Impact of zirconia frames surface treatments on the shear bond strength of veneering ceramics

Uvod: Pojav razpok in razslojevanje sta najpogostejša vzroka za neuspeh restavracij z cirkonijevim dioksidom, kjer je stopnja razpok bistveno pogostejša kot v primerjavi s kovinsko porcelanskimi restavracijami. Dokazano je, da se razpoke tvorijo zaradi številnih dejavnikov. To je lahko posledica v nezadostni adheziji med ZrO2 ogrodjem in plastjo porcelanske mase, silami, ki nastajajo zaradi različnih koeficientov toplotne razteznosti dveh materialov, krčenja keramike pri sintranju, razlik v debelini med jedrom in oblogo materiala pri neustreznem načrtovanju nadomestka. Namen: V diplomskem delu smo se ukvarjali z vprašanjem vezi med ogrodjem cirkonij dioksidne keramike in porcelanskim plaščem. Raziskali smo vpliv različnih načinov obdelave površine konstrukcije iz cirkonijevega dioksida na jakost vezi s porcelansko maso. Jakost vezi smo določili s pomočjo strižnega preizkusa. Metode dela: V diplomskem delu smo uporabili deskriptivno in analitično metodo. Diplomsko delo temelji na pregledu strokovne literature. Praktično delo in priprava vzorcev sta opravljena v zobotehničnih laboratorijih na Reki. Preizkusi strižne trdnosti pa so bili izvedeni na Inštitutu za tehnologijo materialov na Fakulteti za strojništvo v Mariboru. Rezultati: Pri izvedbi strižnega preizkusa je prišlo do preloma preizkušancev na spoju med cirkonijevim dioksidom in porcelanom. Naprava za izvedbo mehanskih preizkusov, Zwick Roell Z010 nam je izrisala diagram F- Δl, s pomočjo katerega smo določili silo, pri kateri je prišlo do porušitve preizkušancev. Na podlagi eksperimentalno dobljenih vrednosti sil porušitve smo določili strižne trdnosti preizkušancev v odvisnosti od sestave in površinske obdelave cirkon dioksidnega ogrodja. Razprava in sklep: Rezultati opravljenih strižnih preizkusov, katerih namen je bil ugotoviti jakost vezi med ogrodjem iz cirkonijevega dioksida in porcelansko maso, so bili pričakovani ter ustrezajo lastnostim, ki so predvidene s strani proizvajalca. Razumevanje kombinacije funkcije, estetike in trajnosti materiala je ključ uspešnega dela. Da bi zagotovili vse tri elemente, potrebujemo material, ki izpolnjuje vse pogoje. Cirkonijev dioksid je eden od takšnih materialov. Čeprav je še vedno predmet raziskav, ima z vsemi svojimi pomanjkljivostmi odlične predpogoje, da v celoti pokrije vse kriterije treh elementov.Introduction: The occurrence of cracks and stratifications is the most common cause of the failure of zirconium-dioxide restorations, where the rate of cracks is significantly more frequent than compared to metallic porcelain restorations. It has been proven that cracks are formed due to number of factors. This may be due to inadequate adhesion between the ZrO2 framework and the layer of porcelain mass, forces generated by the coefficients of the thermal expansion of two materials, shrinkage of ceramics in sintering, difference in thickness between the core and the coating of the material in the inadequate design of the structure. Purpose: The purpose and scope of this diploma work is to present the influence of various methods of surface treatment of zirconium dioxide on the strength of the bond with the porcelain mass. We will test, analyze and present the analysis of the sample. The binding strength will be determined by a shear test. Methods: We used in this work the descriptive and analytical methods. The diploma work is based on a review of professional literature. Practical work and preparation of samples were done in dental laboratories in Rijeka. The test was done at the Institute of Technology Materials at the Faculty of Mechanical Engineering in Maribor. Results: In the case of a shear test, there was a connection between zirconium dioxide and porcelain. The device for carrying out mechanical tests the Zwick Roell Z010 produced a F- Δl diagram to determine the force by which the test pieces were broken. Based on experimentally obtained values of breaking forces, we determined the shear strength of the test pieces depending on the composition and surface treatment of the zirconium dioxide frame. Discussion and conclusion: The results of the experiment to determine the binding strength between the zirconium dioxide and porcelain were expected. They also comply with the manufacturer\u27s instructions. Understanding the combination of functionality, aesthetics and durability of materials is a key to a good product. For the sake of ensuring all three elements, we need a material that meets all the requirements. Zirconium dioxide is one of such materials, however, it is still the subject of researches and, despite of its disadvantages, has excellent preconditions