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How to polish a composite restoration in posterior area?

By Dr. Aleksandra Łyżwińska, Warsaw, Poland.

 

Every dentist aims to polish to a high gloss without damaging the freshly modeled occlusal surface. Firstly, use high-quality polishing rubbers. The plural form is not accidental (Fig. 1). In my opinion, a single rubber systems are not capable of achieving an impeccable gloss in a safe manner. Be patient and gentle. Polishing requires time and a delicate touch.

 

Fig. 1.

 

Immediately after polymerization the composite is covered with an oxygen inhibition layer (Fig. 2). It is imperative to remove it by a brush and any polishing paste or a prophylactic sandblaster. The next step is to remove excess composite using abrasive discs, burs and firm polishing rubber points.

 

Fig. 2.

 

During polishing without water cooling, the rubber leaves crumbling on the composite surface (Fig. 3). These fragments can be spread across the restoration surface using a fine nylon brush. This allows for the polishing of each fissure and pit (Fig. 4).

 

Fig. 3.

 

Fig. 4.

 

The key to long lasting shine is polishing with gradation. Time to change a rubber point to the dark blue TWIST DIA for Composite rubber, which is more abrasive than light blue one (Fig. 5). Remember to apply gentle pressure and maintain a maximum speed of 8000 revolutions per minute. This way, you will achieve fine particles without the risk of overheating the pulp. The particles were once again spread over the entire surface. The thinner the bristle, the better the polishing effect in the grooves (Fig. 6).

 

Fig. 5.

 

Fig. 6.

 

Third round: use the light blue TWIST DIA for Composite rubber for a mirror-like gloss (Fig. 7). A beautiful gloss emerges beneath the particles. An alternative to thin nylon brushes is brushes made from natural goat hair (Fig. 8).

 

Fig. 7.

 

Fig. 8.

 

Polishing is not only a matter of aesthetics but, above all, function. The adherence of bacterial biofilm to a polished composite is significantly lower than to a rough surface (Fig. 9). My recipe for achieving a mirror-like gloss polish: high-quality diamond rubber points with gradation, used with sensitivity over an extended period (Fig. 10).

 

Fig. 9.

 

Fig. 10.

 

Dentist:

DR. ALEKSANDRA ŁYŻWIŃSKA
Warsaw, Poland

 

Dr. Aleksandra Łyżwińska is a restorative dentist. She graduated from the Warsaw Medical University in 2017, where she was an assistant professor at the Department of Conservative Dentistry and Endodontics. Her focus lies in modern adhesive techniques, resin composites and biomaterials.

 

Kuraray Noritake Dental receives top honors as innovative company of the year

We are proud and delighted to announce that Kuraray Noritake Dental has been honored as the INNOVATIVE COMPANY OF THE YEAR by DENTAL ADVISOR.

 

DENTAL ADVISOR conducts annual practice-based clinical evaluations and product performance tests. The results are published online in the January/February issue, aiding potential users in identifying high-quality new dental materials and selecting those best suited to their individual requirements.

 

Quoting DENTAL ADVISOR: “Kuraray Noritake was chosen as innovative company of the year because of their constant ability to adapt to market needs and change. Their products are universally accepted by dental professionals as market leaders due to their ease of use and consistently high laboratory performance, making them ideal choices for long-term clinical results.”

 

In addition to being recognized as an innovative company, our products underwent testing and received prestigious DENTAL ADVISOR medals:

 

 

We extend our heartfelt gratitude to the dedicated practitioners worldwide who have placed their trust in Kuraray Noritake Dental products. Your unwavering commitment to excellence fuels our ongoing pursuit of innovation and quality. We are honored to stand alongside you in advancing dental care, and we look forward to continuing this journey together.

 

Thank you for choosing Kuraray Noritake Dental – where innovation meets trust, and quality meets precision.

 

Wishing you a powerful new year!

2024 MARKS THE YEAR OF THE DRAGON

 

  • Dragons, those mythical beings, embody innate courage, unyielding tenacity, and boundless intelligence. They fearlessly embrace challenges and eagerly venture into uncharted territories.
  • The Year of the Dragon is hailed as a time of great power, auspicious beginnings, and transformative possibilities.
  • This image, inspired by the traditional Japanese art of kirigami, combines age-old craftsmanship with cutting-edge AI technology. Just like the dragon, it represents a harmonious blend of ancient wisdom and modern innovation.

 

EMBRACE 2024 WITH OPEN ARMS –
IT BRINGS FORTH A YEAR OF NEW POSSIBILITIES

 

The enduring legacy of MDP monomer

It is probably the best-known component of a dental product Kuraray Noritake Dental Inc. (Kuraray Noritake Dental) has ever developed: 10-Methacryloyloxydecyl Dihydrogen Phosphate, in short, the MDP monomer. Invented more than 40 years ago – the first product containing it was introduced in 1983 – MDP is still the leading functional monomer used to establish a long-term, durable and stable bond to hydroxyapatite in tooth structure and to metal oxides in restorative materials (oxide ceramics and metal alloys).

 

Nowadays, it is found in every dental adhesive and every component of a resin cement system with adhesive properties from Kuraray Noritake Dental. These include:

In addition, MDP has become an integral part of most universal adhesives and many adhesive cementation systems of other manufacturers as well. However, not all MDP is alike …

 

MDP: Chemical structure and mechanism of adhesion

 

The MDP monomer consists of three essential parts: A polymerizable group, a hydrophobic group and a hydrophilic group. The co-polymerizable methacrylate group has a terminal double bond enabling polymerisation. The large hydrophobic alkylene group – also referred to as the spacer – has the task to maintain a delicate balance between hydrophobic and hydrophilic properties of the monomer and offers great resistance to degradation. Finally, the hydrophilic phosphate group is responsible for acidic demineralisation, for chemical bonding with calcium in hydroxyapatite and for bonding with zirconia1 (as well as with metal).

 

Bonding performance

 

Lots of in-vitro studies have been carried out to investigate the bonding behaviour of 10-MDP in the context of direct and indirect restorative procedures. No matter whether a cavity is to be filled with resin composite or an indirect restoration is to be placed, a strong and long-lasting bond to tooth structure needs to be established.Chemical structure of adhesive monomer 10-Methacryloyloxydecyl Dihydrogen Phosphate (MDP).

 

The critical substrate in this context is dentin, while bonding to enamel is found to be less challenging. That is why it is so important that (self-etch) adhesives containing 10-MDP show an extraordinarily high bond strength to tooth structure, particularly to dentin2. In fact, 10-MDP also provides for a high bond stability over time by establishing an acid-base resistant zone on the adhesive interface3. This means that a great long-term performance may be expected. Fortunately, a great clinical long-term performance of products containing the MDP monomer has already been confirmed: A group from the University of Leuven (Belgium) has presented excellent results of a thirteen-year clinical trial involving the use of CLEARFIL™ SE Bond in 20154.

 

When bonding to indirect restorations made of zirconia, the surface area of the ceramic should be increased by sandblasting5. Pre-treated in the recommended way, the bond strength to zirconia tends to be particularly high when MDP-based resin cement systems are used6. It is thus widely recommended by experts in the field of adhesive dentistry to employ MDP-containing primers or resin cements for the placement of zirconia-based restorations, especially those with a non- or less retentive preparation. The fact that products containing 10-MDP work well in this context has been confirmed in different clinical studies with observation periods of up to 10 years7,8. The products used in these studies were PANAVIA™ 21, PANAVIA™ F2.0 and the latest version of the multi-component cementation system from Kuraray Noritake Dental, PANAVIA™ V5, which performed best.

 

Not all MDP is alike

 

Ever since the basic patent for MDP has expired, other manufacturers of dental adhesives and adhesive resin cements have started integrating the functional monomers in their own products. However, it has been revealed that there are differences in the purity of the MDP monomers synthesized and used, and that these differences have an impact on the long-term bonding performance of the products containing the MDP9. According to in-vitro test results, the Original MDP Monomer synthesized by Kuraray Noritake Dental stands out due to an unmatched level of purity. This purity has a positive effect on the microstructure and thickness of the hybrid layer formed on dentin, the intensity of nano-layering and the bond strength measured immediately as well as after artificial aging9.

 

Conclusion

 

The data summarized above reveals that after 40 years in clinical service, the Original MDP Monomer from Kuraray Noritake Dental is still a class of its own. It has everything needed to establish a strong and long-lasting bond to tooth structure, resin composite and metal oxides, and is therefore a valuable component in virtually every adhesive system. In order to provide for a high bond quality, however, it may be best to use an MDP monomer with a confirmed high purity – the Original MDP Monomer.

 

References

 

1. Nagaoka N, Yoshihara K, Feitosa VP, Tamada Y, Irie M, Yoshida Y, Van Meerbeek B, Hayakawa S. Chemical interaction mechanism of 10-MDP with zirconia. Sci Rep. 2017 Mar 30;7:45563.
2. Fehrenbach J, Isolan CP, Münchow EA. Is the presence of 10-MDP associated to higher bonding performance for self-etching adhesive systems? A meta-analysis of in vitro studies. Dent Mater. 2021 Oct;37(10):1463-1485.
3. Carrilho E, Cardoso M, Marques Ferreira M, Marto CM, Paula A, Coelho AS. 10-MDP Based Dental Adhesives: Adhesive Interface Characterization and Adhesive Stability-A Systematic Review.
4. Peumans M, De Munck J, Van Landuyt K, Van Meerbeek B. Thirteen-year randomized controlled clinical trial of a two-step self-etch adhesive in non-carious cervical lesions. Dent Mater. 2015 Mar;31(3):308-14.
5. Kern M, Barloi A, Yang B. Surface conditioning influences zirconia ceramic bonding. J Dent Res. 2009; 88: 817–822.
6. Özcan M, Bernasconi M. Adhesion to zirconia used for dental restorations: a systematic review and meta-analysis. J Adhes Dent. 2015 Feb;17(1):7-26.
7. 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.
8. 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.
9. Yoshihara K. et al. Functional monomer impurity affects adhesive performance. Dent Mater. 2015 Dec;31(12):1493–1501.

 

Scientific information

Is it safe to use the single-component PANAVIA™ SA Cement Universal to lute virtually all your indirect restorations?

 

Did you ever ask yourself how many components are really needed to safely cement your silicate-ceramic, zirconia or resin-based restorations? With PANAVIA™ SA Cement Universal, a single component is usually sufficient. Containing an unreacted silane coupling agent – the LCSi monomer – and the original MDP monomer, the dual-cure, self-adhesive resin cement adheres to tooth structure and to various restorative materials including the popular silica-based ceramics without the need for a separate primer.

 

For those wondering how it works and if it really works as well as desired, Kuraray Noritake Dental Inc. has created a scientific brochure. It contains in-depth information about the drivers of chemical adhesion contained in PANAVIA™ SA Cement Universal and its characteristic properties. The main part, however, focuses on the results of scientific studies – most of which have been conducted in external laboratories. With the aid of artificial aging, different testing devices and various experimental set-ups, the researchers have checked the resin cement thoroughly. The study results shed light on the behaviour of the material when used in the context of bonding to different restorative materials and different types of tooth structure. Self- and light-curing modes are compared, aging effects investigated and different moisture conditions taken into account.

 

As a whole, the collected data allows for a precise prediction of the clinical behaviour of PANAVIA™ SA Cement Universal. This valuation has already been confirmed by clinical experience of dental practitioners from all around the world. Moreover, the results of a first clinical study, which is also found in this compilation, are a proof of its exceptional performance.

 

Download the brochure to learn more about the properties and behaviour of the single-component universal resin cement!

 

 

BOND Magazine, 10th edition

ADHESIVE LUTING: A DRIVER OF INNOVATION

 

What would modern restorative treatments be like without the availability of high-performance (self-)adhesive resin cements? Tooth preparations would still be much more invasive due to the need for sufficient mechanical retention between the tooth and the restoration. At the same time, it would be impossible to restore teeth with many innovative, tooth-coloured materials such as low-strength ceramics and composite. In short, restorative dentistry would be much less developed than it is today.

 

When the first resin cements were introduced several decades ago, however, the achieved progress came at the expense of simplicity: Adhesive luting procedures were highly complex and the many different components quite technique sensitive. Luckily, this has changed over the years due to continued development efforts ultimately resulting in the products that are currently available. The resin cement line-up of Kuraray Noritake Dental Inc. consists of three main products: the dual-cure three-component system PANAVIA™ V5, the single-component dual-cure universal resin cement PANAVIA™ SA Cement Universal and the light-curing PANAVIA™ Veneer LC.

 

For those who would like to learn more about the three systems, this 10th issue of the BOND Magazine is definitely worth reading. It reveals important details about the 40-year history of the PANAVIA™ brand, sheds light on the strengths of each resin cement to facilitate indication-specific cement selection and provides in-depth information about their clinical use. In addition, two articles are dedicated to hot topics around the luting of restorations made of zirconia, a popular restorative material that some still consider to be unsuitable for adhesive luting procedures. For everyone wondering how it is possible to successfully lute minimally invasive restorations made of zirconia, the article titled “Innovative resin cements forming the basis of minimally invasive prosthodontics” is highly recommended. Those unsure about how to proceed with 5Y-TZP should read the article “How to cement restorations made of high-translucency zirconia”. Interesting information about cleaning options prior to adhesive luting rounds out the content of this magazine.

 

Click here to read. Enjoy reading!

 

Start Reading: BOND | VOLUME 10 | 10/2023

 

 

Previous versions:

 

BOND | VOLUME 9 | 08/2022

BOND | VOLUME 8 | 12/2021

BOND | VOLUME 7 | 10/2020

 

A new smile with only 4 zirconia crowns

Case by Kanstantsin Vyshamirski

 

A male patient (47 years of age) presented to his dentist with severe damage to his teeth. His main request was to increase aesthetics, to achieve a more pleasing envisaged aesthetic area. A side request was to achieve a ‘whitening but natural look’. This was achieved by using a lighter colour palette of zirconia and porcelain materials.

 

The final result was achieved through the creation of a wax-up, followed by a mock-up, provisional restoration and finally adhesive bonding of the zirconia crowns.

 

INITIAL SITUATION

 

Fig. 1. Initial situation. Male patient (47 years of age).

 

Fig. 2. Planning the new smile according to patient’s aesthetic and functional parameters.

 

Fig. 3. Mock-up in place to check the new look in the patient’s mouth.

 

Fig. 4. KATANA™ Zirconia YML shade A1 crowns with labial cutback after milling.

 

Fig. 5. Crowns after sintering on the plaster model.

 

Fig. 6. Noritake CERABIEN™ ZR porcelain layering map.

 

Fig. 7. Finishing the labial surface using both polishing and selfglaze. On the palatal side of the crowns only CERABIEN™ FC Paste Stain stains and glaze were used for finishing. To aid in optimisation of the soft tissue condition the palato-cervical and near proximal areas were polished.

 

Fig. 8. Finished crowns on the plaster model.

 

Fig. 9. Try-in using PANAVIA™ V5 White try-in paste, to confirm the proper appearance. For the final adhesive cementation PANAVIA™ V5 White has been used.

 

FINAL SITUATION

 

Fig. 10. Situation after seven months. The result is aesthetically pleasing and the gingival condition excellent.

 

Fig. 11. Recall after 1.5 years.

 

Dentist:

 

KANSTANTSIN VYSHAMIRSKI

 

Kanstantsin started his dental technician career in 2014. His speciality is aesthetic prosthetic porcelain works. Kanstantsin is an experienced user of KATANA™ Zirconia and Noritake porcelains. He owns his lab in Riga, Latvia.

 

10 years KATANA™ Zirconia multi-layered series

Photo credits to Giuliano Moustakis

 

Can you imagine a world without multi-layered zirconia? The invention of a zirconia material with natural colour gradation and well-balanced translucency and strength led to fundamental changes in the way zirconia-based restorations are produced. When the first product of its kind – KATANA™ Zirconia ML – was introduced to the dental market exactly ten years ago, dental technicians all over the world suddenly started rethinking their manufacturing concepts.

 

Since then, the trend towards a decreased thickness of the porcelain layer, a limiting of this layer to the vestibular area and the production of monolithic restorations is clearly perceivable. Technicians have developed their own concepts of micro-layering, which allow for more patient-centred approaches. This is also due to the fact that the total wall thicknesses of the restorations may be decreased without compromising the aesthetics. The line-up of multi-layered zirconia currently available from Kuraray Noritake Dental Inc. (KATANA™ Zirconia UTML, STML, HTML Plus and KATANA™ Zirconia YML with additional translucency and strength gradation) enables users to make indication-related material choices for the production of restorations that are precisely aligned to the individual demands of each case.

 

The reasons to choose KATANA™ quality

 

But why choose KATANA™ Zirconia instead of any other multi-layered zirconia disc? According to experienced users of the KATANA™ Zirconia Multi-Layered series, there are many reasons to opt for KATANA™.

 

For Jean Chiha, owner at North Star Dental Laboratories and Milling Center in Santa Ana, California, it is the combination of optical and mechanical properties that makes the difference: 

 

“KATANA™ Zirconia is the game changing material with well-balanced esthetics and strength!”. 

 

Naoki Hayashi, president of Ultimate Styles Dental Laboratory in Irvine, California, aesthetics is the most decisive argument to opt for the discs from Kuraray Noritake Dental Inc. He states:


“KATANA™ Zirconia discs offer trusted esthetics which gives me confidence in my clinical cases”.

 

Naoto Yuasa, chief ceramist at Otani Dental Clinic in Tokyo, adds predictability as an important factor:


“KATANA™ sustains my passions for aesthetic restorations and those of a predictable future in the long run”
, whereas dependability is the key element.

 

For Hiroki Goto, the laboratory manager at Sheets and Paquette Dental Practice in Newport Beach, California reports:

 

“Without KATANA™ there is no pride. Haven’t experienced it yet? You have to see how reliable it is!”

 

Finally, we have asked Kazunobu Yamada, a pioneer in making porcelain laminate veneers using complementary color techniques and a first-hour user of KATANA™ Zirconia, what comes to his mind when thinking about KATANA™ Zirconia. According to the president of CUSP Dental Laboratory in Nagoya City, there is a clear link between the product name and its characteristics:

“Did you know that the word "KATANA" also means "protection against misfortune and evil"? Katana zirconia, the culmination of many years of research and development by Kuraray Noritake, has an unparalleled quality. KATANA™, for me, is truly "Protection for all technicians".”

 

The origin of well-balanced properties

 

It seems that the KATANA™ Zirconia Multi-Layered line-up stands out due to set of valuable properties enabling a dental technician to produce beautiful, high-quality restorations every time. The secret of success lies in meticulous raw material selection and controlled processing from the powder to the pre- sintered blank carried out at the production facilities of Kuraray Noritake Dental Inc. in Japan. They provide for the high product quality that is responsible for the materials’ outstanding behaviour supporting the best possible outcomes.

 

Unilateral bite elevation with a zirconia bridge and a lithium disilicate onlay

Clinical case by Dr. Florian Zwiener

 

The 85-year-old female patient presented after osteosynthesis of a multiple mandibular fracture she had sustained after a fall. During fixation, a massive nonocclusion had occurred in the left posterior region of the mandible (teeth 34 to 37; FDI notation). The patient desired to be able to chew properly again in this area. After endodontic treatment of the two avulsed central incisors, which had been replanted in the hospital, and periodontal therapy, a bite elevation was planned on the left side.

 

The idea was to restore the teeth and elevate the bite with three onlays and a crown made of lithium disilicate (IPS e.max CAD, Ivoclar Vivadent). During tooth preparation, however, a longitudinal root fracture was detected on the first molar. Therefore, only the first premolar was restored in this session. For this purpose, an onlay was produced chairside (with the CEREC system, Dentsply Sirona) and adhesively luted with PANAVIA™ V5 (Kuraray Noritake Dental Inc.). The first molar was extracted. One week later, the extraction socket, which was still healing, was modelled for the ovoid pontic using an electrotome loop. The second premolar and molar were prepared as abutment teeth for a bridge. The bridge was then milled from KATANA™ Zirconia Block for Bridge in the shade A3.5 and individualized with CERABIEN™ ZR FC Paste Stain (both Kuraray Noritake Dental inc.). After another week, the bridge was luted with the self-adhesive resin cement PANAVIA™ SA Cement Universal (Kuraray Noritake Dental Inc.) following sandblasting.

 

Fig. 1. Situation after multiple mandibular fracture on the left side.

 

Fig. 2. Clinical situation at the initial appointment in the dental practice.

 

Fig. 3. Open bite in the mandibular left posterior region.

 

Fig. 4. Bridge design …

 

Fig. 5. … using the CEREC Software.

 

Fig. 6. Due to the bright shade of the teeth in the cusp area, the restoration was positioned high in the KATANA™ Zirconia Multi-Layered Block.

 

Fig. 7. Surface texturing in the pre-sintered state (prior to the final sintering procedure).

 

Fig. 8. Bridge after a seven-hour sintering cycle.

 

Fig. 9. Appearance of the bridge after individualization with CERABIEN™ ZR FC Paste Stain …

 

Fig. 10. … and two glaze firings.

 

Fig. 11. Clinical situation after restoring the teeth with a lithium disilicate onlay and a zirconia bridge.

 

FINAL SITUATION

 

Fig. 12. Onlay and bridge in place (after adhesive luting with PANAVIA™ V5 and self-adhesive luting with PANAVIA™ SA Cement Universal).

 

Fig. 13. Final X-ray used to check for excess cement around the bridge.

 

Dentist:

DR. FLORIAN ZWIENER

 

Dr. Florian Zwiener is a distinguished dental professional known for his expertise in Endodontics, Prosthodontics, and CAD/CAM technology. Born in Cologne, Germany, he developed a passion for dentistry and pursued his education at the University of Cologne, where he obtained his degree in Dentistry. Currently, Dr. Florian Zwiener practices at the Dr. Frank Döring Dental Clinic in Hilden, Germany. Here, he continues to apply his specialized knowledge and skills, ensuring that his patients receive the highest quality of care. Follow Dr. Zwiener on Instagram: @dr.florian_zwiener.

 

Clinical case with KATANA™ Zirconia YML

Case by Kanstantsin Vyshamirski

 

A male patient (47 years of age) presented to his dentist with severe damage to his teeth. His main request was to increase aesthetics, to achieve a more pleasing envisaged aesthetic area. A side request was to achieve a ‘whitening but natural look’. This was achieved by using a lighter colour palette of zirconia and porcelain materials. The final result was achieved through the creation of a wax-up, followed by a mock-up, provisional restoration and finally adhesive bonding of the zirconia crowns.

 

Initial situation

Fig. 1. Initial situation. Male patient (47 years of age)

 

Fig. 2. Planning the new smile according to patient’s aesthetic and functional parameters.

 

Fig. 3. Mock-up in place to check the new look in the patient’s mouth.

 

Fig. 4. KATANA™ Zirconia YML shade A1 crowns with labial cutback after milling.

 

Fig. 5. Crowns after sintering on on the plaster model.

 

Fig. 6. Noritake CERABIEN™ ZR porcelain layering map.

 

Fig. 7. Finishing the labial surface using both polishing and selfglaze. On the palatal side of the crowns only CERABIEN™ FC Paste Stain stains and glaze were used for finishing. To aid in optimisation of the soft tissue condition the palato-cervical and near proximal areas were polished.

 

Fig. 8. Finished crowns on the plaster model.

 

Fig. 9. Try-in using PANAVIA™ V5 White try-in paste, to confirm the proper appearance. For the final adhesive cementation PANAVIA™ V5 White has been used.

 

Final situation

Fig. 10. Situation after seven months. The result is aesthetically pleasing and the gingival condition excellent.

 

Fig. 11. Recall after 1.5 years

 

Click here for the product page for more details

What can you expect to find online

- General information about:
- KATANA™ Zirconia YML
- CERABIEN™ ZR porcelains
- FC Paste Stain
- PANAVIA™ V5
- Full Product Assortment
- Safety Data Sheets
- Instructions For Use
- Technical Information

Kanstantsin started his dental technician career in 2014. His speciality is aesthetic prosthetic porcelain works. Kanstantsin is an experienced user of KATANA™ Zirconia and Noritake porcelains. He owns his lab in Riga, Latvia.