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Purpose/objectives: Treating intraosseous lesions (IOLs) and interradicular bone lesions (IRLs) is an extremely technical dental procedure in periodontics. Instrumentation of these lesions is often perceived as difficult by students and inexperienced dentists before they perform a certain number of procedures on patients in the clinic. The aim of this article is to evaluate a cost‐effective three‐dimensional (3D)‐printed educational simulator for the periodontal treatment of IOLs/IRLs (including scaling, incisions and sutures). Methods: The simulators were first developed digitally, and then manufactured using printable resins and specific materials; finally, they were assembled using different bonding systems. To evaluate the simulators, assessments were gathered from two target populations: undergraduate students and periodontics experts. These individuals tested the simulator and completed a cross‐sectional questionnaire based on a Likert scale with comparative and pedagogical items scored from one to five. The purpose of the questionnaire was to compare our simulator to clinical reality (i.e., operation on human jaws) and to an animal simulator (i.e., simulation of porcine jaws). The results are expressed as the mean and standard deviation and were statistically analyzed with the Wilcoxon signed‐rank test. Results: Overall, the results were satisfactory for both groups of testers (4.70 and 4.61 out of five for students and experts, respectively, for global satisfaction). Conclusions: The overall educational relevance of the simulator designed herein highlights the fact that 3D‐printed educational simulators could enable efficient cognitive‐functional learning for clinical IOL/IRL treatment. [ABSTRACT FROM AUTHOR]

We present a set of single-well injection withdrawal tracer tests in a paleoreef porous reservoir displaying important small-scale heterogeneity. An improved dual-packer probe was designed to perform dirac-like tracer injection and accurate downhole automatic measurements of the tracer concentration during the recovery phase. By flushing the tracer, at constant flow rate, for increasing time duration, we can probe distinctly different reservoir volumes and test the multiscale predictability of the (non-Fickian) dispersion models. First we describe the characteristics, from microscale to meter scale, of the reservoir rock. Second, the specificity of the tracer test setup and the results obtained using two different tracers and measurement methods (salinity-conductivity and fluorescent dye-optical measurement, respectively) are presented. All the tracer tests display strongly tailed breakthrough curves (BTC) consistent with diffusion in immobile regions. Conductivity results, measured over 3 orders of magnitude only, could have been easily interpreted by the conventional mobile-immobile (MIM) diffusive mass transfer model of asymptotic log-log slope of −2. However, the fluorescent dye sensor, which allows exploring much lower concentration values, shows that a change in the log-log slope occurs at larger time with an asymptotic value of −1.5, corresponding to the double-porosity model. These results suggest that the conventional, one-slope MIM transfer rate model is too simplistic to account for the real multiscale heterogeneity of the diffusion-dominant fraction of the reservoir. [ABSTRACT FROM AUTHOR]

We aim at testing and validating a mobile-immobile mass transfer model from a set of single-well injection withdrawal tracer tests in a heterogeneous porous aquifer. By varying the duration of the injection phase, different volumes of aquifer are investigated by the tracer. Hence, we focus the transport model validation not only on reproducing a single breakthrough curve (BTC) but also on the model's capacity to predict the amount of mixing as a function of the volume visited by the tracer. All the BTCs are strongly asymmetric, as expected when dispersion is controlled by diffusive mass transfers between the mobile water and the immobile water part of the porosity. However, the BTC cannot be modeled by a conventional mobile-immobile mass transfer model with a simple power law memory function. To account for that, we implement a continuous time random walk model in which the transition time distribution ψ ( t), which is related to the excursion time probability of the tracer in the immobile domain, is a dual-slope power law distribution. The model best fits the BTC data set with a transitional regime controlled by ψ( t) ∼ t−2 and an asymptotic regime characteristic of the conventional double-porosity model with ψ( t) ∼ t−1.5 . This work emphasizes that high-resolution concentration measurement and multiple-scale tracer tests are required for assessing solute dispersion models in heterogeneous reservoirs and for subsequently obtaining reliable predictions. [ABSTRACT FROM AUTHOR]