429 Too Many Requests

429 Too Many Requests


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A photo of Mathias Fernandez Y Lombardi

Mathias Fernandez Y Lombardi

EU Scientific Manager Dental Ceramics & CAD/CAM Materials

 

 

2013
Successful completion of an apprenticeship as a dental technician at Seuthe dental laboratory in Plettenberg, Germany


2018
Successful completion of dental technology studies at the University of Osnabrück, Germany. Graduation as an engineer in dental technology


Since March 2018
Employee of Kuraray Europe GmbH

Gør dit dentallaboratorium endnu mere effektivt

Mathias Fernandez Y Lombardi, EU Scientific Manager, Kuraray Europe GmbH

Kuraray Noritake Dental Inc. har genopfundet sin originale zirkonia-flerlagsteknologi ved at integrere nyudviklede råmaterialer med forskelligt yttriaindhold i den velkendte flerlagsfarvestruktur. Materialet, som er baseret på denne innovative teknologi, “KATANA™ Zirconia” YML, giver en velafbalanceret gradation af bøjestyrke, farvetone og translucens gennem hele materialet.

Ifølge pilotbrugerne af de nye zirkoniaskiver er den største fordel ved brugen af "KATANA™ Zirconia" YML, at laboratoriet kan arbejde mere effektivt. Vi har bedt Kuraray Noritakes videnskabelige manager for dentalkeramik og CAD/CAM-materialer i EU, Mathias Fernandez Lombardi, om at forklare, hvordan det nye materiale kan have en positiv effekt på de daglige arbejdsrutiner i dentallaboratoriet.

 

Den største fordel ved brugen af "KATANA™ Zirconia" YML er, at laboratoriet kan arbejde mere effektivt.

 

Mathias Fernandez Lombardi - hvem bør overveje at arbejde med "KATANA™ Zirconia" YML?

 

"KATANA™ Zirconia" YML er designet til laboratorier og fræsecentre med høj fokus på forenkling. Med sit kraftige body-lag og højtranslucente emaljelag har KATANA™ Zirconia YML præcist de egenskaber, der kræves til et ubegrænset indikationsområde. Ved at være perfekt egnet til fremstilling af holdbare monolitiske lange postoriore broer og æstetiske kroner eller partielle restaureringer med høj æstetik er "KATANA™ Zirconia" YML en ægte universalløsning, der fjerner behovet for andre zirkonia eller endda keramiske CAD/CAM-materialer. Samtidigt understøtter det højt automatiserede fremstillingsprocedurer og kræver kun minimalt manuelt arbejde.

 

Hvilke fordele er der ved at anvende et enkelt materiale til alle indikationer?

 

Der er flere fordele ved at bruge et enkelt universalmateriale. Det nedbringer antallet af materialer, der skal opbevares, hvilket gør lagerkontrollen nemmere og
minimerer den krævede plads til opbevaring. Derudover sørger det for en standardisering af arbejdsgangen på laboratoriet. At benytte det samme materiale betyder, at man ikke behøver at tage hensyn til forskelle i de grundlæggende design- og fræseparametre som f.eks. minimal vægtykkelse og styrker for forbindelsesdele eller forskelle i sintringsprotokollerne og mulighederne for finishing. Derfor er der mindre sandsynlighed for fejl, og det bliver nemt at fastlægge daglige rutiner. Sidst men ikke mindst fjernes risikoen for krydskontaminering, når man behandler et enkelt materiale med det tilgængelige udstyr (fræsemaskine, fræse- og efterbehandlingsværktøjer og sintringsovn). Det gør, at man som regel kan opnå forudsigelige resultater og få en perfekt æstetik.

 

Hvilke fordele er knyttet til brugen af "KATANA™ Zirconia" YML som det eneste keramiske CAD/CAM-materiale?
 

Jeg tror det vigtigste argument er, at de æstetiske resultater kan opnås nemt og effektivt med "KATANA™ Zirconia" YML i forbindelse med alle typer restaureringer, selv ved lange broer. Det er som regel tilstrækkeligt at fremstille monotolitiske restaureringer til det posteriore område, som kun bliver poleret
eller glaceret. Anteriore restaureringer kan designes monolitisk eller med minimalt cutback, og brugeren kan vælge mellem "CERABIEN™ ZR" (CZR) FC Paste Stains og CZR Internal Stains plus glaze for at opnå et naturligt udseende. En anden fordel ved "KATANA™ Zirconia" YML er den glidende flerlagsstruktur
kombineret med en ekstraordinær kvalitet.

 

 

Hvorfor er denne glidende struktur og høje kvalitet så vigtigt for brugerne?

Den glidende flerlagsstruktur med en blød overgang mellem lagene er forudsætningen for en strukturel integritet og perfekt æstetik. Det sikrer, at materialet ikke har overgangslinjer, at målene er præcise efter sintring (som følge af den ensartede krympning), og at der opnås en pålidelig langvarig
ydeevne, der ikke bringes i fare af interne spændinger. "KATANA™ Zirconia" YML giver denne fordel ved at være en helt homogen sammensætning med nøjagtigt tilpassede CTE-værdier og krympeforhold for hele materialet.

 

De æstetiske resultater kan opnås nemt og effektivt med "KATANA™ Zirconia" YML i forbindelse med alle typer restaureringer, selv ved lange broer.

 

for dentalkeramik og fordelene, der er forbundet med at have en komplet intern fremstillingsproces, som man ikke ville have kunnet opnå det krævede kvalitetsniveau uden. Takket være det faktum, at materialet er så godt tilpasset, var det endda muligt at udvikle et 54 minutters sintringsprogram, der opnår
lignende gode resultater som de velkendte programmer på 90 minutter eller 7 timer. Dermed har man en hurtig løsning til alle hastesager. Med denne egenskab bliver "KATANA™ Zirconia" YML den perfekte materialeløsning. Sagt på bilsprog: Det har den samme høje komfort og sikkerhed som en firehjulstrækker,
men det er lige så hurtigt som en sportsbil.

 


TheDe ovennævnte sintringsanbefalinger er kun vejledende. Afhængigt af den individuelle ovn samt betingelserne kan enkelte justeringer være nødvendige.
Hvis din ovn ikke kan programmeres til sintringsprogrammer på 54 eller 90 minutter, vil det ikke være muligt at indstille ovnen i henhold til disse brændeskemaer.
*Materialet fjernes fra ovnen ved 800°C. Der kræves en ovn med et konfigurerbart YML-sintringsprogram.

 

Brugere, som allerede har prøvet keramiske materialer med en styrkegradient ved, at restaureringer med lang spændvidde i disken kan være vanskelige. Hvad skal man være opmærksom på, når man positionerer en lang bro i en YML-disk?

 

Positionering af restaureringer i "KATANA™ Zirconia" YML-diske er særdeles nemt. Årsagen er, at mellemrummet mellem den laveste bøjestyrke, der findes i emaljeområdet, og den højeste bøjestyrke, der findes i det nederste body-lag, er forholdsmæssig lille. Body-lag 1, som støder op til emaljelaget, har desuden en bøjestyrke, der er højere end de 800 MPa, der kræves til broer med fire eller flere led. Det betyder, at brugerne er på den sikre side, når de anbringer
restaureringer med lang spændvidde i midten af disken. Mere specifikt skal halvdelen af forbindelsesdelens tværsnit være i den nedre halvdel af disken, hvilket er ret forskelligt fra andre materialer med en styrkegradation, der kun giver mulighed for at anbringe forbindelsesdelen i body området. "KATANA™ Zirconia" YML-restaureringer med maksimalt tre enheder kan anbringes i alle lag. I denne forbindelse er det en fordel, at tykkelsen for hvert lag forøges proportionelt
med diskens højde: Emaljelaget er stort nok til at udnytte dets æstetiske potentiale i forbindelse med en enkelt enhed eller små broer.

 



Positionering af restaureringer med lang spændvidde i midten af disken.

 

Hvad vil du anbefaler tandteknikere, som vil effektivisere arbejdet på deres laboratorie eller fræsecenter?

 

Jeg kan især anbefale dem at prøve "KATANA™ Zirconia" YML i laboratorieomgivelserne for at se, hvordan det er at arbejde med og for kunne bedømme dets potentiale. Den fremragende kvalitet af materialet og den glidende integrering af de forskellige lag, den nemme positionering og bearbejdningseffektivitet er faktorer, som potentielle brugere skal opleve i praksis for at forstå, hvad det betyder for deres daglige arbejde. Desuden skal de æstetiske resultater bedømmes i det kliniske miljø for at få et ægte indtryk af det naturlige udseende og den naturlige følelse. Jeg er sikker på, at "KATANA™ Zirconia" YML kan overbevise stort set alle, som vil arbejde mere effektivt på laboratoriet takket være den brugervenlige og effektive universale zirkonialøsning, der passer til stort set alle patienters og tandlægers behov! Kuraray Noritake Dental ved, at tandteknikere og tandlæger har brug for produkter, der hjælper dem med at forenkle og
standardisere processerne samt at forøge effektiviteten, hvilket er afgørende i dag. Derfor er målet med alle vores produktinnovationer at forbedre ydeevnen og mindske det påkrævede arbejde. "KATANA™ Zirconia" YML er det seneste produkt i en hel serie af materialer, der har dette formål.

 



Minimumstværsnittene for forbindelsesdelen skal overholdes under computerunderstøttet design (CAD) af "KATANA™ Zirconia" YML-restaureringer.

 

Mathias Fernandez Y Lombardi

 

EU Scientific Manager
Dental Ceramics & CAD/CAM Materials
Kuraray Europe GmbH

 

2013
Successful completion of an apprenticeship as a dental technician at Seuthe dental laboratory in Plettenberg, Germany

 

2018
Successful completion of dental technology studies at the University of Osnabrück, Germany. Graduation as an engineer in dental technology

 

Since March 2018
Employee of Kuraray Europe GmbH

 

KATANA™ Zirconia Block: Useful tips for processing

KATANA™ Zirconia Block has hardly any common features with the zirconium oxide that captured dental laboratories two decades ago and was used as a framework material. In many cases, the innovative zirconia serves as a functionally and aesthetically sensible alternative to high-strength glass ceramics. Its flexural strength is higher than that of lithium disilicate, its translucency on a level with the LT variant of the ceramic and its surface – if smoothly polished – antagonist-friendly causing low wear. Apart from its natural translucency, the multi-layered structure of KATANA™ Zirconia Block with four gradient shades precisely imitating natural colour gradients found in anterior and posterior teeth leads to highly aesthetic outcomes.

 

In order to exploit the full potential of the cubic zirconia KATANA™ Zirconia Block, users of the CEREC system need to adopt slightly different automatic and manual processing strategies than for glass ceramic processing. The following answers to frequently asked questions provide information on the most important differences and tips and tricks that help achieve the best possible results.

 

COMPUTER-AIDED DESIGN

 

What is the best position of the restoration in the block to leverage all benefits related to the multi-layered structure?

Ideally, a restoration is positioned in the middle of the block. In addition, the selected block should be one shade darker than the determined shade. This will lead to a natural shade appearance of the resulting restoration. If the restoration is placed at the upper margin of the block, parts of the body shade – and with it chroma – are lost, which makes the restoration appear too light.

 


How are chipping effects in the area of the milling sprues (most often occurring in bridges) effectively prevented?

Marginal chipping in these areas might appear due to an uneven force distribution during milling. The problem is easily overcome by designing two milling sprues per crown or bridge unit.

 

COMPUTER-MANUFACTURING

 

Is wet or dry milling the best option to process KATANA™ Zirconia Block?

The best results are obtained with dry milling. This procedure also leads to time-savings, as there is no need for drying after processing.

 

When opting for wet milling: Are there any particularities that need to be respected for KATANA™ Zirconia Block?

Those users opting for wet milling and utilizing the same machine for the processing of zirconia and glass ceramics should implement a system utilizing three water tanks. One tank is filled with wash water, the tank used for processing of glass-based ceramics is filled with water and additives (such as Dentatec, Dentsply Sirona) and the one used for processing of zirconia contains purified/distilled water without any additives.

 

 

Moreover, a prerequisite for a high quality of the manufactured restorations is that the machine is cleaned thoroughly every time before a different material is processed.

The following components need to be cleaned:

  • the milling tools
  • the interior of the machine
  • the water tank(s)
  • all filters

Typically, zirconia reacts to milling additives (Dentatec) in the water with a reduced translucency, so that their use cannot be recommended. Residues of glass ceramic particles found on milling tools, in the water or in the interior of the machine might also have a negative impact on the aesthetic appearance of KATANA™ restorations (typical effect: white spots on the surface).

 


When is it necessary to replace milling tools used for the processing of KATANA™ Zirconia Block?

It is recommended to replace the tool sets every 10 to 15 units. At this time, the degree of tool wear amounts to approximately 50 percent. Those who continue using the tools accept an increased risk of weakening the oxide ceramic’s microstructure: worn milling tools are likely to produce micro cracks and micro chipping. When these defects occur between the different units of a bridge, they increase the risk for chipping and fractures.

 

MANUAL POST-PROCESSING

 

Are there any specific measures to be taken when removing the block from the machine?

When machining is completed, the restoration should be touched only by individuals wearing gloves. Even after thorough washing, bare hands will release fats, which may lead to smear formation and a reduced translucency of the oxide ceramic material.

 

How are the restorations cleaned after sprue removal?

Powder residues should be removed after processing with a gentle stream of air. Alternatively, a fine (and obviously clean) brush may be used for the removal of the zirconia dust. Powder residues remaining on the restoration surface might lead to the occurrence or white spots or to smear formation. Steam-cleaning of the restoration should be avoided as this measure dramatically increases the pores in the material and alters the material properties.

 

When is the right time to add fissures and texture to the surface of the restoration and how is this task accomplished?

Ideally, all those details that cannot be incorporated by a milling machine (surface texture, fissures etc.) are added in the restoration’s pre-sintered state, i.e. between milling and final sintering. Diamond milling tools for oxide ceramics should be used at a low speed (7,000 to 10,000 rpm) for this purpose.

 

TANK MANAGEMENT: CLEANING PROCEDURE AFTER USING GLASS CERAMICS

 

Be sure the glass ceramic cooling-water tank is installed. Press the Pump button on the touch panel to wash away any glass ceramic powder that is inside the milling chamber. Then, thoroughly flush milling debris from the milling chamber filter and milling powder from beneath the milling chamber filter.

 

FINAL SINTERING

 

What are the particularities to be respected during final sintering of restorations made of KATANA™ Zirconia Block material?

Zirconia restorations are subject to volumetric shrinkage (approximately 20 percent) during sintering. Therefore, it is essential to not place the restoration on a rigid carrier during sintering. If the volume of the restoration is reduced while the volume of the carrier is not, the risk of fracture is high. Ideally, the restoration is placed on its largest side.

 

What measures should be taken to avoid discoloration of a restoration during sintering?

Discoloration (usually leading to a green-yellowish appearance) might be the result of contamination of the sintering furnace with metal oxides. These metal oxides originate from other materials processed in the furnace. They are released during sintering and absorbed by the restoration. Running a decontamination programme on a regular basis is an effective measure that helps prevent discoloration. For this purpose, white zirconium oxide (either collected from odds and ends of non-shaded blanks or purchased) is placed in the furnace chamber and a sintering programme is started. As the furnace CEREC® SpeedFire does not offer a specific decontamination programme, there is no way around working a fiddle: the user simply creates two separate jobs for the sintering of two single crowns, but sinters them together. The second job is used for the decontamination cycle. During this procedure, the white zirconium oxide absorbs the metal oxides, which has a cleaning effect on the furnace.

 

CHARACTERISATION

 

Which techniques are best suited for an optical refinement of monolithic restorations made of KATANA™ Zirconia Block?

A material designed for this kind of refinement is CERABIEN™ ZR FC Paste Stain from Kuraray Noritake Dental. The paste-like shading solutions are filled with ceramic particles. Therefore, the optical effects achievable with these pastes are much more durable than those obtained with classical stains. As all pastes are fluorescent, it is possible to produce a natural long-term fluorescence effect without an additional work step. With just four shades of the liquid ceramic – A+, Grayish Blue, Value and Clear Glaze – it is possible to perfectly characterize 85 percent of all restorations made of KATANA™ Zirconia Block material. The firing temperature is 750 °C and the CTE values of CERABIEN™ ZR FC Paste Stain and KATANA™ Zirconia Block are precisely adjusted to each other. The product is also very well suited for glass ceramic characterization.

 

 

How is it possible to hold the restoration during characterization?

The easiest option is the use of putty material on a carrier. The crown is simply placed on the unset putty and then positioned on the carrier. The surface of the restoration should be cleaned with a gentle stream of air before applying the pastes. Thanks to the ceramic particles in CERABIEN™ ZR FC Paste Stain, the pastes stay put during processing and do not flow away.


POLISHING


How to ensure a low wear of the antagonist?

Zirconium oxide stands out due to its hardness, which makes careful polishing of the surface a prerequisite for clinical use. After characterization with CERABIEN™ ZR FC Paste Stain, polishing of all occlusal contact areas is mandatory as well. The polishing set Polierset KATANA™ Twist DIA even allows for intraoral use.

 

PLACEMENT

 

What kind of resin cement is recommended for the definitive placement of restorations made of KATANA™ Zirconia Block material?

The best possible results are obtained with PANAVIA™ V5. This adhesive resin cement system is responsible for the development of a particularly strong bond between the tooth structure and the restoration, which also has a strengthening effect on the restoration.