The effect of platelet‐rich plasma as a scaffold in regeneration/revitalization endodontics of immature permanent teeth assessed using 2‐dimensional radiographs and cone beam computed tomography: a randomized controlled trial

Aim: To assess the outcomes of platelet‐rich plasma as a scaffold in regenerative/revitalization endodontics (RET) using cone beam computed tomography (CBCT) and 2‐dimensional radiographs. Methodology: Twenty‐six healthy patients with mean age of 12.66 ± 4.47, and immature permanent anterior teeth with necrotic pulps, were randomly allocated to two groups, whereby RET was performed using platelet‐rich plasma (PRP, test group) and blood clot (BLC, control group). Changes in root length (RL), root dentinal thickness (RDT), apical foramen width (AFW) and radiographic root area (RRA), were assessed using both radiographic methods, whilst changes in periapical area diameter (PAD) were assessed using CBCT, over a period of 12 months. T ‐test and chi‐square/Fisher’s exact tests were used to compare continuous and categorical data between BLC and PRP groups, respectively. Changes in RL, RDT, AFW, RRA and PAD were examined by comparing the two groups (PRP versus BLC) using multilevel modelling, considering the clustering effect of repeated measures of several teeth originating from the same participant. Results: Changes in RL, RDT, AFW, RRA and PAD, over time, were found to be significant for both groups. There was, however, no difference between the RET techniques (PRP versus BLC), using both radiographic and CBCT methods. The results of both assessment techniques (CBCT and 2‐dimensional radiographic methods) were highly consistent (overall ICC ranged between 0.80 and 0.94). In addition, a significant effect of baseline PAD was found on RL, RRA and AD at 12 months (RL effect = −0.68, P < 0.001; RRA effect = −1.91, P = 0.025; AD effect = 0.08, P = 0.024). Conclusion: The current study highlights successful and comparable clinical and radiographic outcomes of RET techniques using PRP and BLC. Standardized and calibrated 2‐dimensional radiographic assessment was as effective as CBCT in assessing RET outcomes; therefore, the routine use of CBCT in RET is not recommended. Although an effect of baseline periapical lesion diameter on root development outcomes, at 12 months, were observed, more studies are recommended in order to assess such an effect

Urban Systems Between National and Global: Recent Reconfiguration Through Transnational Networks

Because the whole book’s issue assumes the uneven integrations of national/continental urban systems inside the global economy, this chapter evaluates the rates and qualitative modes of integration of the national urban systems by the economic networks that are dominated by multinational firms. The empirical study encompasses the largest 1250 cities of the world delineated in a comparative way according to common definitions of large urban regions (LURs). The position of LURs in multinational firms’ ownership networks in 2 years, 2010 and 2013, corresponds to the deepest period of the crisis and the following recovery, respectively. Thus, we checked that the fast reorganization of multinational firms facing this crisis between 2010 and 2013 did not fundamentally transform their strong urban organization but rather introduced some minor changes, particularly due to the simultaneous breakthrough of emergent countries’ companies (especially the Chinese ones). Synthetic network clustering methods partitioning cities of the world offer clear visions of the structure of the multipolar urban networks. They reveal “regions” of integration of cities for all kinds of multinational companies but also distinguishing companies according to their skill levels either in industry or in services. A special attention is given to some highly integrated cities appearing with properties of “city-states,” i.e., without a strong national urban system

Development dynamics of port-cities interface in the Arab Middle Eastern world - The case of Dubai global hub port-city

Many scholars in the field of architecture, urban planning, transportation, geography, economics and sociology have studied port-cities from different perspectives. Yet, the majority of literature on this topic is concerned about the Developed Western and East Asian World. With the aim to contribute to the existing studies and to fill this gap in the literature, this paper makes an attempt to study an example in the fast-developing Arab States in the Middle East, which has recently drawn a particular attention among the scholars. Dubai provides an interesting case study, as it currently hosts the major transhipment hubport of the region. Centred on a single case-study approach, a four-phase model is hypothesized as a tool to investigate the changing spatial and functional dynamics at the port-city interface from the 1900s to the 2010s. The argument is based on a reciprocal relationship between the port and the city, since the advent of a free port. Historically the port has been the economic backbone. Consequently the Creek dredging and newly constructed ports integrated with ancillary infrastructures (such as FTZs) have played an important role in boosting the growth. Some concluding remarks underline the main trends in Dubai's port-city development, compared to the existing European and Asian models. This dynamic evolution is influenced by internal factors, such as oil revenues and governmental strategies, as well as external ones, like the regional and global forces. Despite sharing common features with the Asian consolidation model, this study suggests that Dubai may demonstrate a particular pattern of port-city development