Naslov
Procjena snage vezivanja ortodontskih bravica ljepljenih na različite keramičke površine
(Evaluation of the shear bond strength of orthodontic brackets bonded to different ceramic surfaces)

Autori
Mehmeti, Blerim

Vrsta, podvrsta i kategorija rada
Ocjenski radovi, doktorska disertacija

Fakultet
Stomatološki fakultet

Mjesto
Zagreb

Datum
22.02

Godina
2018

Stranica
117

Mentor
Anić Milošević, Sandra

Ključne riječi
Feldspar ; Zirconia ; Lithium disilicate ; orthodontic brackets ; phosphoric acid ; HFA ; SBS ; ARI ; PFI

Sažetak
Due to the increase in the number of adults seeking orthodontic treatment, new challenges have risen for orthodontists, such as the need to bond orthodontic brackets to ceramic restorations, whose glazed surfaces are not amenable to resin penetration and have a higher degree of failure compared with bonding to enamel. The aim of this study was to conduct an inclusive and substantial analysis of the factors affecting shear bond strength (SBS) of metallic and ceramic orthodontic brackets bonded to different ceramic surfaces used for prosthetic restorations. The research was conducted with 144 ceramic specimens of three different types (feldspar-porcelain fused to metal, zirconia and lithium disilicate), on which orthodontic brackets consisting of different materials (metallic and polycrystalline ceramic) were bonded. The bonding surface of the specimens was conditioned with two different etching materials (hydrofluoric acid or phosphoric acid), and then silane was applied. SBS was tested in Universal Testing Machine and values were calculated in MPa. The samples were also analyzed using a digital microscope and Scanning Electron Microscope (SEM) in order to determine the Adhesive Remnant Index (ARI) and Porcelain Fracture Index (PFI). The results showed that the use of HFA for surface etching of feldspar, all-contour zirconia and/or lithium disilicate, does not cause a significant increase in the SBS values as compared to etching with PhA and silane application, which is a safer method to use in clinical conditions. However, ceramic brackets show significantly higher SBS values than metallic brackets in feldspar and lithium disilicate. Also, ARI significantly depends on the type of bracket (p = 0.005). Furthermore, since PFI depends on the type of etchant (p = 0.029), HFA can weaken the surface structure of the ceramic, and considering its noxious effect, might not be the best suitable conditioner prior to orthodontic bonding to feldspar, lithium disilicate, and in particular to zirconia, also taking into account its crystalline structure.

Izvorni jezik
Engleski

Znanstvena područja
Dentalna medicina

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