Statement of problem: "POWER BLEACHING" which is a new an in-office whitening technique with a combination of a whitening agent (peroxide) and an auxiliary (plasma-Arch light), has been claimed to be an effective and fast method in tooth BLEACHING. What is more important in using this method is the maintenance of the pulp health after tooth whitening.Purpose: The aim of this study was to evaluate the human pulpal response after BLEACHING with H2O2 38% and plasma-Arc light.Materials and method: Eighty seven sound first premolars from 27 patients were selected and divided into 3 groups of 29, based on the time intervals of histologic evaluation. In each group 9 teeth were considered as a control. Vitality tests were done before BLEACHING (base line) and in four intervals of 2, 7, 30 and 60 days, but histologic evaluation was performed in three intervals 2, 7 and 60 days. Immediately after extraction, apical one third of the roots were sectioned off and each specimen was placed in 10% buffered formalin solution for pulpal fixation. EDTA was used for decalcification and sections were prepared from each specimen and stained with H&E and subsequently assessed microscopically for the following criteria: Irregularities in the odontoblastic layer, the presence of inflammatory cell, vasodilatation and pulpal fibrosis. Data was analyzed using Friedman test and Wilcoxon test (a= 0.05). Results: There were significant differences between the 2 and 60 days groups and between 7 and 60 days groups with respect to inflammatory responses and vasodilatation (p<0.05).Comparison of the control and experimental groups of the 2 and 7 days revealed statistically significant differences in inflammation and vasodilatation (p<0.05). No patient had experienced sensitivity, after different BLEACHING periods.Conclusion: BLEACHING of teeth with H2O2 38% and plasma-Arc light might cause slight to moderate pulp reactions after 2 and 7 days confined to the coronal pulp. However, the observed histological changes did not affect the overall health of the pulp tissue permanently.

In this paper, a novel risk-based, two-objective (technical and economical) optimal reactive POWER dispatch method in a wind-integrated POWER system is proposed which is more consistent with operational criteria.  The technical objective includes the minimization of the new voltage instability risk index. The economical objective includes cost minimization of reactive POWER generation and active POWER loss. The proposed voltage instability risk employs a hybrid possibilistic (Delphi-Fuzzy)-probabilistic approach that takes into consideration the operator’s experience, the wind speed and demand forecast uncertainties when quantifying the risk index. The decision variables are the reactive POWER resources of the system. To solve the problem, the modified multi-objective particle swarm optimization algorithm with sine and cosine acceleration coefficients is utilized. The method is implemented on the modified IEEE 30-bus system. The proposed method is compared with those in the previously published literature, and the results confirm that the proposed risk index is better at estimating the voltage instability risk of the system, especially in cases with severe impact and low probability. In addition, according to the simulation results compared to typical security-based planning, the proposed risk-based planning may increase the security and economy of the system due to better utilization of system resources.

Introduction: The increased demand by patient to whiten their teeth in short time had made in-office BLEACHING procedure the common one. The accompanying tooth sensitivity remains an important factor affecting patients physically and psychologically. The aim of this in vivo study was to observe the effectiveness of 940 nm diode laser in combination with BLEACHING gel by analyzing tooth sensitivity and colour change. Methods: Fourteen patients treated by laser-assisted BLEACHING using diode laser at 940 nm and BLEACHING gel containing 38% hydrogen peroxide. Tooth sensitivity recorded during and after treatment at 6 hours and 1 day using visual analogue scale (VAS). Tooth shade had recorded before and after BLEACHING using Vita classical brightness scale. Results: Patients whom did not experienced pain during and after the treatment were 78. 60% and 92. 90%, respectively. Tooth brightness change after treatment was statistically different (P = 0. 001). Conclusion: Diode laser of 940 nm is an effective adjunctive tool for reducing tooth sensitivity originated from high concentration H2O2 BLEACHING gel.

Background and aim: the demand for dental BLEACHING has increased because individual's appearance plays an important role in social relations. The present study aimed to compare the efficacy of an Iranian carbamide peroxide gel (Kimia) with its foreign counterpart (Opalescence PF 15%) used for intracoronal BLEACHING of discolored teeth.Materials and methods: This experimental study was performed on 30 extracted intact central incisors. Root canals were cleaned and shaped with step back technique and were filled with lateral condensation method. Afterwards, gutta percha was removed from 1mm below CEJ and 1mm thick zinc phosphate cement was placed as a liner. Then, the teeth were placed inside 5.25% sodium hypochlorite solution for 24 hours. Whole blood and centrifuge system were used to stain the teeth. Samples were randomly assigned to three groups: 1. Opalescence PF 15% carbamide peroxide 2. Kimia 16% carbamide peroxide 3. Control group (cotton ball impregnated with physiologic serum). Evaluation of the color changes was done once before BLEACHING and once on the seventh day after application of the BLEACHING gel. This evaluation was performed with digital camera and Adobe Photoshop 8.0 software. Data were analyzed by SPSS software and T-test.Results: The BLEACHING value was significantly increased in Kimia group. There was a significant statistical difference between the control group and Kimia and Opalescence PF groups (p=0.001) Moreover, there was a significant difference between Kimia and Opalescence PF groups. (p=0.038).Conclusions: According to the results of the present study, Kimia carbamide peroxide gel is more efficient than Opalescence PF gel in BLEACHING the endodontically treated teeth.

In this paper, a new method for extending and relaxing the noise-coupling (NC) technique is proposed to enhance the noise-shaping order without adding the number of integrators. The noise-shaping order of the introduced ∑∆ modulator whit applying a second-order noise-coupling technique is enhanced and its performance with optimizing the noise transfer function (NTF) zeros is improved. Also, by removing the analog adder at feedforward path and transferring it to a new feedback branch before the last integrator and adding second-order NC path can be decreased the input voltage swing to the quantizer. Thus, by improving the modulator resolution, POWER consumption can be reduced. Mathematical analyses and behavioural simulation results confirm the effectiveness of the new NC method. To examine its performance, a 2nd-order single loop ΣΔ modulator was designed. The new noise-coupling method is used to achieve the three-order noise shaping to increase the resolution with low complexity and low-POWER. The results show an outstanding improvement in signal-to-noise and distortion ratio (SNDR) compared to the conventional structure.

Background and Objective: Tooth whitening has become apopular treatment in esthtic dentistry. The aim of this in vitrostudy was to compare 4 different methods of BLEACHINGincluding home BLEACHING, in-office BLEACHING, combination ofthese techniques and laser on the amount of color change in thenatural teeth. Materials and Methods: A total of 50 intact human premolersteeth of matched size were prepared and divided into 5 groupsof 10 teeth. Group 1: home BLEACHING using 15% carbamideperoxide (CP); Group 2: In-office BLEACHING using 40%hydrogen peroxide; Group 3: combination of first and secondmethods; Group4: 40% hydrogen peroxide combined with 2sections of 30 s of diode laser; Group 5: control (withouttreatment). Tooth color measurements were performedaccording to the CIELab system using spectrophotometerbefore treatment procedure and 1 week after. Results: Comparing the different treatments showed that homeBLEACHING and combination methods were significantly moreeffective (P<0. 05), and the mean total Δ E was 9. 80± 2. 02 and9. 94± 1. 96 respectively. This value for in-office BLEACHINGtreatment was 5. 35± 0. 72. There was no significant difference inΔ E value between laser (4. 14± 1. 82) and control (3. 03± 1. 41)groups by the end of treatment (P>0. 05). Conclusion: The results suggested that the use of diode laser innot a suitable BLEACHING technique and did not improve the colorchanges. In addition, in-office BLEACHING did not provideeffective tooth whitening. However, home BLEACHING andcombination methods are more effective BLEACHING techniques.