.

So how is it possible to safeguard zirconia product quality from the dental office? The good news is that there are some simple rules available. By following them, you are able to avoid placing counterfeit or low-quality dental zirconia restorations in your patients’ mouths.

Avoid placing counterfeit or low-quality dental zirconia restorations in your patients’ mouths.

Three golden rules to provide your patients with high-quality zirconia restorations:

• Only order restorations that are produced domestically or in a region with the same standards as your own: restorations produced in dental laboratories in China, for example, need to fulfil lower standards (thus lacking CE mark) and might not live up to your expectations.
• Talk to your (domestic) laboratory partner about the source of their zirconia: make sure they are purchasing zirconia from leading manufacturers (e.g. Kuraray Noritake Dental Inc.) via authorized distributors or sellers they really know.
• Avoid deals that are too good to be true: low prices may be tempting, but the final cost of a treatment may be even higher than usual when complications occur.

Long-term impact for patients when using certified zirconia restorations

Making certain that the zirconia placed in your dental office fulfils the highest possible quality standards is an important contribution to long-term patient satisfaction. Even if the initial cost of high-quality zirconia restorations is somewhat higher than that of inferior-quality work, the overall investment may be lower when the restorations last longer and remakes are eliminated. Your happy patients are likely to be more engaged and compliant with oral hygiene regimens as well as loyal, with a positive impact on your reputation and patient base.

Research zirconia options and choose for products from certified manufacturers

If you would like to go one step further, you can even compare certified zirconia variants from several manufacturers and detect differences. Kuraray Noritake Dental Inc., for example, is one of very few manufacturers of dental zirconia carrying out the whole manufacturing process including raw material production in-house. In this way, the company is able to control every step in the procedure and provide for an outstanding product quality – no matter which material variant is selected. With the available portfolio consisting of KATANA™ Zirconia UTML (ultra translucent multi-layered), KATANA™ Zirconia STML (superior translucent multi-layered) and the high-translucent multi-layered HTML PLUS as well as YML (with additional strength and translucency gradation), it is possible to cover virtually every indication.

By DT Simone Maffei and Dr. Filippo Menini

EVOLUTION IN PROSTHODONTICS

Nowadays, digital workflows in prosthodontics are well-established, and many modern dental laboratories have already embraced the option of producing monolithic restorations or restorations with a minimal cut-back for micro-layering in a fully digital environment.

The spread of digital technologies and the availability of new restorative materials with improved aesthetic properties have increased the popularity of this technique among dental technicians. This way of working offers considerable advantages for daily procedures, starting with improved ways of communication between the clinician and dental technician. For example, it is now possible to view and evaluate impressions with the whole treatment team including the dental technician almost instantaneously after impression taking – and without anyone having to leave their office.

In addition to advanced communication options, digital technologies have allowed us to use materials that otherwise could not be processed, such as zirconia and hybrid composites. As a consequence, lots of innovative materials conquered the market, and this has opened up the possibility to always select what is perfectly suited for each specific clinical situation. Adapting to these trends is absolutely essential for anyone who wants to meet a modern dental practitioner’s increased demands.

LONG DISTANCE DENTAL COLLABORATION

Working with digital workflows has allowed us to broaden the scope of action of the modern laboratory, enabling virtually effortless collaboration with clinicians hundreds or thousands of kilometres away. The case presented below is a perfect example: In our dental laboratory in Modena, we produced two anatomical crowns made of KATANA™ Zirconia for a patient who needed a combination of direct and indirect restorative treatment to be carried out by Dr. Filippo Menini in Belluno, about 300 km to the northwest. The whole communication and coordination between practice and laboratory was performed remotely and without us seeing the patient.

MATERIAL CHOICES

Monolithic restorations offer countless clinical and technical advantages. With a major part of the process accomplished by machines, they truly rationalize procedures. The challenge resulting from this simplification, however, lies in the achieving of excellent aesthetics.

Whereas until a few years ago, it was very difficult to accomplish this task due to the poor optical properties of the available materials, today we can safely say that we have materials, techniques and protocols at our disposal that allow us to obtain aesthetically acceptable results. At the same time, those materials offer excellent mechanical resistance to the forces and stress to which they are exposed in the oral cavity and a very high precision of fit, if these restorations are produced in a fully digital workflow.

We have chosen to work with prosthetic materials and finishing solutions from a company that manufactures and develops them in-house: Kuraray Noritake Dental Inc. (Kuraray Noritake). They offer zirconia discs for milling as well as effect liquids, veneering porcelain and liquid ceramics for an aesthetic finish and even resin cement systems for adhesive luting – all from a single source. This gives us the advantage of using clear and predictable working protocols from fabrication to cementation of the restoration.

CLINICAL CASE

The 31-year-old patient presented with multiple carious lesions, inadequate restorations and in particular a destructive caries in the maxillary right second premolar (tooth #15, FDI notation, Fig. 1). The latter tooth was endodontically treated and built up using a glass fibre post. The X-ray revealed carious lesions and infiltrated margins of the restorations (Fig. 2). The treatment plan for this quadrant included direct composite restorations on the first premolar and first molar (teeth # 14 and 16) and an indirect zirconia crown used to restore the second premolar (tooth #15; Fig. 3). In addition, a zirconia crown needed to be produced for the mandibular right second premolar (tooth #45).

Fig. 1. Initial clinical situation in the maxillary right quadrant.

Fig. 2. Radiograph showing carious lesions and restorations with marginal leakage.

Fig. 3. Marked surfaces that will be treated.

During the first session, the clinician restored the first molar and premolar with composite (Figs. 4 and 5). In addition, the tooth preparation on the maxillary and the mandibular second premolar was performed using the biologically oriented preparation technique (BOPT; Figs. 6 and 7). Two single-tooth temporaries were then produced, recreating a cervical profile according to the BOPT (Fig. 8). In the next step, the digital impression was taken using the double chord technique (Fig. 9). The file generated by the intraoral scanner was first analysed using a greyscale view. This view allows for a better assessment of the quality of the acquired data than the coloured image (Fig. 10). The temporary restorations were finished, polished and placed on the teeth using temporary cement (Fig. 11).

Fig. 4. Restoration procedure on the maxillary first molar.

Fig. 5. Restoration procedure on the maxillary first premolar.

Fig. 6. BOPT crown preparation on the maxillary second premolar.

Fig. 7. Detail of the subgingival preparation, using burs with calibrated notches, taking care not to touch the supra-crestal attachment complex, but precisely taking care to remain within the width of the sulcus.

In the dental laboratory, we received the intraoral scans in the STL format: Both arches with the prepared teeth and the usual bit register (vestibular scan of the arches in occlusion). Following a careful evaluation of the impressions and the quality of the triangulation of the points of the STL file detected by the scan, a full-contour design of the crowns was performed (zero cutback crowns). This allows us to obtain an emergence profile, according to the BOPT, which is extremely accurate. The anatomy was developed taking into account the functional movements of the patient, which were based on information retrieved from a virtual articulator integrated in the CAD software. These movements can be verified and – if necessary – corrected on the physical articulator in a subsequent step. As it is possible to use the same type of articulator (in our case ARTEX by Amann Girrbach) both in the virtual environment and the real one (control phase) offers the advantage of using the same settings and consequently the same movements in both worlds (Fig. 12).

Fig. 8. Production of the temporary restoration.

Fig. 9. Digital impression taken using the double cord technique: a 000-sized cord soaked in aluminium chloride is placed in the sulcus as the first cord, followed by a non-soaked cord of size 1.

Fig. 10. Greyscale view of the impression, facilitating the clinical evaluation.

Fig. 11. Cementation of the temporary restoration.

Fig. 12. Virtual models based on the digital impression of both arches, with the software-designed full-contour crowns in different views.

The STL files of the designed restorations were sent to the CAM software for milling of the zirconia crowns with a 5-axis CNC machine. The material of choice was in this case KATANA™ Zirconia YML (Kuraray Noritake Dental Inc), which is multi-layered in strength, translucency and colour, and thus suitable for a variety of cases (Fig. 13). Once milling was finished, the elements were removed from the disc and their surface treated with diamond burs and specific rubbers designed for the processing of pre-sintered zirconia. In this phase, it is possible to individualise the anatomy and surface texture of the restorations, a task that is very difficult to accomplish in the milling process. With the dedicated rubbers, the surface can also be smoothened, which will improve the appearance of our restorations after sintering (Fig. 14).

On top, individualization of the pre-sintered restorations was accomplished with Esthetic Colorant (Kuraray Noritake). These new effect liquids have been specifically developed for KATANA™ Zirconia. They contain a special primer that limits the depth of penetration, which results in an appearance similar to external stains, while a depth effect is created. Precise application of the liquids is possible with the Liquid Brush Pen. The Esthetic Colorant line-up consists of twelve colours to facilitate stock management in the dental laboratory, while still providing for natural aesthetics and perfect harmony in the oral cavity. Impact on the flexural strength of the zirconia substructure by the liquids is kept to a minimum, as they have been optimised to limit this effect and avoid fractures. (Fig. 15).

Sintering is carried out in a specially calibrated furnace, scrupulously following the protocol recommended by the manufacturer. Afterwards, the finishing procedure can be continued. With special stones, the cervical edge was first regularised: In the deeper, subgingival areas, the intraoral scanner usually has some difficulties capturing all the necessary information. As a consequence, the STL file is triangulated with some irregularities at the cervical margin. These irregularities need to be regularised, before the thickness of the margin is reduced to '0'. In fact, during milling it, is created with a thickness of 0.2 mm to avoid micro-chipping that would compromise the accuracy of the cervical margin. Figure 16 shows both the thickness of the cervical margin, which, despite the finishing preparation, retains a thickness of 0.2 mm, and the irregular course of the same due to the irregular shape of the STL file around the sulcus.

Fig. 13. KATANA™ Zirconia YML blank with milled crowns.

Fig. 14. Finishing with diamond burs and specific rubbers for pre-sintered zirconia.

Fig. 15. Individualisation with Esthetic Colorant.

Fig. 16. Finishing of the restorations after sintering.

The restorations were then sandblasted with 50-μm aluminium dioxide at 2 bar pressure and cleaned under a steam jet. After an evaluation of the colour revealed after sintering, the finishing phase was completed with the aid of CERABIEN™ ZR FC Paste Stain (Kuraray Noritake Dental Inc.) and polishing instruments. The ceramic emulsions FC Paste Stain allow us to adjust the chroma and value of the restorations and to imitate all those aesthetic features that will improve integration in the oral cavity. With this technique, it is very easy to achieve the desired shade match, as the appearance of the stain applied to the surface is exactly like its appearance after firing. In this way, it is easy to monitor the outcome and – if desired – compare with a reference and adjust whenever necessary (Figs. 17 and 18).

For cementation of the restorations, the clinician used PANAVIA™ SA Cement Universal in combination with KATANA™ Cleaner (both Kuraray Noritake Dental Inc.). The cleaner has a pH value of 4.5 be used both intra and extra-orally, improving adhesion in all restorative procedures. PANAVIA™ SA Cement Universal is the only self-adhesive resin cement containing the unique LCSi monomer – a long carbon-chain silane coupling agent. In combination with the original MDP monomer, which is also present in the paste and enables chemical adhesion with zirconia, dentin, enamel and metal alloys, this coupling agent provides for adhesion of the cement to any material, including glass-ceramics, without the need for a separate primer (Figs. 19, 20 and 21). At the cementation appointment, the last planned direct reconstruction of the maxillary second molar (tooth #17) was also carried out.

Fig. 17. Characterisation with CERABIEN™ ZR FC Paste Stain.

Fig. 18. Finished restorations ready to be handed over to the clinician.

Fig. 19. Cementation procedure in the maxilla: Sandblasting of the tooth and cleaning of the tooth structure with KATANA™ Cleaner.

Fig. 20. Cementation procedure in the maxilla: Sandblasting of the crown’s intaglio and cleaning of the restoration with KATANA™ Cleaner.

Fig. 21. Cementation procedure in the maxilla: Self-adhesive cementation with PANAVIA™ SA Cement Universal.

Fig. 22. Direct restoration procedure on the second molar.

Fig. 23. Restorations immediately after finishing and polishing.

Fig. 24. Detailed view of the restored quadrant.

Fig. 25. Occlusal view of the maxillary teeth.

RESULT

The aesthetic integration provided by the high quality of KATANA™ Zirconia YML, combined with the pre- and post-sintering individualisation, made it possible to achieve an excellent integration of the anatomical zirconia crowns. Figures 22 to 25 show the outcome in the newly restored maxillary right quadrant with natural tooth structure, direct composite restorations and the monolithic zirconia crown.

ABOUT THE AUTHORS

DT SIMONE MAFFEI

Simone Maffei, a dental technician since 1996 (IPSIA L.Galvani Reggio Emilia), embarked on his career in Modena at his father William's laboratory. Throughout his professional journey, he has demonstrated a commitment to excellence by participating in numerous courses led by prominent international speakers. These courses span the realms of dental technology and photography. Presently, Maffei is not only a respected speaker at national and international conferences but has also contributed articles to both Italian and foreign sector magazines. His written works delve into the intricate intersection of dental photography and the aesthetics of the smile. A testament to his expertise, Maffei earned recognition as the recipient of the prestigious AIOP International Award in 2014. He actively shares his knowledge by conducting courses in Italy and abroad, focusing on dental technology, dental photography, natural ceramic layering techniques, and the three-dimensional coloring of monolithic restorations. As a valued member of the Digital Dental Revolution (DDR) Team, Maffei serves as a speaker at courses and international conferences, where he imparts insights on various facets of digital dentistry. Simone Maffei is also the proud owner of the Laboratorio Odontotecnico Maffei in Modena. Collaborating with his sister Elisa, the laboratory specializes in crafting aesthetic ceramic reconstructions for both natural teeth and implants, showcasing a dedication to the art and science of dental aesthetics. Active Member of AIOP SOSPESO – Accademia Italiana di Odontoiatria Protesica (Italian Academy of Prosthetic Dentistry). Ordinary Member of SIPRO Società Italiana Protesi e Riabilitazione Orale (Italian Society of Oral Prosthetics and Rehabilitation).

FILIPPO MENINI

Dr. Filippo Menini graduated in Dentistry and Dental Prosthetics from the Universidad Europea De Madrid in 2017. He has been passionately dedicated to the study of direct and indirect adhesive techniques in the field of conservative dentistry. He became a Regular Member of the Italian Academy of Conservative Dentistry in 2018 and the Italian Academy of Prosthetic Dentistry in 2019. In November 2021, he joined the Think Adhesive Members, and since February 2022, he has been a contract tutor at the University of Siena in the Endo-Resto master program taught by Professor Grandini. Dr. Menini has attended numerous courses in conservative dentistry, endodontics, periodontology, and adhesive prosthetics to manage his work in a multidisciplinary perspective. He has his dental practice in Belluno.

Case by Dr. Ioannis Memis

Single-shade or two-shade approach? Using modern resin composites, it is possible to treat virtually every patient in need of a direct restoration in an aesthetic way using one of those two techniques. If the defect is rather small, a single shade of composite restorative in a body opacity may be sufficient – especially when the tooth to be restored is in the posterior region. Larger defects and those located in the aesthetic zone may require a combination of two different shades – one as a dentin replacement and one as translucent as enamel – to closely imitate the optical characteristics of the natural tooth.

With CLEARFIL MAJESTY™ ES-2, Kuraray Noritake Dental Inc. offers a complete composite system designed to simplify procedures in bot, the single-shade and the two-shade approach. CLEARFIL MAJESTY™ ES-2 Classic is a typical composite for the single-shade technique consisting of 18 shades offered in a single universal opacity. Shade determination is brightness-based, meaning that the brightness is selected first and the hue and colour saturation in a second step (using the VITA Classical A1 – D4 shade guide). For those who want to skip shade determination completely, CLEARFIL MAJESTY™ ES-2 Universal has been introduced. It consists of only two shades for the anterior and one shade for the posterior region, selectable without using shade tabs. For the two-shade technique, CLEARFIL MAJESTY™ ES-2 Premium is the solution: It allows users to copy natural enamel and dentin layers with a total of seven enamel, seven dentin and four translucent shades. Its exceptional feature: pre-defined colour combinations with one Premium shade combination covering three VITA Classical shades. A natural blending into the environment is achieved with the Light Diffusion Technology in the formulation.

All three versions of CLEARFIL MAJESTY™ ES-2 are compatible with each other and offer the same favourable handling properties. The use of different techniques, shades and opacities is demonstrated using the following patient case.

YOUNG PATIENT WITH MULTIPLE CARIOUS LESIONS

A 24-year-old female patient was referred from undergraduate clinic of Operative Dentistry of the Aristotle’s University of Thessaloniki - School of Dentistry (Greece). Patient presented multiple interproximal carious lesions in need of restorative treatment. In the clinical and radiographic examination, the following defects were identified:

Quadrant 1 (maxillary right):

- Distal lesion on the lateral incisor (Class III)

- Mesial and distal lesions on the first premolar (Class II)

- Mesial and distal lesions on the second premolar (Class II)

- Mesial lesion on the first molar (Class II)

Quadrant 2 (maxillary left):

- Distal lesion on the lateral incisor (Class III)

- Mesial lesion on the first premolar (Class II)

- Mesial and distal lesions on the second premolar (both Class II)

- Mesial lesion on the first molar (Class II)

Quadrant 3 (mandibular left):

- Distal lesion on the first molar (Class II)

- Mesial lesion on the second molar (Class II)

In a stepwise procedure, the teeth were restored with CLEARFIL MAJESTY™ ES-2 either in a single-shade or in a two-shade approach depending on the size of the lesions.

INITIAL SITUATION

Fig. 1. Initial situation: Frontal view.

Fig. 2. Occlusal view of the maxilla.

Fig. 3. Occlusal view of the mandible.

RESTORING THE TEETH IN QUADRANT 1

The six carious lesions in this quadrant were restored in three steps. At first, the focus was on the first molar and second premolar. Opening the larger cavity mesially of the first molar provided access to the smaller lesion on the premolar’s distal surface. After caries excavation and cavity preparation, rubber dam was placed and fixed with a clamp on the second molar. The enamel in the cavities was treated with phosphoric acid etchant for 15 seconds before CLEARFIL™ Universal Bond Quick (Kuraray Noritake Dental Inc.) was applied according to the manufacturer’s instructions. For a morphologically correct designing of the proximal contact point and area, the use of a sectional matrix system with rings was utilized. Both cavities were restored with CLEARFIL MAJESTY™ ES-2 Premium in the shades A3D and A2E. Finishing and polishing of the occlusal surface accomplished with silicon cups and Twist Dia disks on a slow speed handpiece.

In the second step, the distal lesion on the first and mesial lesion on the second premolar were restored in an identical procedure with CLEARFIL MAJESTY™ ES-2 Premium in the shade A3D and CLEARFIL MAJESTY™ ES-2 Classic in the shade A3. A different approach was selected in step 3 for the lesions on the distal part of the lateral incisor and the mesial part of the first premolar. Due to the small size and the all-but-prominent position of the lesions, a single-shade technique using CLEARFIL MAJESTY™ ES-2 Classic in the shade A3 was selected. Between the lateral incisor and canine, a posterior sectional matrix was placed in an upright position and fixed with a wedge to support a proper restoration of the contact point, while both elements were used in the usual way between the canine and first premolar.

Fig. 4. Simultaneous restoration of the mesial lesion on the first molar and the distal lesion on the second premolar with CLEARFIL MAJESTY™ ES-2 Premium.

Fig. 5. Restoration of the distal lesion on the lateral incisor and the mesial lesion on the first premolar with CLEARFIL MAJESTY™ ES-2 Classic.

RESTORING THE TEETH IN QUADRANT 2

For the small disto-palatal lesion on the maxillary left lateral incisor, a single-shade technique with CLEARFIL MAJESTY™ ES-2 Classic in the shade A3 also produced aesthetic outcomes. The four lesions at the posterior region of the quadrant were restored in two steps – one for each pair of proximal lesions – with a combination of CLEARFIL MAJESTY™ ES-2 Premium in the shade A3D and CLEARFIL MAJESTY™ ES-2 Classic in the shade A1.

Fig. 6. A single-shade technique is sufficient to aesthetically restore this small lesion on the left lateral incisor.

Fig. 7. Simultaneous restoration of the mesial lesion on the second premolar and the distal lesion on the first premolar.

Fig. 8. Simultaneous restoration of the mesial lesion on the first molar and distal lesion on the second premolar.

RESTORING THE TEETH IN QUADRANT 3

In this quadrant, only a single pair of proximal lesions needed treatment. A simultaneous restoration procedure was selected once again due to the favourable space conditions. Although the size of the lesion was like those in the posterior region of the maxilla, a single-shade restoration was selected with the use of CLEARFIL MAJESTY™ ES-2 Classic (shade A3).

Fig. 9. Treatment of the lesions in quadrant 3.

CONCLUSION

In the present patient case, several different shades, opacities, and combinations of CLEARFIL MAJESTY™ ES-2 were utilized either in a single- or in a two-shade approach. All combinations and techniques produced good outcomes. As shown in Figure 4, the enamel opacity of CLEARFIL MAJESTY™ ES-2 Premium is visibly more translucent than the universal opacity of CLEARFIL MAJESTY™ ES-2 Classic. Experience shows that enamel shades translucency is highly valuable for aesthetic anterior restorations, while in posterior restorations, the universal shade approach is aesthetically adequate, particularly for medium-sized restorations, as shown in Figure 9. This is clearly an evidence of Light Diffusion Technology which is blending hue and colour saturation to the surrounding tooth structure.

Handling of all selected composite pastes is comfortable: non-sticky, adaptable to cavity walls and allowing precise occlusal sculpting. Polishing with Silicone Cups and TWIST DIA for Composite is easy, quick and leaves a natural gloss on the surface.Dentist:

DR. IOANNIS MEMIS

Postgraduate Student, Operative Dentistry Dept., School of Dentistry
Aristotle University of Thessaloniki, Greece

AWARD WINNING PRODUCT

For the 10th time, the self-etch adhesive CLEARFIL™ SE Protect has been named a Top Product by DENTAL ADVISOR, which announced its choices for dental materials and equipment found by its evaluators to deliver the best practice-based performance in its JAN/FEB 2024 issue.

The publication included CLEARFIL™ SE Protect among honorees in the Bonding Agent Self-Etch category, noting attributes that go far beyond providing a reliable bond.

ABOUT THE PRODUCT

This outstanding toolbox staple is built on the same system of the gold-standard adhesive CLEARFIL™ SE BOND, so it offers excellent bond strength for enamel and dentin. Its MMP inhibiting effect protects the bond from degradation over time and hence supports bond durability. Beyond that reliable bond, it provides an antibacterial cavity-cleansing effect that eliminates the need for the use of a separate cavity cleanser, thanks to the proprietary MDPB monomer it contains.

In short, CLEARFIL™ SE Protect offers you following benefits:

• Fast and simple procedure with low technique sensitivity
• Excellent bond strength for enamel and dentin
• Long-lasting bond strength
• Antibacterial cavity-cleansing effect
• Virtually no post-operative sensitivity

It is also a highly versatile adhesive system that can be used in the context of:

• Placing direct restorations
• As a cavity sealant
• For the treatment of hypersensitive or exposed root surfaces

Among the extended indications are cementation with composite resin cement or core build-up with self- or dual-cured resin materials in combination with CLEARFIL™ DC Activator.

EVALUATION

Its attributes are reflected in the study findings and comments of DENTAL ADVISOR’s editors and consultants, who assessed it over a six-week period during which over 150 restorations were placed. It received a 98% clinical rating by consultants using a 1-5 rating scale.

The practitioners evaluating the product found no post-operative sensitivity. Among their observations mentioned in the online DA report were the fact that the primer and bond wet the tooth evenly. They also considered the antibacterial and fluoride releasing qualities “an added benefit”. On the topic of sensitivity, they mentioned that “CLEARFIL SE Protect is effective in the reduction of sensitivity when placed on areas of recession or similar areas of sensitive tooth structure.”.

ABOUT DENTAL ADVISOR

The Top Product or Preferred Product Awards conferred by US-based DENTAL ADVISOR were initially introduced to help busy practitioners make sense of the numerous new solutions indicated for less invasive techniques, standardised or simplified procedures, ultimately to achieve better outcomes regularly.

DENTAL ADVISOR conducts its practice-based clinical evaluations and product performance tests shortly after product launch, and publishes results annually online to help potential users identify high-quality new dental materials and determine which among them are best suited to fulfill their individual requirements.

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

By Dr. Michał Jaczewski

The durability of a composite restoration depends on many factors. Some are outside the practitioner's sphere of influence and are strongly patient-related. For example toothbrush and toothpaste type, brushing technique, diet, stimulants and hygiene habits all have an impact on the restoration. Following the best finishing and polishing protocol, however, is fully up to the dentist.

Correct polishing aims to remove the oxygen inhibition layer and produce a smooth restoration surface. A properly polished restoration will not absorb staining agents from food, drink or stimulants that lead to discoloration of the composite, ensuring a long-lasting aesthetic result of the restoration.

Polishing the composite is a process to which special attention should be paid. It consists of several steps and principles:

• The use of finishing discs allows for a smooth restoration surface , excess composite to be removed and the final shape to be given to the restoration. It is important to remember to work on a moistened surface with a maximum speed of 5,000-10,000 rpm on a 1:1 dental handpiece.

• Polishing rubbers, there are many types and shapes on the market. One of the most universal designed specifically for composite is TWIST™ DIA for Composite. This is a set consisting of two rubbers with different levels of abrasion. The first (dark blue) is used for preliminary rough polishing, the second (light-blue) for final gloss and smoothness. It should be remembered that working with these tools should be carried out on a dry surface without water cooling. Dry working carries the risk of irritating the dental pulp, so the working speed should be limited to between 5000 and 10000 rpm and excessive pressure must be avoided.

• The next step is to use a diamond polishing paste with a gradient of 1 to 5 microns. The use of a polishing goat wheel brush is recommended to use with this paste. The type of brush is not important, however, don’t use rigid bristles that could scratch the composite. Using the polishing brush and polishing paste make it possible to reach places which are difficult to access, such as the cervical area and proximal surfaces. In addition to this step, a celluloid diamond containing abrasive strip is used to polish the proximal surfaces more precisely. In order not to alter the contact points, low abrasive (Super Fine) strips should be used.

• A further step to increase the gloss of the restoration and to protect it against discoloration is an aluminum oxide paste with a cotton polishing brush. The use of such paste, originally dedicated to ceramics, results in an exceptionally smooth surface and a high gloss of the restoration surface. This step is carried out in a dry environment at a maximum speed of 5,000-10,000 rpm.

In all techniques, thus also the Flowable Injection Technique, the level of polishing influences the durability and the optical and aesthetic properties of the restoration. This key step in tooth restoration should therefore devoted sufficient time. Composites are characterized by different compositions and amounts of fillers which not only influence their properties, but also the ease with which they can be polished. In some cases, the procedure has to be repeated several times to achieve a "mirror effect". CLEARFIL MAJESTY™ ES Flow is a composite which is very easy to polish to a high shine level, despite its high filler content. Specially adapted rubbers, brushers and pastes enable easy creation of a smooth surface thereby contributing to a lasting result.

BEFORE

AFTER

3-YEARS RECALL

MAKE THEM SHINE, MAKE THEM SMILE!

Would you like to know more about Flowable Injection Technique? Read the insightful and inspirational interview with Dr. Michał Jaczewski.

Dentist:

MICHAL JACZEWSKI

Michał Jaczewski graduated from Wroclaw Medical University in 2006 and today runs his private practice in the city of Legnica, Poland. He specializes in minimally invasive dentistry and digital dentistry and is the founder of the Biofunctional School of Occlusion. Here he lectures and runs workshops with focus on full comprehensive patient treatments.

AWARD WINNING PRODUCT

DENTAL ADVISOR has once again recognized PANAVIA™ SA Cement Universal as a Top Product in the category of Indirect Restoratives. This dual-cure, fluoride-releasing, radiopaque self-adhesive resin cement adheres to virtually all substrates — including lithium disilicate — in a single-step procedure without the need for a separate primer or silane. It also offers easy, gingival-friendly removal of excess cement and requires no refrigeration.

SCIENCE BEHIND THE PRODUCT

It is because PANAVIA™ SA Cement Universal combines two innovative technologies in a single product that a strong and durable bond can be achieved in a single step. The silane-coupling agent, LCSi monomer, establishes a durable, chemical bond with porcelain, lithium disilicate, and composite resin; and the original MDP monomer provides for chemical reactiveness with zirconia, dentin and enamel.

WIDE INDICATION RANGE

Due to its unique chemistry PANAVIA™ SA Cement Universal represents a convenient, versatile, and efficacious single solution to practitioners’ everyday cementation needs for a wide variety of indications, including cementation of crowns/bridges, inlays/onlays, posts, splints, and even adhesion bridges.

EVALUATION

In its commendation, DENTAL ADVISOR stated, “As tested in DENTAL ADVISOR Laboratories, PANAVIA™ SA Cement Universal with an incorporated silane primer had exceptional initial bond strength to dentin, lithium disilicate, and zirconia.”

The benefits and quality of PANAVIA™ SA Cement Universal were further reflected in the findings and feedback of the 31 clinical evaluators who tested the cement during 516 applications. They praised its ease of use, handling characteristics, and aesthetics, and gave it an overall clinical rating of 96 percent. Among their comments: "Has an ideal film thickness and flows well.”,  "You can use this in a moist environment with no issues.” , and “Excess cement peels right away from the margin.”

ABOUT DENTAL ADVISOR

The Top Product and Preferred Product Awards conferred by US-based DENTAL ADVISOR were initially introduced to help busy practitioners make sense of the numerous new solutions indicated for less invasive techniques and standardised or simplified procedures, ultimately, to achieve better outcomes regularly.

DENTAL ADVISOR conducts its practice-based clinical evaluations and product performance tests shortly after product launch. It publishes results annually online in its January/February issue to help potential users identify high-quality new dental materials and determine which among them are best suited to fulfil their individual requirements.

AWARD WINNING PRODUCT

CLEARFIL™ Universal Bond Quick has again been named a 2024 Preferred Product in the bonding agent category by DENTAL ADVISOR, which also recognized this universal bonding agent as an Editor’s Choice bonding agent. DENTAL ADVISOR’S roster of award-winning dental materials and equipment found by its evaluators to deliver the best practice-based performance was announced in its JAN/FEB 2024 issue.

ABOUT THE PRODUCT

CLEARFIL™ Universal Bond Quick is a single-bottle, fluoride-releasing universal adhesive suitable for all direct and indirect restorations using a quick and simple technique. The material utilizes Rapid Bond Technology, merger of MDP monomer with new hydrophilic amide monomers, which creates a strong chemical bond to hydroxyapatite. Thanks to the amide monomer, which is highly hydrophilic, the adhesive quickly penetrates dental tissue to create a fast chemical bond to dentin and enamel, eliminating the need for prolonged scrubbing application of the adhesive into the dentin and long waiting times. After curing, the innovative amide monomer forms a moisture-resistant cross-linked polymer network.

APPLY AND PROCEED

Despite its ease of use and reduced application and wait times, there is no tradeoff in terms of bond strength: CLEARFIL™ Universal Bond Quick delivers a bond that is moisture-resistant, stable, and durable.

VERSATILITY OF APPLICATION

This fast and versatile agent bonds directly to dentin, enamel, metals, zirconia and lithium disilicate restorative materials, and is appropriate for bonding direct and indirect restorations; it can also be used for total-etch, selective-etch, or self-etch methods.

CLEARFIL™ Universal Bond Quick is also an excellent choice when doing post cementation and core build-up procedures with CLEARFIL™ DC CORE PLUS . It can be used for treatment of the post surface, be it fiber or metal, but also for the tooth surface preparation before cementing with PANAVIA™ SA Cement Universal, for example. Universal excellence at its best!

REMARKS FROM EVALUATORS

practitioners evaluating the CLEARFIL™ Universal Bond Quick commented on its ease in dispensing and placement, viscosity, suitability for all bonding procedures, and convenience. Among their remarks were: "Quick application and cure time is ideal for situations where isolation is difficult, especially in a high moisture area.", "Loved that it is compatible with dual/self-cured resins and that it can be used in self-cure mode with CLEARFIL™ DC Activator”. and “It is compatible with virtually any bonding procedure."

ABOUT DENTAL ADVISOR

Honors such as Editor’s Choice and Preferred Product that are conferred by US-based DENTAL ADVISOR were introduced to help busy practitioners make sense of the numerous new solutions indicated for less invasive techniques and standardised or simplified procedures, ultimately to achieve better outcomes regularly.

DENTAL ADVISOR conducts its practice-based clinical evaluations and product performance tests shortly after product launch, and publishes results annually online to help potential users identify high-quality new dental materials and determine which among them are best suited to fulfill their individual requirements.

Selective Adhesive Luting (SAL) is a hybrid technique for universal resin cements. It entails the application of a universal adhesive system only on easily accessible abutment surfaces, enabling simultaneous adhesive and self-adhesive luting in different portions of the abutment. A description of this novel technique and scientific evidence for the achieved effects is provided in this article authored by Prof. Breschi and colleagues from the University of Bologna. Its title:“Selective adhesive luting: A novel technique for improving adhesion achieved by universal resin cements”.

A VERSATILE RESIN CEMENT

PANAVIA™ SA Cement Universal is a universal resin cement that may be applied in the self-adhesive mode – without any additional components – in many clinical situations. It even offers great bonding performance to lithium disilicate without the need for a separate bottle of silane. In-vitro studies have shown that the resin cement is moisture tolerant and versatile, establishing a strong and durable bond to virtually all kinds of restorative materials as well as to enamel and dentin.

ENHANCING THE BONDING PERFORMANCE

On the side of the tooth, however, the best possible bonding performance is obtained by applying CLEARFIL™ Universal Bond Quick as a separate tooth primer. Hence, you may want to settle for this two-component adhesive luting technique in particularly challenging situations. It is still less complex than traditional adhesive luting and produces excellent outcomes.

MOISTURE SENSITIVITY AND WORKING FIELD CONSIDERATIONS

To function properly, however, universal adhesives need a completely dry working field, while self-adhesive resin cements are less sensitive to moisture. Thus, you might wonder which technique is best suited if you need the strongest possible chemical bond to enamel and dentin, but proper isolation with rubber dam is challenging or impossible – for example, because the abutment is short or the preparation margin is in a subgingival position. The solution in this case is termed Selective Adhesive Luting.

Selective application of a universal adhesive to those areas of etched enamel that are not at risk of being contaminated by moisture.

Article by Dr. Michał Jaczewski

COMPOSITE RESTORATIONS IN DENTISTRY

Composite restoration is the most common procedure performed by the dentist. There are many restorative techniques and a variety of restorative materials used in dentistry. Regardless of the type of material, the method of restoration and where it is applied, common issue is air bubbles in or at the surface of the composite layers. The composite restoration should be homogeneous to ensure the tightness of the filling and its durability. Repairing bubble defects is tedious and sometimes requires the replacement of the filling or part of it. Depending on the type of composite (flowable or paste composite) and/or the placement technique, the amount of defects may vary, but there are several causing factors.

MATERIAL CHOICE

In the Flowable Injection Technique, we use flowable composites, which obviously flow easily but are also sensitive to incorrect application. The first cause of forming air bubbles is the homogeneity of the material itself. Bubbles can be incorporated in the syringe at the manufacturing stage or during use. By using premium products, we can be sure that the highest quality material is supplied, and that the structure and design of the syringe allows for proper operation to reduce the formation of air bubbles within the material.

IMPORTANCE OF SYRINGE DESIGN 

CLEARFIL MAJESTY™ ES Flow composite is designed to prevent the formation of air bubbles during dispensing. The special design of the syringe and plunger limit the possibility of dripping as well as backflow of the material during or after dispensing.

A unique safety feature inside the syringe is the special O-ring construction which prevents the material from flowing after pressure is released and at the same takes care for minimal retraction but avoiding the plunger from retracting too much.

RETRACTION OF PLUNGER

Another cause of air bubble formation is the incorporation of air into the syringe by deliberate retraction of the plunger. If the practitioner or ancillary staff have a habit of retracting the plunger after administering the composite, they may cause air to enter the syringe. During a following use the air will more than likely show up in the restoration as an air void.

IMPORTANCE OF PRESSURE ON THE INDEX

In the Flowable Injection Technique, we use a silicone index in which we apply the material to build up the tooth. The index should fit tightly to the tooth and should not move or being moved during injection. If it does air bubbles may show up. Pressing and then releasing the index will cause a suctioning effect and pull the composite away from the tooth as well as from the index. To avoid defects, constant pressure on the index should be maintained from the moment the material is injected until polymerisation.

Various modifications of the silicone index can be used to limit its mobility and reduce the risk of uncontrolled pressure on the tooth. Such an example is the index made on the interlip ("one yes one no") model, which provides a very high degree of stability as well as working safety.

WIDTH OF THE INJECTION HOLE

Another cause for getting air in the restoration is the width of the injection hole. If the hole is too tight, the index can be moved by the application tip during insertion or application. To avoid this problem, the hole could be widened to allow free insertion as well as manipulation of the tip during injection. A wider opening also allows any air to escape during dispensing. Most important , however, is to apply the material at continuous pressure and avoiding pulling out and reinserting the tip into the index. This may result in a non-uniform composite layer.

Would you like to know more about Flowable Injection Technique? Read the insightful and inspirational interview with Dr. Michal Jachzewski.

Dentist:

MICHAL JACZEWSKI

Michał Jaczewski graduated from Wroclaw Medical University in 2006 and today runs his private practice in the city of Legnica, Poland. He specializes in minimally invasive dentistry and digital dentistry and is the founder of the Biofunctional School of Occlusion. Here he lectures and runs workshops with focus on full comprehensive patient treatments.

AWARD WINNING PRODUCT

For the 9^th year in a row, CLEARFIL MAJESTY™ ES Flow (Low) has been named a Top Product by Dental Advisor, which announced in its JAN/FEB 2024 issue its choices for dental materials and equipment found to deliver the best practice-based performance based on the publication’s annual review of such products.

ABOUT THE PRODUCT

CLEARFIL MAJESTY™ ES Flow, which is available in three different levels of flowability, was the Top Product honoree in the Direct Restorative Category and was also given Editor’s Choice award for its medium viscosity version - Low.

Rather than limit practitioners to a single viscosity that might not be ideal for all flowable composite indications, CLEARFIL MAJESTY™ ES Flow comes in one version firm enough to stay in place when applied, another malleable enough to fashion a specific shape, and a third runny enough to flow into every corner or undercut. The practitioner would thus be able to select the best version for the job at hand—choosing the high flowability variant for cavity linings and as a resin coat in immediate dentin sealing (IDS) procedures, but instead, the super low flowability option for direct veneer procedures and for the build-up of cusps, etc.

Beyond its handling advantages, this universal flowable composite, which incorporates Kuraray Noritake Dental Inc.’s Light Diffusion Technology, is highly esthetic, with optical properties that enable the practitioner to fashion lifelike restorations that integrate seamlessly with the surrounding tooth structure.

EVALUATION

The flowable composite tested by the 29 DENTAL ADVISOR consultants in 909 uses in their dental practices was the medium flowability variant CLEARFIL MAJESTY™ ES Flow (Low). Their evaluations focused on properties including placement/handling, esthetics, viscosity, and polishability, and they rated all these key features to be “excellent”. This led to a recommendation rate of 100% and a 98% overall clinical rating.

REMARKS FROM EVALUATORS

Among their comments were: “The material blended so well with the tooth structure that you had to really look to find the interface.”. “Readily apparent on radiographs.” and “One of the best flowable composites I have used.”.

ABOUT DENTAL ADVISOR

The Top Product and Preferred Product Awards conferred by US-based DENTAL ADVISOR were initially introduced to help busy practitioners make sense of the numerous new solutions indicated for less invasive techniques and standardised or simplified procedures, ultimately, to achieve better outcomes regularly.

DENTAL ADVISOR conducts its practice-based clinical evaluations and product performance tests shortly after product launch. It publishes results annually online in its January/February issue to help potential users identify high-quality new dental materials and determine which among them are best suited to fulfil their individual requirements.