Syfte: Syftet med denna studie var att undersöka om det finns en skillnad i böjhållfasthet mellan zirkoniumdioxid som sintras med konventionella sintringstider jämfört med snabbsintrad zirkoniumdioxid. Material och metod: Totalt 40 diskar i zirkoniumdioxid framställdes med hjälp av Sironas Dental CAD/CAM system, 20 i märket Cerec Zirconia A2 och 20 i märket Ivoclar IPS e.max Zircad LT A2. Diskarna delades in i 4 grupper (n=10) varav hälften av grupperna sintrades med ett konventionellt protokoll i Programat S1 1600, och hälften snabbsintrades i Cerec SpeedFire. Alla diskar genomgick termocykling, förbelastning och slutligen ett biaxialt böjhållfasthetstest. Resultat: Ingen signifikant skillnad i böjhållfasthet kunde ses (p=0,56) när Cerec Zirconia A2 (grupp 1) snabbsintrades i SpeedFire jämfört med när Cerec Zirconia A2 (grupp 2) sintrades med konventionellt protokoll i Programat S1 1600. När Ivoclars IPS e.max ZirCad LT A2 (grupp 3) som snabbsintrades i SpeedFire jämfördes med Ivoclars IPS e.max ZirCad LT A2 (grupp 4) som sintrades i ett konventionellt protokoll i Programat S1 1600, hade grupp 4 en signifikant högre böjhållfasthet (p=0.0066). Alla resultat bekräftades av en Mann-Whitney analys. Slutsats: Det kan finnas skillnader i böjhållfasthet mellan zirkoniumdioxid som sintras med konventionella sintringstider jämfört med snabbsintrad zirkoniumdioxid. Dessa skillnader varierar emellertid från material till material och verkar vara så små att det sannolikt har en begränsad klinisk betydelse.

Objective: The aim of this study was to investigate if there is a difference in flexural strength when comparing zirconium dioxide sintered with a conventional sintering protocol, compared to zirconium dioxide sintered with a high-speed protocol. Material and Methods: A total of 40 discs made of zirconium dioxide were produced using Sironas Dental CAD/CAM system, 20 of the brand Cerec Zirconia A2 and 20 of the brand Ivoclar IPS e.max Zircad LT A2. The discs were separated into four different groups (n=10) of which half of the groups were sintered with a conventional protocol in Programat S1 1600, and the other half were sintered with a high-speed protocol in Cerec SpeedFire. All discs were thermocycled, cyclically pre-loaded and finally a piston-on-three-ball test was used to determine the flexural strength of all discs. Result: No significant difference was found in flexural strength when Cerec Zirconia A2 (group 1), sintered with a high-speed protocol in SpeedFire, was compared to Cerec Zirconia A2 (group 2) sintered with a conventional protocol in Programat S1 1600 (p=0,56). When Ivoclars IPS e.max ZirCad LT A2 (group 3), sintered with a high-speed protocol in SpeedFire, was compared to Ivoclars IPS e.max ZirCad LT A2 (group 3), sintered with a conventional protocol in Programat S1 1600, a significant higher flexural strength was found (p=0.0066). All results were confirmed with a Mann-Whitney analysis. Conclusion: There might be a difference between zirconium dioxide sintered with a conventional sintering protocol, compared to zirconium dioxide sintered with a high-speed protocol. However, this difference seems to be dependent on the material used and the difference is so small that the impact on the clinical relevance seems to be very limited.