PURPOSE The aim of this study was to compare the cleanliness of root canal walls after retreatment using ProTaper Next (PTN), ProTaper Universal Retreatment (PTR) nickel-titanium (NiTi) systems and Hedström hand files in curved mesial canals of mandibular molar teeth and the time required for gutta-percha and sealer removal. MATERIALS AND METHODS Ninety mandibular molar teeth with curved mesi...

OBJECTIVES The aim of this study was to evaluate the sealing ability of lateral compaction and tapered single cone gutta-percha techniques in root canals prepared with stainless steel and rotary nickel titanium root canal instruments by fluid filtration method. STUDY DESIGN The root canals were prepared with stainless steel (SS) and nickel titanium (NiTi) instruments. The canals prepared with...

The purpose of this paper is to utilize the signaling pathway polymerase chain reaction (PCR) arrays to investigate the activation of two important biological signaling pathways in endothelial cell adhesion and growth mediated by adsorbed serum protein on the surface of bare and titanium nitride (TiN)-coated nickel titanium (NiTi) alloys. First, the endothelial cells were cultured on the bare a...

The growing use of NiTi rotary instruments in dental practice demands a good understanding of their concept of alloy and design in relation to improved properties and inherent limitations. Nickel titanium's super elasticity allows more centered canal preparations with less transportation and a decreased incidence of canal aberrations. Furthermore, the production of files with increased taper be...

OBJECTIVES The aim of this study is to investigate the role of dry cryogenic treatment (CT) temperature and time on the Vickers hardness and wear resistance of new martensitic shape memory (SM) nickel-titanium (NiTi) alloy. The null hypothesis tested was that there is no difference in Vickers hardness and wear resistance between SM NiTi alloys following CT under two soaking temperatures and tim...

Dental alloys as CoCrMo, SS 316L stainless steel and NiTi were electrochemically investigated in artificial Fusayama saliva, unmodified and modified with two different concentrations of natrium fluoride. Electrochemical tests include measurements of open circuit, measurements of linear polarization, potentiodinamic polarization curves and electrochemical impedance spectra. The best electrochemi...

Pronalazak konstrukcije pravoga kuta odrazio se i u građevinarstvu i urbanizmu te limitiranju poljoprivrednih površina. Auktor opisuje nadgrobni spomenik rimskog agrimenzora iz Pompeja i zagonetni nalaz iz Pfiinza. Prihvaća rekonstrukciju pompejanskoga nalaza s tim da se jednonožni stalak radi stabilizacije instrumenta zamijeni tronolnim. Slobodno ovješene vizirne niti nategnute viškovima na vj...

Both the superelastic and the shape memory properties of the cubic NiTi alloy known as Nitinol arise from two-phase transitions; from a simple cubic austenite phase to a trigonal R-phase and to a lower symmetry martensite phase. In this article, we speculate that two competing forces drive these transitions. One is “mechanical” in nature and it takes the cubic austenite structure of NiTi to a d...

The in ̄uences of grain boundaries and relative grain misorientations on stress-induced martensitic transformations in NiTi are studied using unique experiments and ®nite element modeling. Tensile and compressive mechanical tests reveal that polycrystalline NiTi with a dominant <111> ®ber texture and single crystal NiTi oriented along the [111] direction exhibit nearly identical stress±strain cu...