Amalgam replacement with flowable composite

Case by Dr. Julien Molia

 

YES, IT WORKS!

In the minds of many dental practitioners, it has become firmly established that flowable composites are nice liner or base materials below stronger packable composites and indirect restorations or as a temporization material. Many of them assume, however, that their use is limited due to their poor mechanical properties.

 

A NEW GENERATION OF FLOWABLES

Luckily, this is no longer true: Several flowable composites of the latest generation – like CLEARFIL MAJESTY™ ES Flow and CLEARFIL MAJESTY™ ES Flow Universal (both Kuraray Noritake Dental Inc.) – are equipped with mechanical properties, which are on par with those of many packable alternatives. Consequently, the range of indications is extended. For example, CLEARFIL MAJESTY™ ES Flow Universal, has a high filler loading of 75 to 78 wt/%, a flexural strength of more than 150 MPa and a compressive strength exceeding 370 MPa according to the manufacturer. Thanks to its high strength, it serves as a reliable and permanent solution, even suitable for stress-bearing areas such as the occlusal surfaces of posterior teeth.

 

However, this flowable composite has even more to offer: It is available in two levels of flowability – LOW and SUPER LOW – to serve a wider range of personal preferences and individual indication-specific needs and in just two shades (universal and universal dark). The latter offers the benefit of intuitive shade selection even in the anterior area and is enabled by a mixture of shade matching technologies, including optimized light diffusion technology and an enamel-like translucency.

 

The following case example reveals how CLEARFIL MAJESTY™ ES Flow Universal makes my life easier in posterior restoration procedures.

 

CASE EXAMPLE

This patient presented for the replacement of two amalgam restorations in the mandibular right molars (teeth # 46 and 47 according to the FDI notation) (Fig. 1). As it would facilitate filling and provide for great adaptation to the cavity walls, it was decided to use CLEARFIL MAJESTY™ ES Flow Universal LOW as the only restorative material. The position of the teeth to be restored made shade selection easy: Shade U (universal) is designed to work perfectly for all posterior restorations.

 

The amalgam restorations were removed and caries was excavated, while saving as much of the healthy tooth structure as possible (Figs. 2 and 3). A selective enamel etching technique was chosen, followed by the application of a universal adhesive (CLEARFIL™ Universal Bond Quick 2, Kuraray Noritake Dental Inc.). Subsequently, CLEARFIL MAJESTY™ ES Flow Universal in the LOW version and the selected shade U was applied into the cavities (Fig. 4). Thanks to the innovative syringe design, the applied flowable composite is virtually free of voids. In line with the instructions for use of the product, the thickness of each layer did not exceed 2 millimetres to provide for a complete cure (Figs. 5 and 6), which has a decisive impact on the long-term performance of the final restorations. Each layer should be thoroughly cured for 10 to 20 seconds (depending on the curing light) before the next layer is applied. As shown in Figure 7, the low flowability of the selected material allows for some modelling of the occlusal surface morphology. When more anatomical details need to be restored, the steadier SUPER LOW variant may be an option. It took just a few seconds to polish the restorations to high gloss (Fig. 8).

 

Fig. 1. Two amalgam restorations to be replaced.

 

Fig. 2. Situation after removal of the existing amalgam restorations.

 

Fig. 3. Typical amalgam staining is visible at the bottom of the larger cavity.

 

Fig. 4. Filling procedure: Application of the first layer of flowable composite.

 

Fig. 5. Second molar already filled, first molar in need of another layer of flowable composite.

 

Fig. 6. Filling completed.

 

Fig. 7. Nice surface morphology and shade blend-in.

 

Fig. 8. Treatment outcome after rubber dam removal. The restorations blend in nicely with the surrounding dentition – qua shade and surface gloss.

 

EASY-TO-USE ALTERNATIVE TO PACKABLE COMPOSITES

Especially in difficult-to-reach areas in the mouth, the use of a flowable composite with well-balanced mechanical properties can be a nice alternative to packable ones. Advanced shade-matching abilities, virtually void-free application, easy adaptation and modelling, and quick polishing truly simplify the life of the dental practitioner. However, many assume their use is limited due to poor mechanical properties.

Dentist:

JULIEN MOLIA

 

Dr. Julien Molia graduated in 2008 with a thesis on computer-assisted implantology. He established a general dental practice in Saint-Jean-de-Luz, where he has since focused on implant surgery and jawbone reconstruction. In 2017, he completed a second university degree in implantology to update and deepen his expertise. He has also pursued advanced training in digital dentistry, orthodontic miniscrews, and mucogingival surgery. Committed to tissue preservation, he trained privately with Drs. Gil Tirlet and Jean-Pierre Attal in Paris. Dr. Molia is a founding member of the French Southwest BioTeam, a collaborative group dedicated to clinical research and innovation.

 

Restoring confidence after trauma: a biomimetic approach

Case by Dt. Koray Kendir, DDS, Turkey (İzmir)

 

INTRODUCTION

Trauma-related fractures of anterior teeth require a precise balance between aesthetics and function, often under emotional pressure from the patient. This clinical case demonstrates the restorative rehabilitation of a previously mismanaged central incisor using CLEARFIL MAJESTY™ ES-2 Premium and PANAVIA™ V5 (both Kuraray Noritake Dental Inc.). The team followed a biomimetic approach to re-establish biological, functional, and aesthetic harmony.

 

CASE SUMMARY

A 23-year-old female patient presented one month after a traumatic injury involving tooth #11 (FDI notation). Immediate root canal treatment and a direct composite build-up had been performed elsewhere in a single visit. The existing restoration showed poor aesthetics and marginal adaptation (Fig. 1).

 

Fig. 1. Initial clinical situation.

 

CLINICAL PROCEDURE

STEP 1: ISOLATION AND REMOVAL OF OLD RESTORATION

For the planned rehabilitation, the tooth was isolated with rubber dam (Figs. 2 and 3) and the existing composite restoration was removed. Gutta-percha from the previous endodontic treatment was found to be severely coronally trimmed (Fig. 4). This poses a risk of future discolouration. Consequently, the gutta-percha was condensed apically to a more biologically appropriate level using a downpack device (Figs. 5 to 9).

 

Fig. 2. Isolation of the working field with rubber dam: Labial view.

 

Fig. 3. Isolation of the working field with rubber dam: Occlusal view.

 

Fig. 4. Gutta-percha from the previous treatment.

 

Fig. 5. Gutta-percha removed, …

 

Fig. 6. … placed back into the root canal …

 

Fig. 7. … and condensed …

 

Fig. 8. … with a downpack device.

 

Fig. 9. Result of the procedure: Occlusal view.

 

STEP 2: CORE BUILD-UP

Subsequently, a fiber-reinforced composite was used to provide root-anchored support for the core structure. Then, the bonding surface was treated with phosphoric acid etchant, CLEARFIL™ Universal Bond Quick (Kuraray Noritake Dental Inc.) was applied as a universal adhesive and the core build-up was performed with CLEARFIL MAJESTY™ ES-2 Premium A1D (Figs. 10 to 13).

 

Fig. 10. Etching with phosphoric acid etchant.

 

Fig. 11. Application of the universal adhesive.

 

Fig. 12. Core build-up after thorough light curing.

 

Fig. 13. Intra-oral periapical radiograph or the treated tooth.

 

STEP 3: PREPARATION AND DIGITAL IMPRESSION

For definitive restoration, a 3/4 crown preparation was performed and an intraoral scan was taken. Moreover, a temporary crown was fabricated (Fig. 14) and shade photos were taken to finalize the session.

 

Fig. 14. Temporary restoration in place.

 

STEP 4: FINAL CEMENTATION

Once the lithium disilicate restoration was received from the laboratory, the temporary crown was removed and the abutment tooth was evaluated (Figs. 15 and 16). Try-in was performed using PANAVIA™ V5 Try-in Paste White to check shade and fit (Fig. 17). No modifications were required; the selected try-in paste contributed to a lifelike appearance of the restoration. For definitive placement, the intaglio surface of the crown was etched with hydrofluoric acid (Fig. 18). Figure 19 shows the appearance of the intaglio after this measure. To provide for optimal bonding conditions, the tooth surface was then cleaned with KATANA™ Cleaner (Kuraray Noritake Dental Inc.), which should be applied with a rubbing motion to the contaminated prepared tooth for more than ten seconds (Figs. 20 to 22). It may also be used to clean the intaglio of a restoration, which is contaminated with blood and saliva e.g. after try-in.

 

Fig. 15. Situation after removal of the temporary crown: Labial view.

 

Fig. 16. Situation after removal of the temporary crown: Occlusal view.

 

Fig. 17. Try-in of the lithium disilicate crown.

 

Fig. 18. Etching of the crown’s intaglio surface with hydrofluoric acid.

 

Fig. 19. Appearance of the etched surface.

 

Fig. 20. Cleaning of the abutment tooth …

 

Fig. 21. … surface covered with the cleaning agent.

 

Fig. 22. Thorough rinsing, which should be followed by drying with air.

 

Adhesive cementation itself was accomplished with the three-component PANAVIA™ V5 (Figs. 23 to 28): The prepared tooth structure and build-up was treated with PANAVIA™ V5 Tooth Primer, the intaglio surface of the crown with CLEARFIL™ CERAMIC PRIMER PLUS. Finally, PANAVIA™ V5 Universal (White) was extruded into the crown and the crown placed. Excess cement is best removed in the gel phase – i.e. after brief polymerization for 3 to 5 seconds before final light curing is performed. Alternatively, it may be removed immediately after seating the restoration with a brush or similar instrument. In this case the first option was chosen. The treatment outcome after rubber dam removal and final clinical and aesthetic evaluation is displayed in Figure 29.

 

Fig. 23. Priming of the tooth structure.

 

Fig. 24. Selected resin cement.

 

Fig. 25. Tooth structure ready for crown placement.

 

Fig. 26. Restoration in place.

 

Fig. 27. Lateral view of the restoration.

 

Fig. 28. Final light curing of the crown.

 

Fig. 29. Treatment outcome immediately after rubber dam removal.

 

CONCLUSION

This case highlights a comprehensive restorative approach to preserving a traumatized anterior tooth at risk of loss, while restoring both function and aesthetics. The strong core foundation provided by CLEARFIL MAJESTY™ ES-2 Premium and the reliable adhesive performance of PANAVIA™ V5 played a pivotal role in the successful procedure and outcome.

 

Dentist:

KORAY KENDIR

 

Dt. Koray Kendir is a graduate of Hacettepe University Faculty of Dentistry and the co-founder of a private dental clinic in İzmir. He specializes in digital dentistry, smile design, and computer-aided restorative treatments. Known for his innovative approach, Dr. Kendir is a frequent speaker at national dental congresses and serves as an advisor to several dental companies.

 

Performance and practicality

Case by A/Prof Alan Yap, BDS (Syd), MDSc Hons (Pros)(Syd), FAANZP

 

Since 1983 PANAVIA™ by Kuraray Noritake Dental Inc. has been the gold standard for dental cements throughout the world. Their latest cement, PANAVIA™ Veneer LC, sets a new standard for porcelain veneer cements through incredible performance and ease of use. The following clinical case demonstrates the use of PANAVIA™ Veneer LC.

 

A 31-year-old female (Fig. 1) was referred for porcelain veneers to replace lost tooth structure and to improve aesthetics. The patient exhibited moderate attrition of her anterior and bicuspid teeth (Fig. 2), the result of nocturnal bruxism and a tendency to an edge-to-edge occlusion. She had a Class I malocclusion on a Skeletal Class I tending III base with the right maxillary canine in cross-bite. The treatment plan included orthodontic treatment, porcelain veneers, and an occlusal splint.

 

Fig. 1

 

Fig. 2

 

Orthodontic treatment (by Dr Nour Tarraf) included full-fixed appliances with TADs and IPR of mandibular anteriors, and arch retractions to reduce protrusion (Fig. 3, post-orthodontic treatment). A preliminary digital design (Fig. 4) was performed to guide the diagnostic wax-up and a digital mock-up (Fig. 5) was utilised to verify the diagnostic wax-up prior to carrying out the intra-oral mock-up. The patient was unable to afford the restoration of the maxillary bicuspids until a later stage so the reconstruction was limited to the maxillary anterior teeth.

 

Fig. 3

 

Fig. 4

 

Fig. 5

 

Using the diagnostic wax-up, silicone keys were fabricated to guide tooth preparations. Orthodontic treatment allowed prosthetic treatment to be additive in design which meant that tooth preparations could be conservative. Labial reductions were limited to 0.3 mm and incisal reductions were performed only where needed to create an incisal butt joint for the veneer (Fig. 6). Minimal preparations allowed the veneers to be bonded almost entirely to enamel, which is important for the long-term survival of porcelain veneers (Ref 1). There was no need to significantly mask the colour of the cervical region of the tooth and non-carious cervical lesions were absent, so fine chamfer margins were prepared at equi-gingival level.

 

Fig. 6

 

Splinted provisional veneers (Fig. 7) were fabricated using bisacryl ensuring sufficient interdental space to allow hygiene access for small interdental brushes. The labial surface of the provisional veneers were glazed with a unfilled resin and cemented using the spot-etch technique, ensuring all excess flowable composite was removed prior to curing (Fig. 8). Twice daily interdental cleaning of the provisional veneers and thorough brushing of labial margins during the provisional phase maintained soft tissue health, important for the try-in and cementation of the definitive veneers.

 

Fig. 7

 

Fig. 8

 

A dry try-in of the definitive veneers was performed to check the fit of the veneers and a wet try-in was performed using try-in paste to assess aesthetics. The PANAVIA™ Try-in pastes accurately mimic the cement shades. Four useful shades are available (Fig. 9). The White and Brown shades are useful to correct small discrepancies in shade requiring subtle increases or decreases in shade value respectively. Conveniently the try-in pastes are the same as the PANAVIA™ V5 range of try-in pastes (excluding opaque). Following the try-in procedure the teeth were isolated using rubber dam and the floss ligature technique. KATANA™ Cleaner (Fig. 10) was used to clean the veneers prior to silanating with CLEARFIL™ CERAMIC PRIMER PLUS (Fig. 11).

 

Fig. 9

 

Fig. 10

 

Fig. 11

 

Veneers that have not been pre-etched should be etched with hydrofluoric acid prior to silanization. The use of the ProsMate™ Baton allows the cleaning, etching and silanization of all veneers simultaneously (Fig. 12). The veneers are arranged systematically on the ProsMate™ Tray ready for the cementation procedure (Fig. 13). Tooth surfaces were pre-treated with phosphoric acid (K-ETCHANT Syringe) and PANAVIA™ V5 Tooth Primer (Fig. 14).

 

Fig. 12

 

Fig. 13

 

Fig. 14

 

The newly designed cement applicator tip reduces air bubbles and the wide 16-gauge tip (Fig. 15) allows light and easy control of cement extrusion while also providing efficient wide coverage during application. PANAVIA™ Veneer LC has excellent handling because of its ideal paste consistency. It is non-sticky and its viscosity prevents the cement from flowing beyond the veneer margins until the veneer is seated. It is not runny or stringy. Furthermore its thixotropic properties results in lower film thickness during seating of the veneer. These excellent handling properties are due to the development of new filler technology which consists of spherical silica and nano cluster fillers (Fig. 16). The “touch-cure” mechanism of PANAVIA™ V5 Tooth Primer importantly seals the bonding interface while the extended working time and stability of the cement under ambient light allows the simultaneous cementation of multiple veneers. In this case all six lithium disilicate veneers (technical work by Yugo Hatai) were cemented simultaneously with PANAVIA™ Veneer LC Paste (Clear).

 

Fig. 15

 

Fig. 16

 

Tack-curing each veneer for one second allowed smooth and easy bulk removal of excess cement with an explorer (Fig. 17). Remaining excess of uncured paste was removed with brushes. Final curing was performed by light curing lingual and labial surfaces.

 

Fig. 17

 

The optical characteristics of PANAVIA™ Veneer LC, use of fine chamfer margins, and well-fitting translucent restorations produces a gradual and smooth transition of colour from tooth to veneer where margins disappear and soft tissues respond in a healthy way (Fig. 18). The color stability, excellent abrasion resistance and high gloss durability of PANAVIA™ Veneer LC preserves integrity and aesthetics at the margins over the long term. The extraordinary bond strength of PANAVIA™ products, so familiar to our profession over the last 20 years, is still second to none (Fig. 19).

 

Fig. 18

 

Fig. 19

 

“KATANA” is a registered trademark or trademark of NORITAKE CO., LIMITED - “PANAVIA” and “CLEARFIL” are registered trademarks or trademarks of KURARAY CO., LTD.

 

References

1. Layton DM, Walton TR. The up to 21-year clinical outcome and survival of feldspathic porcelain veneers: accounting for clustering. Int J Prosthodont. 2012 Nov-Dec; 25(6):604-12. PMID: 23101040.

 

Optimalisering av funksjonelle og estetiske parametre ved sementering av skallfasetter

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

 

Anvendelse av skallfasetter av porselen for å forbedre form, farge og stilling på fortenner er en vanlig teknikk innen estetisk tannbehandling. Det biomimetiske målet ved tannrestaurering er ikke bare kosmetisk, men også funksjonelt. Det er avgjørende å huske på at det intakte emaljeskallet palatinalt og buccalt på anteriore tenner er ansvarlig for deres medfødte bøyestyrke. Når tannstrukturen er skadet ved endodontisk behandling, karies eller traumer, må ingen anstrengelser skys når det gjelder å bevare gjenværende tannstruktur og etterstrebe å gjenopprette eller øke styrken så den er på linje med en intakt tann.

 

BAKGRUNN

 

En 55 år gammel kvinnelig pasient tok kontakt på klinikken fordi hun ønsket å bleke tennene. Hun ble forklart at blekingen ikke ville ha effekt på en eksisterende skallfasett på 12. Denne ville måtte byttes ut etter blekingen. Pasientens utgangsfarge var VITA* 1M1 og 2M1 (på gingivale halvpart) Blekeprotokollen var nattbleking med 10% karbamidperoksid i 3-4 uker. Fargen var da VITA* 0M3 både på overkjeve og underkjeve. Det var derfor en vesentlig fargeforskjell på 12 og de øvrige tennene. Dessuten var en klasse III komposittfylling på 22 blitt mere synlig. Tann 22 matchet heller ikke 12 i dimensjon, og det ble derfor besluttet å fremstille skallfasetter av litium disilikat på begge lateraler. Tann 23 hadde mild attrisjon på cuspen, men pasienten ønsket ingen behandling av dette på det nåværende stadium. Behandlingen besto derfor i å etablere bilateral harmoni, for så å gjenopprette buccal kontur og cusp på 23 i nær fremtid.

 

BEHANDLINGEN

 

En digital smile design protokoll var ikke nødvendig for denne behandlingen, som besto i å behandle lateralene. En viss individuell og kjønnsbasert variasjon er vanlig for disse tennene. Før LA ble fargen for restaureringen tatt ut ved hjelp av fotos i polarisert og upolarisert lys.

 

Fig. 1. Referansefoto med 18% nøytral grått kort.

 

Grunnfargen (body) var Vita OM2 med en blokkfarge BL2. Pas ble bedøvd med 1,5 karpule med 2% Lignocaine med 1:100,000 adrenalin, før kofferdam ble satt på.(Split dam teknikk). Skallfasetten på 12 ble spaltet og fjernet fra tannen, og en minimal invasiv preparering gjort ferdig på 22 (Fig.2). Det ble gjort en delvis utskifting av den gamle komposittfyllingen mbp på12. Adhesjon til gammel kompositt ble oppnådd både ved sandblåsing og en silan (CLEARFIL™ CERAMIC PRIMER PLUS. Prepareringsgrensene ble frisket opp, og retraksjonstråd dyppet i aluminiumklorid-løsning ble pakket i sulcus. Fargen på de preparerte tennene ble notert. Endelig avtrykk ble tatt med light-body og heavy-body silikonmateriale i metall-skje. Pasienten fikk temporære restaureringer og fikk beskjed om å få fargen bekreftet på laboratoriet (grovbrent). Modellene som er fremstilt på laboratoriet bekrefter den minimal invasive fremgangsmåten.

 

 

Fig. 2. Preparering for skallfasetter på 12 og 22.

 

Da arbeidene kom fra laboratoriet, ble pas. bedøvd og provisoriene ble fjernet. Prepareringene ble rengjort og forberedt for bonding ved sandblåsing med 27 mikron aluminiumoksid-pulver med trykk på 30-40 psi. Skallfasettene ble prøvd på plass med innprøvingspasata (PANAVIA™ V5 Tryin- Paste Clear, Kuraray Noritake Dental Inc.). Retraksjonstråder ble plassert og adhesiv overflate på restaureringene ble behandlet med 5% flussyre i 20 sek. før silanet (CLEARFIL™ CERAMIC PRIMER PLUS) ble applisert. (Fig. 3). Tannoverflaten ble etset med 33% fosforsyre i 20 sek. og skylt. En primer med MDP (PANAVIA™ V5 Tooth Primer) ble så applisert på tannen (Fig. 4) og lufttørket som beskrevet i bruksanvisningen. Så ble sementen (PANAVIA™ Veneer LC Paste Clear) (Fig. 5) applisert og skallfasetten ble satt på plass. Overskuddssementen hadde en ikke-rennende konsistens og holdt skallfasetten på plass mens kanttilpasning ble sjekket, og ble så raskt lysherdet i 1 sek. (tack cure) (Fig.6).

 

Fig. 3. CLEARFIL™ CERAMIC PRIMER PLUS ble applisert på de flatene som skulle bondes.

 

Fig. 4. PANAVIA™ V5 Tooth Primer applisert på etsede tannflater.

 

Fig. 5. PANAVIA™ Venneer LC Paste Clear appliseres på skallfasettens innside.

 

Fig. 6. PANAVIA™ Veneer LC Paste Clear umiddelbart etter at fasetten er satt på plass. Legg merke til den viskøse, ikkerennende konsistensen som gjør det enkelt å fjerne sementen både i uherdet fase og i gel-fasen.

 

Sementen forvandles til gel-form, noe som gjør fjerning av overskudd og rengjøring av restaureringen mye enklere (Fig. 7). Kantene på restaureringen dekkes med en klar glycerin-gel før endelig herding for å eliminere oksygeninhibisjon. (Fig. 8).

 

Fig. 7. Fjerning av overskudds-sement etter lysherding i 1 sek. (tack-cure)

 

Fig. 8. Sluttherding av skallfasetter samtidig buccalt fra og palatinalt fra.

 

Kantene pusses til høyglans og restaureringene sjekkes i okklusjon og artikulasjon. Postoperative bilder viser usynlige skjøter (Fig. 9).

 

 

Fig. 9. Postoperativ estetisk tilpasning av skallfasetter på 12 og 22.

 

Vurdering med foto i polarisert lys viser at restaureringene er integrert både estetisk og funksjonelt (Fig. 10), Nå venter estetisk forbedring av tann 23 for å matche 13.

 

SLUTTRESULTAT

 

Fig. 10. Endelig resultat vurdert i polarisert lys.

 

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.

 

Amalgam replacement: Why and when hybrid ceramics are a great option

Case by Dr. Enzo Attanasio

 

The selection of the restorative material is a crucial step in prosthodontics. Hybrid ceramics offer a range of properties well-suited for various therapeutic situations, both in the presence of vital teeth and of endodontically treated teeth. Using the example of a clinical case, this article will explore the advantages associated with the use of hybrid ceramics in a cracked tooth syndrome scenario.

 

INITIAL SITUATION

The affected tooth in this case was a mandibular right second premolar (45 according to the FDI notation) with an old amalgam restoration (Figs. 1 and 2). The patient experienced pain upon chewing (specifically upon release). Clinically, there were visible horizontal and vertical crack lines. The tooth was vital and showed no signs of pulpal pathology. It was decided to replace the amalgam restoration and restore the tooth with an overlay made of the hybrid ceramic KATANA™ AVENCIA™ Block. There were two main reasons for this decision. First, whenever root canal treatment would be necessary in the future, the hybrid ceramic material would facilitate endodontic access cavity preparation (compared to any other ceramic material) and subsequent restoration with composite filling material. Second, hybrid ceramics offer greater resistance and improved mechanical properties compared to composite filling materials applied in an incremental layering technique.

 

Fig. 1. Initial situation: Occlusal view.

 

Fig. 2. Initial situation: Buccal view.

 

PREPARATION AND IMMEDIATE DENTIN SEALING

To remove the amalgam restoration and weakened surrounding tooth structure, the occlusal surface of the tooth was reduced by approximately 2 mm. For a smooth colour transition between the tooth and the restoration, the preparation outline was created at the level of interproximal boxes with a vestibular inclined plane (Fig. 3). Subsequently, Immediate Dentinal Sealing (IDS) was carried out (Figs. 4 to 10). This technique involves the use of a universal adhesive like CLEARFIL™ Universal Bond Quick, which is applied to the preparation without prior etching of the peripheral enamel. In the second step, a highly filled flowable composite is applied. In the present case, the material of choice was CLEARFIL MAJESTY™ ES Flow Super Low, applied in a thickness of just 0.5 mm. The preparation was refined using ultrasonic instrumentation: Sonic tips SFM7 and SFD7 (Komet Dental) for refining the boxes; SFD1F and SFM1F (Komet Dental) for margins and steps. Sharp edges were rounded with abrasive discs and then polished with fine polishers. It is crucial that the residual occlusal thickness (prosthetic space) is 1.5 mm, as required by the selected material.

 

Fig. 3. Prepared tooth structure prior to immediate dentin sealing.

 

Fig. 4. IDS: Application of the universal adhesive.

 

Fig. 5. IDS: Light curing of the adhesive layer.

 

Fig. 6. Thin layer of flowable composite applied to the preparation.

 

Fig. 7. Contouring, …

 

Fig. 8. … rounding off sharp edges …

 

Fig. 9. … and polishing of the sealed surface with dedicated instruments.

 

Fig. 10. Sealed tooth preparation ready for impression taking.

 

FROM SCANNING TO TRY-IN

Following digital scanning with the intraoral scanner Primescan™ (Dentsply Sirona), MDT Daniele Rondoni produced the restoration (Figs. 11 and 12). The cementation process involves an initial try in phase to assess the marginal fit of the overlay and the contact areas. Testing occlusion at this stage could be risky as it may lead to fracture of the restoration in case of excessive premature contacts. After try-in (when carried out without rubber dam), the restoration may be contaminated by blood, saliva, or glycerin gel used for the evaluation of fit and aesthetics. Therefore, it is necessary to clean the restoration before proceeding with adhesive phases. The use of a cotton pellet soaked in alcohol is an option, a cleaning agent like KATANA™ Cleaner may be even better as it chemically cleans the restoration and eliminates the contaminants.

 

Fig. 11. Hybrid ceramic overlay on the printed model.

 

Fig. 12. Separate overlay.

 

CONDITIONING OF THE TOOTH AND THE RESTORATION

Afterwards, the restoration was sandblasted (as recommended for most hybrid ceramics) with 50 μm aluminum oxide using AquaCare (Akura Medical) (Fig. 13), and then immersed in distilled water in an ultrasonic bath for 5 minutes. Meanwhile, rubber dam was placed over the entire sextant, the build-up was sandblasted like the intaglio of the overlay and a phosphoric acid etchant (Ultra Etch, Ultradent) was applied to the enamel, rinsed off and the area dried (Figs. 14 to 17). The clean restoration was subsequently conditioned with a silane containing 10-MDP (CLEARFIL™ Ceramic Primer Plus, Kuraray Noritake Dental Inc.) according to the manufacturer’s instructions (Fig. 18). What followed was the application of the universal adhesive (CLEARFIL™ Universal Bond Quick) to the intaglio of the overlay and to the preparation and light curing on both sites (Figs. 19 and 20). One of the advantages of universal adhesives compared to three-step adhesive systems is their minimal film thickness, which does not compromise the fit of the restoration.

 

It is important to protect adjacent teeth with metal matrix strips during adhesive phases to provide for proper fitting. These elements do not create operational difficulties, but serve their purpose: After restoration placement, the composite or cement used for placement will be easily removable from the mesial and distal surfaces of the adjacent teeth, as they are free of adhesive.

 

Fig. 13. Sandblasting of the overlay …

 

Fig. 14. … and the tooth structure.

 

Fig. 15. Selective etching of the enamel, …

 

Fig. 16. … followed by thorough rinsing. Adjacent teeth are protected by a metal matrix strip.

 

Fig. 17. Tooth structure after selective etching, rinsing and drying.

 

Fig. 18. Silane application.

 

Fig. 19. Application of the universal adhesive into the overlay.

 

Fig. 20. Treatment of the tooth structure with the universal adhesive.

 

DEFINITIVE PLACEMENT

In the present case, a heated composite paste (heated to a temperature of 55 °C) was extruded into the restoration, which was then placed by applying slow, gradual, and strong pressure (Figs. 21 and 22). Excess composite was removed with a scaler in the buccal and lingual areas and floss (e.g. SuperFloss®, Oral-B) in the interproximal areas. Several pressurization phases were performed until no more composite was observed at the tooth-restoration interface.

 

Fig. 21. Heated composite paste used for definitive placement.

 

Fig. 22. Restoration placed under rubber dam isolation.

 

Then, the composite was polymerized for 30 seconds from the buccal and lingual sides with two curing lights, before applying glycerin gel to the margins and polymerizing from occlusal for another minute (Fig. 23). If thorough attention is given to removing excess composite during placement phases, subsequent finishing steps will be quick and easy (Figs. 24 to 27). Finishing and polishing of the interproximal areas was accomplished with an EVA handpiece and 3M™ Sof-Lex™ Finishing Strips (3M). For finishing of the buccal and lingual areas, a medium-grit, flame-shaped diamond bur (diameter 14/16) was used. Finally, the margins should be polished using composite polishers like TWIST™ DIA for Composite (Kuraray Noritake Dental Inc.). After the local anesthesia wears off, one should observe the cessation of pain symptoms, as seen in the present case. The treatment outcome is displayed in Figures 28 and 29.

 

Fig. 23. Light curing through a layer of glycerin gel blocking the oxygen.

 

Fig. 24. Finishing of the buccal and lingual margin with a medium-grid, flame-shaped diamond bur.

 

Fig. 25. Finishing of the interproximal areas with EVA handpiece (fine grain).

 

Fig. 26. Checking the occlusal contacts.

 

Fig. 27. Occlusal polishing.

 

FINAL SITUATION

Fig. 28. Treatment outcome – buccal view.

 

Fig. 29. Treatment outcome – occlusal view.

 

CONCLUSION

For posterior teeth restored with amalgam and a significant level of destruction, restoration replacement with hybrid ceramic overlays can be a great option. Mechanical material properties are usually superior to those of layered composites, processing is possible chairside or labside and comparatively quick (no firing required), while the clinical placement procedure is similar to that involved in placing glass ceramics – with the major difference of sandblasting instead of etching the intaglio of the restoration. One of the most important benefits of hybrid ceramics over glass ceramics, however, is the ability to modify the restoration whenever desired. Endodontic access cavities are easily prepared and closed with composite, contact points are quickly adjusted and the surface is polished or re-polished in next to no time. Moreover, the wear properties are similar to those of tooth structure and patients are happy about a natural touch and feel. The aesthetic properties are quite impressive, too.

 

Dentist:

ENZO ATTANASIO

 

Enzo Attanasio graduated in 2008 in Dentistry and Dental Prosthetics from the Magna Graecia University of Catanzaro. In 2009, he went on to specialize in the use of laser and new technologies in the treatment of oral and perioral tissues at the University of Florence. That year he also attended Prof. Arnaldo Castellucci’s course in Clinical Endodontics at the Teaching Center of Microendodontics in Florence where, in 2012, he went on to complete his training in Surgical Microendodontics. In 2017 he attended a course on Direct and indirect Adhesive Restorations at Prof. Riccardo Becciani’s Think Adhesive training center in Florence where he later become a tutor. Today, as a member of the Italian AIC and based in Lamezia Terme, Italy, Dr Attanasio has a special interest in Endodontics and Aesthetic Conservative.

 

Same-day dentistry: Replacement of two PFM crowns with zirconia restorations

Clinical case by Dr. Frank Heldenbergh

 

The advancements in zirconia in contemporary dentistry nowadays allow for a wider range of applications, including in the anterior sector, and for chairside production using dedicated CAD/CAM systems. Even without a cutback, KATANA™ Zirconia Block (STML), combined with CERABIEN™ ZR FC Paste Stain (both Kuraray Noritake Dental Inc.), offer an extremely satisfactory aesthetic solution.

 

In the present patient case, the materials were chosen to replace old PFM crowns on the maxillary central incisors. The planned treatment was in accordance with the patient's wishes, and carried out in a single appointment.

 

CASE DESCRIPTION

The patient asked for a replacement of the existing crowns on the two maxillary central incisors (teeth 11 and 21, FDI notation). The porcelain-fused-to-metal (PFM) restorations had been in place for about thirty years (Figure 1). She desired aesthetic improvements and slight repositioning of these two teeth.

 

TREATMENT PLAN

In agreement with the patient, it was decided to perform the entire procedure in one appointment: removal of the existing crowns, digital impressions, production, and bonding of new restorations. The periodontium was healthy with no bleeding. The only uncertainty was whether the existing crowns were cemented onto inlay-cores or if they were Richmond crowns. A preliminary silicone impression was taken as a precautious measure: in case something unexpected prevented the new crowns from being bonded during the session, it would be easily possible to produce temporary crowns.

 

Fig. 1. Initial clinical situation.

 

TREATMENT

Using a diamond bur followed by a tungsten carbide bur, the existing crowns were removed, revealing that they indeed were Richmond crowns. Because the anatomy of the intra-radicular posts clearly contraindicates an attempt to remove these posts, it was decided to trim the crowns to transform them into inlay cores rather than risk further damage. The corono-peripheral preparations were reworked at the same time. One of the major challenges was related to the necessity of masking the metal of the transformed coronal-radicular reconstructions. Luckily, the space available was sufficient for the production of full zirconia crowns with a significant thickness (Figure 2). The target shade of the crowns was chosen in consultation with the patient (Figure 3).

 

Fig. 2. Situation after removal of the existing restorations.

 

Fig. 3. Shade determination using a shade tab: A2 was the appropriate shade.

 

Subsequently, impressions were taken using and intraoral scanner, the virtual models were checked and the crowns designed, considering the patient's request to have her two incisors slightly retracted (Figures 4 and 5).

 

Fig. 4. Virtual models of the patient’s teeth with the newly designed crowns, revealing the space available for a slight retraction.

 

Fig. 5. Designing of the two crowns.

 

The two crowns were milled from KATANA™ Zirconia Block 14Z A2 (Figure 6). A quick reminder: unlike lithium disilicate, zirconia prosthetic parts cannot be tried in immediately after milling, as they are around 20 percent larger than their final size after sintering. Final sintering was performed within about 18 minutes using the furnace SINTRA CS (ShenPaz Dental Ltd). After this process, the crowns may be tried on to check their fit, shape, shade and optical integration.

 

Fig. 6. Milled crowns in the CAD/CAM blocks.

 

For finishing of the restorations, different options are available. In this case, we decided not to limit ourselves to mechanical polishing of the prosthetic parts, as zirconia does not fluoresce like natural teeth. To add fluorescence as an optical feature, the surface was lightly stained and glazed with CERABIEN™ ZR FC Paste Stain (Figure 7).

 

Fig. 7. Crowns in the furnace after staining and glazing with liquid ceramics.

 

After firing, the two incisor crowns were tried in again using a try-in paste corresponding to the chosen resin cement system (PANAVIA™ V5, Kuraray Noritake Dental). In this way, the final appearance was simulated to validate the shade of the cement. The intaglio surfaces of the crowns were then sandblasted before applying CLEARFIL™ CERAMIC PRIMER PLUS as the restoration primer. The prepared teeth were treated with KATANA™ Cleaner (Kuraray Noritake Dental Inc.) to decontaminate the surface from proteins in saliva and possibly blood. Those clean surfaces are ideal for bonding. After thorough rinsing and drying, PANAVIA™ V5 Tooth Primer (containing MDP monomer for bonding with the hydroxyapatite and metal of the preparation) was applied according to the manufacturer’s instructions (Figure 8).

 

Fig. 8. Selected cementation system and try-in.

 

Subsequently, PANAVIA™ V5 Paste was applied into the first crown, which was then seated, followed by tack curing (brief photopolymerization for three to five seconds), excess removal and final light curing from all sides.

 

The procedure was then repeated for the second maxillary central incisor. The result instantly satisfied the patient, both in terms of aesthetics (adaptation, position of the new crowns, mimicry) and the comfort provided (Figures 9 and 10).

 

Fig. 9. Crowns immediately after placement.

 

Fig. 10. Aesthetically pleasing and comfortable result.

 

At a recall after four months, soft tissue conditions were ideal and the patient was happy with the outcome (Figures 11 to 13). The selected zirconia had nice optical properties, masking of the metal posts was successful and the natural surface texture contributed its share to a nice overall picture. The retracted position of the teeth was also perceived positively by the patient, while comfort and function were excellent.

 

DISCUSSION

Although lithium disilicate has so far been considered the material of choice for prosthetic work in the anterior region, zirconia is nowadays proving to be an extremely satisfactory alternative from every point of view: milling, strength, aesthetics, assembly (among other things, no hydrofluoric acid is required for bonding). KATANA™ Zirconia Blocks (STML) with a multi-layered colour structure in a single 4Y-TZP zirconia block, combined with CERABIEN™ ZR FC Paste Stain, offer a remarkable solution. This applies to treatments around the replacement of existing crowns as well as first-line treatments with less invasive preparations (verti-prep) than those required by other types of ceramics.

 

Fig. 11. The patient’s smile at a recall after four months.

 

Fig. 12. Great optical integration.

 

Fig. 13. Natural surface texture contributing to success Control pictures after four months taken by Emmanuel Charleux.

 

Dentist:

FRANK HELDENBERGH

 

Dr. Frank Heldenbergh graduated with a Doctor of Dental Surgery degree from the University of Reims in 1988.Driven by a passion for prosthetics, he pursued further specialization as a Prosthetic Resident at the UFR Odontology of Reims from 1990 to 1992. Dr. Heldenbergh’s dedication to advancing dental practices led him to join the Board of the Academy of Adhesive Dentistry in 1999. His commitment to this field has been unwavering, and he currently serves as the Vice President of A.D.D.A.-R.C.A.

 

Recognized for his expertise in ceramic veneers, inlays and onlays, Dr. Heldenbergh supervised practical work for the Paris Odontological Society from 2000 to 2018, shaping the skills of many aspiring dentists. His influence extended to the A.D.F. Congress, where he supervised practical work on ceramic veneers from 2000 to 2016. In 2017, he was the Head of Practical Work at A.D.F., a role that allowed him to further contribute to the advancement of dental education and practices. In 2018, he was the Head of Practical Work for ceramic veneers at the Paris Odontological Society.

 

Recognizing the importance of technology in modern dentistry, Dr. Heldenbergh pursued a University Degree in CAD/CAM from Toulouse in 2022. This addition to his qualifications highlights his dedication to staying at the forefront of dental innovation.

Trauma case: Cementation of a fractured crown fragment

Case by Aleksandra Łyżwińska DMD, Warsaw, Poland

 

Dental injuries can be stressful for patients, parents of pediatric patients, and dentists alike. The following tips offer support in turning the treatment of crown fractures into a simple, quick and predictable procedure. In the case described, we opted for a reattachment of fractured crown fragments.

 

YOUNG PATIENT WITH A FRACTURED CENTRAL INCISOR

A 16-year-old patient presented immediately after an accident. Her maxillary left central incisor was fractured, involving half of the coronal enamel and dentin (Fig. 1). The pulp was not involved, but the fracture line was quite close to the pulp (Fig. 2). After examination and radiographic evaluation, the patient was anesthetized. When placing the rubber dam, it tore between the left central and lateral incisor (Figs. 3 and 4). Due to the patient’s young age and limited willingness to cooperate, the decision was made to proceed without replacing the rubber dam. This was expected to work well in this specific region due to the limited flow of saliva from the palate and a low associated risk of contamination.

 

Fig. 1. Fractured maxillary left central incisor at the day of the accident.

 

Fig. 2. Occlusal view of the maxillary anterior teeth with the pulp of the fractured central incisor shining through.

 

Fig. 3. Rubber dam placed and torn between the left central and lateral incisor.

 

Fig. 4. Occlusal view of the teeth isolated with rubber dam.

 

REMOVAL OF UNSUPPORTED ENAMEL PRISMS

In order to provide for a high-quality bond and natural aesthetics, unsupported enamel prisms should be removed. As the use of burs might be too invasive (removing too much structure) and thus hinder the alignment of crown fragments, air-abrasion with 50 μm alumina particles was the method of choice. To avoid iatrogenic pulp exposure, the deepest part of the affected tooth was protected with a colored flowable composite before sandblasting (Fig. 5). The adjacent teeth were protected using a metal strip (Fig. 6). Several seconds of air abrasion were sufficient to remove the enamel prisms and obtain a homogeneous enamel surface (Fig. 7). Subsequently, the colored flowable composite was removed from the dentin surface and the tooth fragment was treated in the same way.

 

Fig. 5. Preparations for sandblasting: Dentin area near the pulp protected with flowable composite.

 

Fig. 6. Protection of the adjacent teeth with a metal strip.

 

Fig. 7. Homogeneous enamel surface after air abrasion.

 

JOINING OF THE FRAGMENT WITH THE REMAINING TOOTH STRUCTURE

After air-abrasion treatment, the fit of the tooth and the fragment was checked and approved (Fig. 8). To improve retention of the fractured crown portion, it was bonded to a micro applicator using composite resin. Alternatively, prefabricated prosthetic carriers may be used. Then, selective etching of the enamel was performed on the tooth and the fragment (Figs. 9 and 10). During this procedure, the adjacent teeth were protected with a celluloid strip (Fig. 11). To better adapt the strip to the distal surface, a curved wedge was placed interproximally (Fig. 12).

 

The bonding system of choice was CLEARFIL™ SE Bond 2 (Kuraray Noritake Dental Inc.). After applying this adhesive to the tooth and the fragment (Fig. 13), a small portion of CLEARFIL MAJESTY™ ES Flow Super Low (Kuraray Noritake Dental Inc.) in the shade A2 was applied to the part of the fragment treated with adhesive.* After careful repositioning of the fragment and while holding it in place with the micro applicator, the composite was light cured.

 

Fig. 8. Perfect fit of the fragment to the tooth.

 

Fig. 9. Selective etching of the enamel on the tooth …

 

Fig. 10. … and the fragment.

 

Fig. 11. Position of the wedge …

 

Fig. 12. … used for better adaptation to the distal surface.

 

Fig. 13. Fragment treated with CLEARFIL™ SE Bond 2 PRIMER and BOND, which were both carefully air-dried, while the Bond was also light cured.

 

Fig. 14. Fragment back in place.

 

Fig. 15. Occlusal view of the teeth with the reattached fragment perfectly fitting the mould.

 

EXCESS REMOVAL AND POLISHING

Excess composite was removed with a scalpel blade and abrasive discs. The entire restoration was then polished using TWIST™ DIA for Composite (Kuraray Noritake Dental Inc., Fig. 16). A nice optical integration was obtained immediately after finishing due to fact that the fragment was stored in water during the waiting time and treatment. As observed with teeth isolated with rubber dam during treatment, teeth undergo dehydration outside the oral cavity. The effect is much stronger in the latter setting, making a fragment become chalky white. By keeping the fragment in water, dehydration is limited to a minimum and it is possible to properly evaluate the aesthetic outcome. This has a positive impact on patient satisfaction. In the present case, the fragment and the tooth structure had a similar appearance, both showing a slightly increased brightness as a result of manipulation under rubber dam or in the air, respectively.

 

Fig. 16. Immediately after polishing, the fragment has almost the same brightness as the tooth thanks to water storage. A slight dehydration effect is visible.

 

TREATMENT OUTCOME

To achieve optimal aesthetics and long-lasting gloss, the composite was repolished one week later (Fig. 17). This was accomplished with a light blue high-shine rubber polisher of the TWIST™ DIA for Composite system, followed by polishing with diamond paste and a goat hair brush.

 

Fig. 17. Treatment outcome after one week.

 

Teeth previously isolated with a rubber dam and the fractured crown fragment had undergone rehydration and returned to their natural colour. The colour adaptation is satisfactory. Harmonious light reflections on the labial surface of the treated tooth a beautiful, natural shine have made the fracture site nearly invisible. In addition to aesthetic value, good therapeutic results were also achieved - the tooth responds appropriately to stimuli and is pain-free.

 

CONCLUSION

The described approach is a valuable treatment option for anterior trauma cases with relatively large fragments that are still available. By reattaching the natural structure, the need for complicated and time-consuming multi-shade layering and free-hand modeling is eliminated, while all the remaining natural tooth structure is saved. Instead of preparing the tooth, a removal of the unsupported enamel prisms and roughening of the surface is absolutely sufficient. Key elements for a great optical integration and long-lasting success are the proper use of a high-performance adhesive as well as the selection of a composite that has the ability to properly blend into its environment and offers a nature-like gloss retention. The selected materials offer precisely these features, so that the great outcome may be expected to last.

 

*CLEARFIL MAJESTY™ ES Flow Super Low is indicated for cementation purposes. The cementation of tooth fragments, however, is not explicitly mentioned in the instructions for use. The decision to use the product in this context was made by the dental practitioner in charge of the treatment.

 

Dentist:

ALEKSANDRA ŁYŻWIŃSKA DMD

 

Aleksandra Łyżwińska graduated from the Medical University of Warsaw, where she later served as a lecturer and assistant in the Department of Conservative Dentistry with Endodontics. In her daily practice, she focuses on the broad field of adhesive dentistry. She is passionate about minimally invasive techniques and vital pulp therapy. Since 2020, she has been conducting courses in conservative dentistry, collaborating with major training centers in Poland and around the world. She is a key opinion leader for Kuraray Noritake. In her training sessions, she demonstrates that dental caries management doesn‘t have to be boring, and that the bond in the bottle is just as exciting as a spy movie. Instagram users know her as the creator of the educational profile for dentist @aleksandra.lyzwinska.

 

Universal White: For all patients asking for a bleached effect

Case by Dr. Jusuf Lukarcanin

 

For all cases that require a particularly bright tooth shade – e.g. children or patients with bleached teeth / asking for a bleached effect in their restorations – CLEARFIL MAJESTY™ ES-2 Universal in the shade UW is likely to be the first choice. The young patient aged 28 shown below asked for diastema closure including shape and shade correction: She wanted to have a brighter, more beautiful smile.

 

Fig. 1. Initial clinical situation.

 

Fig. 2. Shape and shade correction were desired in this case.

 

Fig. 3. Treatment outcome …

 

Fig. 4. … leading to the beautiful smile the patient desired.

 

Reasons for selecting universal white:

- Cases requiring a particularly high brightness or value

- Restorations in deciduous teeth

- Restorations in bleached teeth

 

Universal white properties:

- Well-balanced translucency

- High light-scattering effect

 

CONCLUSION

One universal composite, four shades: In the case of CLEARFIL MAJESTY™ ES-2 Universal, this portfolio is absolutely sufficient for single-shade restorations even in the aesthetically demanding anterior region. Properties such as a nice blend-in effect, a great polishability and gloss retention over time support dental practitioners in creating beautiful restorations. As shade determination may be based on very few criteria instead of a complex shade guide, the whole restoration procedure becomes less stressful and more efficient. Furthermore, with only four shades to stock and usually no blocker needed, the number of materials on stock is reduced, leading to facilitations in stock management as well.

Dentist:

JUSUF LUKARCANIN

 

Dr. Jusuf Lukarcanin is a Certified Dental Technician (DCT) and a Doctor of Dental Science (DDS). He studied dentistry at the Ege University Dental Faculty in Izmir, Turkey, where he obtained a Master‘s degree in 2011. In 2017, he received a Ph.D. degree from the Department of Restorative Dentistry of the same university. Between 2012 and 2019, Dr. Lukarcanin was the head doctor and general manager at a private clinic in Izmir.

 

Between 2019 and 2020, he worked at Tinaztepe GALEN Hospital as a Restorative Dentistry specialist, between 2020-2022 he worked at MEDICANA International Hospital Izmir as a Restorative Dentistry specialist. Currently he is an owner of a private clinic for aesthetics and cosmetics in Izmir.

 

BEST.FIT: A hybrid technique for an efficient and aesthetic restoration of anterior teeth

Case by Dr. Enzo Attanasio

The introduction of new-generation composites, equipped with nanofillers and highly loaded, has opened doors to new techniques for managing direct and semi-direct restorations. In particular, over the last ten years, there has been a significant revolution in the world of flowable composites. Nowadays, these materials offer a filler percentage very similar to packable composites through precise interventions in resin matrix management. They come in various viscosities, offering numerous advantages both in terms of handling and clinical use, as well as beneficial mechanical and physical characteristics.

 

FLOWABLE INJECTION TECHNIQUE

This new era of flowable composites has seen the development of a technique known as the Flowable Injection Technique (also referred to as injection moulding). It enables dental practitioners to reproduce anatomical forms created by a dental technician in the laboratory through a diagnostic wax-up. The shapes planned on the model are transferred directly in the patient's mouth using transparent silicone matrices or indexes, into which the composite is injected through specific injection holes.

 

The main difference compared to traditional mock-ups is that the reproduced dental elements remain separate from each other. This technique provides predictable results identical to those developed on the technician's wax-up, requiring less chair time than direct veneering and offering a longevity similar to traditional composite restorations.

 

BENEFITS AND CHALLENGES

The major benefit of this technique is the faithful reproduction of morphological details that the technician creates on the diagnostic wax-up, which the clinician can reproduce with minimal effort. The restoration produced through the flowable injection technique, if all steps are followed correctly, requires minimal finishing by the clinican, who only needs to focus on polishing the composite.

 

However, one limitation is the difficulty in isolating the operative field, often requiring a split-dam technique or labial retractors, with all the associated adhesive challenges. The use of a rubber dam is only feasible if the peripheral dental tissues around the restoration are euchromatic, allowing the technician to create a wax-up with supragingival preparation margins.

 

Another compromise with the flowable injection technique is the management of the composite as a single mass. This makes it only possible to reproduce natural incisal translucencies typical of young patients by performing complex cutbacks and subsequent incisal painting. Without specific operator skills, the outcomes of this time-consuming manual procedure are unpredictable.

 

HYBRID TECHNIQUE: BEST.FIT

To leverage the advantages of both classical direct anterior restoration and flowable injection techniques and eliminate the limitations, a hybrid technique known as BEST.FIT (Buccal Enamel Shade Through Flow Injection Technique) has emerged. This technique allows the operator to manage the delicate phase of reproducing the buccal enamel layer of the anterior restoration through the flowable injection technique, keeping certain aspects in mind during the injection phase.

 

PROCEDURE

The transparent silicone key used for the creation of the buccal enamel layer is similar to the one used in the original flowable injection technique. The initial phase of restoration management follows all the classical steps of direct technique, requiring isolation with rubber dam. The palatal enamel layer is recreated with a highly translucent packable composite, and the palatal portion of the interproximal walls is produced using a suitable matrix system. Then, the core of the restoration is defined with opaque masses, creating mamelons and adding incisal effects. It's crucial to control the residual enamel thickness using a vestibular silicone index, aiming for about 0.3 mm of space. The buccal portion is finally reconstructed during the injection phase. The transparent silicone index created on the wax-up should be tested after each reconstruction phase to ensure passive insertion.

 

After creating the restoration core, the element to be injected is separated from the contiguous ones with thin PTFE tape. The transparent mask is then inserted, and fluid composite is injected through the injection holes to precisely reconstruct the buccal enamel thickness. The composite tip should be positioned at least halfway through the buccal surface, and the injection should be slow and controlled to avoid air bubbles in the material.

 

FINISHING

Following a 40-second polymerization vestibularly and occlusally, the transparent matrix is carefully removed, and excess interproximal composite above the PTFE tape as well as any remaining composite cylinder from the injection holes are removed. After completing all restorative elements, the rubber dam is dismantled, and composite excess is finished. After checking the occlusion, the composite is polished, usually requiring no further intervention.

 

CASE EXAMPLE

Fig. 1. Female patient with discoloured anterior restorations desiring a smile makeover.

 

Fig. 2. Close-up of her maxillary anterior teeth.

 

Fig. 3. Restorations in need of replacement: Lateral view from the right.

 

Fig. 4. Restorations in need of replacement: Lateral view from the left.

 

Fig. 5. Printed model based on a digital diagnostic wax-up based on a digital impression.

 

Fig. 6. Palatal silicone index produced for the conventional direct restoration steps.

 

Fig. 7. Transparent matrix with injection holes produced for the build-up of the buccal enamel layer using the flowable injection technique.

 

Fig. 8. Operative field isolated with rubber dam.

 

Fig. 9. Existing restorations removed and tooth surfaces roughened at the start of treatment.

 

Fig. 10. Palatal silicone index positioned intraorally for the build-up of the palatal wall.

 

Fig. 11. Checking of the space available in the vestibular area with a second silicone index.

 

Fig. 12. Etching with phosphoric acid etchant.

 

Fig. 13. Application of a universal adhesive (CLEARFIL™ Universal Bond Quick, Kuraray Noritake Dental Inc.).

 

Fig. 14. Palatal walls built up with CLEARFIL MAJESTY™ ES-2 Premium in the shade A1E with the aid of the palatal silicone index.

 

Fig. 15. Build-up of the interproximal walls with CLEARFIL MAJESTY™ ES-2 Premium in the shade A1D and establishing of the contact points using anatomical sectional matrices for the posterior area placed vertically.

 

Fig. 16. Dentin core built up with CLEARFIL MAJESTY™ ES-2 Premium in the shade A2D. CLEARFIL MAJESTY™ ES Flow Super Low in the shade XW was applied on the mamelons, while CHROMA ZONE™ COLOR STAIN Blue (Kuraray Noritake Dental Inc.) was used to reproduce incisal translucencies in the spaces not covered by the dentin core.

 

Fig. 17. Try-in of the transparent matrix for flowable injection.

 

Fig. 18. Isolation of the adjacent teeth with PTFE tape for a one-by-one injection.

 

Fig. 19. CLEARFIL MAJESTY™ ES FLOW Low in the shade A2 (Kuraray Noritake Dental Inc.) injected for the anatomical shaping of the maxillary right central incisor.

 

Fig. 20. Situation after flowable injection for all four anterior teeth, light curing through the matrix, final matrix removal and excess removal.

 

Fig. 21. Treatment outcome …

 

Fig. 22. … with visible mamelons, natural incisal translucencies …

 

Fig. 23. … and a lifelike anatomical shape …

 

Fig. 24. … of the restorations.

 

CONCLUSION

Each work phase must be executed with extreme care to lay the foundations for a passive linking of all subsequent steps without creating difficult management situations. The BEST.FIT technique is a convenient and useful method for dental practitioners to manage multiple direct anterior restorations simply and predictably, especially in situations requiring complex rehabilitations with large restorations.

 

Dentist:

ENZO ATTANASIO

 

Enzo Attanasio graduated in 2008 in Dentistry and Dental Prosthetics from the Magna Graecia University of Catanzaro. In 2009, he went on to specialize in the use of laser and new technologies in the treatment of oral and perioral tissues at the University of Florence. That year he also attended Prof. Arnaldo Castellucci’s course in Clinical Endodontics at the Teaching Center of Microendodontics in Florence where, in 2012, he went on to complete his training in Surgical Microendodontics. In 2017 he attended a course on Direct and indirect Adhesive Restorations at Prof. Riccardo Becciani’s Think Adhesive training center in Florence where he later become a tutor. Today, as a member of the Italian AIC and based in Lamezia Terme, Italy, Dr Attanasio has a special interest in Endodontics and Aesthetic Conservative.

 

Universal: Whenever a high translucency is desired

Case by Dr. Jusuf Lukarcanin

 

In teeth in which the areas to be restored are surrounded by a lot of non-discoloured tooth structure - as may be the case in Class I, II and Class V cavities - the use of CLEARFIL MAJESTY™ ES-2 Universal in the shade U may be an option. The 28-year-old patient, who presented for diastema closure, had teeth with a comparatively low translucency and different shades due to smoking and excessive coffee consumption. As the composite was applied in enamel areas only, the relatively high translucency of the universal shade seemed beneficial in this case.

 

Fig. 1. Initial clinical situation.

 

Fig. 2. New smile of the patient.

 

Reasons for selecting universal:

- Large amounts of underlying or surrounding tooth structure present

- Medium light-scattering desired

 

Universal properties:

- High translucency

- Medium light-scattering effect

 

Dentist:

JUSUF LUKARCANIN

 

Dr. Jusuf Lukarcanin is a Certified Dental Technician (DCT) and a Doctor of Dental Science (DDS). He studied dentistry at the Ege University Dental Faculty in Izmir, Turkey, where he obtained a Master‘s degree in 2011. In 2017, he received a Ph.D. degree from the Department of Restorative Dentistry of the same university. Between 2012 and 2019, Dr. Lukarcanin was the head doctor and general manager at a private clinic in Izmir.

 

Between 2019 and 2020, he worked at Tinaztepe GALEN Hospital as a Restorative Dentistry specialist, between 2020-2022 he worked at MEDICANA International Hospital Izmir as a Restorative Dentistry specialist. Currently he is an owner of a private clinic for aesthetics and cosmetics in Izmir.