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Optimal operation of multi-objective reservoirs is one of the complex and, sometimes nonlinear, issues in multi-objective hydrologic system optimization. Meta-heuristic algorithms are good optimization tools which look for decision space via simulating the behavior of animals and providing the possibility for presenting a set of points as a set of problem solutions. Therefore, in this study, developing multi-objective water cycle algorithm (MOWCA) was investigated for the optimal operation issue of Halilrood basin reservoir system (Baft, Safarood, and Jiroft Dams) in order to hydropower energy generation of Jiroft Dam, downstream demand supply (drinking, agricultural, and environmental requirements), and flood control for a period of 223 months (from October 2000 to April 2019). Also, the results of the algorithm were compared with those of the well-known non-dominated sorting genetic algorithm II (NSGA-II). To evaluate the efficiency of the used multi-objective algorithms, four performance evaluation criteria including generational distance (GD), metric of spacing (S), metric of spread (Δ), and maximum spread (MS) were used. The results of applying multi-objective performance evaluation criteria showed the superiority of the developed MOWCA method in three criteria of distance, spread, and maximum spread criteria, while the NSGA-II algorithm was superior to the MOWCA only in metric of spacing (S) criterion. Moreover, the MOWCA algorithm with total 236.07 objectives performed better than the NSGA-II algorithm with total 268.01 objectives. In Jiroft Dam’s hydropower energy generation, the MOWCA algorithm with 4278.69 MW power generation was considerably superior to the NSGA-II algorithm with 3138.55 MW MW generation during the studied period. Finally, the obtained results showed higher performance of the MOWCA algorithm than the NSGA-II algorithm in the optimal operation of Halilrood basin multi-objective reservoirs systems with different objectives.

Background. The aim of this study was to investigate the effect of different mixing methods (ultrasonic, amalgamator, and conventional) on the bacterial microleakage of white Portland cement (WPC) and white MTA (Tooth-colored Formula, Dentsply, Tulsa Dental, Tulsa, OK). Methods. A hundred human single-rooted permanent teeth were decoronated to obtain 14 mm of root length in all the samples. The root canals were cleaned, shaped and obturated. Three millimeters of each root apex were cut off and randomly divided into 6 groups of 15 each (3 groups for WMTA and 3 groups for WPC, each with 3 different mixing methods) and 2 positive and negative control groups (each containing 5 samples). Brain-heart infusion agar (BHI) suspension containing the bacterial species Enterococcus faecalis (ATCC 29212) was used for leakage assessment. Statistical analysis was carried out using descriptive statistics and Kaplan Mayer survival analysis with censored data and log rank test using SPSS 18. Statistical significance was set at P0.05). Conclusion. Bacterial microleakage in the studied samples was not significantly different in terms of the type of the mixing method.

Background. Further studies on the adhesion properties of MTA-based materials seem necessary due to their growing use in endodontic treatment. This research aimed to assess the effect of retreatment on the bond strength of MTA-based (MTA Fillapex) and epoxy resin-based (AH Plus) sealers. Methods. ProTaper rotary files were applied to prepare the root canals of 80 human mandibular premolars. Then, the roots were randomly divided intotwo groups of A (n=40) and B (n=40), which were obturated with gutta-percha and MTA Filla-pex and AH Plus sealer, respectively. In both groups, the teeth were randomly subdivided into 2 subgroups. No retreatment was carried out in subgroups A1 and B1, while subgroups A2 and B2 were retreated with rotary files and a solvent. Then, a push-out test was performed on four 2-mm slices of each tooth at a distance of 2 mm from the coronal surface after two weeks of incubation. Data were analyzed with two-way ANOVA and statistical significance was set at P

Introduction Previous studies have reported that it is difficult to obtain proper anesthesia in mandibular molars with symptomatic irreversible pulpitis, and supplemental injections are usually unavoidable. The aim of the present study was to determine the anesthetic efficacy of articaine in mandibular first molars with symptomatic irreversible pulpitis with 3 injection methods: an inferior alveolar nerve block (IANB), an IANB with an intraligamentary injection, and an IANB with buccal infiltration before initiating the endodontic treatment. Methods Ninety-six patients (54 women and 42 men) with a diagnosis of symptomatic irreversible pulpitis in mandibular first molars were selected and randomly assigned into 3 groups (n = 32) according to the injection method as follows: group 1, a conventional IANB injection; group 2, an IANB injection, and after profound lip numbness after the IANB (after 15 minutes), buccal infiltration was administered; and group 3, an IANB injection, and after profound lip numbness after the IANB (after 15 minutes), an intraligamentary injection was performed, and after 20 minutes from the IANB, the endodontic treatment was initiated. The anesthetic solution was articaine 4% with 1:100,000 epinephrine. Success was defined as no or mild pain on the basis of the visual analog scale recording upon access cavity preparation or initial instrumentation. Data were statistically analyzed using the chi-square and Mann-Whitney U tests, and P Results The success rate for IANBs with an intraligamentary injection was 75%, and for IANBs with a buccal injection, it was 65.6%. For IANBs alone, the success rate was 28.1%. Conclusions Considering the limitations of the present study, in can be concluded that the success rate of IANBs increased with intraligamentary injections and buccal infiltrations with articaine that were performed before initiating treatment. Also, none of the injection methods showed complete success in anesthesia in all patients.

Introduction The aim of the present investigation was to study the effect of local infiltration of corticosteroids on postoperative pain and quality of life (QOL) in teeth with irreversible pulpitis after 1-visit endodontic treatment. Methods In this double-blind randomized clinical trial, 242 healthy patients with irreversible pulpitis undergoing 1-visit endodontic treatment were included. Forty-five patients were lost during the follow-up, and the remaining 197 patients were followed for 7 days (67 patients in the placebo group, 66 in the long-acting betamethasone group, and 64 in the dexamethasone group). The patients marked their level of pain and QOL before treatment and at 6-, 12-, 24-, 48-, and 72-hour and 7-day postoperative intervals using a questionnaire. Freidman and Kruskal-Wallis tests were used for statistical analysis. P ≤ .05 was considered significant. Results The pain was more severe in the placebo group compared with the other groups at all time intervals. A significant increase was observed in pain severity after 12 hours in all 3 groups. In general, the pain was less severe in the dexamethasone group compared with the betamethasone group at 6-, 12-, and 24-hour intervals. The pain severity was similar in both groups at 48 hours, and it was less severe in the long-acting betamethasone group compared with the dexamethasone group after 72 hours and 7 days. There were no significant differences in the betamethasone and dexamethasone groups in pain intensity between males and females. Moreover, overall pain perception was higher in the mandible than in the maxilla. There was an inverse and significant relationship between pain severity and QOL. Conclusions Infiltration of long-acting betamethasone and dexamethasone resulted in decreased postoperative pain experience. Dexamethasone was more effective in alleviating pain within the first 24-hour period after treatment. Infiltration of long-acting betamethasone and dexamethasone exhibited the same efficacy in 48 hours. The efficacy of long-acting betamethasone in pain relief lasted for 7 days. The QOL in the 2 groups receiving corticosteroids was higher than that in the placebo group.

Introduction. The aim of this study was to compare the coronal seal of different thicknesses of MTA with gutta-percha after post space preparation.Materials and Methods. A total of 50 maxillary central incisors randomly divided into 5 experimental groups (n=8). After preparation of the root canals with step back technique, in groups 1 and 2, post spaces were prepared and 4 or 5 mm gutta-percha remained in the apical, respectively. In groups 3, 4, and 5, there was 1-2 and 3 mm MTA in the apical, respectively. The ten teeth serve as control groups. The teeth were connected to a bacterial microleakage evaluation system. The study period was 120 days and the samples were evaluated on ten-day intervals; Meier-Kaplan technique was used for estimation of the mean time of microleakage to occur. Log-rank test was used for comparison of microleakage.Results. Number of samples exhibiting microleakage in MTA was less than those of gutta-percha at all intervals. Means of days with no microleakage were maximum and minimum with 3 mm MTA and 4 mm gutta-percha, respectively.Conclusion. Obturation of root canals using the MTA technique provides a proper seal with the minimum thickness of MTA in teeth requiring post space preparation.

BACKGROUND The aim of this in vitrostudy was to examine and compare the effect of photodynamic therapy and solution containing nano particles Ag/ZnO on adhesion of endodontic sealers to dentinal walls of human root canal. MATERIAL AND METHODS Ninty single-rooted human teeth were selected and their clinical crown was cut from the cemento-enamel junction zone. Canals were prepared by RaCe rotary system and the smear layer was removed using 17% EDTA and 5.25% NaOCl. Samples were randomly divided into two groups of AH Plus and MTA Fillapex based on the sealer type and each group based on antimicrobial method was divided into two sub-groups of photodynamic therapy and polymer containing nano particles of Ag / ZnO and a control sub-group (N = 15). After obturation of canals with gutta-percha and sealers mentioned, the samples were incubated for a week at a humidity of 95% and 37°C and then 2mm thick discs were prepared from the middle region of roots for Push-out test. The maximum failure force was recorded in newton and converted to MPa. Then, 3 random specimens of each subgroup were evaluated by scanning electron microscopy. Statistical analysis was performed by Two way ANOVA and (P

Background The Portland cement is hydrophilic cement; as a result, the powder-to-liquid ratio affects the properties of the final mix. In addition, the mixing technique affects hydration. The aim of this study was to evaluate the effect of different mixing techniques (conventional, amalgamator and ultrasonic) on some selective physical properties of Portland cement. Material and Methods The physical properties to be evaluated were determined using the ISO 6786:2001 specification. One hundred sixty two samples of Portland cement were prepared for three mixing techniques for each physical property (each 6 samples). Data were analyzed using descriptive statistics, one-way ANOVA and post hoc Tukey tests. Statistical significance was set at P0.05). Dimensional changes (shrinkage), solubility and pH increased significantly by amalgamator and ultrasonic mixing techniques (P

Introduction The aim of this study was to evaluate the effect of 3 different mixing methods on push-out bond strength of white tooth-colored mineral trioxide aggregate (MTA). Methods Sixty 2-mm-thick root sections were prepared from 60 single-rooted human teeth and filled with MTA. The samples were randomly divided into 3 groups (n = 20) of MTA mixed by ultrasonic, trituration, or conventional methods and then allowed to set for 72 hours in a synthetic tissue fluid environment. Push-out bond strength values of the specimens were measured by a universal testing machine and examined under a stereomicroscope at ×4 to determine the nature of the bond failure. Results The means of push-out bond strength values of white MTA in the ultrasonic, conventional, and trituration groups were 105.67 ± 12.79, 118.95 ± 12.76, and 99.60 ± 14.27 MPa, respectively. The differences between the 3 groups were not statistically significant. Conclusions On the basis of the results of this study, it can be concluded that different mixing methods have no significant effect on push-out bond strength of white MTA.

Recently, some studies have compared mineral trioxide aggregate (MTA) with Portland cements, concluding that the principal ingredients of Portland cements are similar to those of MTA. The purpose of the present study was to evaluate the effect of gray MTA, white MTA, and gray and white Portland cements on inflammatory cells in rats.Fresh mixtures mixed with distilled water were placed in polyethylene tubes, which were implanted in the dorsal subcutaneous connective tissue of 60 Sprague-Dawley rats along with empty tubes as controls. Tissue specimens were collected after the rats were sacrificed after 7, 15, 30, 60, and 90 days. The specimens were fixed, stained, processed, and histologically evaluated under a light microscope. Inflammatory reactions were classified as grade 0: without inflammatory cells, grade I: sporadic infiltration of inflammatory cells, grade II: moderate infiltration (25 cells), grade III: dense and severe infiltration (25-125 cells), and grade IV: very dense and severe infiltration (125 cells). Data were analyzed with the nonparametric (two factor) analysis of variance and Kruskal-Wallis H-test.All the groups showed grade III inflammation after 7 and 15 days; there was a decrease in the inflammatory process after 30, 60, and 90 days. After 90 days, gray MTA, white MTA, and control groups had grade 0 inflammatory process, but gray Portland cement and white Portland cement groups showed grade 0 to grade I inflammatory processes.MTAs were more biocompatible; however, more studies are required.

Background and aims. It is critical to have a proper knowledge of the normal anatomy of the pulp and its variations for the success of endodontic treatment. The purpose of this study was to investigate variations in the root canal system of maxillary first permanent molars in an Iranian population. Materials and methods. In this study, 137 maxillary first molars were decalcified, dye-injected, cleared and studied. Results. The results demonstrated that 37.96% of the maxillary first molars under study had three canals, 58.4% had four canals and 3.64% had five canals. Conclusion. According to the results of this study and considering variations in the root canal systems of maxillary first molars, it seems that great care should be taken in the root canal treatment of these teeth., Journal of Dental Research, Dental Clinics, Dental Prospects; ISSN 2008-210X

This paper reports a simple and highly selective method for the separation, preconcentration, and determinationoftraceamountsofthoriumanduraniuminsomecomplexsamplesviastaircaseflotation.The method is based on the initial flotation of the Th(IV)-arsenazo III complex in the presence of U(VI) from a solution of 5 mol dm -3 HCl, then reduction of U(VI) to U(IV) and repetition of the flotation step. In both steps, the floated complex was dissolved in a 5-mL portion of methanol and its absorbance was measured at 655 nm, spectrophotometrically. For a 30-mL portion of the sample, Beer’s law was obeyed over the concentration ranges of 3.40 10 -7 to 3.06 10 -6 mol dm -3 for Th(IV) and 3.40 10 -7 to 3.40 10 -6 mol dm -3 for U(IV) with the apparent molar absorptivity of 4.20 10 5 dm 3 mol -1 cm -1 and 3.59 10 5 dm 3 mol -1 cm -1 , respectively. The RSDs (n = 7) corresponding to 1.7 10 -6 mol dm -3 of Th(IV) and U(IV) were obtained as 1.7% and 1.87%. The detection limits (7 blanks) for both the metal ions were found to be 1.7 10 -7 moldm -3 .Theimportantbenefitofthemethodisthatthedeterminationsarefreefromtheinterference of almost all cations and anions found in the complex matrixes, such as seawater samples. The proposed method was also applied to reference materials, and the determinations were shown to have good agreement with the certified values.

In this work, synergistic flotation of U(VI)–alizarin complex at the presence of some diamine compounds was firstly investigated by the spectrophotometric method. The flotation process was carried out on aliquots of 100 ml of U(VI) solutions containing alizarin and the diamine at pH of 5.00 using n-heptane. The floated layer was then dissolved in acetonitrile and its absorbance was measured. Since the synergistic effect of 4,4′-diaminophenylmethane (dapm) was much more than the others, it was used for the determination of U(VI) by this method. Beer's law was obeyed (λmax = 591 nm) in the range of 5 × 10−7 to 1 × 10−5 mol l−1 with the apparent molar absorptivity of 1.12 × 106 l mol−1 cm−1, and a correlation coefficient of 0.9991. The detection limit (n = 7) was 1 × 10−7 mol l−1, and the R.S.D. (n = 7) obtained for 4 × 10−6 mol l−1 of U(VI) was 2.23%. Except that only a few analogous cations, which could be masked by EDTA, no interference was observed at the presence of various conventional ions, even at high concentrations. The reliability and applicability of the method were confirmed using some geological standard reference materials and spiked synthetic water samples, respectively.

Objectives: The aim of this study was to evaluate microleakage of white mineral trioxide aggregate (WMTA) after its exposure to a range of alkaline environments during hydration. Study Design: Seventy single-rooted teeth were divided into 4 experimental and 2 control groups. All the teeth were instrumented, and their apices were resected. Root-end cavities were filled with WMTA in the experimental groups. In the control groups, root-end cavities were not filled. Root-end fillings were exposed to alkaline environments with pH values of 7.4, 8.4, 9.4, or 10.4 for 3 days. Microleakage was evaluated by bovine serum albumin. Evaluations were carried out at 24-hour intervals for 80 days. Data were analyzed by one-way analysis of variance and a post hoc Tukey test at the 0.05 level of confidence. Results: The number of days (mean ± standard deviation) needed for color change at pH values of 7.4, 8.4, 9.4, and 10.4 were 78.53 ± 5.68, 80.00 ± 0.00, 68.93 ± 19.00, and 34.46 ± 12.73, respectively. The time needed for leakage to occur was significantly shorter in samples stored at a pH value of 10.4 (P

Introduction: The aim of this study was to evaluate the effect of different mixing techniques on the pH and solubility of mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM). Methods and Materials: Five samples were prepared from each biomaterial with different mixing techniques including hand-, amalgamator- or ultrasonic-mixing and were then placed in pre-weighted plastic tubes to determine their pH values. Each tube was then incubated in 10 mL deionized distilled water for 1 h at 37ºC. An electrode was placed in the fluid in each flask at 24ºC and the pH was recorded. In the next stage, six samples from each mixing technique/material were separately placed in glass bottles containing 50 mL of distilled water at 37ºC for 1 h and were let dry for 1 h at 37ºC. The samples’ weights were measured and recorded twice. The procedure was repeated at 1-, 7- and 21-day intervals. Data were analyzed with the repeated measures ANOVA (for solubility) and two-way ANOVA (for pH) and then the post-hoc Tukey’s test was done. Results: The pH of the materials was not significantly affected by mixing methods. (P=0.8 for CEM and P=0.1 for MTA). The solubility of all test groups was within the acceptable range (=3%). However, the solubility of CEM at 1- and 21-day intervals was significantly different (P=0.03 for 1 day and P=0.001 for 21 days). Different mixing techniques had significant effects on the solubility of MTA at the three time points (P=0.004, 0.003 and 0.002 for 1-, 7- and 21-day intervals, respectively). Conclusion: The pH of biomaterials was not influenced by the mixing technique and their solubility was within the acceptable range.

Introduction The aim of this study was to compare 2 kinds of anti-inflammatory medicines (ie, dexamethasone and ibuprofen) with a placebo according to their effects on the success rates of an inferior alveolar nerve block (IANB) for the endodontic treatment of mandibular molars with irreversible pulpitis. Methods A total of 165 patients were divided into 3 groups of 55 patients each and were given a capsule of the same color and size (ie, a placebo of lactose powder, 400 mg ibuprofen, or 0.5 mg dexamethasone). One hour after the oral administration of the capsules, all the patients received a standard IANB. In patients with a successful IANB, the teeth were examined with a cold pulp test. Patients were asked to assess their pain using the visual analog scale. Then, endodontic access cavity preparation was initiated. In case of pain during the treatment, the patients were asked to rate the pain on the visual analog scale. Success was defined as no or mild pain during treatment. The chi-square test and analysis of variance were used to compare qualitative and quantitative data among the groups. Results No significant differences were found regarding the sex of the patients in the 3 groups ( P > .05). The dexamethasone group showed significantly higher success rates compared with the placebo group ( P = .001). There were no significant differences between the ibuprofen and placebo groups ( P = .055) or the dexamethasone and ibuprofen groups ( P = .34). Conclusions Premedication with dexamethasone increased the success rate of an IANB in mandibular molars with asymptomatic irreversible pulpitis.

The purpose of this study was to investigate the eradication of Enterococcus faecalis by high-power settings of Er, Cr:YSGG laser irradiation in root canals of extracted teeth.The bacteria entering the root canal system invade dentinal tubules, resulting in persistent infections in root canals due to limited penetration of irrigation solutions into the dentinal tubules. The antibacterial effects of different lasers have been investigated in previous studies.Sixty newly extracted maxillary central incisors were enlarged chemomechanically and sterilized after removal of the smear layer. Root canals were inoculated with E. faecalis, and bacteria were incubated in root canals for 48 h. Samples were randomly divided into four groups, each containing 15 teeth. One group was considered as control with no intervention. Two groups were irradiated with 2- and 3-W output powers of Er, Cr:YSGG laser for 16 s. In the last group, the canals were irrigated with 1% sodium hypochlorite for 20 min.In the laser groups at 2- and 3-W powers, the number of bacteria was reduced 2.4% and 1.53%, respectively, compared with the controls. No significant differences were found between the two laser groups (p0.05). The canals irrigated with 1% NaOCl solution demonstrated no bacterial growth.According to the results of the present study, 2- and 3-W powers of Er, Cr:YSGG laser have antibacterial effects on E. faecalis in root canals of infected teeth; however, the effect is less remarkable than that of NaOCl solution.

INTRODUCTION: The purpose of this study was to compare the histocompatibility of white (WMTA) and gray (GMTA) mineral trioxide aggregate mixed with 0.12% chlorhexidine (CHX) and distilled water (DW) in subcutaneous connective tissues of rats. MATERIALS AND METHODS: The freshly mixed WMTA and GMTA with CHX or DW were inserted in polyethylene tubes and implanted into dorsal subcutaneous connective tissue of 50 Wistar Albino rats; tissue biopsies were collected and were then examined histologically 7, 15, 30, 60 and 90 days after the implantation procedure. The histology results were scored from 1-4; score 4 was considered as the worst finding. Data were analyzed using one-way ANOVA tests. RESULTS: All experimented materials were tolerated well by the connective tissues after 90-day evaluation, except for the WMTA/CHX group that had significantly more mean inflammatory scores (P

This in vitro study used dye penetration to compare the sealing ability of white and gray mineral trioxide aggregate mixed with distilled water and 0.12% chlorhexidine gluconate when used as root-end filling materials. Ninety-six single-rooted human teeth were cleaned, shaped, and obturated with gutta-percha and AH26 root canal sealer. The apical 3 mm of each root was resected, and 3-mm deep root-end cavity preparations were made. The teeth were randomly divided into 4 experimental groups, each containing 20 teeth, and 2 negative and positive control groups, each containing 8 teeth. Root-end cavities in the experimental groups were filled with the experimental materials. After decoronation of the teeth and application of nail polish, the teeth were exposed to India ink for 72 hours and longitudinally sectioned, and the extent of dye penetration was measured with a stereomicroscope. Statistical analysis showed that there were no significant differences among the 4 experimental groups.

The purpose of this study was to compare the biocompatibility of amalgam, gray MTA and white MTA in the connective tissue of rats. We used 45 Sprague-Dawley rats in this study. The rats were divided into three groups. Root end filling materials were placed in polyethylene tubes and inserted into the rats' connective tissue through incisions. The rats were sacrificed after 3 days, 1 wk, and 3 wk, respectively. Histologic samples were sectioned in 5-mum thicknesses and stained with hematoxylin and eosin. Kruskal-Wallis test was used for statistical analysis. The results showed that after 3 days, white MTA was more biocompatible than gray MTA and amalgam. After 1 week, gray MTA was more biocompatible than white MTA and Amalgam. After 3 wk, there were no significant differences between experimental groups and the control group.

Aims: The aim of the present study was to evaluate solubility of white mineral trioxide aggregate (WMTA) in an acidic environment. Materials and Methods: Twenty-four metal rings were prepared, filled with WMTA and randomly divided into two groups. The samples in groups 1 and 2 were set in synthetic tissue fluid with pH values of 7.4 and 4.4, respectively and then were transferred to beakers containing synthetic tissue fluid with pH values of 7.7 and 4.4. Solubility of WMTA samples were calculated at the 9 experimental intervals. Data was analyzed with two-factor ANOVA and Bonferroni test (P < 0.03). Results: The total solubility of WMTA in groups 1 and 2 were −9.1796 ± 1.9158% and −1.1192 ± 2.6236%, (P = 0.028) with weight changes of 9.1574 ± 2.1432% and 7.3276 ± 1.5823%, respectively (P = 0.002). Statistical analysis revealed significant differences between the two groups. Conclusions: It was concluded that solubility of WMTA increases in acidic environments and additional therapeutic precautions should be taken to decrease inflammation in endodontic treatment.

Introduction: The purpose of this study was to evaluate the radiographic quality of root canal fillings by fourth-, fifth-, and sixth-year undergraduate students at Tabriz Faculty of Dentistry between 2006 and 2012. Methods and Materials: A total of 1183 root canal fillings in 620 teeth were evaluated by two investigators (and in case of disagreement by a third investigator) regarding the presence or absence of under-fillings, over-fillings and perforations. For each tooth, preoperative, working and postoperative radiographs were checked. The Pearson’s chi-square test was used for statistical evaluation of the data. Inter-examiner agreement was measured by Cohen’s kappa (k) values. The level of significance was set at 0.05. Results: Total frequencies of over-filling, under-filling and perforation were 5.6%, 20.4% and 1.9%, respectively. There were significant differences between frequencies of over- and under-fillings (P