Overextension of Nonsetting Calcium Hydroxide in Endodontic Treatment: Literature Review and Case Report

Premixed non-setting calcium hydroxide (CaOH2) paste in pressure syringe system is commonly used in root canal therapy. The aim of this paper is to present a case involving an iatrogenic extrusion of the medicament during endodontic treatment and a literature review of similar reports. The present case demonstrates severe tissue necrosis and other deleterious effects following the extrusion of CaOH2 paste beyond root apex. A 21-year old female was referred for endodontic treatment of her maxillary left first premolar. After completion of the canal preparation, root canals were filled by premixed CaOH2 paste. In the second appointment, a gingival detachment and an irregular zone of necrosis adjacent to the tooth apex was observed. To treat this complication, a mucoperiosteal flap was raised and the extruded material and necrotic tissues were currettaged and the area sutured. The patient was prescribed antibiotics and followed up at 2 weeks, 6 months and 2 years. Two week follow up showed good soft tissue healing. Two years postoperatively, complete radiographic and clinical healing was observed. We can conclude that the application of CaOH2 should be carried out with care and preferably applied free hand or with a lentulo spiral rather than in a pressure syringe

Cytotoxicity evaluation of Persica mouthwash on cultured human and mouse cell lines in the presence and absence of fetal calf serum

Background and Aims: The effectiveness of an ideal antimicrobial agent depends on its ability to kill microbes while causing minimal toxicity to host cells. Several studies have been reported on the antimicrobial effects of chewing sticks (Salvadora persica) on oral bacteria. The purpose of this study was to evaluate the cytotoxic effects of Persica™ and chlorhexidine (CHX) mouthwashes on cultured human and mouse cell lines. Materials and Methods: This was an experimental study. The toxic effects of four dilutions of Persica™ and CHX mouthwashes on KB, Saos-2, J744 A1, and gingival fibroblast cells were evaluated by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay. The effect of fetal calf serum (FCS) components on the cytotoxicity of these mouthwashes was also investigated. Statistical Analysis: Analysis of variance and the Kruskal-Wallis test were used to evaluate the results. Results: The results indicated that Persica™, at concentrations higher than 0.1%, exerted a very significant cytotoxic effect on all the cell lines (P ≤ 0.01). CHX, at a concentration of 0.001%, exerted toxic effects only on gingival fibroblasts; concentrations higher than 0.001% were required to produce significant cell death in the other cell lines. At all the concentrations under study, both Persica™ and CHX exerted significantly greater cytotoxic effects in the absence of FCS than in its presence (i.e., in control culture medium). The toxicities of both mouthwashes were attenuated in the presence of FCS (10%). Conclusion: Our results indicate that both Persica™ and CHX mouthwashes are toxic to macrophage, epithelial, fibroblast, and osteoblast cells in a concentration-dependent manner

Strategic Communication Approach to the Implementation of the Theory of Good Governance in Iranian Government (Case Study of the Ministry of Cooperatives, Labor and Social Welfare) and Presenting an Optimal Model

The Ministry of Cooperatives, Labor and Social Welfare, in order to gain public trust and achieve its mission, including organizing the cooperative sector and promoting efficiency in cooperatives, can establish good governance components through the use of strategic communications. The aim of this study was to investigate the effect of strategic relationships on the establishment of good governance theory in the ministry and provide a favorable model And in terms of practical purpose and method of data collection is descriptive and its method is survey. A questionnaire was used to test the research hypotheses and Cronbach's alpha index was used to assess the reliability of the questionnaire. The results of this study show that there is a linear relationship between strategic communication and good governance components including transparency, accountability, participation, accountability, rule of law and flexibility, and the priorities of good governance components in this ministry are establishing transparency and accountability . Also, strategic relations in the Ministry of Cooperatives, Labor and Social Welfare in order to implement the theory of good governance need to be established with characteristics such as: leadership-based unity, credibility, dialogue-oriented, based on concerted effort and synergy Being inclusive, result-oriented, providing a deep understanding of the country, being forward-looking and the result of a cycle of evaluation, review and redesign

Investigation of Mixing Non-Spherical Particles in a Double Paddle Blender via Experiments and GPU-Based DEM Modeling

In this study, we have investigated the mixing kinetics and flow patterns of non-spherical particles in a horizontal double paddle blender using both experiments and the discrete element method (DEM). The experimental data were obtained using image analysis from a rotary drum containing cubical and cylindrical particles. Then, the experimental data were used in order to calibrate the DEM model. Using the calibrated DEM model, the effects of operating parameters such as vessel fill level, particle loading arrangement, and impeller rotational speed on the mixing performance were examined. The diffusivity coefficient was calculated to assess the mixing performance