Article by Dr. Michał Jaczewski

When working with composite, one of the most important aspects is to understand the mechanisms of adhesion. Choosing the right composite is one thing, but choosing a suitable bonding system and using it correctly is an equally important aspect affecting the long-term performance of a direct restoration.

There are many bonding products on the market - two-bottle (primer and bond) but also single-bottle systems. For anyone trying to select an ideal adhesive for a specific clinical case, the sheer number of available products can be challenging. The temptation to use them all, in slightly different ways, has the potential to create errors. In my dental practice, I am committed to simplifying procedures.

This is why I started looking for a bonding system that would offer a sense of security in terms of adhesion, but also ease of use in different clinical situations. I have opted for the 8^th-generation bonding agent with the desired features - CLEARFIL™ Universal Bond Quick (Kuraray Noritake Dental Inc.). The single-bottle universal adhesive is ideal for a broad variety of bonding procedures carried out in the dental office.

IMPRESSIVE FEATURES

CLEARFIL™ Universal Bond Quick can be used in the total-etch as well as the selective enamel etching technique in combination with an etching gel such as K-ETCHANT Syringe (Kuraray Noritake Dental Inc.). It is also a self-etching adhesive. Used in combination with the dual-cure build-up material CLEARFIL™ DC CORE PLUS or the dual-cure universal resin cement PANAVIA™ SA Cement Universal (both Kuraray Noritake Dental Inc.), it is also an ideal choice for cementation in the root canal and for cementing inlays or crowns made of a variety of different restorative materials – from metal to zirconia or lithium disilicate. Efficient clinical procedures are supported by the incorporated Rapid Bond Technology, which eliminates the need for extensive rubbing or waiting for the adhesive to penetrate the substrate and the solvent to evaporate. Among the key components of this technology are hydrophilic amide monomers, which allow the adhesive solution to penetrate moist dentin extraordinarily quickly, while also having a high curing ability. In addition, the original MDP monomer is included in the formulation. Together with the amide monomers, it provides for a high bond strength to enamel and dentin – achievable in a simple procedure of application, air-drying and light-curing.

The described properties turn CLEARFIL™ Universal Bond Quick into one of the most versatile and easy-to-use adhesive bonding solutions in the dental office. Operator sensitivity is low, as is its technique sensitivity, since the three-step procedure is always the same. The following case examples illustrate its use in the context of different repair procedures.

REPAIR OF COMPOSITE RESTORATIONS

One of the major benefits of using composite as a restorative material lies in the fact that it may be modified and repaired at any time. Regardless of whether an air bubble is detected on the surface, the shade needs to be adjusted, a fracture occurs or materials need to be added as a result of wear, modification or repair is easily accomplished without needing to sacrifice additional amounts of healthy tooth structure. Whenever a silicone index has been produced for the initial treatment and is still available, and the user knows which composite has been utilized for the original restoration, the Flowable Injection Technique may be selected as a particularly easy and efficient way of repairing a restoration. However the recommended protocol is slightly different depending on the state of the restoration surface.

CASE EXAMPLE 1: IMMEDIATE REPAIR PROCEDURE

When a restoration has been damaged or an air bubble has appeared during injection of a flowable composite, the procedure is slightly different. In this case, the oxygen inhibition layer is usually still present on the surface of the restoration. Therefore, it is possible to simply apply an additional portion of composite (Figs. 1a to 1d). Even after contamination of the composite surface with water, saliva or blood, this measure is possible. The surface merely needs to be rinsed thoroughly and dried before applying the new portion of composite. For maximum safety, a universal adhesive may be used as well.

Fig. 1a. Repair procedure applicable for defect within a composite restoration whenever the oxygen inhibition layer has not yet been removed: Air bubble detected in the interproximal region.

Fig. 1b. Application of a new portion of composite after rinsing and drying. The adjacent surface is protected with PTFE tape.

Fig. 1c. Repositioned silicone index used to give the restoration the originally planned shape.

Fig. 1d. Final restoration.

CASE EXAMPLE 2: REPAIR PROCEDURE AFTER POLISHING

If a similar defect is detected during finishing and polishing, i.e. when the oxygen inhibition layer has already been removed (Fig. 2), a roughening of the surface is strictly necessary. With a bevelled preparation of the area with the air bubble, optimal conditions are created for another layer of composite that blends in well with the surrounding material (Fig. 3). After bevelling, the surface needs to be sandblasted and cleaned either with KATANA™ Cleaner (Kuraray Noritake Dental Inc.) (Fig. 4a) or with 37 % orthophosphoric acid (Fig. 4b). After thorough rinsing and drying, an additional portion of composite may be applied to the surface (Figs. 5a to 5c). As the defect is small, the composite may be applied instead of injected and the silicone index repositioned afterwards.

Fig. 2. Void on the surface, detected during finishing.

Fig. 3.  Removed void and bevelled area around the defect.

Fig. 4a. Option 1: Cleaning of the surface with KATANA™ Cleaner.

Fig. 4b. Option 2: Etching with K-ETCHANT Syringe.

Fig. 5a. Application of composite (CLEARFIL MAJESTY™ ES Flow Low).

Fig. 5b. Repositioning of the original silicone index to obtain the desired shape.

Fig. 5c. Final restoration with a nice blend-in of the different layers of composite.

CASE EXAMPLE 3: REPAIR PROCEDURE AFTER TWO OR MORE WEEKS

For damaged restorations which have been in place for more than two weeks, an ideal composite-composite interface needs to be created by bevelling and roughening of the surface. A perfect example is presented in Figure 6. The most important step influencing the success of the procedure is proper preparation of the composite surface. To lay the foundation for a strong bond between the new and the old composite as well as for aesthetic outcomes, a bevel needs to be created (Figs 7a and 7b) to facilitate a smooth transition between the two layers. Once the bevel is completed, the surface should be sandblasted with alumina particles sized 27 μm (Fig. 8). The following recommended steps are etching of the composite with 37 % orthophosphoric acid (Fig. 9) and finally application of CLEARFIL™ Universal Bond Quick (Fig. 10). As the universal adhesive contains a silane coupling agent, separate silane application is not necessary. Instead, the new layer of composite may be applied immediately e.g. using the flowable injection technique with an existing matrix (Fig. 11).

Fig. 6. Fractured anterior composite restoration benefitting hugely from repair – the remaining composite is in a great state regarding colour and shape.

Fig. 7a.  Bevelling with dedicated instruments.

Fig. 7b.  Ideal bevel created to provide for a strong bond and great optical blend-in.

Fig. 8. Sandblasting of the surface with alumina particles.

Fig. 9.  Phosphoric acid etching.

Fig. 10. Application of the universal adhesive.

Fig. 11. Composite applied using the flowable injection technique.

Fig. 12. Treatment outcome.

CONCLUSION

The three described repair protocols are straightforward and work well – provided that a strong bond is established at the composite-composite interface. The way it is established may be slightly different depending on whether the oxygen inhibition layer is still present or has already been removed. Using a universal adhesive like CLEARFIL™ Universal Bond Quick, the procedure is simplified owing to elimination of steps such as the separate application of silane.

Dentist:

MICHAŁ JACZEWSKI

Michał Jaczewski graduated from Wroclaw Medical University in 2006 and today runs his private practice in the city of Legnica, Poland. He specializes in minimally invasive dentistry and digital dentistry and is the founder of the Biofunctional School of Occlusion. Here he lectures and runs workshops with focus on full comprehensive patient treatments.

Artikli autor dr. Michał Jaczewski

KOMPOSIITTAASTUSED HAMBARAVIS

Komposiitrestauratsioon on kõige tavalisem protseduur, mida hambaarst läbi viib. Hambaarstide kasutuses on palju erinevaid restauratiivseid tehnikaid ja materjale. Sõltumata materjali tüübist, restaureerimismeetodist ja selle kasutuskohast on põhiliseks probleemiks õhumullid komposiitkihtide pinnal või sees. Komposiitrestauratsioon peab olema homogeenne, et tagada täidise tihedus ja vastupidavus. Mullide defektide parandamine on tülikas ja nõuab mõnikord täidise või selle osa asendamist. Defektide hulk võib varieeruda sõltuvalt komposiidi tüübist (voolav või pasta) ja/või paigaldustehnikast, kuid teada on mitu peamist tegurit.

MATERJALI VALIK

Voolava komposiidi süstimistehnika puhul kasutame voolavaid komposiite, mis ilmselgelt voolavad kergesti, kuid on ka tundlikud kasutustehnika suhtes. Esimene õhumullide tekkimise põhjus on materjali enda homogeensus. Mulle võib süstlasse sattuda tootmise etapis või kasutamise ajal. Kasutades parimaid tooteid, saame olla kindlad, et materjal on kõrgeima kvaliteediga ja et süstla struktuur ja disain vähendavad kasutamisel õhumullide tekkimise tõenäosust materjalis.

SÜSTLA KONSTRUKTSIOONI TÄHTSUS

CLEARFIL MAJESTY™ ES Flow komposiit on loodud vältima õhumullide teket doseerimise ajal. Süstla ja kolvi eriline disain piiravad materjali tagasivoolu võimalust doseerimise ajal või pärast seda ja samuti vähendavad tilkumise võimalust.

Unikaalne O-rõnga konstruktsioon süstla sees takistab materjali voolamist pärast rõhu vabanemist ja väldib kolvi liigset tagasitõmbumist.

KOLVI VÄLJA tõmmates

Teine õhumullide tekkimise põhjus on õhu sattumine süstlasse kolvi tahtliku tagasitõmbamise teel. Kui hambaarst või assistent on harjunud pärast komposiidi manustamist kolbi tagasi tõmbama, võib õhk süstlasse pääseda. Edasisel kasutamisel tekib restauratsiooni tõenäoliselt õhutühimik.

RÕHU TÄHTSUS INDEKSILE

Voolava komposiidi süstetehnikas kasutatakse silikoonvormi, millesse lisatakse materjali hamba ülesehitamiseks. Vorm peaks hamba külge tihedalt sobituma ja ei tohi süstimise ajal liikuda. Kui see juhtub, võivad tekkida õhumullid. Vormi vajutamine ja seejärel vabastamine põhjustab vaakumefekti ja tõmbab komposiidi nii hamba kui ka vormi küljest eemale. Defektide vältimiseks tuleks vormile pidevat survet avaldada alates materjali süstimisest kuni polümerisatsioonini.

Silikoonvormi erinevaid modifikatsioone saab kasutada selle liikuvuse piiramiseks ja hamba suhtes kontrollimatu surve riski vähendamiseks. Selline näide on interlip (vahelduva hamba) mudeli põhjal valmistatud vorm, mis tagab suure stabiilsuse ja tööohutuse.

SÜSTEAVA LAIUS

Teine põhjus õhu sattumiseks restauratsiooni on süsteaugu suurus. Kui auk on liiga kitsas, võib otsiku sisestamise või kasutamise ajal vorm paigast liikuda. Selle probleemi vältimiseks võiks auku laiendada, et võimaldada otsiku lihtne sisestamine ja kasutamine süstimise ajal. Laiem avaus võimaldab õhul doseerimise ajal väljuda. Kõige olulisem on aga materjali peale kanda pidevat rõhku avaldades ja vältida otsiku vormist väljatõmbamist ja uuesti sisestamist. See võib põhjustada ebaühtlast komposiitkihti.

Kas soovite rohkem teada voolava süstimistehnika kohta? Lugege põhjalikku ja inspireerivat intervjuud Michal Jachzewski

Hambaarst:

MICHAL JACZEWSKI

Michał Jaczewski lõpetas 2006. aastal Wroclawi Meditsiiniülikooli ja juhib praegu erapraksist Legnica linnas Poolas. Ta on spetsialiseerunud minimaalselt invasiivsele hambaravile ja digitaalsele hambaravile ning on biofunktsionaalse oklusioonikooli asutaja. Siin peab ta loenguid ja viib läbi töötubasid, mis keskenduvad patsiendi täielikule tervikravile.

Intervjuu Michał Jaczewski

Voolavate komposiitide süstimise tehnika on muutumas populaarseks tehnikaks, mida kasutatakse mitme hamba esteetiliselt restaureerimiseks voolava komposiidiga. Michał Jaczewski on tunnustatud instruktor, kes õpetab hambaarstidele seda tehnikat. Ta lõpetas Wroclawi Meditsiiniülikooli (Poola) 2006. aastal ja juhib alates 2011. aastast oma erapraksist Legnica linnas. Michal on Biofunktsionaalse Oklusiooni Kooli asutaja, mis viib läbi koolitusi tervikliku hambaravi valdkonnas ning tunneb suurt huvi digitaalse esteetilise hambaravi vastu. 2023. aastal Kölnis rahvusvahelisel hambaarstide näitusel näitas ta meile, millal, miks ja kuidas ta kasutab oma hambaarstipraksises voolava komposiidi süstimise tehnikat. 

Kas võiksite seda tehnikat lühidalt kirjeldada? 

Voolava komposiidi süstimise tehnika võimaldab lihtsal, ootuspärasel ja korrataval moel taastada hambaid voolava komposiidiga. See põhineb vahamudelil, mille põhjal valmistatakse silikoonist vorm. See vorm täidetakse seejärel voolava komposiidiga, mis valguskõvastatakse läbipaistva silikooni kaudu. Selle tehnika suurim eelis on, et see toimib hamba ettevalmistuseta või väga vähese ettevalmistusega. See on minimaalselt invasiivne tehnika, mida võivad kasutada nii algajad kui ka kogenud hambaarstid. Kasutades hästi tasakaalustatud opaaksusega komposiiti paksusega 0,3 mm ja spetsiaalset poleerimisprotokolli, on võimalik saavutada suurepäraseid morfoloogilisi ja optilisi tulemusi. 

Millal hakkasite kasutama voolava komposiidi süstimise tehnikat ja mis on selle peamised näidustused? 

Seda tehnikat hakkasin kasutama 2018. aastal. See leiutati algselt esihammaste restaureerimiseks, kuid tänapäeval kasutatakse seda edukalt ka tagumises piirkonnas. Minu arvates on see eriti kasulik, kui patsiendi naeratuse nimel on vaja parandada mitme hamba kuju, olenemata sellest, kas patsient on noor või vana. See võib olla vajalik pärast ortodontilist ravi. Hambad ühtlustatakse ja seejärel taastatakse nende täiuslik kuju selle mitteinvasiivse tehnikaga. Kasutan ka voolava komposiidi süstimist naeratuse ümberkujundamiseks, kulunud hammaste taastamiseks ja oklusiooni vertikaalse mõõtme muutmiseks kogu suu rekonstrueerimise kontekstis. Viimasel juhul võib restauratsioon olla ajutine ja seda kasutatakse keskmise kuni pikaajalise ravi „testimiseks“. Kuid see võib olla ka lõplik restauratsioon. 

Kuidas alustada, kui tahta ravida patsiendi hambaid voolava komposiidi süstimise tehnikaga? 

Plaanimise etapp mõjutab selle tehnika edukust kõige rohkem. See hõlmab dokumenteerimisest, jäljendi võtmist ning vahamudeli ja näidisvormi loomist, samuti silikoonist vormi loomist. Muidugi saate ka töötada traditsioonilisel viisil, kasutades silikoonjäljendit ja harilikku näidisvormi, kuid selles etapis teeb digitaaltehnoloogiate kasutamine töövoo palju lihtsamaks. Alustan tavaliselt foto ja video tegemisega ja digitaalse jäljendi loomisega. Samuti on vaja dokumenteerida kesktelg ja oklusioon. Seejärel saab luua virtuaalse näidisvormi, kasutades digitaalset hammaste kujundamistarkvara. Selles etapis on oluline arvestada patsiendi näo omapäradega. Seda saab parimini saavutada näo harmoonia (facial flow) kontseptsiooni põhjal. Loodud kujunduse põhjal saab näidata virtuaalse ravi tulemust ja seda patsiendiga arutada. Kui see on heaks kiidetud, prinditakse vahamudel erinevates versioonides: täielik vahamudel ja interlip-mudel, millel vahelduvad vahamudeliga ja vahamudelita hambad. Neid mudeleid kasutatakse, et luua läbipaistvast silikoonist soovitud vorm. 

Digitaalne naeratuse kujundamine: tugevalt kulunud hammastega patsient. 

Virtuaalne vahamudel patsiendi suus. 

Virtuaalse maketi alusel prinditud mudelid. 

Silikoonmudel, mis on valmistatud vahelduva (interlip) mudeli alusel. 

Millal ja miks te valmistate rohkem kui ühe silikoonvormi? 

Täieliku ja vahelduva (osalise) silikoonvormi kasutamine on eriti kasulik, kui kavatsete taastada kõik ülalõua hambad. Vahelduva vormiga alustamine on stabiilsem ja loob aluse täpse tulemuse saavutamiseks, eriti seoses kavandatud oklusiooni kõrgusega. Alalõual, kus vormi ja komposiidi käsitlemine on sülje ja liikuvate pehmete kudede tõttu raskem, soovitan alati töövälja jagada kolmeks osaks - üks eesmine ja kaks tagumist piirkonda - ja nendega eraldi tegeleda. 

Kuidas hambaid ette valmistada ja voolavat komposiiti süstida? 

Enamikul juhtudel on vaja ainult sidustamiseks karestada emaili pinnad, mida saab tavaliselt teha õhkabrasiooniga alumiiniumoksiidiga (50 pm madalal rõhul). Seejärel söövitatakse email fosforhappega ja kantakse peale universaalne sidusaine. Silikoonvorm on varustatud süstimisavaga lõikeserva ääres. See on kergesti tehtav, surudes voolava komposiidi süstla nõela läbi materjali seestpoolt väljaspoole. Tagahammaste piirkonnas võib olla kasulik kasutada kõvemat materjali ja teha iga hamba jaoks eraldi köbrukestel kaks auku - üks süstimiseks ja teine väljavooluks. Kõva vormi puhul võib selle protseduuri jaoks vaja minna teemantpuuri. Panen vormi paika, süstin voolavat komposiiti alt üles, valguskõvastan materjali natuke aega ja eemaldan vormi. Lõplik polümerisatsioon viiakse läbi pärast vormi eemaldamist ja glütseriinigeeli kihi pealekandmist. Kui liigne materjal on eemaldatud ja restauratsiooni proksimaalne osa on täielikult viimistletud, korratakse protseduuri teiste hammaste puhul enne restauratsioonide poleerimist. 

Kas teil on selle tehnika jaoks välja kujunenud mõni lemmiktoode? 

Silikoonvormi jaoks kasutan EXACLEAR-i (GC), kuna see on turul saadaolevast silikoonist kõige läbipaistvam. Minu lemmik komposiit voolava süstimistehnika jaoks on vähese viskoossusega CLEARFIL MAJESTY™ ES Flow (Kuraray Noritake Dental Inc.). Olen enda hambaarstipraksises ja kursuste ajal saanud võimaluse testida palju erinevaid tooteid. Selle põhjal arvan, et Kuraray Noritake Dental materjalidel on mõned eelised. See on kaasaegne nano-komposiit, millel on lai kasutusala ja suur toonide valik. Kolme viskoossuse astmega saab seda kasutada erinevates kliinilistes olukordades. Ma hakkasin seda kasutama viis aastat tagasi ja voolava süstemeetodi jaoks on minu esimene valik vähese viskoossusega variant, kuna see on kõige universaalsem ja sobib nii eesmiste kui ka tagumiste hammaste jaoks. Peamised eeliseid, mis mõjutasid minu otsust seda kasutada, on selle loomulik esteetika ja parem poleeritavus. Hea tulemus on võimalik saavutada ilma eriliste oskusteta. Sidusainena eelistan kasutada CLEARFIL™ Universal Bond Quicki, mis muudab tööprotsessi veelgi lihtsamaks, kiiremaks ja korratavamaks. Poleerimiseks olen välja töötanud oma protokolli. 

Kuidas te viimistlete ja poleerite oma restauratsioone? 

Alustan proksimaalsest piirkonnast poleerimisribadega ja mõnikord proksimaalse saega. Kuju kohandamiseks on osutunud kasulikuks kolm erinevat teemant- ja karbiidpuuri. Seejärel jätkan peenete või eriti peenete Sof-Lex™-i viimistlus- ja poleerimisketastega (3M), mida kasutatakse kontuurimiseks ja viimistlemiseks, ning komposiidi kummist poleerijatega TWIST DIA™ (Kuraray Noritake Dental Inc.), millega saab väikse vaevaga anda hea ja loomuliku pinnaläike. Seejärel kasutan kitsekarvadest ratasharja ja teemantpoleerimispastat (Diamond excel, FGM) ning viimasena puuvillast ketast alumiiniumoksiidist poleerimispastaga (Pasta Grigia II, anaxDENT). Sel viisil on võimalik luua peegelsile pind. 

Emaili söövitamine fosforhappega. 

Silikoonvorm on paigas. 

Toote CLEARFIL™ Universal Bond Quick kasutamine.

Olukord vahetult pärast CLEARFIL MAJESTY™ ES Flow (Low) süstimist, valguskõvastamist ja silikoonvormi eemaldamist.

Proksimaalsed kohandused pöörlevate instrumentidega. 

Mis on voolava komposiidi süstimise tehnika peamised eelised? 

Suurim eelis patsientidele ja hambaarstidele on ajasääst ja odav hind. Paljud patsiendid ei saa endale keraamilisi laminaate lubada ning võtavad avasüli vastu kvaliteetse alternatiivi, mille saab ära teha ühe visiidi jooksul. Protseduur ei nõua ettevalmistamist ja restauratsiooni saab hõlpsalt parandada või selle värvust muuta, mis tähendab, et protseduur on peaaegu riskivaba. Hambaarstid saavad tavaliselt alustada patsientide ravimist koheselt peale ühe koolituse läbimist. Kuigi harjutamine teeb meistriks, on selle toote puhul juba esimesed tulemused tihti üpris muljetavaldavad. Seetõttu ei ole algajate puhul aja- ja materjalikulu kuigi suur. Muidugi võite pühendada palju aega viimistlus- ja poleerimisprotseduuridele, kuid samas suudate kindlasti leida optimaalse tasakaalu töö ja tulemuse vahel. 

Voolava süstetehnika instrumentide komplekt. 

Kas teil on soovitusi, kuidas seda tehnikat hakata kasutama? 

Esiteks tahaksin julgustada kõiki pidevalt oma mugavustsoonist välja tulema ja proovima midagi uut. Minu jaoks oli voolava süstetehnika kasutusele võtmine tõeline mängumuutja ja ma ei tahaks kunagi enam ilma selleta töötada. Enne selle tehnika kasutamist soovitaksin kindlasti osaleda kursusel, mis õpetab kogu teoreetilist poolt, mida on vaja teada edukaks esimeseks juhtumiks, ja võib-olla isegi praktilist töötuba.  

Michał Jaczewski esitluse ajal Kuraray Noritake Dentali alal Kölnis. 

DELICATE BALANCE BETWEEN COSTS AND AESTHETICS IN DENTAL LAB

When you are a lab owner striving to achieve high-end results using modern digital techniques, the initial investment in CAD/CAM technology is significant, followed by ongoing costs for expendable items such as milling tools and blanks. That cost can be reduced by selecting universal, high-quality materials.

Undoubtedly, zirconia stands out as one of the most popular materials on the market. From an inventory perspective, however, lab owners often find themselves purchasing multiple discs of the same shade and thickness. The reason is that they need to meet all requirements for strength and aesthetics in different settings – enabling them to cover all kinds of restorations and deliver excellent patient outcomes.

UNIVERSAL SOLUTION FOR DENTAL LABS

At Kuraray Noritake Dental Inc., we take pride in not only developing the first-ever multilayer zirconia, KATANA™ Zirconia ML, but also in our commitment to delivering the highest quality materials that we can.

KATANA™ Zirconia YML, our latest addition to the KATANA™ Zirconia line-up, exemplifies this dedication and offers universal applicability. The universal feature is based on the fact that KATANA™ Zirconia YML disc not only offers colour gradation, but also impressive flexural strength and translucency gradation, with maximum values of up to 1,100 MPa and 49 % translucency, respectively.

INHOUSE PRODUCTION - THE PATH TO HIGH QUALITY ZIRCONIA DISC

Like all our zirconia offerings, KATANA™ Zirconia YML begins its journey to the dental lab in our Japanese facility where raw zirconia powder undergoes special treatment process before the addition of essential components.

Once the material has undergone this thorough initial stage, it progresses to the pressing and pre-sintering phase to form the disc. Every detail is carefully calculated, managed and controlled. This phase of the process takes several days, underscoring our goal to achieve the most aesthetic product.

HIGH-SPEED SINTERING PROGRAM: 54 MINUTES

The unique powder formulation and refinement process, as well as the pressing and pre-sintering technique, is the key to allow our customers to realize restorations of up to three-unit bridges without any compromise in terms of aesthetics or mechanical properties using the 54-minute high-speed sintering* process.

This high quality, lengthy production process results in an exceptionally dense material, which once sintered, goes on to deliver a high strength, high aesthetic final restoration.

HIGH PRECISION SHRINKAGE AND STABLE CTE VALUES FOR EXCEPTIONAL FIT

Outstanding deformation stability during the sintering procedure, contributes to the stability during the final sintering process in the dental laboratory, providing for an exceptional fit of large-span bridges and other restorations.

MULTI-LAYERED STRUCTURE AND EASE OF POSITIONING OF RESTORATIONS IN THE BLANK

To enhance aesthetic qualities, all KATANA™ Zirconia YML discs are designed using ratios rather than fixed measurements of different layers in the multi-layered structure. This means that regardless of the disc's thickness, there is always a consistent ratio of 35 % of raw material that constitutes the translucent enamel zone. Hence, discs with an increased height, which are typically used for the production of larger restorations, will always offer sufficient space in the enamel zone, while smaller discs are optimized for smaller restorations.

ONE DISC. ALL INDICATIONS.

These qualities empower dental lab owners to deliver a wide range of restorations. The material is suitable for single crowns to full-arch structures, for full-contour designs to conventional frameworks, using a single material without compromising on aesthetics: KATANA™ Zirconia YML. For finishing, we offer a well-aligned portfolio of solutions designed for internal and external staining, micro-layering and full layering.

EXPLORE KATANA™ Zirconia YML: WEALTH OF RESOURCES, CLINICAL CASES AND FAQS

Visit our website to discover more about KATANA™ Zirconia YML. You will find useful materials such as brochure, technical guide, in-depth technical information.

Would you like to see the material in action – browse the blog section of our website that offers a variety of clinical cases and articles by world-renowned experts showcasing and proving the versatility and aesthetics of KATANA™ Zirconia YML.

*The material is removed from the furnace at 800°C. A furnace with a configurable KATANA™ Zirconia YML firing program is required.

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.

FLOWABLE INJECTION AND STAMP TECHNIQUE: RESTORING TEETH IN THE POSTERIOR REGION

Restoring the occlusal surface of posterior teeth while preserving the natural morphology and re-establishing correct occlusal contacts has always been challenging for dental practitioners. Free-hand layering requires knowledge of tooth anatomy, composite handling skills and experience. When the occlusal surface of a tooth is damaged at the start of treatment (as is usually the case in teeth with large MOD cavities) or an increase of the vertical dimension of occlusion is planned (e.g. in severely worn teeth), the use of the flowable injection technique may be a suitable alternative. It truly speeds up and facilitates the process of building up the restoration to a natural shape, but requires thorough planning and preparation. In cases with an intact occlusal surface, the stamp technique might be the first choice.

FLOWABLE INJECTION TECHNIQUE: GENERAL CONSIDERATIONS

It is up to the user how exactly the restorations, to be built up by flowable injection, are planned and how the plan is implemented: One can either opt for a conventional wax-up or make use of digital tools in the planning phase. Dedicated design software offers the benefit of facilitating the creation of a natural shape and morphology of the desired restoration and allows for the establishing of an ideal occlusal relationship. Once the wax-up is ready, it needs to be transferred into the patient’s mouth. This is accomplished via a printed or classical model with wax-up, which forms the basis for the production of a matrix or silicon index. This index is then used intraorally for the injection of the flowable composite. To enable proper light curing through the index, the index material should be as transparent as possible.

AREA-SPECIFIC CONSIDERATIONS

In the posterior area, an index made of two different materials – a soft inner silicon structure and a hard outer shell – may be advisable. Due to its higher dimensional stability compared to a soft silicon index, it is possible to put pressure on it for proper adaptation to the isolated teeth and soft tissue without the risk of altering the shape of the tooth. Figure 1 shows such an index on and next to a printed model. It consists of a hard shell made of acrylic and a soft inner structure made of a transparent silicone material (e.g. EXACLEAR™, GC). For production, a high-capacity hydraulic pressure curing unit designed for use with self-curing resins (Aquapres™, Lang Dental) has proven its worth: It ensures a highly accurate reproduction of the (digital) wax-up.

Fig. 1. Printed model and silicone index.

Reconstruction of posterior teeth with the flowable injection technique requires prior removal of all carious lesions and reconstruction of the proximal surfaces to restore the contact points. Hence, the injected composite serves the exclusive purpose of restoring the occlusal surface. When several teeth are treated, a two-step procedure with an alternating technique is recommended to provide for proper separation of the teeth. Blocking the proximal surfaces below the contact point with PTFE tape will reduce the amount of excess material in these areas and make it easier to clean and prepare the proximal surfaces after flowable injection. Proximal and deeper occlusal lesions should be restored with the aid of a matrix, wedge and ring.

CLINICAL PROTOCOL

A possible clinical protocol is illustrated in Figures 2 to 5: After caries excavation and tooth preparation, sectional matrices, wedges and rings were placed to allow for simultaneous treatment of the mesial and occlusal cavities. Following etching and application of the universal adhesive CLEARFIL™ Universal Bond Quick (Kuraray Noritake Dental Inc.), the cavities were restored with CLEARFIL MAJESTY™ ES Flow Super Low in the shade A1 and CLEARFIL MAJESTY™ ES-2 Universal in the shade U. The distal cavity of the first molar was filled in the last step of the free-hand modeling procedure. In order to restore the occlusal surfaces in their original vertical dimension, every second tooth was isolated with rubber dam and the exposed molar etched (total-etch technique with K-ETCHANT Syringe, Kuraray Noritake Dental Inc.). the alternating index was positioned with some pressure and the flowable composite (CLEARFIL MAJESTY™ ES Flow Super Low) injected. Once light curing was completed, it was possible to remove the index, chip off the excess and finish and polish the restoration before repeating the procedure for the adjacent molar.

Fig. 2. Restoration of two molars: Teeth preparation and caries excavation.

Fig. 3. Restoration of two molars: Filling of the proximal and occlusal cavities.

Fig. 4.  Restoration of two molars: Re-establishing the occlusion with the aid of the flowable injection technique.

Fig. 5. Alternating approach: Restoration of the second molar by injecting flowable composite.

DISCUSSION

The use of the flowable injection technique allows for rapid restoration of teeth and the establishment of precise occlusal contacts. This reduces the time spend on occlusal surface modelling and minimizes the risk for prolonged treatment due to a repeated need for occlusal adjustments. In addition to saving time, it is possible with this technique to restore a greater number of teeth in a single appointment. The aesthetics of this type of restoration may be somewhat limited: A skilled practitioner is able to achieve better aesthetic results on the occlusal surface. However, with a detailed wax-up and high-quality model great outcomes can be obtained. The surface quality of printed models can be increased by adjusting the printing parameters including the layer height (Fig. 6). The use of a hydraulic pressure curing unit for silicone index production further increases the quality of the occlusal surface.

When planned and implemented correctly, the established occlusal surface and contacts reflect the natural anatomy without the need for adjustments (Fig. 7). Especially when restoring an entire quadrant, it is possible to increase the efficiency by opting for the flowable injection technique. Doing so reduces the number of appointments and the chair time decisively (Fig. 8).

STAMP TECHNIQUE: CONSIDERATIONS

If the occlusal surface of the tooth is intact, a wax-up may not be necessary. In this case, the better strategy is to duplicate what is still available before initiating treatment. A flowable composite or liquid rubber dam can be used for this purpose. It is important to coat the tooth surface with glycerin gel before applying the material. This will facilitate separation of the stamp from the tooth. It is always advisable to create a stamp that covers not only the details that need to be recorded and duplicated, but is extended over the cusps. This offers better stability in the restoration phase.

CLINICAL PROTOCOL

Figures 9 to 11 illustrate a possible clinical procedure. In this case, a molar with an occlusal carious lesion needed to be restored. The tooth surface was cleaned and a thin layer of glycerin gel applied, followed by a thick layer of liquid rubber dam, which covered the entire occlusal surface. Then, a micro applicator was immersed into the material and the stamp cured. After preparation, etching and application of the bonding system, the cavity was restored with flowable composite (CLEARFIL MAJESTY™ ES Flow Super Low in the shade A2). When the cavity is larger and depending on personal preferences, a paste-type composite (CLEARFIL MAJESTY™ ES-2 Universal) may also be used. Prior to light curing of the composite, the occlusal surface was covered with PTFE tape and the stamp pressed onto it. After firm pressing, the tape and excess material were removed and the restoration polymerized. This restoration faithfully reproduces the occlusal surface and did not require any occlusal adjustments.

Fig. 6. Stamp production with liquid rubber dam.

Fig. 7. The stamp.

Fig. 8. Restoration procedure: From preparation to bonding.

Fig. 9. Restoration procedure: Filling with flowable composite.

Fig. 10. Restoration procedure: Duplication the original occlusal surface with the stamp.

Fig. 11. Tooth before and after treatment using the stamp technique.

CONCLUSION

Techniques that add simplicity and efficiency to clinical procedures are always welcome in the busy practice environment. Depending on the information available at the start of treatment and the number of teeth to be restored, the flowable injection or the stamp technique may be an ideal choice. They are easily implemented and speed up the clinical procedure, but most importantly support predictable outcomes. This saves time in the finishing phase and minimized the risk of repeated adjustments, hence protecting everyone involved from additional appointments and frustration. Especially for practitioners with limited routine in free-hand modelling and for those with maximum patient comfort in mind, both techniques are worth being integrated in their clinical procedures.

Dentist:

MICHAL JACZEWSKI

Michał Jaczewski graduated from Wroclaw Medical University in 2006 and today runs his private practice in the city of Legnica, Poland. He specializes in minimally invasive dentistry and digital dentistry and is the founder of the Biofunctional School of Occlusion. Here he lectures and runs workshops with focus on full comprehensive patient treatments.

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.

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.

Dental technician:

ANDREAS CHATZIMPATZAKIS

Andreas graduated from the Dental Technology Institute (TEI) of Athens in 1999. During his studies he followed a program at the Helsinki Polytechnic Department of Dental Technique, where he trained on implant superstructures and all ceramic prosthetic restorations. As of 2000, he is running the ACH Dental Laboratory in Athens, Greece, specialized on refractory veneers, zirconia and long span implant prosthesis. In 2017 Andreas visited Japan where he trained under the guidance of Hitoshi Aoshima, Naoto Yuasa and Kazunabu Yamanda and become International Trainer for Kuraray Noritake Dental Inc..

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

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

Portselanlaminaatide kasutamine eesmiste hammaste kuju, tooni ja visuaalse asukoha parandamiseks ja taastamiseks on esteetilises hambaravis levinud tehnika. Restauratsioonide biomimeetika ei kätke ainult kosmeetilisi, vaid ka funktsionaalseid aspekte. On oluline märkida, et eesmiste hammaste puhul määrab nende palatinaalse ja labiaalse seina emaili terviklikkus nende sisemise paindetugevuse. Kui hamba struktuur on rikutud endodontilise ravi, kaariese ja/või trauma tõttu, tuleb teha kõik, et säilitada olemasolev struktuur ja taastada algse hamba funktsionaalsed näitajad.

TAUSTTEAVE

55 aastane ASA II klassifikatsiooniga naine tuli praksisesse hambaid valgendama. Eeldati, et hambavalgendus ei mõjuta juba olemasoleva hamba 1.2 portselanlaminaadi tooni. Seda peaks protseduuri järgselt uuesti töödelda, eriti kui toonimuutused on märkimisväärsed. Patsiendi algne toon ülemiste esihammaste piirkonnas oli VITA* 1M1:2M1; 50:50 suhtega ja alumiste esihammaste piirkonnas 1M1. Pärast öise hambavalgenduse protokolli järgimist, kus kasutati 10% karbamiidperoksiidi, mida kanti üleöö 3-4 nädala jooksul, saavutas patsient nii ülemisel kui ka alumisel hambakaarel tooni VITA* 0M3. Selle tulemusena oli laminaadiga kaetud hamba 1.2 ja kõrvalolevate hammaste vahel märkimisväärne heleduse erinevus ning märgati tugevamat värvust kontralateraalsel hambal 2.2, mis oli tingitud huulmiselt asetsevast klass III komposiitrestauratsioonist. Lisaks viimati mainitud hammas ei sobinud kontralateraalse hambaga mõõtmete poolest ja seega otsustati mõlemaid külgmisi lõikehambaid ravida liimitavate liitiumdisilikaadist laminaatidega. Kõrvalolev silmahambal (2.3) olid köbrukesed kohati kergelt kuni mõõdukalt kulunud, kuid patsient ei soovinud sellega tegeleda enne, kui need laminaadid olid paigaldatud. Selles etapis on hammaste esteetilise ravi eesmärk lõppkokkuvõttes saavutada kahepoolne harmoonia, ning tulevikus paigaldada hambale 2.3 täiendav indirektne restauratsioon, mis taastab selle huulmise pinna ja hamba köbrukeste puudujäägid.

PROTSEDUUR

Digitaalne esteetilise ravi protokoll ei olnud algseks eesmärgiks ehk külgmiste lõikehammaste individuaalseks raviks vajalik. Sellel hambatüübil on lubatud väike variatsioon, kuna see on naeratuse isikupära ja soo marker. Enne anesteesiat valiti sihttoon töödeldud fotode põhjal, millel olid nii polariseeritud kui ka polariseerimata valikud. Fotod valmistati ette digitaalse tooni kalibreerimiseks, tehes võrdlusvaateid 18% neutraalse halliskaala tasakaalukaardi abil (joonis 1).

Joonis 1. 18% neutraalse halliskaala kaardi abil tehtud võrdlusfoto.

Põhitoon oli VITA* 0M2 ja valuploki toon BL2. Patsient tuimestati 2% lignokaiini ja epinefriini 1:100 000 lahusega (1,5 süstlatäit) enne kofferdami paigaldamist lõhestatud orientatsioonis. Laminaat hambal 1.2 lõigati välja ja eemaldati ning hambal 2.2 tehti minimaalselt invasiivne laminaadi preparatsioon (joonis 2). Vana komposiitvaigu restauratsiooni osaline asendamine viidi lõpule 12. hamba keskjoonmisel, lõike-, labiaalsel ja palatinaalsel pinnal, säilitades segmendi terviklikkuse. Adhesioon vanale komposiidile saavutati mikroosakestega hõõrumise ja silaanist sidusainega (CLEARFIL™ CERAMIC PRIMER PLUS). Servad viimistleti ja retraktsiooniniidid leotati alumiiniumkloriidi lahuses ja pakiti. Preparatsiooni köndi toonid registreeriti. Lõplikud jäljendid võeti kasutades metallist aluses nii kerget kui ka rasket polüvinüülsiloksaani. Patsiendile paigaldati ajutine lahendus ja saadeti laborisse tooni kontrollima esimesel paagutusetapil. Labori valmistatud mudelid kinnitasid juhtumi minimaalselt invasiivset laadi.

Joonis 2. Laminaadi jaoks prepareeritud hammas 1.2, 2.2

Pärast töö saamist tehti patsiendile anesteesia ja eemaldati ajutised laminaadid. Preparatsioonid puhastati ja valmistati ette sidustamiseks, kasutades pindade lihvimiseks 27-mikronilist alumiiniumoksiidi pulbrit 30-40 psi juures. Laminaate hinnati läbipaistva glütseriinist proovimispastaga (PANAVIA™ V5 Try- in Paste Clear, Kuraray Noritake Dental Inc.). Sisestati retraktsiooniniidid ja restauratsioonide jäljendi pinda töödeldi 20 sekundit 5% vesinikfluoriidhappega, enne kui kasutati 10-MDP-d sisaldavat silaanist sidusainet (CLEARFIL™ CERAMIC PRIMER PLUS (joonis 3)). Hammaste pinda söövitati 20 sekundit 33% ortofosforhappega ja loputati. Hamba pinnale kanti 10-MDP sisaldavat praimerit (PANAVIA™ V5 Tooth Primer (joonis 4)) ja kuivatati õhuga vastavalt tootja juhistele. Lisati laminaadi tsement (PANAVIA™ Veneer LC Paste Clear) (joonis 5) ja laminaat paigaldati. Liigne tsement ei vajunud ja hoidis laminaati hästi paigal kõigi servade kontrollide ajal enne 1-sekundilist nakkekõvastamist (joonis 6).

Joonis 3. Laminaatide jäljendi pindadele kanti CLEARFIL™ CERAMIC PRIMER PLUSi.

Joonis 4. Hambapindadele kanti praimerit PANAVIA™ V5 Tooth Praimer.

Joonis 5. Laminaatide ettevalmistatud jäljendi pindadele kanti tooni PANAVIA™ Veneer LC Paste Clear.

Joonis 6. PANAVIA™ Veneer LC Paste kohe pärast paigaldamist. Täheldage tsemendi viskoosset mittevajuvat omadust, mis võimaldab hõlpsat eemaldamist nii märja kui ka geelja etapi ajal.

Tsement viidi geeljasse olekusse, mis hõlbustas tsemendijääkide eemaldamist minimaalse puhastamise vajadusega (joonis 7). Servad kaeti enne lõplikku kõvendamist läbipaistva glütseriinigeeliga, et eemaldada hapniku inhibitsioonikiht (joonis 8).

Joonis 7. Tsemendijääkide eemaldamine pärast 1-sekundilist nakkekõvastamist.

Joonis 8. Laminaatide lõplik kõvendamine üheaegselt nii palatinaalselt kui ka labiaalselt.

Servad viimistleti ja poleeriti läikima ning kontrolliti restauratsioonide oklusiooni vastavust. Operatsioonijärgsetel piltidel on suurepärane servade sobivus (joonis 9).

Joonis 9. Hamba 1.2 ja 2.2 laminaatide operatsioonijärgne esteetiline integratsioon.

Polariseeritud fotode ümbervaatamisel on restauratsioonid esteetiliselt ja funktsionaalselt hästi integreeritud (joonis 10); järgmisena tuleb hammast 2.3 esteetiliselt kohandada, et see sobituks kontralateraalse silmahambaga.

LÕPPTULEMUS

Joonis 10. Lõpptulemus polariseeritud fotona.

Dentist:

CLARENCE TAM

References

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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.