Vicente Tadeu Lopes Buono

Aim: To evaluate the behaviour of the XP‐Endo Finisher and the variation in the intracanal temperature of the irrigant at rest and when activated over time.Methodology: Differential scanning calorimetry (DSC) determined the transformation temperatures of XP‐Endo Finisher instruments. A digital thermocouple was used to measure the temperature of the irrigant inside the pulp chamber. Two measurements were performed for each tooth (n = 12): with the irrigant at rest and during XP‐Endo agitation for 60 s to observe the temperature evolution. The data were statistically analysed using a t‐test with a confidence level of 95%.Results: DSC results suggested that the XP‐Endo Finisher had a mixed R‐phase and austenitic structure at room temperature. The temperature values at predetermined time points (0, 10, 40, 70, 120 and 240 s) were measured, and no statistical difference was observed between the values of the resting and activated solutions at any of the selected points (p > .05). For the protocol performed with the XP‐Endo file, the mean irrigant temperature observed at instrument insertion inside the root canal was 28.65°C. After 60 s of agitation, the temperature was 34.02°C. The solution temperature stabilized inside the canal only after 211 s at 35.5°C. The mean maximum irrigation solution temperature recorded inside the canal was 35.5°C without agitation and after XP‐endo agitation (p > .05).Conclusions: Although the XP‐Endo Finisher system does not promote heating of the irrigation solution, file expansion responsible for improved instrument cleaning starts at a temperature below the expected value.

The solidification process of Ti_52-xNi₃₈Cu₁₀Nb_x alloys was evaluated using the CALPHAD method and microstructural analyses of as-cast alloys with Nb additions of x = 4, 6, 8 and 10 at%. Both in Scheil calculator and structural analyses, the observed phases were TiNi, β-Nb/Ti, and Ti₂Ni. TiNi is the matrix phase, and it presented similar amounts of Ti and Ni with varying Nb contents. Enrichments of Ti content and depletion of Ni are expected in the liquid with the solidification of this phase. Formation of Ti₂Ni and β-Ti is related to the excess of Ti. Increasing Nb content hinders the formation of Ti₂Ni, favoring β-Ti. In turn, Ni depletion and Nb accumulation led to the TiNi/β-Nb eutectic. In the intermetallic phases, coherent ratios were obtained when Cu was considered a substitute for Ni, and Nb, for Ti.

ISHS VI International Symposium on Applications of Modelling as an Innovative Technology in the Horticultural Supply Chain Model-IT 2019 Experimental testing of a model-based decision support system integrated with smart sensors to optimize irrigation strategies for processing tomato: a case study in southern Italy

Heat treatments and geometries have a significant influence on the mechanical behavior of endodontic files. Finite element analyses were performed to verify the effects due to each of these parameters in NiTi files. Two designs and three NiTi atomic structures (resultant from different heat treatments) were selected for this study. The geometries of the ProTaper Next X1 and ProTaper Universal S2 files, and the structures of fully austenitic (conventional superelastic), austenite treated, and fully R-phased were used. The mechanical responses were evaluated under flexion and torsion loading conditions described by ISO 3630-1 specification. According to the results, the design of the X1 file exhibit higher flexibility in comparison to the S2 model. Under torsional loads, S2 showed higher stiffness. The structures of fully austenitic showed the least flexibility under flexion and the highest torsional stiffness. The stress levels reached for the austenitic condition were uppermost. The treated condition that resulted in a fully R-phase file usually presented a higher level of flexibility with lower stress levels, indicating a longer life in fatigue when compared to the other treatments.

Aim To compare the martensitic transformation temperatures and torsional resistance behaviour of classic M-Wire Reciproc and Reciproc blue files (VDW, Munich, Germany). Methodology M-Wire classic Reciproc R25 and Reciproc blue R25 instruments were used. Transformation temperatures were determined by differential scanning calorimetry (DSC-DSC 60, Shimadzu, Kyoto, Japan). Three samples with approximately 20 mg of each system were cooled to -120 degrees C and then heated to 100 degrees C and then cooled to -100 degrees C at a rate of 10 degrees C min(-1). The maximum torque values and angular deflection until fracture of new instruments (n = 10) were measured according to ISO 3630-1. Results were analysed statistically using the Student's t-test at a significance level of P DSC results revealed the absence of martensitic transformation for Reciproc instruments in the temperature range analysed. In both systems, the instruments were composed of a mixture of R-phase and austenite at room temperature. After torsional tests, Reciproc blue had significantly lower values for mean maximum torque at rupture (P < 0.05), although the angular deflection values were significantly higher than the Reciproc classic group (P < 0.05). Conclusions Both Reciproc and Reciproc blue instruments were composed of a mixture of R-phase and austenite. Reciproc Blue instruments had a greater angle of rotation to fracture but a lower torque to failure than M-Wire Reciproc instruments.