Key Clinical Message
Veneer crowns can be used in anterior endodontically‐treated teeth with light occlusal force and enamel substrate consideration as a more conservative approach instead of ...conventional all ceramic crowns.
All‐ceramic anterior crowns and veneers have been used widely in dentistry with high clinical success rate. The development of new reinforced ceramics in recent years has led to more use of extended defect‐oriented preparation designs, that is, extended veneers, instead of full crown preparations which are less invasive. A veneer crown is simply a veneer that covers the entire tooth. The preparation preserves remaining enamel and uses a conservative preparation design. Its indication should be carefully raised taking into consideration various factors. The preparation design is crucial to ensure longevity of such restoration. The balance is between sufficient preparation for the material thickness and adequate strength against occlusal load and the enamel preservation. A 24‐year‐old man referred to the restorative department of the Dentistry School of Tehran University of Medical Sciences complaining from his poor esthetics in the maxillary incisors. In clinical and radiographic evaluation, he had open bite, composite discoloration due to corrosion of the pre‐fabricated posts in all four incisors, a periapical lesion in tooth 21 and under‐filled root canal therapy in tooth 22. All four posts and composite restorations were removed and teeth 21 and 22 were retreated. Although the amount of remaining tooth tissue was low, it had enough enamel thickness, especially in the buccal area. Taking into consideration this mixed enamel and dentin substrate, endodontics access, esthetics needs and canine guidance occlusion with no parafunction history, bonded lithium disilicate veneer crowns were selected to restore the maxillary incisors. A 12‐month follow‐up showed promising clinical (healthy gingival tissue and successful restorations) and radiographic (reduced periapical lesion) outcomes.
A case of veneer crowns in anterior teeth.
Chagas disease is one of the major neglected diseases of the world. Existing drug therapies are limited, ineffective, and highly toxic. We describe a novel strategy of drug discovery of adapting an ...existing clinical compound with excellent pharmaceutical properties to target a pathogenic organism. The protein farnesyltransferase (PFT) inhibitor tipifarnib, now in phase III anticancer clinical trials, was previously found to kill Trypanosoma cruzi by blocking sterol 14α-demethylase (14DM). We rationally developed tipifarnib analogues that display reduced affinity for human PFT to reduce toxicity while increasing affinity for parasite 14DM. The lead compound has picomolar activity against cultured T. cruzi and is efficacious in a mouse model of acute Chagas disease.
Objectives. This in vitro study was aimed to assess the effect of wet and dry finishing and polishing techniques on the flexural strength and microhardness of different commercial nanoparticle ...contained composite resins. Methods and Materials. The samples were made of Z250 (microhybrid), Z350 XT (nanofilled), and Z550 (nanohybrid) resin composites. Each group was subdivided into 2 subgroups according to polishing protocols. Subgroup 1 for each composite underwent wet polishing, and subgroup 2 was subject to dry polishing technique. Flexural strength and microhardness of the samples were measured at two different times of polishing (T0 and T24). The flexural strength test and microhardness test were measured by a 3-point bending test using a universal testing machine, and a Vickers machine, respectively. Data were analyzed by Kolmogorov–Smirnov, two-way ANOVA, and Tukey HSD tests. Results. ANOVA showed that the type of composite has a significant effect on flexural strength. Two-way ANOVA showed that, at T0, flexural strength of all composites in the dry technique was higher than in the wet technique (p=0.019). At T24, Z350 XT had the lowest, and Z250 had the highest flexural strength in both techniques. The time and technique of polishing were also significantly effective on hardness. At T0, hardness was higher in the wet compared to the dry method (p=0.008). Tukey test showed that, at T24, the hardness of Z350 XT was significantly higher than the other materials in both techniques. Conclusion. Immediate wet finishing and polishing presented lower flexural strength. Delayed dry/wet finishing and polishing significantly enhanced the hardness of the samples.
Aim. The present study investigated the effects of laser and conventional in-office bleaching, and polishing on the color of stained composite resin. Materials and Methods. A microhybrid composite ...(Clearfil AP-X) and a nanohybrid composite (Grandio) were selected. Twenty-four discs (2 × 10 mm) for each composite were prepared. The samples were immersed in coffee solution (25 g of coffee in 250 mL water) for seven days. Then the samples were divided into three groups (n = 8) and the stains were removed using bleaching (with Opalescence Xtra Boost), diode laser irradiation with Heydent material and a Sof-Lex polishing kit. The L ∗a ∗b ∗ color parameters were determined using a spectrophotometer before and after immersion and after stain removal procedures, and the overall color changes (ΔE) were calculated. The data were analyzed with two-way analysis of variance. Results. In the Clearfil composite resin group, the mean ΔE compared to the baseline using in-office bleaching, laser irradiation, and Sof-Lex polishing kit were 3.31, 3.35, and 4.93, respectively. These values with the Grandio composite resin were 3.31, 6.35, and 4.57, respectively. The highest capacity to remove stains was related to the conventional in-office bleaching method. Grandio composite resin underwent more color changes than Clearfil composite resin significantly (P-value < 0.05). Conclusion. Both composite resins exhibited color changes after immersion in the discoloring solution. However, after staining-removing procedures, the ΔE values decreased. Decreases in the ΔE values were not sufficient to restore the color to that before immersion in the discoloring solution with any stain-removing methods.
Adverse socio-economic and environmental impacts of climate change on wetlands have enforced the international community and many nations to develop adaptive policies for wetland management, which ...require effective leadership to influence relevant stakeholders. This study identifies and prioritizes leadership functions and theories for climate change adaptation (CCA) in wetlands ecosystems, particularly in arid and semi-arid regions. A mixed qualitative-quantitative research methodology was applied through focus groups and a survey with a sample of national, sub-national, and local experts on wetlands management and climate change in Iran. The Analytic Hierarchy Processing (AHP) technique identified the political-administrative (weight = 0.245), adaptive (W = 0.244), and enabling (W = 0.237) functions for CCA, respectively, as three prioritized leadership functions, followed by the dissemination function (W = 0.102), which emphasizes the necessity of applying and enhancing leaders' social capacities, knowledge, communication skills, and personal networks to facilitate social learning and actions regarding CCA in local communities and among relevant organizations. It is necessary to overcome structural and functional barriers for leaders and their followers to information access and involvement in participatory decision-making platforms. Moreover, network and communication leadership theories (W = 0.368) and sustainable leadership perspectives (W = 0.362), respectively, have the highest priority among leadership theories and are crucial for establishing participatory decision-making among relevant stakeholders and applying adaptive strategies for wetlands governance under climate change conditions. The reconceptualization of leadership as a complex adaptive notion draws attention to the social complexities and emerging characteristics of leadership in contemporary societies and organizations. The understanding of leaders' and followers’ networks and identifying the core role of leaders provides a foundation for developing leadership functions and theories beyond hierarchical, individualistic, and one-way concepts of leadership.
•Climate change adaptation (CCA) in wetlands requires effective leadership.•Political-administrative, adaptive, and enabling leadership has priority for CCA.•Network and sustainable leadership theories are prioritized for CCA in wetlands.•Results highlight leaders' social capacities, knowledge, and networking skills.•Results indicated leadership as a complex adaptive notion for CCA in wetlands.
Objective
To assess the effects of ceramic thickness and background type on the color match of high translucency monolithic zirconia restorations.
Materials and Methods
Fifty A2 shade high ...translucency zirconia disk specimens with five different thicknesses (0.7, 0.9, 1.1, 1.4, 1.6 mm) were placed on 12 backgrounds: A1, A2, A3, A3.5, B1, and B2 shade composite resin, A3 shade zirconia, nonprecious gold‐colored alloy, nickel‐chromium alloy, amalgam, and A2 and A3 shade tooth. Color measurements were performed to determine the specimens' CIELab values. CIEDE2000 formula was used to determine ΔE00 color differences between specimens and A2 VITA classical shade (target). The ΔE00 values were compared with perceptibility (0.8) and acceptability (1.8) thresholds to assess color matches. Data were analyzed using repeated measures ANOVA, Bonferroni, and 1‐sample t tests (P < .05).
Results
Mean ΔE00 values ranged between 1.3 and 5.7. Ceramic thickness, background type, and their interaction significantly affected the ΔE00 (P < .001). Ceramic thicknesses of ≥1.1 mm with the A2 or A3 shade tooth background showed 0.8 < ΔE00 ≤ 1.8 producing acceptable color matches.
Conclusions
High translucency monolithic zirconia restorations with a minimum thickness of 1.1 mm on tooth backgrounds could create acceptable color matches; however, with other backgrounds tested, they could not.
Clinical Significance
Ceramic thickness and background type affect the color of high translucency monolithic zirconia restorations. A minimum zirconia thickness of 1.1 mm and normal color tooth structures, as a background, are essential for achieving the acceptable color match of these restorations.
Understanding the effects of complex issues such as water scarcity on human society from the people's perspective is necessary to show how to adapt to these challenges. This research investigates and ...prioritizes the effects of water scarcity on the sustainability of rural communities through a mixed research methodology, including a case study and a survey in a semi-arid region, located in southern Iran. The results of using the Analytical Hierarchy Processing (AHP) technique showed that local people identify the economic dimension of sustainability as a priority dimension. Moreover, the alternative of unsustainability under water scarcity in the area received the highest priority and had a larger value than the sustainability alternative. This can be the result of the restricting international policies against Iran and the global climatic condition. Local communities, particularly farmers, perceive climate change and water scarcity as a global issue and a local challenge, which causes semi-arid areas to move towards unsustainability rather than sustainability. The sustainability of semi-arid areas under water scarcity requires climate change adaptation, appropriate long-term planning, and the removal of restricting international economic policies against nations.
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•The climate becomes warmer or colder and the annual precipitation of an area increases under climate change conditions.•Climate change and water scarcity are recognized as serious risks threatening sustainable development in various aspects.•Components affecting this prioritization are mostly climate change, poor long-term planning, and restricting global economic policies toward Iran.
This paper seeks to explore the political myths used in the tenth round of the parliamentary election campaign in the city of Shiraz. In this paper we examined the myth of Roland Barthes's view of ...manufacturing. The results of this study showed that the myth of "homeland, nation, championship, divine charisma, democracy, good troops" the most important political myths in the country. Political myth "supportive" used by reformist important and effective role in persuading the audience.
IntroductionWith increasing water crisis and rural poverty, especially in arid and semi-arid areas where famine and floods have increased, access to safe water for livestock and home consumption has ...become more important than access to education and health services. The water crisis has gradually endangered food security and social satisfaction and has emerged in the form of migration, social conflict, and violence. In Iran, the water crisis has led to public dissatisfaction. Recently, there have been some protests in various cities of Iran as a result of the water crisis, water transfer, and related policies. This is especially the case in small towns and cities that are among the driest areas (including Isfahan, Khuzestan, Borazjan, etc.). In the light of water shortage and migration problems in rural areas of Mamasani County, the purpose of this study is to provide a critical ethnography analysis to investigate the challenges associated with the water crisis in the villages of Mamasani County. The study of this issue at the micro-level is important because in the study area, in addition to water shortage, actions and activities done to manage water resources have led to some conflicts between users and policymakers and potentially have created many problems and complications for the rural residents. Materials and Methods This research isdone usingthe critical ethnographic method. In this study, purposive sampling, which is a type of non-probability sampling, was used. The instruments used were observation, interview, and field notes. Data analysis was done through the thematic analysis method. The participants were 25 local residents of rural areas affected by the water crisis in Mamasani. In terms of employment status, 13 participants in the study were both farmers and ranchers while 7 participants were engaged only in livestock. In terms of age, the respondents were from 31 to 65 years old and their education was from illiteracy to high school diploma. In terms of the marital status, all participants were married. Discussion of Results and ConclusionsIn Iran, the water resources policy suffers from non-specialist decisions to solve the problems related to water resources. In fact, the governance structure of water resources, which includes many beneficial owners in the management and utilization of water resources, has led to increased competition and conflict between stakeholders in the field of water resources.In general, it can be said that the development programs of organizations and institutions have been done to control the natural environment than nature management. Therefore, environmental water crises and drying of permanent rivers in rural areas and wetlands are the results of the instrumental and technical views governing the management of water resources in order to technically control the natural environment.Through the six stages of data analysis, one thematic network was derived. The thematic network of ‘Human Water Catastrophe’ includes 28 basic codes, 10 basic teams, and 3 organizing teams (inefficient governance of water resources, vulnerability, and rural deprivation) that are formed around the axis of the comprehensive theme of ‘Human Water Catastrophe’. The frequency and severity of the water crisis in the studied villages have caused water shortage to become an unusual phenomenon and a human disaster. Catastrophe is considered an unusual phenomenon that affects the physical and social structure of societies. In addition, the thematic network analysis in this study revealed that this crisis has brought about consequences for the villagers resulting in vulnerability and rural deprivation. The critical model emerged from the rural residents' perception of the water crisis has shown that in this situation where the water crisis has some consequences for rural residents and leads to vulnerability, social disruption, rural deprivation, and reduced capacity, adaptation has taken place in areas. The studied villagers find themselves in a top-down domination relationship imposed on them by poverty and misery and find themselves trapped in environmental and structural determinism. In their view, the power structure does not try to improve their living conditions and they are abandoned and live in the insecure margin of the society.
One of the most underserved populations among dental patients is the people with Neurodevelopmental Disorders (PNDs). This study aimed to explore the barriers to dental care provision for PNDs from ...the viewpoint of stakeholders in provision in Iran.
We arranged a qualitative study based on an individual in-depth, semi-structured interview between October 2019 and February 2020. We interviewed 30 participants using a snowball sampling strategy with three groups: dentists who provided dental care for PNDs, dental public health professionals, and policymakers/managers in dental care provision in Iran. The interviewer used an interview framework based on Levesque's model of patient-centered access. The main question was: "How do you assess the barriers to the provision of dental services to PNDs in Iran?" The data were analyzed by the qualitative content analysis method described by Graneheim and Lundman.
From the 30 interviewees (11 women), there were 11 dentists, nine dental public health professionals, and 10 participants who worked as policymakers/managers. They were aged 35-62 years and had working experience between 4 and 25 years. In the content analysis, 60 meanings units were extracted, and later classified into 14 subthemes, and four main themes.
Four main barriers were traced regarding access, financial, competency-related, and policy-making aspects.
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