In.direct symposium on Aesthetic Dental Collaboration

Minimally invasive preparations, aesthetic high-quality materials, patient-centered approaches: these are the key ingredients needed for successful restorative dentistry. Eleven renowned dental clinicians, technicians and scientists from all around Europe shared their own strategies for success during the IN.DIRECT SYMPOSIUM on Aesthetic Dental Collaboration that took place on November 5, 2022 at Kristallwelten Swarovski in Wattens near Innsbruck, Austria.

Kazumitsu Nakatsuka, Head of the Business Unit Medical at Kuraray Europe GmbH, extended a warm welcome to the 132 professionals in Wattens and more than 1,500 online participants. He introduced the two chairmen of the event, Prof. Nicola Scotti from the University of Turin (Italy) and Prof. Dr. Mathias Kern from the University of Kiel (Germany). They guided through the programme with its eight lectures focusing on different aspects of restorative dentistry.

The speakers of the IN.DIRECT Symposium: MDT Daniele Rondoni, Prof. Lorenzo Breschi, MDT Nondas Vlachopoulos, Dr. Claudia Scholz, Dr. Andrea Schädler, Prof. Nicola Scotti, Prof. Dr. Mathias Kern, Dr. Davide Cortellini, DT Laura Canale and MUDr. Josef Kunkela, Ph.D. Missing: Prof. Dr. Benedikt Spies.

Consider a feather-edge preparation for full-coverage crowns

Whenever a patient is in need of full-coverage crowns, a clinician should consider opting for a feather-edge preparation instead of a chamfer or shoulder preparation. This was the key message of Dr. Davide Cortellini from Riccione (Italy), who held his lecture together with DT Laura Canale from Rimini. According to the speakers, the feather-edge preparation allows for greater preservation of healthy tooth structures, provides for stability and aesthetics of the gingival tissues and is effortlessly captured with an intraoral scanner. The technique is technically challenging in that the restorative material needs to be thinned out considerably at the margin. With its low minimum wall thickness, high edge stability and superior mechanical properties, monolithic zirconia seems to be the best suited material for this approach.

DT. Laura Canale and Dr. Davide Cortellini.

Offer single-retainer resin-bonded bridges as an alternative to implants

When a single tooth is missing in the anterior region, single-retainer resin-bonded bridges made of 3Y-TZP zirconia may be the best-suitable option preferred by a patient. As Prof. Dr. Mathias Kern stressed during his lecture, they are the only immediate treatment option for young patients with incomplete dentoalveolar development, fit into narrow edentulous spaces (< 7 mm) and are feasible in cases with angulated roots or insufficient bone quantity. Moreover, they have the same positive impact on the patient’s quality of life as implants, while they are clinically proven with high survival rates of 95.4 percent after 15 years¹. Even in the canine and posterior area, zirconia-based single-retainer resin-bonded bridges offer promising results. Key to success is a meticulous bonding procedure involving low-pressure air-borne particle abrasion and the use of an adhesive resin cement system containing MDP (e.g., PANAVIA™ V5).

Give preference to monolithic restorations on implants

On implants, monolithic restorations seem to have the edge over veneered ones. The reason was presented by Prof. Dr. Benedikt Spies from the University of Freiburg (Germany): technical complications are less likely to occur. Lithium disilicate is the proven solution for single units, while zirconia (with its higher strength) leads to promising results in multi-unit reconstructions. One of the beneficial properties of zirconia is the fact that a perfectly polished surface will remain smooth even after aging and loading, which is an indicator of antagonist-friendly behaviour.

Save tooth structure by choosing cubic zirconia with a zero or micro cutback

With its favourable aesthetic properties, cubic zirconia allows users to reduce the wall thickness of their restorations for minimally invasive treatments. As revealed by Prof. Nicola Scotti and MDT Daniele Rondoni from Savona (Italy), the plastic-elastic behaviour of cubic zirconia is similar to that of enamel, so that it is ideally suited as a replacement of enamel structures. The decision to opt for a purely monolithic design and individualization with liquid ceramics (CERABIEN™ ZR FC Paste Stain) or a micro cutback with a micro-layering approach is mainly guided by aesthetics. The amount of reduction in the case of a cutback should be age-related according to Daniele Rondoni, with slightly more porcelain added in young than in older patients. In any case, the occlusal contact surface should be in zirconia and very well polished.

MDT Daniele Rondoni, Prof. Nicola Scotti and Prof. Dr. Manfred Kern during the discussion.

Open the doors for incredible aesthetics with synthetic feldspathic porcelain

The use of synthetic feldspathic porcelain (CERABIEN™ ZR) – either applied solely for porcelain layering on refractory dies or on top of zirconia frameworks – allows for a precise imitation of natural teeth with all their individual characteristics. Tips on how to exploit the full potential of aesthetic zirconia and veneering porcelain were given by MDT Nondas Vlachopoulos from Athens (Greece). He showed several clinical case examples to explain his philosophy and approach, which is minimally to non-invasive and put emphasis on respecting the biological structures. Particularly with the aid of the internal stain technique, the speaker is able to precisely reproduce virtually every characteristic optical effect – from enamel cracks to white spots – depending on the patient’s desires.

MDT Nondas Vlachopoulos.

Adhere to the recommended protocols for success in adhesive cementation

Achieving a strong and durable bond of indirect restorations to tooth structure is easier as it might seem according to Prof. Lorenzo Breschi from the University of Bologna (Italy). He recommended the use of universal resin cement (like PANAVIA™ SA Cement Universal) in the self-adhesive mode for crowns with retentive features made of non-etchable materials. Whenever retention is insufficient and a lot of dentin is exposed, an additional adhesive should be applied to the tooth structure – preferably after selective etching of the enamel. As PANAVIA™ SA Cement Universal contains silane (the LCSi monomer) and the MDP monomer, a separate restoration primer is not needed even with silica-based ceramics. However, a pre-treatment of the restoration’s bonding surface is strictly required, the method depending on whether the material is etchable or not. In cases with a subgingival preparation margin when isolation is difficult, the speaker suggested to use a selective adhesive approach with application of an adhesive everywhere but close to the gingival fluids, so that additional bond strength is offered precisely where needed.

Solve complex cases chairside step by step

Single-visit treatments are the reason for many patients to opt for chairside dentistry. In fact, various clinical situations can be solved chairside, and in many of them, zirconia is the material of choice. Dr. Claudia Scholz and Dr. Andrea Schädler from Kiel (Germany) prefer using KATANA™ Zirconia Block for many indications, and even solve complex cases like full mouth rehabilitations step by step in single units. The shared several tricks e.g. on how to realize bridges on implants by milling and placing the abutments first, scanning them like natural tooth abutments and then producing the bridge. Their experience shows that chairside dentistry is stretched to its limits when the aesthetic demands are particularly high, the insertion direction of implant-based restorations is not clear or the size of a restoration is larger than the largest available block.

Dr. Andrea Schädler and Dr. Claudia Scholz.

Select the restorative material carefully to pave the way for a precise fit

The accuracy of milled CAD/CAM restorations is strongly dependent on the material choice. As MUDr. Josef Kunkela, Ph.D. from Jindřichův Hradec (Czech Republic) showed using his own research results, the internal fit, marginal and dimensional stability (particularly important in complex, long-span reconstructions), and the surface quality of restorations vary not only between, but also within the different material classes. Among all tested materials, different types of KATANA™ Zirconia performed best with regard to the size of the cement gap, margin and surface quality and full-arch distortion. The differences between various types of zirconia may be due to differences in the material composition and blank production. Everyone valuing accuracy and quality of dental restorations should be aware of these factors and carefully select the restorative materials to pave the way for optimal outcomes.

MUDr. Josef Kunkela, Ph.D.

Modern approaches to aesthetic dentistry

CAD/CAM dentistry, innovative restorative materials and adhesive technology have clearly smoothened the way for highly aesthetic, minimally invasive restorative treatment approaches. During the IN.DIRECT Symposium, it became clear that there are many different highly successful strategies available, and that it is the task of the restorative team to select the appropriate option based on the clinical situation and the specific needs of the patient. In the end, patient satisfaction and quality of life are the main indicators of a successful restorative therapy.

The lectures will be available soon on demand on our website, in the newsroom section. Keep an eye out for the announcements on social media. Coming soon…

References

1. Kern M. Fifteen-year survival of anterior all-ceramic cantilever resin-bonded fixed dental prostheses. J Dent. 2017 Jan;56:133-135.

• Nov 11, 2022