Evaluation of surface characteristics of new rotary nickel-titanium instruments - SEM-EDS analysis

Abstract

Introduction. Modern endodontic procedure implies the use of rotary Ni-Ti instruments during chemomechanical treatment of root canals. The aim of this study is to analyze the surfaces of new (unused) rotary endodontic instruments using the SEM-EDS method and determine how frequently manufacture defects or impurities appear on their working surfaces. Material and method. Five new different sets of rotary endodontic Ni-Ti instruments were included in this study: K3, Mtwo, ProTaper Universal, HyFlex and BioRaCe. The working part of endodontic instrument was analyzed using SEMEDS method (magnifications ×150 to ×2000), which determined the morphological characteristics of the instrument surface and chemical composition of the found impurities. Statistical analysis was performed using the Fisher’s test (p < 0.05). Results. The results of SEM-EDS analysis showed that there is no new instrument without defects on its surface. The most common defects were observed in K3 (27.43%) and ProTaper Universal group (27.21%) and the least were in BioRaCe instruments (7.67%). The most common type of defect in tested instruments was fretting. In addition, the presence of debris and metal strips was found on all instruments, while corrosion of the working part was observed only in K3, ProTaper Universal and Mtwo systems in a small percentage. Conclusion. Based on the results of this research, it can be concluded that manufacturing defects were noticed in all examined instruments. The most common defect is pitting. Impurities such as debris and metal strips have also been registered. No organic debris was observed on electropolished surface of BioRaCe instruments, but a small percentage of other types of defects were registered.

Uvod Moderna endodontska procedura podrazumeva upotrebu mašinskih rotirajućih Ni-Ti instrumenata tokom hemomehaničke obrade kanala korena. Cilj ovog rada je bio da se primenom SEM-EDS metode analiziraju površine novih (neupotrebljenih) rotirajućih endodontskih instrumenata i utvrdi učestalost pojave proizvodnih defekata ili nečistoća na njihovim radnim površinama. Materijal i metoda U istraživanje je uključeno pet različitih novih setova mašinskih endodontskih Ni-Ti instrumenata: K3, Mtwo, ProTaper Universal, HyFlex i BioRaCe. Radni deo svakog instrumenta je podvrgnut SEM-EDS analizi (uvećanja ×150 do ×2000), čime su utvrđene morfološke karakteristike površine instrumenata i hemijski sastav zatečenih nečistoća. Statistička analiza je urađena primenom Fišer testa (p < 0,05). Rezultati Rezultati SEM-EDS analize su pokazali da ne postoji nijedan novi instrument bez defekta na svojoj površini. Najučestaliji defekti su uočeni kod K3 (27,43%) i ProTaper Universal grupe (27,21%), a najmanje ih je bilo na BioRaCe instrumentima (7,67%). Najzastupljeniji tip defekata kod testiranih instrumenata je bilo prisustvo žljebova. Osim toga, utvrđeno je i prisustvo debrisa i metalnih opiljaka na svim instrumentima, dok je korozija radnog dela primećena samo kod K3, ProTaper Universal i Mtwo sistema u malom procentu. Zaključak Na osnovu rezultata ovog istraživanja može se zaključiti da su na svim ispitivanim instrumentima uočeni proizvodni defekti, od kojih su najzastupljeniji žljebovi. Takođe su registrovane i nečistoće kao što su debrisa i metalni opiljci. Na elektropoliranoj površini BioRaCe instrumenata nije uočeno prisustvo organskog debrisa, ali je registrovan Mali procenat ostalih tipova defekata.