The Probable Effect of Irrigation Solution and Time on Bond Strength to Coronal Dentin: An In Vitro Evaluation

Introduction: The aim of this study was to evaluate the effect of root canal irrigants on the microtensile bond strength of 2-step self-etch adhesive to dentin. Methods and Materials: In this study 36 sound extracted human third molars were used. After grinding 3 mm of occlusal surface, teeth were randomly divided into 6 groups based on irrigation material naming normal saline, 5.25% sodium hypochlorite (NaOCl) and 2% chlorhexidine (CHX) and also irrigation time (5 or 30 min). Next, teeth were restored with Clearfil SE bond adhesive resin system and Z250 composite. The teeth were then thermo cycled by thermo cycling machine, for 500 cycles between 5º and 55ºC with 60 sec dwell time and 12 sec transfer time. All samples were sectioned into bucco-lingual slabs. The sections were submitted to the micro tensile testing machine at a crosshead speed of 0.5 mm/min until fracture. Data was analyzed using the one-way ANOVA test with the level of significance set at 0.05. Results: Irrigation with normal saline, 5.25% NaOCl and 2% CHX for 5 or 30 min did not significantly change the microtensile bond strength of adhesive to dentin (P=0.729 for time and P=0.153 for material). However the maximum and minimum microtensile bond strength was attributed to normal saline (44.13 N) and NaOCl (31.29 N) groups, respectively. Conclusion: Iirrigation solution and time have no influence on microtensile bond strength of two-step self-etch adhesive to coronal dentin.Keywords: Bond Strength, Dentin, Irrigation Solution

Comparison between the performance of four metaheuristic algorithms in training a multilayer perceptron machine for gold grade estimation

Reserve evaluation is a very difficult and complex process. The most important and yet most challenging part of this process is grade estimation. Its difficulty derived from challenges in obtaining required data from the deposit by drilling boreholes, which is a very time consuming and costly act itself. Classic methods which are used to model the deposit are based on some preliminary assumptions about reserve continuity and grade spatial distribution which are not true about all kind of reserves. In this paper, a multilayer perceptron (MLP) artificial neural network (ANN) is applied to solve the problem of ore grade estimation of highly sparse data from zarshouran gold deposit in Iran. The network is trained using four metaheuristic algorithms in separate stages for each algorithm. These algorithms are artificial bee colony (ABC), genetic algorithm (GA), imperialist competitive algorithm (ICA) and particle swarm optimization (PSO). The accuracy of predictions obtained from each algorithm in each stage of experiments were compared with real gold grade values. We used unskillful value to check the accuracy and stability of each network. Results showed that the network trained with ABC algorithm outperforms other networks that trained with other algorithms in all stages having least unskillful value of 13.91 for validation data. Therefore, it can be more suitable for solving the problem of predicting ore grade values using highly sparse data

Article 139 of the Constitution in the Light of Judicial and Arbitral Precedent

Article 139 of the Constitution of the Islamic Republic of Iran, which restricts and binds the referral of litigation regarding public and State property to arbitration, for obtaining an approval from the government and the parliament, has led to different views and legal opinions. In general, they can be categorized into “literalist” and “realist” theory”. The result of literalist theory is that article 139 applies to any dispute that on the one hand, there is the State, and it has been agreed upon by arbitration and thus if any dispute exists, it will be resolved by arbitration in which, it should obtain an approval from the government and the parliament, otherwise, the arbitration will not be valid. According to this view, article 139, in general, is not economically beneficial for the State and therefore it must be thought upon. In contrast, there is the realist theory which can be a response to the literalist theory and holds that, with a rational and principled interpretation, the principle can be freed from the problems which are arisen by former theory and also the dynamics of principle 139 is useful for the State in terms of national interes

A hybrid algorithm of BSC and QFD to determine the criteria affecting implementation of successful outsourcing

Successful organizations share some identical factors that pave the way for their success. Among these factors, strategic management is the key to success for organizations to contribute more to the competitive world market of today. In this respect, the pivotal role of outsourcing cannot be denied. This research parallelizes the criteria affecting the outsourcing success as presented in Elmuti model with the Balanced score card method in the Tose'e Ta'avon Bank. In this research, questionnaires and interviews with experts helped determine the strategic goals at four perspectives of balanced score card method (at Tose'e Ta'avon Bank) and the relative weights were computed for each of balance score card (BSC) perspectives by using AHP method. As the next step, the indexes were prioritized by applying the quality function development(QFD) technique and considering strategic goals at four perspectives in section "WHAT" and the outsourcing success criteria of Elmuti model in section "HOW". At the end of algorithm, the results are compared with the Elmuti method. Based on the results, the hybrid proposed technique seems to perform better than Elmuti

Comparison of Cone Beam Computed Tomography and Digital Radiography in Detecting Separated Endodontic Files and Strip Perforation

The separation of endodontic files and strip perforation are among procedural intraoperative complications which may ultimately lead to the failure of root canal treatment. The aim of the present study was to compare the diagnostic potential of cone beam computed tomography (CBCT) and digital periapical radiographs in detecting separated rotary files and strip perforation in filled canals. Fifty human mandibular molars were selected for this study. The teeth were randomly divided into two groups based on endodontic errors (i.e., file separation and strip perforation). In each group, 25 of 50 mesial canals were randomly chosen for simulating the errors, while the other 25 canals were considered as the control group. In group one, a simulation of the separation of rotary files was performed using ProTaper F2 files. Strip perforation of the root canals in group two was achieved by number 2 and 3 Gates Glidden drills in the coronal third of the root canals. Digital periapical radiographs in two different horizontal angles and high-resolution CBCT scans were obtained from the teeth mounted on a dry human mandible with simulated soft tissue covering. Three experienced observers who were unaware of the study groups evaluated the digital periapical and CBCT image sets in two separate readings. Intraobserver and interobserver agreements, as well as accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), were calculated and compared. Intraobserver and interobserver agreements ranged from poor to excellent and poor to good, respectively. The accuracy, sensitivity, specificity, PPV, and NPV for digital radiography in detecting separated files were 0.950, 0.813, 0.957, 0.929, and 0.880, respectively. The same values for CBCT were 0.747, 0.667, 0.900, 0.833, and 0.783, respectively. For the diagnosis of strip perforation, these values were 0.855, 0.800, 0.909, 0.889, and 0.833 for periapical radiography and 0.955, 1.000, 0.920, 0.926, and 1.000 for CBCT. In conclusion, CBCT was superior for diagnosing strip perforation of the filled root canals, while digital periapical radiographs performed better in the detection of separated rotary files