Case by Dr. Clarence P. Tam, HBSC, DDS, AAACD, FIADFE

Case background

A stable ASA 2 65 year old female presented to the practice for restorative dentistry with a medical history significant for a non-descript immunoglobulin deficiency, for which she receives regular infusions. She reports no known drug allergies. Clinically, she was diagnosed with an occlusal peripheral rim fracture leaving a food trap on tooth 14 (FDI notation). Tooth 15 featured an extensive amalgam with extreme proximity to the distal marginal ridge, which exhibited distal vertical axial fractures as a result of cyclic expansion-contraction over time. The restorative goal of minimally invasive direct dentistry would be complicated by the undoubtedly dark dentin substrate under the amalgam. A material was sought that featured both an excellent chameleon mechanism as well as physical properties to maximize the prognosis of direct restorations in this area.

Restorative procedure

The patient was subjected to topical anesthetic prior to buccal infiltration using 1 carpule of 2% Lignocaine with 1:100,000 epinephrine. A rubber dam was affixed prior to preparation of tooth 15MO with dissection of the distal vertical marginal ridge fracture. The margins of tooth 14O and 15MOD were refined before bevelling as the ends of enamel rods facilitate better bonding relative to the sides of enamel rods. A 27 micron aluminum oxide micro air abrasion treatment was completed prior to affixing, wedge and matrix to reconstruct the mesial marginal ridge of tooth 15. A matrix-in-matrix solution was used to recreate the proximoaxial contour of 15D. This provided hermetic closure at the proximogingival cavosurface margin as well as an ideal contour for the missing axial wall.

Following a total etch technique, a 2% Chlorhexidine scrub was completed for 30 seconds and the dentin blot dried to a moist state. A 5th generation bond was applied, air thinned and cured as per manufacturer instructions. Microlayers are important during the delicate first 5 minutes of hybrid layer formation, and were completed using 0.25 mm increments of CLEARFIL MAJESTY™ Flow (Kuraray Noritake Dental Inc.). This technique can be expected to increase significantly the shear bond strength to dentin^1,2.

This was completed both in the proximal box floor area as well as mid-occlusally. The marginal ridge was completed using CLEARFIL MAJESTY™ ES-2 Universal (Kuraray Noritake Dental Inc.). Since the dentin base was heavily stained, CLEARFIL MAJESTY™ Flow was used before utilizing CLEARFIL MAJESTY™ ES-2 Universal in a lobe-by-lobe creation of occlusal anatomy. Post-operative occlusal checks verify that the restoration is conformative to occlusion and esthetically excellent with no visible marginal show.

Rationale for material choice

The marginal ridges were micro-layered horizontally as was the floor of the resulting Class I preparation as per a reduced layer thickness-technique modification of Nikolaenko et al³, whereas the highest shear bond strengths were found when a 1mm horizontal layering technique was used.

CLEARFIL MAJESTY™ ES-2 Universal is at the forefront of a simplified restorative armamentarium for the modern practice. It takes cloud-shading one step further by offering a “Universal” shaded composite featuring Light Diffusion Technology (LDT) with simultaneous ideal sculptability, optical metamerism and physical properties for use in any restorative situation in the mouth. Featuring barium glass nano fillers and proprietary pre-polymerized nanoparticle fillers, the latter boasts a high refractive matrix that is able to disperse light and fool the eye with even the thinnest of layers, obviating the need for opaquer composites in cases like the one featured. When paired with CLEARFIL MAJESTY™ Flow in a conservative layered technique, the 81% filled flowable produces a radiographically well-demarcated layer, and the superficial CLEARFIL MAJESTY™ ES-2 Universal boasts an easy-to-polish robust single shade restorative solution that will virtually fulfil all of your restorative needs for non-bleaching patients. Physically, with compressive strength is rated at 348 MPa and flexural strength at 116 MPa, CLEARFIL MAJESTY™ ES-2 Universal is in the range of natural enamel and dentin. The built-in fluorescence is very enamelomimetic, which is excellent for nightclub social situations.

FINAL SITUATION

Dentist:

DR CLARENCE P. TAM, HBSC, DDS, AAACD, FIADFE

Clarence is originally from Toronto, Canada, where she completed her Doctor of Dental Surgery and General Practice Residency at the University of Western Ontario and the University of Toronto, respectively. Clarence’s practice is limited to cosmetic and restorative dentistry and she is well-published to both the local and international dental press, writing articles, reviewing and developing prototype products and techniques in clinical dentistry. She frequently and continually lectures internationally. Clarence is the Immediate Past Chairperson of the New Zealand Academy of Cosmetic Dentistry.

She is currently one of two individuals in Australasia to hold Board-Certified Accredited Member Status with the American Academy of Cosmetic Dentistry. Clarence is an Opinion Leader for multinational dental companies Kuraray Noritake, J Morita Corp, Henry Schein NZ, Ivoclar Vivadent, Dentsply Sirona, 3M, Kerr, GC Australasia, SDI and Coltene and is the only Voco Fellow in Australia and New Zealand. She holds Fellowship status with the International Academy for DentoFacial Esthetics and is a passionate and approachable individual, committed to having an interactive approach with patients in all of her cases to maximize predictability.

References

1. Bertschinger C, Paul SJ, Luthy H, Scharer P. Dual application of dentin bonding agents: effect on bond strength. Am J Dent. 1996;9(3):115-119.
2. Magne P, Kim TH, Cassione D, Donovan TE. Immediate dentin sealing improves bond strengths of indirect restorations. J Prosthet Dent. 2005;94(6):511-519.
3. Nikolaenko SA, Lohbauer U, Roggendorf M, Petschelt A, Dasch W, Franenberberger R. Influence of C-Factor and layering technique on microtensile bond strength to dentin. Dental Mater. 2004;20(6):579-585.

Hear about Aesthetic Dentistry in Optima Forma

Do you believe in an ultimate success formula of aesthetic dentistry? We do, and the speakers of our “IN.DIRECT SYMPOSIUM: Aesthetic Dentistry in Optima Forma” are ready to share all the secrets about it. In a total of eight lectures, eleven extremely knowledgeable dental clinicians, technicians and scientists from all around Europe reveal their own strategies for success in specific clinical situations.

The event takes place on November 5, 2022 at Kristallwelten Swarovski in Wattens near Innsbruck, Austria, and will also be broadcasted online for you free of charge. The symposium will be opened by Kazumitsu Nakatsuka, Head of the Business Unit Medical at Kuraray Europe GmbH, and chaired by Prof. Nicola Scotti from the University of Turin (Italy) and Prof. Dr. Mathias Kern from the University of Kiel (Germany).

Are digital technologies, minimally invasive preparations and zirconia the key factors for success in prosthodontics?

For DT Laura Canale and Dr. Davide Cortellini from Rimini (Italy), they are. In their lecture, they will show us why, focusing on their own philosophy called F.N.P., and on how to create different types of conservative monolithic zirconia restorations with a high level of aesthetics.

Is there an alternative to single-tooth implants especially in the anterior region?

According to Prof. Dr. Mathias Kern, single-retainer resin-bonded bridges made of zirconia are in many cases the better option. He will reveal why they are not only suitable for adolescents with missing anterior teeth, but also for adults with narrow gaps in the anterior region, and why and when they may even be useful in the canine and posterior area.

When to use what type of dental zirconia?

This will be the central question to be answered by Prof. Dr. Benedikt Spies from the University of Freiburg (Germany). With a focus on implant prosthodontics, he will elaborate on the specifications of different zirconia generations and their application as well as integration into a digital workflow.

What is the role of cubic zirconia in modern aesthetic dentistry?

Prof. Nicola Scotti and MDT Daniele Rondoni from Savona (Italy) have chosen to answer this central question, revealing how to realize less invasive preparations, select and process the materials, finish the restorations and place them in the patient’s mouth to provide for aesthetic outcomes that last.

How to proceed when the aesthetic demands are really high?

There is probably nobody who could answer this question better than MDT Nondas Vlachopoulos from Athens (Greece). In his lecture titled “(Micro)veneering”, he shares some ideas on how to exploit the full potential of aesthetic zirconia and veneering porcelain.

What are the key success factors of adhesive cementation?

Prof. Lorenzo Breschi from the University of Bologna (Italy) is the expert of the day on adhesive luting. He will show how to achieve the best bonding performance in terms of bond strength, bond durability, aesthetics and clinical excellence with different restorative materials and in different clinical situations.

What are the indications for the chairside processing of zirconia and when should the laboratory technician take over?

Dr. Claudia Scholz and Dr. Andrea Schädler from Kiel (Germany) have a clear conception of this, and they cannot wait to share it with the audience of the IN.DIRECT SYMPOSIUM. Their practical tips about processing and adhesive cementation are definitely worth gold for CEREC users.

Which factors are likely to influence the accuracy of milled CAD/CAM restorations?

This is the special subject of MUDr. Josef Kunkela, Ph.D. from Jindřichův Hradec (Czech Republic). Based on his own research and clinical experience, he will shed light on production-related differences between CAD/CAM blanks and their impact on the final restoration.

By answering these questions and spreading their ground-breaking ideas, our speakers will surely help us all move several steps closer to our goal of changing dentistry for the better. All this will happen in an inspiring atmosphere, which will be perceivable for you as an online participant as well. To register for live streaming and to obtain additional information about the speakers, lectures and schedule, please visit our symposium website.

We look forward to sharing the vibes with you!

Does 10-MDP primer performs better incorporated or separated from the resin cement?

The secret behind the performance

Kuraray Noritake Dental Inc. developed with success the 10-MDP during the last decades with clinical and scientific evidence. This molecule was incorporated inside the resin paste of different version of PANAVIA™ (21, F2.0). The new formulation of PANAVIA™ V5 offers a new strategy with a primer bottle incorporating the 10-MDP while the resin cement is free of it.

The presentation will show the performance of two cements (PANAVIA™ F 2.0 and V5) on different surfaces with zirconia and zirconia modified glass-ceramic coating. The goal is to evaluate the shear bond strength of enamel to glass-ceramic-coated zirconia and to compare to the results obtained with conventional zirconia and lithium disilicate separately.

Secondly, the presentation aims to compare bond strength between samples luted with a 10-MDP containing resin cement and the ones luted with a 10-MDP monomer separated from the resin cement, on different surfaces. More details will be presented about the most appropriate protocol for an efficient adhesion to ceramic surfaces.

Interested? Come by at IADR in Marseille on September 17^th and join the session with Dr. Etienne at 10:30 AM.

DR. OLIVIER ETIENNE

Dr. Olivier Etienne is University Senior Lecturer and head of the Prosthodontics at the Dental Faculty of Strasbourg. Graduated in 1992, he obtained several post-graduate in prosthodontics (fixed, removable, maxillo-facial) during the following years. He also holds a PhD in Odontological Sciences and devotes his research to biomaterial surfaces and their interactions with biological tissues.

His clinical practice is oriented towards complex prosthetic rehabilitations and esthetics, on natural teeth and implants. He is referent for the maxillofacial prosthesis and for the dental Rare Diseases (O’rare) in Strasbourg. He has been practicing for more than 25 years in a private practice, in parallel of his university activity.

Author and co-author of several books and numerous articles and communications (+200 articles and +30 international) on the topics of esthetic dentistry and implant dentistry, Dr Etienne also actively participates in various National University Diplomas. Head for the Post-graduate diploma in esthetic dentistry since 2018, he also co-directs the Post-graduate diploma of rehabilitation of cleft palate and is involved in the diploma of oral implantology of Strasbourg.

In 2012, Kuraray Medical and Noritake Dental Supply joined forces, and Kuraray Noritake Dental was born. By bringing together the materials and technologies developed by these market-leading companies, Kuraray Noritake Dental has continued to deliver a range of innovative and reliable products to more than 90 countries worldwide. Now, the company is inviting everyone to celebrate its tenth anniversary by attending its upcoming symposium, which has the theme “Up to now and from now on: From innovation to simplification”.

More than four decades ago, Kuraray shook up the dental market with the introduction of CLEARFIL BOND SYSTEM F, the world’s first total-etch adhesive system. Having inaugurated the era of adhesive dentistry, the company continued to introduce new products over the following years and focused on innovation backed by sustained investment in R & D.

The merger of the dental divisions of Kuraray and Noritake means that Kuraray Noritake Dental now benefits from an exceptional knowledge of organic and inorganic chemistry across its suite of dental solutions. The KATANA Zirconia range, for example, employs the company’s unique multi-layered zirconia technology to provide a ceramic restorative material with superior translucency and perfect blending properties, whereas rapid bond technology ensures that CLEARFIL Universal Bond Quick delivers a lasting bond faster and more easily than ever. This ability to deliver products that are easy to use yet do not compromise on quality is what makes Kuraray Noritake Dental stand out.

Join the celebrations on 7 October

For its tenth anniversary symposium, Kuraray Noritake Dental has invited various international key opinion leaders to discuss their experiences with the company’s products. Prof. Bart Van Meerbeek, co-editor-in-chief of the Journal of Adhesive Dentistry and one of the most respected authorities on the topic of dental bonding agents, will pair up with the renowned Prof. Junji Tagami to examine the latest direct bonding and adhesive luting technologies. After this, Drs Michael Skramstad and Sameer Puri will discuss their day-to-day use of translucent dental zirconia and how it can optimise aesthetic outcomes for patients.

Dental technicians Aki Yoshida and Nondas Vlachopoulos will then show participants how to select the best variety of zirconia for various prosthetic production processes, after which Dr Nicola Scotti and Prof. Lorenzo Breschi will demonstrate the reality of modern user-friendly products for direct composite restorations. Finally, Prof. Markus Blatz and Dr Gerard Chiche will outline their decade of experience in using Kuraray Noritake Dental’s self-etching adhesives to bond all-ceramic crowns and onlays.

In between these presentations, a range of short videos will shine a spotlight on Kuraray Noritake Dental’s employees, who will share development stories and interesting facts.

“We’re proud to be experts in creating science-based dental solutions focused on reliability and predictability, and are committed to improving oral health and enhancing quality of life across the world through these products,” a company spokesperson said, adding: “We invite the whole dental team to join us in celebrating ten years of innovation and breakthrough products.”

More information about the symposium can be found here.

Testimonial article by Dr. Troy Schmedding, USA

From PANAVIA™ EX to PANAVIA™ V5, Kuraray Noritake Dental Inc.‘s flagship product line of cements continues to evolve to offer reliable adhesion, enhanced ease of use, and superior esthetics.

Dentistry has certainly evolved in the years since Kuraray Noritake Dental Inc. developed the phosphate monomer MDP. But over the past 4 decades, it has rooted itself in restorative dentistry as the tried-and-true ingredient that clinicians rely on for strong adhesion to tooth structure as well as metals and zirconia. MDP is a key ingredient in the manufacturer’s flagship PANAVIA™ line of cements, which continues to evolve in line with a growing variety of indirect restorative materials from which to choose.

One example of this evolution is PANAVIA™ SA Cement Universal, one of the first true universal self-adhesive resin cements to hit the market. In addition to the original MDP monomer, it incorporates the LCSi monomer, a silane-based carbon chain in a dual-barrel system that forms a chemical bond with glass and ceramic materials.

“PANAVIA™ SA Cement Universal allows you to achieve a strong bond no matter which substrate is being used.”

- Troy Schmedding, DDS –

A STRONG BOND THAT’S SIMPLE TO CREATE

But all chemistry aside, what’s in it for the clinician? As dental educator and author Dr. Troy Schmedding points out, the key benefit of PANAVIA™ SA Cement Universal is eliminating the confusion over how to treat different substrates. This is because the material adheres to virtually every material without the need for a separate primer. “The plus side for the practitioner is that the confusion of ‚how do I condition zirconia‘ or ‚how do I condition glass ceramics‘ is no longer an issue because the paste formulation allows you to achieve a strong bond no matter which substrate is being used - whether it is the MDP monomer allowing strong adhesion to zirconia or the LCSi monomer forming a chemical bond with glass ceramics,” he shared.

DIALING UP THE AESTHETICS

Kuraray Noritake Dental Inc. considers PANAVIA™ V5 the most esthetic cement it has ever created. Available in 5 shades - White, Brown, Universal, Clear, and Opaque – it took researchers over 10 years to develop and features an anime-free catalyst that allows for superior colour stability and improved bond strength to dentin. And like its predecessors, PANAVIA™ V5 offers a simple cementation procedure that is compatible with all indications, from crown-and-bridge and implant abutments to ceramic inlays and laminate veneers.

“Kuraray Noritake Dental Inc. has an incredibly strong reputation in adhesive dentistry, so it should offer clinicians a lot of comfort and flexibility to partner with not only a reputable company, but one that continues to research and evolve their key products,” concluded Dr. Schmedding.

Dentist:

DR. TROY SCHMEDDING, DDS
USA

Article from Dental product shopper, vol. 14 No. 5

PRESENTATION OF A STUDY WITH ILLUSTRATIVE CASES

by Dr. Yohei Sato, DMD, PhD and Dr. Keisuke Ihara, CDT.

INTRODUCTION

In recent years, the application and advancement of digital technology in dentistry has made it possible to accomplish the fabrication of highly accurate prosthetic zirconia appliances that were difficult to mill using the previously available technology. In addition, thanks to advances in adhesive dentistry and the advent of cements that bond strongly to a diverse range of materials, cements have come into wide clinical use that can cope with the many types of materials used for the fabrication of prosthetic appliances.

At our hospital, we select the treatment method most suitable for each case by appropriately specifying various types of prosthetic appliance according to the status of each case. For example, we may specify zirconia prosthetic restorations fabricated by the CAD/CAM system, or silica-based ceramic prostheses, or those made of lithium disilicate glass, as the case dictates.

PANAVIA™ V5 is a resin cement system that bonds strongly to various types of prosthetic appliance, as well as to tooth structure. PANAVIA™ Veneer LC, a new resin cement system developed by Kuraray Noritake Dental Inc., has suitable characteristics for bonding laminate veneers, using two types of primer that can be used in common with PANAVIA™ V5. Here are some clinical examples of its advantages as a resin cement system used for laminate veneers restorations.

JOIN US to celebrate the 10^th anniversary of Kuraray Noritake Dental Inc. on October 7^th, 2022.

Improving dentistry with high-end dental products and solutions – that was the idea behind the merger of the two multinational companies Kuraray Medical and Noritake Dental Supply exactly ten years ago. By combining their expertise in polymer chemistry, chemical engineering and ceramics, Kuraray Noritake Dental Inc. successfully developed a whole range of innovative products and solutions. They support dental professionals in delivering minimally-invasive, sometimes even bio-active dental treatments in straightforward procedures. In the virtual symposium titled “Up to now and from now on: From innovation to simplification”, ten internationally renowned experts will share their scientific, technical and clinical know-how around these materials and approaches. The programme is divided into five sessions that may be attended separately or as a whole.

An update on modern direct bonding and adhesive luting technologies is provided by two eminent authorities in their field, Prof. Junji Tagami (Tokyo Medical and Dental University, Japan) and Prof. Bart Van Meerbeek (University of Leuven, Belgium). The focus will be on the technology behind and the use of the latest generation of universal adhesives and adhesive resin cements.

Is it a good idea to start processing translucent zirconia in the dental office? According to Dr. Mike Skramstad (CEREC trainer and practitioner form Orono, Minnesota) and Dr. Sameer Puri (Director of CAD/CAM at CDOCS), it clearly is, as it may change everyone’s way of practicing dentistry for the better. In their lecture, the two experts describe their chairside workflow in detail, including finishing and polishing steps.

How to select the best zirconia for a specific case? In their lecture, the popular master ceramists RDT Aki Yoshida (Gnathos Dental Studio in Weston, Massachusetts) and DT Nondas Vlachopoulos (AestheticLab in Athens, Greece) present their success strategies. Their focus is on the selection of the best suitable type of zirconia and finishing technique depending on the indication and on patient-specific needs.

Is it possible to simplify direct restorative procedures without compromising the outcomes? In many situations, it is – provided that the right materials and techniques are selected. Dr. Nicola Scotti (University of Turin, Italy) and Prof. Lorenzo Breschi (University of Bologna, Italy) will focus on the single-shade technique, discussing its capabilities and limitations.

How to condition ceramic surfaces prior to their cementation? And what are the parameters guiding the decision for adhesive, self-adhesive or conventional systems? Dr. Gerard Chiche (Augusta University, Dental College of Georgia) and Prof. Dr. Markus B. Blatz (University of Pennsylvania School of Dental Medicine, Philadelphia, Pennsylvania) know the answers. In their lecture, they share exactly the knowledge needed to achieve predictable results.

Register for free!

The symposium starts on October 7, 2022 at 1:00 pm Central European Standard Time. Registration is required and possible for the whole symposium or for specific sessions. Between the lectures, employees from Kuraray Noritake Dental will provide some company insights by sharing facts and stories from their everyday work. In the president’s closing message, an interesting outlook will be given.

Dental professionals attending the full symposium will receive five CE credits, but attending particular sessions of your interest separately is also possible.

For more information and registration, please visit www.kuraraynoritakecampus.com.

Looking for dental opinion leaders

Kuraray Noritake Dental Inc. is dedicated to the fulfilment and success of every dental professional’s career. That is why we never stop developing high-quality dental products and services, while supporting highest-level functional and enduring aesthetic outcomes. Born in Japan; we are proud to be masters in creating science-based, reliable and predictable dental solutions.

Surround yourself with the right people

In order to set the course for ground-breaking future innovations and to put our dental portfolio to the test, we are looking for you! We have established a team of knowledgeable, approachable and friendly professionals to support you and open up access to a vast network of experienced scientists and clinicians to further your career and research efforts whether that is in vitro or in vivo.

Now you know who we are, how about you?

Your insights, ideas and expertise are invaluable to us whether you are working as a general clinician or as a researcher at the university. We are always on the lookout for persons who are interested in investing time to help the dental world understand our product portfolio in detail.

It is your kind of expertise we cannot wait to utilize, be that:

✔ testing and evaluating our products in different stages of development
✔ conducting in-vitro and in-vivo studies with our products and solutions
✔ documenting clinical procedures executed with our products and describing your path to success.

Interested? Come by at IADR in Marseille, September 15-17, 2022, and meet our Scientific Marketing team at booth No. 23.

Case by Dr. Aleksandra Łyżwińska, Warsaw, Poland

ABSTRACT

Indirect overlays are the contemporary restoration standard for posterior teeth with extensive hard tissue loss. They provide for cuspal coverage, which decreases the likeliness of coronal and/or root fracture. At the same time and in contrast to crowns, overlay preparations minimize the removal of sound tooth structure especially in the cervical region, which is a critical factor.¹ Modern dental resin composites allow for direct cuspal coverage in a single-visit appointment. The results of in-vitro studies suggest that these direct overlays are a suitable alternative to their indirect counterparts in specific situations.^2-6 The following case report is used to describe the direct restoration procedure by means of a maxillary right molar with an extensive, deep MOD lesion.

INTRODUCTION

In the context of treating a tooth with an extensive carious lesion, a biomechanical risk assessment should be performed. The primary method of reducing the likeliness of tooth fracture is treatment with a restoration that provides cuspal coverage. The contemporary gold standard for biomechanically compromised teeth are adhesively cemented overlays as an alternative to crowns.¹ Another option that does not involve labwork is a direct overlay restoration.^2-6 The direct approach is especially suitable for long-term temporization, which may be required during orthodontic treatment, for example.

CLINICAL CASE

The 40-year-old male patient was referred to my office before an orthodontic and prosthetic treatment. Intraoral examination (Figs. 1 and 2) revealed:

• Tetracycline discolouration,
• Multiple extensive composite restorations with marginal leakage,
• Primary and secondary carious lesions, and
• Significant mechanical weakness^7,8 (mesio-occluso-distal (MOD) cavities, cusp loss, cracks).

Fig. 1. Initial situation – extensive MOD composite resin restoration.

Fig. 2. Initial situation – unacceptable contact points, palatal wall crack line.

Based on a clinical and radiological examination (Fig. 3), it was decided to restore the maxillary right first molar with a direct overlay, which should serve as a long-term temporary for the duration of orthodontic treatment. Once the local anaesthetic had been administered, rubber dam was placed in the first quadrant and the cusps of the affected first molar were reduced. For subgingival tooth preparation, a rubber dam sheet was temporarily moved behind the second upper molar (Fig. 4). In order to obtain a good emergence profile of the restoration and a tight fit of the sectional matrix, the gingivectomy was performed with an electric surgical knife (Surtron 50D, LED SPA) (Fig. 5). The main advantages of a diathermal cut are instant tissue coagulation and hemostasis⁹.

Fig. 3. Bite-wing radiograph: Maxillary fist molar with an overhang and negative profile of the distal wall.

Fig. 4. Initial preparation with reduction of the cusps and exposure of gingiva.

Fig. 5. Gingivectomy performed using a surgical electric knife.

In accordance with the European Society of Endodontology’s guidelines on the management of deep caries¹⁰, the deepest part of the cavity was cleaned in full rubber dam isolation (Nic Tone Dental Dam, MDC Dental) (Fig. 6). Carious-tissue excavation was carried out using round burs, then the enamel and dentin were air-abraded with 50-μm aluminum oxide (Microetcher IIa, Danville). Multiple cracks, penetrating through the enamel and partially the dentin, occurred within the mesial and palatal walls. The presence of cracks crossing the dentin-enamel junction is an absolute indication to cuspal coverage^8,11.

An appropriate rubber dam isolation is essential in adhesive dentistry. Beyond the obvious advantage of a clean operation field uncontaminated by saliva and moisture, the rubber dam contributes to keeping periodontal tissues at a distance form a tooth. In order to ensure both, maximum retraction and sufficient space to work, the rubber dam was inverted (introduced to the gingival sulcus) and stabilized using PTFE tape (Fig. 7). The mesial wall was restored using a blue 3D Composite-Tight 3D Fusion matrix ring (Garrison) and a medium standard Sectional Contoured Metal Matrix (TOR VM, Fig. 8). Due to its extensiveness and shape, restoration of the distal wall was more difficult to perform.

Fig. 6. Rubber dam newly placed in the interproximal area. Full isolation is essential for the excavation of the infected dentin in the deepest part of the cavity.

Fig. 7. PTFE tape placement for improving isolation in the gingival area. Al₂O₃ sandblasting.

Fig. 8. Mesial matrix fit.

The first attempt to adapt an elongated Sectional Contoured Metal Matrix and the green 3D Composite-Tight 3D Fusion (Garrison) ended with failure (Fig. 9). The matrix was changed for a longer and more curved one (Fig. 10). The ring was replaced by a smaller Palodent V3 Ring (Dentsply Sirona, Fig. 11). Due to the depth of the carious lesion, an antibacterial adhesive system was used (CLEARFIL™ SE Protect, Kuraray Noritake Dental Inc.). It contains the MDPB monomer, which offers an antibacterial effect that lasts even after hybrid layer formation^12-14. Furthermore, the fluoride included in the bond liquid intensifies the cariostatic mechanism of CLEARFIL™ SE Protect and supports the so-called “Super Dentin” formation¹⁵.

Fig. 9. Insufficient fit of the distal matrix.

Fig. 10. New, longer and more curved matrix in place.

Fig. 11. Different matrix ring placed in the distal area.

After polymerization of the bonding agent, the nanohybrid flowable composite resin (CLEARFIL MAJESTY™ ES Flow High, Kuraray Noritake Dental Inc.) was applied in a thin layer. The proximal wall was restored using both packable (CLEARFIL MAJESTY™ ES-2 Universal, Kuraray Noritake Dental Inc.) and flowable composite resin (CLEARFIL MAJESTY™ ES Flow Super Low, Kuraray Noritake Dental Inc.) (Figs. 12 and 13). Core build-up was performed with bulk-fill type composite. The cusps were reconstructed free-hand with the previously used CLEARFIL MAJESTY™ ES-2 Universal (Figs. 14 and 15). The universality of this product provides for a good optical integration and blending with the adjusted tissue, regardless of the colour of the underlying tooth structure. The fissures were gently highlighted using brown tints.

Fig. 12. Thin layer of flowable composite resin CLEARFIL MAJESTY™ ES Flow High (A2) applied on the cavity floor. The proximal walls are built up with build-up by CLEARFIL MAJESTY™ ES-2 Universal and CLEARFIL MAJESTY™ ES Flow Super Low (A2).

Fig. 13. Proximal walls build-up – palatal view.

Fig. 14. Core build-up. Free-hand cusp coverage with CLEARFIL MAJESTY™ ES-2 Universal, palatal view.

Fig. 15. Cusp coverage – occlusal view.

The initial polishing was performed with the rubber dam still in place. The excesses of composite resin were removed with the aid of abrasive discs, diamond burs and a “Brownie” polisher (BAL, Nevadent). Pre-polishing and high-shine polishing were executed with TWIST™ DIA for Composite (Kuraray Europe GmbH.) supported by a goat hair brush (Micerium) (Figs. 16 to 17).

Fig. 16. Occlusal surface after surface modeling with CLEARFIL MAJESTY™ ES-2 Universal and initial polishing.

Fig. 17. Occlusal surface after modeling with CLEARFIL MAJESTY™ ES-2 Universal and initial polishing – palatal view.

After removal of the rubber dam, the occlusal contact points of the direct overlay were adjusted (Figs. 18 and 19). Every spot touched by the burr was subsequently repolished according to the previously described protocol (Figs. 20 and 21).

Fig. 18. Occlusal adjustment. Contact points recorded with articulation paper (100 μm).

Fig. 19. Occlusal adjustment. Contact points recorded with articulation paper (100 μm= and articulation foil (16 μm).

Fig. 20. Final effect after polishing with TWIST™ DIA for Composite.

FINAL SITUATION

Fig. 21. Final effect – palatal view.

CONCLUSION

As a result of decades of improvements mainly with regard to the filler density and polishability, modern dental composites offer a great gloss retention and favourable wear properties. In addition, polymerization shrinkage has been decreased due to the integration of nanohybrid filler technology. Those features allow us to restore biomechanically compromised teeth using a direct restoration technique.

Direct overlays are a suitable alternative for a conventional indirect restoration in many situations.^18,19 According to researchers, the advantages of direct restorations with cuspal coverage include minimal tooth preparation, vital pulp-oriented treatment, the possibility to treat patients in a single appointment and a potentially lower cost of the treatment.^18-20 However, it should be emphasized that the presented technique requires advanced restorative skills that need to be acquired first before starting to implement it.

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 Dentisyty and Endodontics. Her focus lies in modern adhesive techniques, resin composites and biomaterials.

REFERENCES

1. Dietschi D, Duc O, Krejci I, Sadan A. Biomechanical considerations for the restoration of endodontically treated teeth: a systematic review of the literature--Part 1. Composition and micro- and macrostructure alterations. Quintessence Int. 2007 Oct;38(9):733-43.
2. van Dijken JW. Direct resin composite inlays/onlays: an 11 year follow-up. J Dent. 2000 Jul;28(5):299-306. doi: 10.1016/s0300-5712(00)00010-5. PMID: 10785294.
3. Mondelli RF, Ishikiriama SK, de Oliveira Filho O, Mondelli J. Fracture resistance of weakened teeth restored with condensable resin with and without cusp coverage. J Appl Oral Sci. 2009 May-Jun;17(3):161-5.
4. Deliperi S, Bardwell DN. Multiple cuspal-coverage direct composite restorations: functional and esthetic guidelines. J Esthet Restor Dent. 2008;20(5):300-8; discussion 309-12.
5. Deliperi S, Bardwell DN. Clinical evaluation of direct cuspal coverage with posterior composite resin restorations. J Esthet Restor Dent. 2006;18(5):256-65; discussion 266-7.
6. Mincik J, Urban D, Timkova S, Urban R. Fracture Resistance of Endodontically Treated Maxillary Premolars Restored by Various Direct Filling Materials: An In Vitro Study. Int J Biomater. 2016;2016:9138945.
7. Reeh ES, Messer HH, Douglas WH. Reduction in tooth stiffness as a result of endodontic and restorative procedures. J Endod. 1989 Nov;15(11):512-6.
8. Banerji S, Mehta SB, Millar BJ. The management of cracked tooth syndrome in dental practice. Br Dent J. 2017 May 12;222(9):659-666.
9. Bashetty K, Nadig G, Kapoor S. Electrosurgery in aesthetic and restorative dentistry: A literature review and case reports. J Conserv Dent. 2009 Oct;12(4):139-44.
10. European Society of Endodontology (ESE) developed by:, Duncan HF, Galler KM, Tomson PL, Simon S, El-Karim I, Kundzina R, Krastl G, Dammaschke T, Fransson H, Markvart M, Zehnder M, Bjørndal L. European Society of Endodontology position statement: Management of deep caries and the exposed pulp. Int Endod J. 2019 Jul;52(7):923-934.
11. Lynch CD, McConnell RJ. The cracked tooth syndrome. J Can Dent Assoc. 2002 Sep;68(8):470-5.
12. Hashimoto M, Hirose N, Kitagawa H, Yamaguchi S, Imazato S. Improving the durability of resindentin bonds with an antibacterial monomer MDPB. Dent Mater J. 2018 Jul 29;37(4):620-627.
13. Imazato S, Kinomoto Y, Tarumi H, Torii M, Russell RR, McCabe JF. Incorporation of antibacterial monomer MDPB into dentin primer. J Dent Res. 1997 Mar;76(3):768-72.
14. Imazato S, Kinomoto Y, Tarumi H, Ebisu S, Tay FR. Antibacterial activity and bonding characteristics of an adhesive resin containing antibacterial monomer MDPB. Dent Mater. 2003 Jun;19(4):313-9.
15. Nakajima M, Okuda M, Ogata M, Pereira PN, Tagami J, Pashley DH. The durability of a fluoride-releasing resin adhesive system to dentin. Oper Dent. 2003 Mar-Apr;28(2):186-92.
16. Bore Gowda V, Sreenivasa Murthy BV, Hegde S, Venkataramanaswamy SD, Pai VS, Krishna R. Evaluation of Gingival Microleakage in Class II Composite Restorations with Different Lining Techniques: An In Vitro Study. Scientifica (Cairo). 2015;2015:896507.
17. Oficjalne informacje producenta Kuraray Noritake Dental https://www.kuraraynoritake.eu/pl/clearfil-majesty-es-flow (dostęp 08.02.2022).
18. Angeletaki F, Gkogkos A, Papazoglou E, Kloukos D. Direct versus indirect inlay/onlay composite restorations in posterior teeth. A systematic review and meta-analysis. J Dent. 2016 Oct;53:12-21.
19. Dhadwal AS, Hurst D. No difference in the long-term clinical performance of direct and indirect inlay/onlay composite restorations in posterior teeth. Evid Based Dent. 2017 Dec 22;18(4):121-122.
20. Banerji S, Mehta SB, Millar BJ. Cracked tooth syndrome. Part 2: restorative options for the management of cracked tooth syndrome. Br Dent J. 2010 Jun;208(11):503-14.
21. Opdam NJ, Roeters JJ, Loomans BA, Bronkhorst EM. Seven-year clinical evaluation of painful cracked teeth restored with a direct composite restoration. J Endod. 2008 Jul;34(7):808-11.
22. van Dijken JW. Direct resin composite inlays/onlays: an 11 year follow-up. J Dent. 2000 Jul;28(5):299-306.

The vacation period is over and we all are slowly returning back to our everyday routines and work. With all the travel and holidays in the last months you might have missed this great article in the LabLine Summer edition: Graftless solutions and implant-supported monolithic zirconia fixed prostheses.

It is an extensive, beautiful and detailed case report created and documented by team of well known and respected KOLs: Fortunato Alfonsi, Antonio Barone, Marco Stoppaccioli, Romeggio Stefano and Vincenzo Marchio.

Check it out by clicking here.