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.

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.

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.

Case by Andreas Chatzimpatzakis

Observe and copy: This is the key to nature-like dental restorations. There are many optical effects, colour transitions and morphological details in natural teeth that need to be taken in and understood – and replicating them is only possible for those who know exactly how their materials work. Once these skills are acquired, however, they enable a dental technician to produce their restorations as truly beautiful copies of nature. Even when restoring a single maxillary central incisor, the technique delivers outstanding – or inconspicuous - outcomes, as revealed by the following example.

Using high-quality, translucent and gradient-shaded zirconia frameworks and porcelains, the layering technique does not have to be highly complicated. Two bakes and a number of selected effect liquids, internal stains and porcelains are usually sufficient for outcomes that exceed expectations.

CASE EXAMPLE

In the present case, a young male patient had a quite opaque crown on his maxillary right central incisor that needed to be replaced. During shade selection in the dental laboratory (Fig. 1), it was observed that the cervical third of the adjacent central incisor is lighter than the rest. Its shade in other areas corresponded to B4 on the VITA classical A1-D4^® Shade Guide. Hence, it was decided to use a somewhat lighter material for the framework and darken the restoration especially in the middle and incisal areas with internal stains.

The concrete plan was to mill a coping made of KATANA™ Zirconia STML (Kuraray Noritake Dental Inc.) in the shade A3, characterize it with Esthetic Colorant (both Kuraray Noritake Dental Inc.) and sinter the piece (Figs 2 to 4). In the following layering procedure including just two bakes, a combination of internal stains and selected porcelains (CERABIEN™ ZR, Kuraray Noritake Dental Inc.) was applied as illustrated in Figures 5 to 12. Figures 13 to 17 display the result on the model, minor adjustments during try-in and the final treatment outcome.

Fig. 1. Shade selection. The cervical third of the adjacent central incisor is lighter than usual compared to the middle and incisal areas.

Fig. 2. Coping made of KATANA™ Zirconia STML in the shade A3.

Fig. 3. Intensification of some shade characteristics of the multi-layered blank using Esthetic Colorant in the shades Grey (middle) and Blue and Grey (incisal area).

Fig. 4. Coping after sintering.

Fig. 5. Colour map for internal staining, using CERABIEN™ ZR Internal Stains.

Fig. 6. Result of the use of Shade Base Stain Modifier Fluoro to increase the fluorescence and internal staining as planned.

Fig. 7. Application of Opacious Body OBA2, …

Fig. 8. … Translucent Tx …

Fig. 9.: … and Luster CCV-2.

Fig. 10. Crown after the first bake.

Fig. 11. Crown after the application of CERABIEN™ ZR Internal Stains: A+, Aqua Blue 2, White mixed with Cervical 2 (ratio: 30/70) for the cracks, and Cervical 2.

Fig. 12. Application of Luster LT1 to finalize the shape.

Fig. 13. Finished crown after the second bake on the model.

Fig. 14. Evaluation of the surface texture: Observing and copying the surface details is as important as the imitation of the shade characteristics.

Fig. 15. Minor texture adjustments during try-in.

Fig. 16. Final restoration in place after cementation with PANAVIA™ V5 (Kuraray Noritake Dental Inc.).

Fig. 17. Treatment outcome.

CONCLUSION

Mastering the art of observing natural teeth is the key to lifelike restorations. It allows a dental technician to develop a deep understanding of shade and morphology, which is – apart from knowing the selected materials very well – the only talent needed to reach a high level of excellence. Those who are observant and take in every detail with their eyes can be sure that their mind will understand and their hands will automatically follow.

Case by Vasiliki Tsertsidou

What kind of resin composite is recommended for core build-up procedures? While there are specific dual-cure core build-up resin composites available on the market, it is not mandatory to use them. Light curing is advisable to be applied even for materials with dual-cure polymerization. Some conventional resin composites demonstrate more favourable properties for a core build-up compared to specific core build-up resin composites itself.¹ Hence, it is possible to utilize a composite generally used in the dental office, provided it is indicated to and it is not applied deep within the root canal, where proper light curing would be impossible. The critical material properties for core build-ups are high filler load, sufficient flexural modulus and flexural strength.

CLEARFIL MAJESTY™ ES-2 composite series (Kuraray Noritake Dental Inc.) are suitable option for this case. With a filler load weight percentage of 78 and a flexural strength of 118 MPa (according to manufacturer), CLEARFIL MAJESTY™ ES-2 Classic corresponds to core build-up prerequisites*. The following case is illustrating the clinical procedure.

*The indication range of CLEARFIL MAJESTY™ ES-2 composite does not cover core build-up. In the specific case it is used for creating a large Class II filling where all conditions from the IFU, such as curing depth, are met.

Fig. 1. Endodontically treated tooth with a vertical fracture of palatal wall on maxillary right second premolar.

Fig. 2. Buccal view of the tooth.

Fig. 3. Clinical image, directly after removal of fragment.

Fig. 4. Fragment of the maxillary right second premolar.

Fig. 5. Circumferential matrix band for build-up to assist endodontic retreatment.

Fig. 6. Build-up of the missing walls (margin relocation) with CLEARFIL MAJESTY™ ES-2 Classic (A3).

Fig. 7. Temporary filling of the cavity.

Fig. 8. Replacement of the temporary filling material with CLEARFIL MAJESTY™ ES-2 Classic.

Fig. 9. Crown preparation.

Fig. 10. Proximal carious lesion present on the adjacent fist premolar.

Fig. 11. Situation after rubber dam placement and caries removal.

Fig. 12. Cavity restored with CLEARFIL MAJESTY™ ES-2 Classic.

Fig. 13. Prepared crown.

Fig. 14. Crown after sandblasting of the intaglio.

Fig. 15. Mechanically cleaned abutment tooth ready for pre-treatment.

Fig. 16. Intaglio of the crown treated with CLEARFIL™ CERAMIC PRIMER PLUS.

Fig. 17. Etching of the composite surface with phosphoric acid gel.

Fig. 18. Air-drying of PANAVIA™ V5 Tooth Primer on the abutment tooth.

Fig. 19. Crown in place after cementation with PANAVIA™ V5 Paste and excess removal.

A GOOD CHOICE

Dual-cure core build-up resin composites are two-component materials that need to be mixed homogeneously, which obstracts composition from containing high filler load. However, to prevent deformation of the core, a highly filled composite is advisable. This better simulates the flexural modulus of natural tissues compared to materials with low filler load. Consequently, a light-curing material like CLEARFIL MAJESTY™ ES-2 might be a better option. Applied in 2-mm increments in the core area (and not in the root canal), it performs well and provides the desired outcomes. Additionaly, the option of utilising the same material as for any other type of direct restorations is simplifying the stock management and supporting dental practitioners striving for a simplification of clinical procedures.

References

1. Spinhayer L, Bui ATB, Leprince JG, Hardy CMF. Core build-up resin composites: an in-vitro comparative study. Biomater Investig Dent. 2020 Nov 3;7(1):159-166. doi: 10.1080/26415275.2020.1838283. PMID: 33210097; PMCID: PMC7646551.

Dentist:

VASILIKI TSERTSIDOU

Tohtori Clarence Tam, HBSC, DDS, AAACD, FIADFE

Posliinilaminaatteja käytetään yleisesti esteettisissä hammashoidoissa etuhampaiden muodon, sävyn ja asennon korjaamiseen. Biomimeettisellä hampaiden korjauksella pyritään parantamaan hampaiden ulkonäön lisäksi myös niiden toiminnallisia ominaisuuksia. On tärkeää pitää mielessä, että etuhampaiden luontainen taivutusmurtolujuus on pitkälti riippuvainen ehjästä suulaki- ja fakiaalipintojen kiillekerroksesta. Jos hammas on vaurioitunut endodonttisen toimenpiteen, karieksen ja/tai trauman seurauksena, on pyrittävä säilyttämään jäljelle jäänyt hammasrakenne mahdollisimman hyvin, ja palauttamaan luonnonhampaan lähtötason ominaisuudet, tai parantamaan niitä.

TAUSTA

55-vuotias naispuolinen potilas, joka hakeutui vastaanotolle hampaiden valkaisua varten. ASA II -luokka. Hampaiden valkaisun ei arvioitu vaikuttavan olemassa olevan hampaan 1,2 posliinilaminaatin sävyyn. Laminaattikäsittely olisi uusittava toimenpiteen jälkeen, etenkin jos sävyarvojen muutokset olisivat merkittäviä. Potilaan yläetuhampaiden lähtötasosävyinä oli VITA* 1M1 ja 2M1 (50:50) ja alaetuhampaiden 1M1. Käytettyään karbamidiperoksidia (10 %) sisältävää valkaisulusikkaa öisin 3-4 viikon ajan potilas onnistui saavuttamaan valkaisutuloksen VITA* 0M3 sekä ylä- että ala hammaskaaressa. Valkaisun seurauksena hampaan 1,2 laminaatilla ja viereisellä hampaalla oli huomattava kirkkausero, minkä lisäksi kontralateraalisessa hampaassa 2,2 havaittiin kroman lisäystä fakiaalipintoihin vaikuttavan luokan III yhdistelmämuovipaikan vuoksi. Jälkimmäinen hammas ei myöskään vastannut kontralateraalihampaan mittoja, minkä vuoksi molempiin lateraaliseen kakkoshampaaseen päätettiin laittaa sidostetut litiumdisilikaattilaminaatit. Viereisessä kulmahampaassa (2,3) oli havaittavissa vähäistä tai kohtalaista kuspien kärkien kulumista, mutta potilas ei halunnut käsitellä asiaa ennen aiemmin mainittujen laminaattien asentamista. Esteettisen hammashoidon päätavoitteena oli tässä vaiheessa bilateraalisen harmonian saavuttaminen. Lähitulevaisuudessa hampaaseen 2,3 oli tarkoitus lisätä epäsuora täyte kuspien kärkien ja fakiaalipintojen normaalin muodon palauttamiseksi.

TOIMENPIDE

Lateraalisten kakkoshampaiden hammaskohtaiseen hoitoon (ensimmäinen hoidonaihe) ei tarvittu Digital Smile Design -protokollaa. Pieni vaihtelu hyväksytään tällaisessa hammastyypissä, sillä se tekee hymystä persoonallisemman ja ilmentää henkilön sukupuolta. Tavoitesävy valittiin ennen anestesiaa polarisoitujen ja polarisoitumattomien kuvien perusteella, jotka oli otettu retraktoria käyttämällä. Valokuvat valmisteltiin digitaalista sävyjen kalibrointia varten ottamalla vertailukuvia, joissa käytettiin 18 % neutraalia harmaavalkotasopainokorttia (kuva 1).

Kuva 1. Vertailukuva, jonka ottamiseen on käytetty 18 % neutraalia harmaakorttia.

Rungon perussävy oli VITA* 0M2 ja aihion sävy BL2. Potilaan anestesiaan käytettiin 1,5 ampullia 2-prosenttista lidokaiiniliuosta ja 1:100 000 adrenaliinia, ennen kuin suuhun asetettiin kofferdamkumi split dam -tekniikalla. Hampaan 1,2 laminaatti leikattiin ja poistettiin hampaasta 1,2. Hampaalle 2,2 tehtiin minimaalisesti invasiivinen laminaattipreparointi (kuva 2). Osa hampaan 1,2 vanhasta mesioinsisiaalibukkaalipalataalipuolisesta yhdistelmämuovipaikasta korvattiin. Ehjä osuus jätettiin paikoilleen. Vanhan yhdistelmämuovipaikan ja uuden täytteen sidostamiseen käytettiin sekä mikrohiukkasabraasiota että silaaniperustaista kiinnitysainetta (CLEARFIL™ CERAMIC PRIMER PLUS). Saumat viimeisteltiin, ja retraktiolankoja liotettiin aluminiinikloridiliuoksessa ennen niiden asettamista ientaskuihin. Preparoitujen tynkien sävyt kirjattiin muistiin. Lopullisten jäljennösten ottamiseen käytettiin metallialustaa ja kevyt- ja paksujuoksuista polyvinyylisiloksaania. Potilaalle asennettiin tilapäislaminaatit, ja mukaan annettiin ohjeet, joissa kehotettiin tarkistamaan sävy laboratoriossa raakapolttovaiheessa (bisque-poltto). Laboratorion valmistamat mallit ovat osoitus tapauksen minimaalisesti invasiivisesta luonteesta.

Kuva 2. Laminaattia varten preparoidut hampaat 1,2 ja 2,2

Tapauksen vastaanoton jälkeen potilas nukutettiin ja tilaspäislaminaatit poistettiin. Preparoidut hampaat revidoitiin, ja sidostettavat pinnat hiekkapuhallettiin, jossa käytettiin 27 mikronin hiukkaskoon alumiinioksidijauhetta 30-40 psi:n (0,2–0,29 Mpa) paineella. Laminaattien lopullisen tuloksen arviointiin käytettiin läpinäkyvää glyseriinipohjaista sovituspastaa (PANAVIA™ V5 Try-in Paste Clear, Kuraray Noritake Dental Inc.) Retraktiolangat asetettiin ientaskuihin ja restauraatioiden sisäpinnan (intaglio) käsittelyyn käytettiin 5-prosenttista fluorivetyhappoa, jonka annettiin vaikuttaa 20 sekuntia, minkä jälkeen hampaalle levitettiin 10-MDP-monomeeria sisältävää silaaniperustaista kiinnitysainetta (CLEARFIL™ CERAMIC PRIMER PLUS) (kuva 3). Hampaan pinta etsattiin 33-prosenttisella ortofosforihapolla, jonka annettiin vaikuttaa 20 sekuntia, minkä jälkeen aine huuhdeltiin pois. Hampaaseen levitettiin 10-DMP-monomeeria sisältävää esikäsittelyainetta (PANAVIA™ V5 Tooth Primer) (kuva 4), joka ilmakuivattiin valmistajan ohjeiden mukaisesti. Laminaattisementtiä (PANAVIA™ Veneer LC Paste Clear) (kuva 5) lisättiin, ja laminaatit asetettiin paikoilleen. Laminaatti pysyi hyvin paikoillaan ylimääräisen sementin jähmeyden ansiosta kaikkien sauman tarkistustoimenpiteiden aikana ennen 1 sekunnin pistekovetusta (kuva 6).

Kuva 3. CLEARFIL™ CERAMIC PRIMER PLUS -esikäsittelyainetta on lisätty laminaattien sisäpinnoille.

Kuva 4. PANAVIA™ V5 Tooth Primer -esikäsittelyainetta lisätään etsatuille hampaan pinnoille.

Kuva 5. PANAVIA™ Veneer LC Paste Clear -pastaa lisätään preparoitujen laminaattien sisäpinnoille.

Kuva 6. PANAVIA™ Veneer LC Paste heti laminaatin paikoilleen asettamisen jälkeen. Huomaa paksujuoksuisen sementin jähmeys, mikä helpottaa sen poistamista sekä nestemäisessä että geelimäisessä olomuodossa.

Kovetuksen jälkeen sementti oli geelimäistä, joten ylimääräinen sementti oli helppo poistaa, eikä puhdistusta juurikaan tarvittu (kuva 7). Saumat peitettiin läpinäkyvällä glyseriinigeelillä ennen lopullista kovetusta happi-inhibitiokerroksen poistamiseksi (kuva 8).

Kuva 7. Ylimääräisen sementin poisto 1 sekunnin pistekovetuksen jälkeen.

Kuva 8. Laminaattien palataali- ja fakiaalipintojen samanaikainen lopullinen kovetus.

Saumat viimeisteltiin, ja ne kiillotettiin korkeakiiltoisen lopputuloksen saamiseksi. Restauraatioiden purennan sopivuus varmistettiin. Postoperatiiviset kuvat todistavat, että saumat sulautuvat erinomaisesti hammasrakenteeseen (kuva 9).

Kuva 9. Laminaattien 1,2 ja 2,2 postoperatiivinen esteettinen integraatio.

Uutta hymyä arvioitiin polarisoiduilla kuvilla, jotka osoittavat, että restauraatiot sopivat uuteen hymyyn hyvin sekä esteettisiltä että toiminnallisilta ominaisuuksiltaan (kuva 10). Enää puuttuu vain hampaan 2,3 esteettinen augmentaatio, jotta hampaan ulkonäkö vastaisi kontralateraalista kulmahammasta.

VALMIS RESTAURAATIO

Kuva 10. Uudelleenarvioinnissa käytettävä polarisoitu kuva, joka näyttää lopullisen lopputuloksen.

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.

Case by Dr. Jusuf Lukarcanin

Abrasion and shape correction was also the major reason for this 58-year-old female patient to ask for cosmetic dental treatment. She was unhappy with the appearance of the anterior teeth in the maxilla, which showed signs of tooth wear and discolouration. The selected treatment approach was composite veneering with CLEARFIL MAJESTY™ ES-2 Universal in the shade UD. The shade was selected based on the indication and the somewhat darker shade of the patient’s natural teeth.

Fig. 1. Initial clinical situation.

Fig. 2. Treatment outcome.

Reasons for selecting universal dark:

- For older patients (tooth shades A3 and darker)

- Situations in which light easily passes through the composite (e.g., Class III, Class IV)

Universal dark properties:

- High light scattering effect

- Well-balanced translucency

4 Clinical cases by Dr. Jusuf Lukarcanin

Composites with a universal shade concept, a reduced number of shades that may be selected without any shade guide are a clear trend in restorative dentistry. With specific blend-in properties, these materials can help streamline restorative procedures and reduce chair time, take some pressure off the dental practitioner and contribute to potentially good outcomes. Some users, however, are skeptical about a wide-scale use of the materials, particularly when it comes to restoring teeth in the anterior region. The reasons may be a comparatively high translucency requiring the separate application of a blocker (or opacious shade) in certain situations, or a too limited shade offering.

Personal experience shows that CLEARFIL MAJESTY™ ES-2 Universal is perfectly suitable for a wide range of single-shade restorations in anterior teeth. It offers great polishability and long-term gloss retention and is available in just four shades: One universal shade (U) originally designed for posterior restorations, universal light (UL) and universal dark (UD) as the two major options for anterior teeth and, finally, universal white (UW) for the imitation of any bleached shade. In general, all four options may be used in the anterior and posterior region. As the blend-in ability is due to proprietary light-diffusion technology and not managed via an increased translucency, the application of a blocker is usually not necessary and even larger areas can be restored quite inconspicuously.

For those asking themselves when to select which shade in the anterior region, the following clinical case examples and comments may provide some useful guidance. The recommendations and practical tips are based on personal experience. All patients were in treatment for diastema closure or shape correction, but the selection criteria are the same for other types of anterior restorations, too.

UNIVERSAL LIGHT: FOR NATURAL RESULTS IN BRIGHTER TEETH

This young patient aged 35 with microdontia presented in the dental office with the desire to have more beautifully shaped teeth. His teeth were almost free of dental caries, but with deficiencies in oral hygiene and signs of gingival inflammation. A deep bite was also evident. After professional tooth cleaning and oral hygiene advice, the teeth were restored with CLEARFIL MAJESTY™ ES-2 Universal in the shade UL.

Fig. 1. Initial situation.

Fig. 2. Initial situation: Deep bite.

Fig. 3. Teeth restored with composite in the single-shade technique.

Fig. 4. Immediate treatment outcome.

Reasons for selecting universal light:

- For younger patients (tooth shades A2 and lighter)

- Situations in which light easily passes through the composite (e.g., Class III, Class IV)

Universal light properties:

- High light scattering effect

- Well-balanced translucency

UNIVERSAL DARK: FOR NATURAL RESULTS IN DARKER TEETH

Abrasion and shape correction was also the major reason for this 58-year-old female patient to ask for cosmetic dental treatment. She was unhappy with the appearance of the anterior teeth in the maxilla, which showed signs of tooth wear and discolouration. The selected treatment approach was composite veneering with CLEARFIL MAJESTY™ ES-2 Universal in the shade UD. The shade was selected based on the indication and the somewhat darker shade of the patient’s natural teeth.

Fig. 1. Initial clinical situation.

Fig. 2. Treatment outcome.

Reasons for selecting universal dark:

- For older patients (tooth shades A3 and darker)

- Situations in which light easily passes through the composite (e.g., Class III, Class IV)

Universal dark properties:

- High light scattering effect

- Well-balanced translucency

UNIVERSAL: WHENEVER A HIGH TRANSLUCENCY IS DESIRED

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

UNIVERSAL WHITE: FOR ALL PATIENTS ASKING FOR A BLEACHED EFFECT

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.

Case by Dr. Ioannis Memis

Single-shade or two-shade approach? Using modern resin composites, it is possible to treat virtually every patient in need of a direct restoration in an aesthetic way using one of those two techniques. If the defect is rather small, a single shade of composite restorative in a body opacity may be sufficient – especially when the tooth to be restored is in the posterior region. Larger defects and those located in the aesthetic zone may require a combination of two different shades – one as a dentin replacement and one as translucent as enamel – to closely imitate the optical characteristics of the natural tooth.

With CLEARFIL MAJESTY™ ES-2, Kuraray Noritake Dental Inc. offers a complete composite system designed to simplify procedures in bot, the single-shade and the two-shade approach. CLEARFIL MAJESTY™ ES-2 Classic is a typical composite for the single-shade technique consisting of 18 shades offered in a single universal opacity. Shade determination is brightness-based, meaning that the brightness is selected first and the hue and colour saturation in a second step (using the VITA Classical A1 – D4 shade guide). For those who want to skip shade determination completely, CLEARFIL MAJESTY™ ES-2 Universal has been introduced. It consists of only two shades for the anterior and one shade for the posterior region, selectable without using shade tabs. For the two-shade technique, CLEARFIL MAJESTY™ ES-2 Premium is the solution: It allows users to copy natural enamel and dentin layers with a total of seven enamel, seven dentin and four translucent shades. Its exceptional feature: pre-defined colour combinations with one Premium shade combination covering three VITA Classical shades. A natural blending into the environment is achieved with the Light Diffusion Technology in the formulation.

All three versions of CLEARFIL MAJESTY™ ES-2 are compatible with each other and offer the same favourable handling properties. The use of different techniques, shades and opacities is demonstrated using the following patient case.

YOUNG PATIENT WITH MULTIPLE CARIOUS LESIONS

A 24-year-old female patient was referred from undergraduate clinic of Operative Dentistry of the Aristotle’s University of Thessaloniki - School of Dentistry (Greece). Patient presented multiple interproximal carious lesions in need of restorative treatment. In the clinical and radiographic examination, the following defects were identified:

Quadrant 1 (maxillary right):

- Distal lesion on the lateral incisor (Class III)

- Mesial and distal lesions on the first premolar (Class II)

- Mesial and distal lesions on the second premolar (Class II)

- Mesial lesion on the first molar (Class II)

Quadrant 2 (maxillary left):

- Distal lesion on the lateral incisor (Class III)

- Mesial lesion on the first premolar (Class II)

- Mesial and distal lesions on the second premolar (both Class II)

- Mesial lesion on the first molar (Class II)

Quadrant 3 (mandibular left):

- Distal lesion on the first molar (Class II)

- Mesial lesion on the second molar (Class II)

In a stepwise procedure, the teeth were restored with CLEARFIL MAJESTY™ ES-2 either in a single-shade or in a two-shade approach depending on the size of the lesions.

INITIAL SITUATION

Fig. 1. Initial situation: Frontal view.

Fig. 2. Occlusal view of the maxilla.

Fig. 3. Occlusal view of the mandible.

RESTORING THE TEETH IN QUADRANT 1

The six carious lesions in this quadrant were restored in three steps. At first, the focus was on the first molar and second premolar. Opening the larger cavity mesially of the first molar provided access to the smaller lesion on the premolar’s distal surface. After caries excavation and cavity preparation, rubber dam was placed and fixed with a clamp on the second molar. The enamel in the cavities was treated with phosphoric acid etchant for 15 seconds before CLEARFIL™ Universal Bond Quick (Kuraray Noritake Dental Inc.) was applied according to the manufacturer’s instructions. For a morphologically correct designing of the proximal contact point and area, the use of a sectional matrix system with rings was utilized. Both cavities were restored with CLEARFIL MAJESTY™ ES-2 Premium in the shades A3D and A2E. Finishing and polishing of the occlusal surface accomplished with silicon cups and Twist Dia disks on a slow speed handpiece.

In the second step, the distal lesion on the first and mesial lesion on the second premolar were restored in an identical procedure with CLEARFIL MAJESTY™ ES-2 Premium in the shade A3D and CLEARFIL MAJESTY™ ES-2 Classic in the shade A3. A different approach was selected in step 3 for the lesions on the distal part of the lateral incisor and the mesial part of the first premolar. Due to the small size and the all-but-prominent position of the lesions, a single-shade technique using CLEARFIL MAJESTY™ ES-2 Classic in the shade A3 was selected. Between the lateral incisor and canine, a posterior sectional matrix was placed in an upright position and fixed with a wedge to support a proper restoration of the contact point, while both elements were used in the usual way between the canine and first premolar.

Fig. 4. Simultaneous restoration of the mesial lesion on the first molar and the distal lesion on the second premolar with CLEARFIL MAJESTY™ ES-2 Premium.

Fig. 5. Restoration of the distal lesion on the lateral incisor and the mesial lesion on the first premolar with CLEARFIL MAJESTY™ ES-2 Classic.

RESTORING THE TEETH IN QUADRANT 2

For the small disto-palatal lesion on the maxillary left lateral incisor, a single-shade technique with CLEARFIL MAJESTY™ ES-2 Classic in the shade A3 also produced aesthetic outcomes. The four lesions at the posterior region of the quadrant were restored in two steps – one for each pair of proximal lesions – with a combination of CLEARFIL MAJESTY™ ES-2 Premium in the shade A3D and CLEARFIL MAJESTY™ ES-2 Classic in the shade A1.

Fig. 6. A single-shade technique is sufficient to aesthetically restore this small lesion on the left lateral incisor.

Fig. 7. Simultaneous restoration of the mesial lesion on the second premolar and the distal lesion on the first premolar.

Fig. 8. Simultaneous restoration of the mesial lesion on the first molar and distal lesion on the second premolar.

RESTORING THE TEETH IN QUADRANT 3

In this quadrant, only a single pair of proximal lesions needed treatment. A simultaneous restoration procedure was selected once again due to the favourable space conditions. Although the size of the lesion was like those in the posterior region of the maxilla, a single-shade restoration was selected with the use of CLEARFIL MAJESTY™ ES-2 Classic (shade A3).

Fig. 9. Treatment of the lesions in quadrant 3.

CONCLUSION

In the present patient case, several different shades, opacities, and combinations of CLEARFIL MAJESTY™ ES-2 were utilized either in a single- or in a two-shade approach. All combinations and techniques produced good outcomes. As shown in Figure 4, the enamel opacity of CLEARFIL MAJESTY™ ES-2 Premium is visibly more translucent than the universal opacity of CLEARFIL MAJESTY™ ES-2 Classic. Experience shows that enamel shades translucency is highly valuable for aesthetic anterior restorations, while in posterior restorations, the universal shade approach is aesthetically adequate, particularly for medium-sized restorations, as shown in Figure 9. This is clearly an evidence of Light Diffusion Technology which is blending hue and colour saturation to the surrounding tooth structure.

Handling of all selected composite pastes is comfortable: non-sticky, adaptable to cavity walls and allowing precise occlusal sculpting. Polishing with Silicone Cups and TWIST DIA for Composite is easy, quick and leaves a natural gloss on the surface.

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.

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.

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.

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.

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.