Background: Complete seal of the root canal system following its chemo-mechanical debridement plays a pivotal role for achieving successful endodontic treatment. This can be established by reducing the gaps between the core filling material and root canal wall. Aim: To assess and compare the dislocation resistance of root canals obturated with GuttaFusion® and TotalFill BC sealer versus single cone obturation technique and TotalFill BC sealer after instrumentation of the canals with WaveOne, ProTaper Next and ProTaper Universal system. Material and Method: Sixty extracted human permanent mandibular premolars were conducted in the current study. The teeth were decorated and left the root with 15mm length; the roots were divided randomly into three main groups, twenty roots in each group. The roots were instrumented with different rotary systems using crown down technique according to the groups: (Group I) was instrumented with WaveOne files. (Group II) was instrumented with ProTaper Next system and (Group III) was instrumented with ProTaper Universal system. For each group the same irrigation regimen was used, 3 mL of 5.25% sodium hypochlorite and 3 mL of 17% EDTA to remove the smear layer. Then, Group I was also subdivided randomly into two subgroups of ten samples each, (Group I A) obturated with single cone gutta-percha and (Group I B) filled with GuttaFusion®. Group II was divided into (Group II A) obturated with single cone gutta-percha and (Group II B) filled with GuttaFusion®. Group III was divided into (Group III A) obturated with single cone gutta-percha and (Group III B) obturated with GuttaFusion®. In the present study, TotalFill BC sealer was used for all the tested groups. Then, the roots were embedded in clear acrylic resin and each root sectioned into three sections of 2mm thick (apical, middle and coronal). The push-out bond strength values represented by (MPa) unit was calculated by dividing the load on the surface area and the last was measured in collaboration with AutoCAD system software program. Failure mode analysis was carried out to examine the type of failure in each sample by using a stereomicroscope. Results: The results showed highly significant differences among the main groups that instrumented with different rotary systems (WaveOne, ProTaper Next and ProTaper Universal system). There were highly significant differences between the two obturation techniques of the subgroups (single cone gutta-percha versus GuttaFusion®). However; Gutta-Fusion® showed highest bond strength value than single cone obturation technique. The coronal third slices of all groups showed highest value of bond strength in comparison to the middle thirds and apical thirds. In the meantime, the middle third slices showed bond strength higher than that of the apical thirds for all groups. Statistical analysis was performed by using two way ANOVA and LSD tests. Conclusions: The instrumentation techniques and the obturation materials significantly affected the push-out bond strength values of obturation system. The highest value was appointed in root canals instrumented with ProTaper Universal System; obturated with GuttaFusion® and BC sealer, whereas, the lowest bond strength was appeared at canals instrumented with ProTaper Next; obturated with single cone gutta-percha and BC sealer.
At atmospheric pressure and at a frequency of 9.1 kHz, a constructed magnetically stabilized tornado gliding arc discharge (MSGAD) system was utilized in this study to generate a non-thermal plasma with an alternating voltage source from 2,4,6,8 to 10 kV. Argon gas was used to generate the arc plasma with an adjustable flow rate using a flow meter regulator to stabilize the gas flow rate to 2 L/min. A gliding plasma discharge is achieved by a magnetic field for the purpose of a planned investigation. The influence of the magnetically stabilized tornado gliding arc discharge parameters such as magnetic field and applied voltage on microscopic tornado plasma parameters was studied. The electron temperature1was measured using a Boltzmann plot
... Show MoreRecently, some of Iraq's newly constructed asphalt concrete pavements showed premature failures with significant negative impacts on roadway safety and the economy. Using Nano hydrated lime (NHL) in pavement construction could be one of the possible steps to improve pavement durability. This article discusses how NHL affects the durability of hot mix asphalt. NHL was added in two methods to the asphalt concrete mixture for the wearing course. The first is the dry method, i.e., on the aggregate, whereas the second is the wet addition method, i.e., to the bitumen. The percentages were tried for each additional method; 1, 2, and 3% by weight of aggregate for the dry method and 0.5, 1, and 1.5% by weight of asphalt concrete for the wet
... Show MoreThe research aims to know the effect of investment risks measured by the beta coefficient on the efficiency of stock pricing measured by the pricing error. The research was applied in the banks listed in the Iraq market for the period (2017-2020). That affects the value of the shares of the companies listed in it and the risks associated with it, as the risks are a dynamic process that changes over time depending on the variables that affect the general development of the economy, so these fluctuations should be taken into account to achieve maximizing returns and reducing risks and what is reflected in stock prices in the Iraqi markets Securities, through which the following question was asked: How does investment risk affect the efficienc
... Show MoreNiO0.99Cu0.01 films have been deposited using thermal evaporation
technique on glass substrates under vacuum 10-5mbar. The thickness
of the films was 220nm. The as -deposited films were annealed to
different annealing temperatures (373, 423, and 473) K under
vacuum 10-3mbar for 1 h. The structural properties of the films were
examined using X-ray diffraction (XRD). The results show that no
clear diffraction peaks in the range 2θ= (20-50)o for the as deposited
films. On the other hand, by annealing the films to 423K in vacuum
for 1 h, a weak reflection peak attributable to cubic NiO was
detected. On heating the films at 473K for 1 h, this peak was
observed to be stronger. The most intense peak is at 2θ = 37
Chlorine doped SnS have been prepared utilizing chemical spray pyrolysis. The effects of chlorine concentration on the optical constants were studied. It was seen that the transmittance decreased with doping, while reflectance, refractive index, extinction coefficient, real and imaginary parts of dielectric constant were increased as the doping percentage increased. The results show also that the skin depth decrease as the chlorine percentage increased which could be assure that it is transmittance related.
This work has been done with using of epoxy resin mixed with Granite powder were weighted by percent volume (5,10,15, and 20)%and then mixed with epoxy polymer to compose polymer composite. Hand lay-up technique is used in fabrication of the composite samples. Hardness test was carried out for the proper samples in both normal condition and after immersion in HCL (1 M and 2 M) solutions for periods ranging up to 10 weeks. After comparing the results between the polymer and their composite, the hardness increased with increasing Granite weight percent, it was found that Hardness were greater for the composites before immersion compared with their values after immersion.