Aim of this study was to analyze Shear Bond Strength (SBS) and Adhesive Remnant Index (ARI) of ceramic and metallic orthodontic brackets bonded to zirconia or lithium-disilicate ceramics used for prosthetic restorations, conditioned with hydrofluoric acid (HFA) or phosphoric acid (PhA), as well as to determine the Porcelain Fracture Index (PFI), in order to examine the condition of the ceramic surface after debonding. Material and methods: The research was conducted on 96 prepared all-ceramic samples divided into 8 groups combined from the type of ceramic material, orthodontic brackets, and surface conditioning. SBS was tested with Universal Testing Machine, and the samples were analyzed using a Scanning Electron Microscope, to determine ARI and PFI. Statistical data were processed using ANOVA, with the level of significance [alpha] = 0.05. Results: Lithium-disilicate showed better bond strength in almost all groups. However, no significant difference between the groups was noticed and none of the factors had a significant influence on the mean values of SBS (p 0.05). Nevertheless, ARI significantly depended on the type of bracket (p = 0.005), and PFI significantly depended on the type of etchant (p = 0.029). Conclusion: The use of HFA for surface etching of zirconia and lithium-disilicate, does not cause a significant increase in the SBS values as compared to etching with PhA and silane application. Furthermore, HFA can weaken the surface structure of the ceramic, and considering its toxicity, might not be the best suitable conditioner prior to orthodontic bonding to lithium disilicate, and in particular to zirconia, also taking into account its crystalline structure. Key words Orthodontic Brackets; Shear Bond Strength; Crowns; Adhesive Remnant Index (ARI); Porcelain Fracture Index (PFI); Zirconia; Lithium Compounds Cilj: Analizirani su posmicna cvrstoca veze (SBS) i indeks zaostatnog sloja adheziva (ARI) keramickih i metalnih ortodontskih bravica nalijepljenih na cirkonijeve i litijeve disilikatne krunice koje se koriste za proteticke restauracije najetkane fluorovodicnom (HFA) ili fosfornom kiselinom (PhA) te se odredivao indeks loma keramike (PFI) kako bi se proucila keramicka povrsina nakon skidanja bravica. Materijali i metode: Istrazivanje je provedeno na 96 potpuno keramickih uzoraka zuba podijeljenih u osam skupina prema vrsti keramike, razlicitosti materijala od kojih su napravljene ortodontske bravice te jetkanju povrsine. Posmicna cvrstoca veze (SBS) testirana je s pomocu univerzalnog uredaja za testiranje, a uzorci su analizirani elektronskim mikroskopom kako bi se odredio indeks zaostatnog sloja adheziva (ARI) i indeks loma keramike (PFI). Statisticki podatci dobiveni su s pomocu testa ANOVA-e s razinom znacajnosti a = 0,05. Rezultati: Litijev disilikat pokazao je bolju mogucnost vezivanja u gotovo svim skupinama. No nije pronadena znacajnija razlika izmedu skupina i ni jedan od cimbenika nije znatnije utjecao na srednje vrijednosti SBS-a (p 0,05). Naime, ARI je znacajno ovisio o vrsti bravica (p = 0,005), a PFI o vrsti jetkaca (p = 0,029). Zakljucak: Uporaba fluorovodicne kiseline (HFA) za hrapavljenje cirkonijeve i litijeve disilikatne povrsine ne utjece na povecanje cvrstoce vezivanja u usporedbi s hrapavljenjem povrsine fosfornom kiselinom i silanom. Nadalje, fluorovodicna kiselina moze oslabiti povrsinsku strukturu keramike, a uzimajuci u obzir njezinu toksicnost, nije najprikladnija za nanosenje prije lijepljenja ortodontskih bravica na litijeve disilikatne i cirkonijeve povrsine, takoder uzimajuci u obzir njihovu kristalicnu strukturu. Kljucne rijeci ortodontske bravice; posmicna cvrstoca veze; krunice; indeks zaostatnog sloja adheziva (ARI); indeks loma keramike (PFI); cirkonij; smjese litija