Publications by authors named "Paulo Jose Dos Reis"

Petroleum is, at present, still the main energy source in the world. Most of it is stored in carbonate rock reservoirs with complex inner structures and pores ranging from nanometers to dozens of meters. Knowing the rock's entire pore network is indispensable to perform an effective petroleum extraction.

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This research aimed to obtain the depth dependence of polymerization contraction and microporosity from irradiated dental resin cements by X-ray computed microtomography (μCT). Samples (n = 5) of commercial Relyx U200 (RU) and AllCem Core (AC) dual-cure resin cements were injected in a cylindrical Teflon sampler (25 mm ) and separated according to polymerization mechanism: self-cured (not irradiated) and dual-cured (irradiated from the top surface with a LED device). The cement's volume was scanned with the μCT scanning conditions kept constant.

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Introduction: This in vitro study compared the performance of the XP-endo Shaper (XP; FKG, La Chaux-de-Fonds, Switzerland) in curved canals when used with a higher speed (3000 rpm) without a glide path with the manufacturer's protocol.

Methods: Twenty extracted mandibular molars with separate mesial curved canals were matched to obtain 2 standardized groups (n = 20). For the XP 1000 group, a glide path up to a size 15 hand file was performed followed by rotary instrumentation with the XP shaper at 1000 rpm, following the manufacturer's recommendations.

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Aedes aegypti and Aedes albopictus are vectors of several arboviruses responsible for causing dengue, chikungunya, Zika, and yellow fever viruses and microcephaly, resulting in a public health problem in several countries worldwide. Even in this scenario, studies on the morphology of mosquito eggs are still lacking. In this paper, X-ray microtomography was used to study mosquito egg morphology.

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Introduction: This study evaluated the accuracy of 3 electronic apex locators (EALs) (CanalPro [Coltene-Endo, Cuyahoga Falls, OH], Apex ID [SybronEndo, Glendora, CA], and Root ZX Mini [J Morita, Tokyo, Japan]) in curved mesial canals of extracted mandibular molars using micro-computed tomographic (micro-CT) scanning.

Methods: The root canal length and the actual working length of 58 canals were measured using the visual method and 3-dimensional micro-CT reconstructions. The measurements of the EALs at marks "APEX/0.

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This research aims to probe the porosity profile and polymerization shrinkage of two different dual cure resin cements with different dentin bonding systems. The self-adhesive resin cement RelyX U200 (named RU) and the conventional Allcem Core (named AC) were analyzed by x-ray microtomography (μCT) and Scanning Electron Microscopy (SEM). Each cement was divided into two groups (n = 5): dual-cured (RUD and ACD) and self-cured (RUC and ACC).

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X-ray microtomography is a 3D non-destructive method which, through digital images, enables a view of the internal structure of samples. Recently, researchers have been extensively performing various methods in the attempt to determine the chemical composition of materials. This paper brings further insight into this matter and proposes a new experimental method for determining the internal chemical composition of samples.

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