Case by CDT Mathias Berger, France

Every patient is unique. Their specific backgrounds, functional needs and aesthetic demands need to be respected in any prosthodontic treatment plan. However, the importance of an individual treatment approach increases with the number of teeth to be replaced: After all, the impact of the restorations on facial aesthetics and on the patient’s quality of life is never greater than when all teeth are missing. Fortunately, adequate dental materials and techniques are available for a patient-centered, individual approach, no matter what challenges need to be overcome.

A patient with bruxism

In the present case, an elderly male patient with bruxism was in need of a new maxillary denture. Since the placement of five implants in the maxilla, he had no proprioception in this jaw. This lack of sensation had an impact on the overdenture to be produced: material and design needed to be carefully selected in a way that it would withstand uncontrolled chewing forces. As technical complications are easier to repair than biological complications, the overdenture should not be unbreakable – instead, the replacement of single units should be easily manageable.

Two-part denture design

The solution was a two-part design with a milled bar consisting of the gum area and tooth abutments (fig. 1) combined with single crowns. The material of choice for the bar was KATANA™ Zirconia HTML Plus (Kuraray Noritake Dental Inc.) with a uniform flexural strength of 1,150 MPa throughout the disc, while the single crowns were milled from KATANA™ Zirconia YML that offers natural translucency and strength gradation. While a monolithic design was selected for the posterior crowns, the six crowns for the anterior region received a micro-cutback for aesthetic micro-layering with CERABIEN™ ZR Porcelain. The shade scheme for individualization of the anterior crowns is shown in fig. 2. In a nutshell, customization was performed with the Internal Stains Cervical 1, Grayish Blue, Dark Grey and A+. The finishing layer on the incisors was created mainly using LT0 materials with some CCV-3 on the cervical and LT Natural on the mesial and distal lobes. On the canines, LT1 was used instead of LT0. The posterior crowns were merely finished with liquid ceramics (CERABIEN™ ZR FC Paste Stain, Kuraray Noritake Dental Inc.).

Fig. 1. Sintered bar milled from KATANA™ Zirconia HTML Plus.

Fig. 2. Chroma map for micro-layering in the anterior region.

Fig. 3 shows the finished single crowns with their individual, age-appropriate shade effects on the sintered bar. After checking the fit of the crowns, the gum areas of the bar were individualized using CERABIEN™ ZR Tissue Porcelain (fig. 4). Subsequently, the crowns were luted to the zirconia abutments (fig. 5), leaving screw access holes in aesthetically uncritical positions (fig. 6). The final overdenture ready for try-in is shown in fig. 7. Due to an excellent fit on the implants (fig. 8), it was possible to immediately fix the overdenture with the screws, close the access holes with composite and discharge the patient. The final appearance is shown in fig. 9.

Fig. 3. Finished crowns on the sintered bar.

Fig. 4. Bar with individualized gum areas.

Fig. 5. Placement of the central incisor crowns on the bar.

Fig. 6. Occlusal screw access hole in the finished overdenture.

Fig. 7. Overdenture ready for try-in.

Fig. 8. Intraoral try-in of the aesthetic overdenture.

FINAL SITUATION

Fig. 9. Treatment outcome.

CONCLUSION

This patient case is a good example of how important it is to respect the patient’s background, age and specific demands when producing dental restorations. Thanks to the great variety of restorative materials with different mechanical and optical properties available, it is possible to create suitable prosthetics for virtually every patient. However, for this purpose, it is important to stay up to date regarding new products launched and techniques developed. This way, it is often even possible to create beautiful and durable solutions in a simplified and efficient procedure such as micro-layering on innovative zirconia with a high aesthetic potential.

Dentist:

CDT MATHIAS BERGER

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.

Quantas cores são necessárias?

Caso apresentado por Gasparatos Spyros, estudante de pós-graduação do programa de Dentisteria Restauradora, Faculdade de Medicina Dentária, Universidade Nacional e de Kapodistrian de Atenas, Grécia

Restaurar dentes anteriores com grandes defeitos utilizando compósito pode ser um grande desafio. No entanto, com materiais de alto desempenho à mão e um conceito sistematizado de estratificação em mente, é possível produzir resultados altamente estéticos de maneira reproduzível. O caso clínico aqui apresentado é utilizado para ilustrar uma técnica de estratificação de duas cores com o CLEARFIL MAJESTY™ ES-2 Premium, um sistema de compósito com combinações de cores predefinidas.

Caso clínico

O paciente, um jovem do sexo masculino, estava insatisfeito com a aparência dos seus dentes anteriores superiores. Há vários anos, os seus incisivos centrais tinham sido restaurados com compósito. Estas restaurações tinham margens defeituosas e muito descoloridas, e a sua cor não correspondia à estrutura dentária natural adjacente. Os incisivos laterais superiores tinham forma conoide (microdontia). As considerações económicas e o desejo de salvar o máximo possível de estrutura dentária natural fizeram com que a equipa decidisse restaurar os quatro incisivos superiores com compósito. O CLEARFIL MAJESTY™ ES-2 Premium tornou-se o material de eleição, uma vez que elimina a necessidade de fórmulas complicadas de combinação de cores e permite resultados previsíveis.

Fig. 1. Sorriso inicial do paciente.

Fig. 2. Imagem intraoral da situação inicial com restaurações de compósito defeituosas e microdontia. Dois botões de compósito no incisivo lateral direito são utilizados para verificar a combinação de cores escolhida.

Restauração dos incisivos centrais

Decidimos restaurar primeiro os incisivos centrais e depois concentramo-nos nos incisivos laterais. A cor do dente foi determinada utilizando a guia de cores VITA™ clássica A1-D4, e os botões de compósito foram aplicados nos dentes para verificar a combinação de cores escolhida. Para simplificar o procedimento de restauração, foi produzida uma chave de silicone palatina antes de remover as restaurações existentes. Durante a preparação minimamente invasiva dos dentes foram criados biséis nas margens para proporcionar uma transição óptica suave da estrutura natural do dente para o compósito.

Foi aplicado um adesivo (CLEARFIL™ Universal Bond Quick) após o condicionamento seletivo do esmalte para obter uma adesão forte. Com a ajuda da chave de silicone, foi fácil criar as paredes palatinas das restaurações com CLEARFIL MAJESTY™ ES-2 Premium na cor A3E (esmalte), que corresponde à cor A3 do dente. O núcleo de dentina foi construído com o mesmo compósito na cor recomendada A3D (dentina), os mamelões foram modelados e foi adicionado um pouco de CLEARFIL MAJESTY™ ES-2 Premium na cor WD para o halo incisal. Alguns efeitos individuais (como fissuras no esmalte) foram imitados com corante castanho. A restauração foi finalizada nas áreas interproximais e vestibulares com compósito na cor A3E. Entre os incisivos centrais, foi utilizada uma cunha para retrair a papila e facilitar o desenho da área de contacto interproximal. As restaurações acabadas e pré-polidas já apresentavam um aspeto natural.

Fig. 3. Incisivos centrais após a remoção das restaurações antigas e do biselamento do esmalte.

Fig. 4. Paredes palatinas fotopolimerizadas realizadas com CLEARFIL MAJESTY™ ES-2 Premium na cor A3E.

Fig. 5. Construção do núcleo de dentina com mamelões individualizados utilizando a cor WD e o corante castanho.

Fig. 6. Situação após a finalização das restaurações dos incisivos centrais com compósito na opacidade do esmalte.

Fig. 7. Restaurações dos incisivos centrais após acabamento e polimento inicial.

Restauração dos incisivos laterais

Não foi necessária preparação dentária nos incisivos laterais. Em vez disso, foram apenas limpos após um ligeiro desgaste para aumentar a rugosidade da superfície de esmalte. O procedimento de reconstrução foi semelhante ao utilizado para os incisivos centrais. O dente adjacente foi protegido com fita de PTFE, e a parede palatina foi criada com a ajuda de um dedo em vez da chave de silicone. A seguir, concentrámo-nos na construção das paredes interproximais, depois colocámos uma pequena quantidade de dentina e finalizámos a forma com a aplicação da camada de esmalte vestibular.

Fig. 8. Reconstrução do incisivo lateral esquerdo.

Fig. 9. Situação após o acabamento e polimento.

Situação final

Fig. 10. Sorriso final que responde às exigências do paciente.

Conclusão

Duas opacidades diferentes, uma única combinação de cor e uma cor branqueada, mais um corante para efeitos especiais. No caso deste paciente, uma fórmula simples permitiu-nos criar restaurações anteriores realistas. Com a utilização de uma pasta de esmalte e uma pasta de dentina, é possível reconstruir de forma simples a anatomia natural do dente, sem correr o risco de acabar com um núcleo volumoso que - uma vez reduzido - perderá a sua estrutura óptica especial. Também é fácil controlar a espessura da camada final de esmalte que tem um impacto enorme nas propriedades ópticas de toda a restauração. Para a maioria dos pacientes e de dentes com uma estrutura de cor interna simples ou média/complexa, o conceito selecionado é muito adequado e conduz a resultados agradáveis.

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.

Case report with Dr. José Ignacio Zorzin

Rationalizing clinical workflows: This is the main reason for the use of universal products in adhesive dentistry. They are suitable for a wide range of indications and different application techniques, fulfil their tasks with fewer components than conventional systems and often involve fewer steps in the clinical procedure. Universal adhesives are a prominent example.

How do universal adhesives contribute to a streamlining of workflows?

When restoring teeth with resin composite, the restorative material will undergo volumetric shrinkage upon curing. By bonding the restorative to the tooth structure with an adhesive, the negative consequences of this shrinkage – marginal gap formation, marginal leakage and staining, hypersensitivity issues and the development of secondary caries – are prevented. The first bonding systems available on the dental market were etch-and-rinse adhesives, which typically consisted of three components: an acid etchant, a primer and a separate adhesive. Later generations combined the primer and the adhesive in one bottle, or were two or one-bottle self-etch adhesives. Universal adhesives (also referred to as multi-mode adhesives) may be used with or without a separate phosphoric acid etchant.

Fig. 1. Volumetric shrinkage of resin composite restoratives and its clinical consequences.

Which technique to choose depends on the indication and the clinical situation. In most cases, the best outcomes are obtained after selective etching of the enamel¹. Bonding to enamel is generally found more effective when the enamel is etched with phosphoric acid, while the application of phosphoric acid on large areas of dentin involves the risk of etching deeper than the adhesive is able to hybridize. When the cavity is small, however, selective application of the phosphoric acid etchant to the enamel surface may not be possible, so that a total-etch approach is most appropriate. Finally, in the context of repair, the self-etch approach may be the first choice, as phosphoric acid might impair the bond strength of certain restorative materials by blocking the binding sites. By using a universal adhesive, all these cases may be treated appropriately, as the best suitable etching technique can be selected in every situation.

Apart from the differences related to the use or non-use of phosphoric acid etchant on the enamel or enamel-and-dentin bonding surface, the clinical procedure is always similar with the same universal adhesive. The following clinical case is used to illustrate how to proceed with CLEARFIL™ Universal Bond Quick (Kuraray Noritake Dental Inc.) in the selective enamel etch mode, and it includes some details about the underlying mechanism of adhesion.

How to proceed with selective enamel etching?

A clinical example.

This patient presented with a fractured maxillary lateral incisor, luckily bringing the fragment with him. Hence, it was decided to adhesively lute the fragment to the tooth with an aesthetic flowable resin composite.

Fig. 2. Patient with a fractured maxillary lateral incisor.

Fig. 3. Close-up of the fractured tooth.

Fig. 4. Working field isolated with rubber dam.

As proper isolation of the working field makes the dental practitioner’s life easier, a rubber dam was placed using the split-dam technique. It works well in the anterior region of the maxilla, as the risk of contamination with saliva from the palate is minimal. Once the rubber dam was placed, the bonding surfaces needed to be slightly roughened to refresh the dentin. As the surfaces were also slightly contaminated with blood and it is important to have a completely clean surface for bonding, KATANA™ Cleaner was subsequently applied to the tooth structure, rubbed into the surfaces for ten seconds and then rinsed off. The cleaning agent contains MDP salt with surface-active characteristics that remove all the organic substances from the substrate. The fragment was fixed on a ball-shaped plugger with (polymerised) composite and also cleaned with KATANA™ Cleaner.

Fig. 5. Cleaning of the tooth …

Fig. 6. … and the fragment with KATANA™ Cleaner.

What followed was selective etching of the enamel on the tooth and the fragment for 15 seconds. Whenever selective enamel etching is the aim, it is essential to select an etchant with a stable (non runny) consistency – a property that is offered by K-ETCHANT Syringe (Kuraray Noritake Dental Inc.). Both surfaces were thoroughly rinsed and lightly dried before applying CLEARFIL™ Universal Bond Quick with a rubbing motion. This adhesive is really quick: Study results show that the bond established immediately after application is as strong and durable as after extensive rubbing into the tooth structure for 20 seconds.^2,3 The adhesive layer was carefully air-dried to a very thin layer and finally polymerized on the tooth and on the fragment.

Fig. 7. Selective etching of the enamel of the tooth …

Fig. 8. … and the fragment with phosphoric acid etchant.

Fig. 9. Application …

Fig. 10. … of the universal bonding agent.

Fig. 11. Polymerization of the ultra-thin adhesive layer on the tooth …

Fig. 12. … and the fragment.

What happens to dentin in the selective enamel etch (or self-etch) mode?

After surface preparation or roughening, there is a smear layer on the dentin surface that occludes the dentinal tubules, forms smear plugs that protect the pulp and prevents liquor from affecting the bond. When self-etching the dentin with a universal adhesive, this smear layer is infiltrated and partially dissolved by the mild self-etch formulation (pH > 2) of the universal adhesive. At the same time, the adhesive infiltrates and demineralizes the peritubular dentin. The acid attacks the hydroxyapatite at the collagen fibrils, dissolves calcium and phosphate and hence enlarges the surface. Then, the 10-MDP contained in the formulation reacts with the positively loaded calcium (and phosphate) ions. This ionic interaction is responsible for linking the dentin with the methacrylate and thus for the formation of the hybrid layer.^4,5

In the total-etch mode, the phosphoric acid is responsible for dissolving the smear layer and demineralising the hydroxyapatite. This leads to a collapsing of the collagen fibrils, which need to be rehydrated by the universal adhesive that is applied in the next step. Whenever the acid penetrates deeper into the structures than the adhesive, the collagen fibrils will remain collapsed. This will most likely result in clinical issues including post-operative sensitivity⁶.

When applying the adhesive system, a dental practitioner rarely thinks about what is happening at the interface⁷. However, every user of a universal adhesive should be aware of the fact that a lot is happening there. This is why it is so important to use a high-performance material with well-balanced properties and strictly adhere to the recommended protocols.

Fig. 13. Schematic representation of dentin after tooth preparation: The smear layer on top with its smear plugs occluding the dentinal tubules protects the pulp and prevents liquor from being released into the cavity.

Fig. 14. Schematic representation of dentin after the application of a universal adhesive containing 10-MDP: The mild self-etch formulation partially dissolves and infiltrates the smear layer, while at the same time demineralizing and infiltrating the peritubular dentin5.

In the present case, the tooth and the fragment now needed to be reconnected. For this purpose, CLEARFIL MAJESTY™ ES-Flow (A2 Low) was applied to the tooth structure. The fragment was then repositioned with a silicone index, held in the right position with a plier and light cured. To obtain a smooth margin and glossy surface, the restoration was merely polished. The patient presented after 1.5 years for a recall and the restoration was still in a perfect condition.

Fig. 15. Reconnecting the fragment with the tooth structure.

Fig. 16. Treatment outcome.

Why is it important to adhere to the product-specific protocols?

Universal adhesives contain lots of different technologies in a single bottle. While this fact indeed allows users to rationalize their clinical procedures, it also requires some special attention. As every highly developed material, universal adhesives need to be used according to the protocols recommended by the manufacturer. In general, materials may only be expected to work well on absolutely clean surfaces, while contamination with blood and saliva is likely to decrease the bond strength significantly. Depending on the type of universal adhesive, active application is similarly important, as is proper air-drying and polymerization of the adhesive layer. In addition, care must be taken to use the material in its original state, which means that it needs to be applied directly from the bottle to avoid premature solvent evaporation or chemical reactions. When adhering to these rules, universal adhesives offer several benefits from streamlined procedures to simplified order management and increased sustainability, as fewer bottles are needed and likely to expire before use.

Dentist:

DR. JOSÉ IGNACIO ZORZIN

Dr. José Ignacio Zorzin graduated as dentist at the Friedrich-Alexander University of Erlangen-Nürnberg, Germany, in 2009. He obtained his Doctorate (Dr. med. dent.) in 2011 and 2019 his Habilitation and venia legendi in conservative dentistry, periodontology and pediatric dentistry (“Materials and Techniques in Modern Restorative Dentistry”). Dr. Zorzin works since 2009 at the Dental Clinic 1 for Operative Dentistry and Periodontology, University Hospital Erlangen. He lectures at the Friedrich-Alexander University of Erlangen-Nürnberg in the field of operative dentistry where he leads clinical and pre-clinical courses. His main fields of research are self-adhesive resin luting composites, dentin adhesives, resin composites and ceramics, publishing in international peer-reviewed journals.

References

1. Van Meerbeek, B.; Yoshihara, K.; Van Landuyt, K.; Yoshida, Y.; Peumans, M. From Buonocore‘s Pioneering Acid-Etch Technique to Self-Adhering Restoratives. A Status Perspective of Rapidly Advancing Dental Adhesive Technology. J Adhes Dent 2020, 22, 7-34.
2. Kuno Y, Hosaka K, Nakajima M, Ikeda M, Klein Junior CA, Foxton RM, Tagami J. Incorporation of a hydrophilic amide monomer into a one-step self-etch adhesive to increase dentin bond strength: Effect of application time. Dent Mater J. 2019 Dec 1;38(6):892-899.
3. Nagura Y, Tsujimoto A, Fischer NG, Baruth AG, Barkmeier WW, Takamizawa T, Latta MA, Miyazaki M. Effect of Reduced Universal Adhesive Application Time on Enamel Bond Fatigue and Surface Morphology. Oper Dent. 2019 Jan/Feb;44(1):42-53.
4. Fehrenbach, J., C.P. Isolan, and E.A. Münchow, Is the presence of 10-MDP associated to higher bonding performance for self-etching adhesive systems? A meta-analysis of in vitro studies. Dental Materials, 2021. 37(10): 1463-1485.
5. Van Meerbeek, B., et al., State of the art of self-etch adhesives. Dental Materials, 2011. 27(1): 17-28.
6. Pashley, D.H., et al., State of the art etchand-rinse adhesives. Dent Mater, 2011. 27(1): 1-16.
7. Vermelho, P.M., et al., Adhesion of multimode adhesives to enamel and dentin after one year of water storage. Clinical Oral Investigations, 21(5): 1707-1715.

Clinical Case by DT Ghaith Alousi

What does it take to reconstruct teeth according to the patient’s individual sense of beauty? Experience shows that copying nature is the secret of success. To become a good duplicator, it is essential to develop an eye for detail with regard to tooth forms, surface morphology and the internal colour structure of the teeth to be copied. In addition, the duplicator needs to develop an understanding of the materials and tools used to copy those details. The last key success factor is taking pleasure in interacting with patients.

Read the clinical case created by Ghaith Alousi and published in the LabLine magazine’s Autumn edition now and learn about his approach to creating aesthetic restorations, mimicking nature and truly individualising restorative treatments.

By Dr. Clarence Tam, HBSC, DDS, AAACD, FIADFE

The use of both porcelain veneers to improve and restore the shape, shade and visual position of anterior teeth is a common technique in esthetic dentistry. The biomimetic aim in the restoration of teeth is not only the cosmetic domain, but also functional considerations. It is critical to note that the intact enamel shell of the palatal and facial walls with respect to anterior teeth are responsible for its innate flexural resistance. When dental structure has been violated by endodontic access, caries and/or trauma, every effort must be made to preserve the residual structure and strive to restore or exceed the baseline performance levels of a virgin tooth.

BACKGROUND

A 55 year old ASA II female with a medical history significant only for controlled hypertension presented to the practice for teeth whitening. It was foreseen that dental bleaching would not have an effect on the shade of a pre-existing porcelain veneer on tooth 1.2, and that this would need to be retreated following the procedure especially if the shade value changes were significant. The patient started with a baseline shade of VITA* 1M1:2M1; 50:50 ratio in the upper anterior region and 1M1 in the lower anterior region. Following a nightguard bleaching protocol with 10% carbamide peroxide worn overnight for 3-4 weeks, the patient succeeded in achieving a VITA* 0M3 shade in both upper and lower arches. As a result, there was a significant value discrepancy between the veneered tooth 1.2 and the adjacent teeth, and also increased chroma noted on the contralateral tooth 2.2 due to a facially-involved Class III composite restoration. This latter tooth also did not match the contralateral tooth in dimension and thus the decision was made to treat both lateral incisors with bonded lithium disilicate laminate veneers. The canine adjacent (2.3) featured localized mild to moderate cusp tip attrition, but the patient did not want to address this until following the currently-discussed veneers were placed. The goal of smile design at this stage is to ultimately establish bilateral harmony with the view to place an additional indirect restoration restoring the facial volume and cusp tip deficiency of tooth 2.3 in the near future.

PROCEDURE

A digital smile design protocol was not required for the initial intention, which was individual treatment of the lateral incisors, as slight variation is permitted in this tooth type, being a personality and gender marker of the smile. Prior to anesthesia, the target shade was selected using retracted photos featuring both polarized and unpolarized selections. The photographs were prepared for digital shade calibration by taking reference views with an 18% neutral gray white balance card (Fig. 1).

Fig. 1. Reference photograph taken with a 18% neutral gray card.

The basic body shade was VITA* 0M2 with an ingot shade of BL2. The patient was anesthetized using 1.5 carpules of a 2% Lignocaine solution with 1:100,000 epinephrine before affixing a rubber dam in a split dam orientation. The veneer on tooth 1.2 was sectioned and removed from tooth 1.2 and a minimally-invasive veneer preparation completed on tooth 2.2 (Fig. 2). Partial replacement of the old composite resin restoration was completed on the mesioincisobuccopalatal aspect of tooth 12 with the intact segment maintained. Adhesion to old composite was achieved using both micro particle abrasion and a silane coupling agent (CLEARFIL™ CERAMIC PRIMER PLUS, Kuraray Noritake Dental Inc.). Margins were refined and retraction cords soaked in an aluminum chloride solution and packed. Preparation stump shades were recorded. Final impressions were taken using both light and heavy body polyvinylsiloxane in a metal tray. The patient was provisionalized and sent away with instructions to verify the shade at the laboratory at the bisque bake stage. The models prepared by the laboratory verify the minimally-invasive nature of the case.

Fig. 2. Veneer preparation tooth 1.2, 2.2.

On receipt of the case, the patient was anesthetized and the provisionals removed. The preparations were debrided and prepared for bonding by abrading the surfaces using a 27 micron aluminum oxide powder at 30-40 psi. The veneers were assessed using a clear glycerin try-in paste (PANAVIA™ V5 Try-in Paste Clear, Kuraray Noritake Dental Inc.). Retraction cords were packed and the intaglio surface of the restorations treated using a 5% hydrofluoric acid for 20 seconds prior to application of a 10-MDP-containing silane coupling agent (CLEARFIL™ CERAMIC PRIMER PLUS, Kuraray Noritake Dental Inc.) (Fig. 3). The tooth surface was etched using 33% orthophosphoric acid for 20 seconds and rinsed. A 10-MDP-containing primer was applied to the tooth (PANAVIA™ V5 Tooth Primer, Kuraray Noritake Dental Inc.) (Fig. 4) and air dried as per manufacturer’s instructions. Veneer cement was loaded (PANAVIA™ Veneer LC Paste Clear, Kuraray Noritake Dental Inc.) (Fig. 5) and the veneer seated. The excess cement featured a non-slumpy character and maintained the veneer well in place during all margin verification exercises prior to a 1 second tack cure (Fig. 6).

Fig. 3. CLEARFIL™ CERAMIC PRIMER PLUS applied to intaglio surfaces of veneers.

Fig. 4. PANAVIA™ V5 Tooth Primer application to etched tooth surfaces.

Fig. 5. PANAVIA™ Veneer LC Paste Clear shade loaded onto prepared intaglio surfaces of veneers.

Fig. 6. PANAVIA™ Veneer LC Paste immediately after seating. Note the viscous, non-slumpy nature of the cement, which allows for ease of removal under both wet and gel-phase options.

The cement was rendered into a gel state, which facilitated “clump” or en masse removal of cement with minimal cleanup required (Fig. 7). The margins were coated using a clear glycerin gel prior to final curing to eliminate the oxygen inhibition layer (Fig. 8).

Fig. 7. Excess cement removal after tack curing for 1 second.

Fig. 8. Final curing of veneers from both palatal and facial aspects simultaneously.

The margins were finished and polished to high shine and the occlusion of the restorations verified as conformative. The post-operative views show excellent esthetic marginal integration (Fig. 9).

Fig. 9. Post-operative esthetic integration of veneers on 1.2 and 2.2.

On polarized photograph reassessment, the restorations are well-integrated into the new smile esthetically and functionally (Fig. 10), now awaiting esthetic augmentation of tooth 2.3 to match the contralateral canine.

FINAL SITUATION

Fig. 10. Final result with polarized photography on reassessment.

RATIONALE FOR MATERIAL SELECTION

Porcelain is often the chosen material for prosthetic dental veneers due to its innate stiffness in thin cross section, ability to modify and transmit light for optimal internal refraction and its bondability by way of adhesive protocols to composite resin. This trifecta allows for a maximal preservation of residual tooth structure whilst bolstering its physical function relative to flexural performance¹. The elastic modulus of a tooth can be restored to 96% of its control virgin value if the facial enamel is replaced with a bonded porcelain laminate veneer². The elastic modulus of lithium disilicate is 94 GPa whereas that of intact enamel is 84 GPa. The elastic modulus of dentin has been found to range from 10-25 GPa, whereas that of the hybrid layer can vary widely, indeed from 7.5 GPa to 13.5 GPa in a study by Pongprueska et al³. This low flexural resistance range reflects that of deep dentin and not that of superficial dentin, which does not reflect an ideal situation where a laminate veneer is bonded in as much enamel as possible, or in the worst case to superficial dentin. Maximal flexural strength of the hybrid layer is invaluable from a biomimetic standpoint. PANAVIA™ V5 Tooth Primer (Kuraray Noritake Dental Inc.) incorporates the use of the original 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) monomer, which elicits a pattern of stable calcium-phosphate nanolayering known as Superdentin, an acid-base resistant zone that is about 600x more insoluble than the monomer 4-MET, which is found in many other adhesives. Indeed, PANAVIA™ V5 Tooth Primer is used solely in conjunction with Kuraray Noritake Dental Inc. PANAVIA™ V5 cement and PANAVIA™ Veneer LC which both allow the primer to act as a bond without the need to cure the layer prior to cementation of the indirect restoration due to its dual cure potential when married together. If a bonding agent would be preferred, CLEARFIL™ Universal Bond Quick (Kuraray Noritake Dental Inc.), a multi-modal adhesive that also contains the essential amide monomer and 10-MDP components created by Kuraray Noritake Dental Inc., can be used. Of note, CLEARFIL™ Universal Bond Quick features exceptional flexural strength due to the accentuated cross-linking during polymerization afforded by the amide monomers, on the order of 120 MPa by itself⁴. PANAVIA™ Veneer LC is a cement system that features cutting edge technology that provides excellent esthetics and adhesive stability of your indirect restorations, whilst allowing a stress free workflow. It is a cement system that is a game changer; one that allows you to restore confidence in the patient, strength in the tooth-restoration interface, and bolsters your clinical confidence in the delivery of biomimetic excellence.

Dentist:

CLARENCE TAM

References

1. Magne P, Douglas WH. Rationalization of esthetic restorative dentistry based on biomimetics. J Esthet Dent. 1999;11(1):5-15. doi: 10.1111/j.1708-8240.1999.tb00371.x. PMID: 10337285.
2. Magne P, Douglas WH. Porcelain veneers: dentin bonding optimization and biomimetic recovery of the crown. Int J Prosthodont. 1999 Mar-Apr;12(2):111-21. PMID: 10371912.
3. Pongprueksa P, Kuphasuk W, Senawongse P. The elastic moduli across various types of resin/dentin interfaces. Dent Mater. 2008 Aug;24(8):1102-6. doi: 10.1016/j.dental.2007.12.008. Epub 2008 Mar 4. PMID: 18304626.
4. Source: Kuraray Noritake Dental Inc. Samples (beam shape; 25 x 2 x 2 mm): The solvents of each material were removed by blowing mild air prior to the test.

Clinical Case by MDT Mathias Berger

Highly reliable implants, advanced surgical techniques and innovative restorative materials, designs and approaches: modern implant dentistry has evolved into a predictable discipline producing aesthetic and functional outcomes, which are successful in the long term. Asking patients what they expect from a complex implant-supported reconstruction in the maxilla, natural aesthetics and biocompatibility are often demanded apart from functional aspects. With modern zirconia materials that offer the flexural strength required and well-balanced aesthetics, these demands are easily met.

The following case example is used to demonstrate how to maximise the potential of the recently introduced KATANA™ Zirconia HTML PLUS (Kuraray Noritake Dental Inc.), a multi-layered zirconia and the successor of KATANA™ Zirconia HTML with further improved strength and aesthetics. A special cutback design refined with hand instruments, shading with Esthetic Colorant for KATANA™ Zirconia and micro-layering with CERABIEN™ ZR porcelains (both Kuraray Noritake Dental Inc.) led to a quite natural result.

Start now reading the clinical case of MDT Mathias Berger by clicking image below!

A combinação de líquidos de efeito e microestratificação em zircónia altamente estética é a forma eficaz de obter resultados excecionais.

Caso por Leonidas Dimitriou, MDT

Como complemento ao seu portfólio bem alinhado de zircónia multicamadas (série KATANA™ Zirconia Multi-Layered) e cerâmica de facetas para zircónia (CERABIEN™ ZR), a Kuraray Noritake Dental Inc. introduziu recentemente um conjunto de líquidos de coloração. O Esthetic Colorant for KATANA™ Zirconia é aplicado na superfície da restauração de zircónia monolítica ou anatomicamente reduzida antes do procedimento de sinterização final. Desta forma, é possível imitar facilmente os efeitos de cor internos típicos dos dentes naturais. Dependendo do resultado desejado, os utilizadores podem adicionar apenas uma camada final de glaze, cerâmica líquida ou stains e cerâmicas às suas restaurações de zircónia tratadas com Esthetic Colorant. Os dois exemplos de casos seguintes são utilizados para demonstrar dois procedimentos diferentes que envolvem a utilização dos líquidos de efeito.

EXEMPLO DE CASO 1

No primeiro caso, produzimos três restaurações de dois elementos para seis dentes anteriores do maxilar. As coroas de zircónia (feitas de KATANA Zirconia YML) foram anatomicamente reduzidas e individualizadas com Esthetic Colorant principalmente nas áreas incisais e cervicais imediatamente após a fresagem. Para a aplicação dos líquidos selecionados, utilizámos a Liquid Brush Pen especificamente desenvolvida para o Esthetic Colorant. As restaurações foram secas durante meia hora, colocadas no forno de sinterização para sinterização de acordo com o protocolo recomendado para a KATANA Zirconia e subsequentemente acabadas com cerâmicas CERABIEN ZR. Finalmente, foi aplicado o CERABIEN™ ZR FC Paste Stain Glaze para o acabamento final de alto brilho.

Fig. 1. Coroas pré-sinterizadas anatomicamente reduzidas após a fresagem.

Fig. 2. Corante Esthetic Colorant aplicado nas restaurações fresadas.

Fig. 3. Aspeto das restaurações individualizadas após o procedimento de sinterização final.

Fig. 4. Restaurações após a estratificação em cerâmica.

Situação final

Fig. 5. Restaurações finais com um aspeto natural. Os efeitos criados com o Esthetic Colorant brilham a partir do interior das restaurações.

Fig. 6. Vista lateral das restaurações finais a partir da esquerda.

Fig. 7. Vista lateral das restaurações finais a partir da direita.

EXEMPLO DE CASO 2

Neste segundo caso, foram produzidas duas restaurações de três elementos utilizando KATANA Zirconia YML na cor A3. Desenhámo-las e fresámo-las em contorno total, depois reduzimo-las com instrumentos manuais em 0,2 mm e adicionámos alguns efeitos de textura à superfície antes de aplicar o Esthetic Colorant. Neste caso, brincámos com diferentes tonalidades de Esthetic Colorant. Mesmo quando aplicado numa superfície minimamente reduzida ou monolítica, os líquidos são capazes de criar um efeito de profundidade agradável à medida que se difundem na estrutura de zircónia. A quantidade de líquido aplicado é facilmente controlada com a caneta Liquid Brush Pen, de modo a que a intensidade das cores seja previsível. Após a sinterização, adicionámos alguns pigmentos internos, cerâmica CERABIEN ZR Luster e uma camada final de CERABIEN ZR FC Paste Stain Glaze para terminar as restaurações. O resultado fala por si.

Fig. 8. Restaurações monolíticas fresadas com uma textura de superfície pronunciada.

Fig. 9. Superfícies vestibulares e palatinas individualizadas com Esthetic Colorant para criar e intensificar alguns efeitos de cor naturais.

Fig. 10. Aspeto das restaurações imediatamente após a sinterização.

Fig. 11. Restaurações após maquiagem interna.

Fig. 12. Uma camada de cerâmica Luster aplicada às restaurações minimamente reduzidas.

Situação final

Fig. 13. Resultado final após o glazeamento.

Técnico dentário:

LEONIDAS DIMITRIOU, MDT

A revista LabLine é uma publicação de língua inglesa que se destina ao campo da medicina dentária em laboratório. Fornece uma cobertura abrangente das mais recentes técnicas e tendências em tecnologia e materiais de laboratório dentário, apresentando-as através de casos clínicos sofisticados, desafiantes e estéticos realizados por alguns dos especialistas mais conhecidos na Europa. Com o seu conteúdo selecionado por especialistas, a LabLine serve como um recurso inestimável para profissionais de medicina dentária que procuram melhorar os seus conhecimentos e manter-se na vanguarda da indústria.

Na edição SPRING da LabLine pode encontrar um maravilhoso CASO ESTÉTICO de Mikel Villar Gonzales e DT Pilar Ballesteros Galan. A paciente, uma mulher de 21 anos de idade, tinha um defeito de hipoplasia nos seus dentes permanentes 1.1 e 1.2, presumivelmente devido a um trauma nos seus dentes anteriores decíduos. Clique na imagem abaixo e veja como o caso foi realizado!