Multivariate analysis of the influence of peri-implant clinical parameters and local factors on radiographic bone loss in the posterior maxilla: a retrospective study on 277 dental implants

Clinical Oral Investigations - The aim of the present study was to investigate whether peri-implant clinical parameters (modified plaque index (mPI), bleeding and/or suppuration on probing (B/SOP))...     

Effect of green tea-loaded chitosan nanoparticles on leathery dentin microhardness

The purpose of this study was to assess the effect of a chitosan-based nanoformulation containing green tea on leathery (remaining) dentin subsurface microhardness. Size distribution, polydispersity index (PDI) and zeta potential (mV) of nanoformulations were previously determined by dynamic light scattering (DLS). Human dentin specimens were exposed to Streptococcus mutans for 14 d. Soft dentin were selectively removed by Er:YAG laser (n?=?30) or bur (n?=?30). Remaining dentin was biomodified with chitosan nanoparticles (Nchi, n?=?10) or green tea-loaded chitosan nanoparticles (Gt?+?Nchi, n?=?10) for 1 min. Control group (n?=?10) did not receive any treatment. Subsurface microhardness (Knoop) was evaluated in hard (sound) and soft dentin, and then, in leathery dentin and after its biomodification, at depths of 30, 60 and 90 μm from the surface. Nchi reached an average size of?≤?300 nm, PDI varied between 0.311 and 0.422, and zeta potential around?+?30 mV. Gt?+?Nchi reached an average size of?≤?350 nm, PDI?<?0.45, and zeta potential around?+?40 mV. Soft dentin showed significantly reduced microhardness at all depths (p?>?0.05). The subsurface microhardness was independent of choice of excavation method (p?>?0.05). At 30 µm from the surface, Gt?+?Nchi increased the leathery dentin microhardness compared to untreated group (p?<?0.05). Nchi promoted intermediate values (p?>?0.05). Both nanoformulations showed an average size less than 350 nm with nanoparticles of different sizes and stability along the 90-day period evaluated. Subsurface microhardness of bur-treated and laser-irradiated dentin was similar. At 30 µm, the biomodification with Gt?+?Nchi improved the microhardness of leathery dentin, independently of caries excavation method used.

     

A Ubiquitous Reflective E-Portfolio Architecture

BackgroundIn nurse and in medicine courses, the use of reflective portfolios as a pedagogical tool is becoming a common practice; in the last years, this practice has gradually migrated from paper-based to electronic-based portfolios. Current approaches for reflective e-portfolios, however, do not widely operate at outdoor sites, where data networks are limited or nonexistent. Considering that many of the activities related to nurse and medicine courses relate to professional practices conducted in such conditions, these network shortcomings restrict the adoption of e-portfolios.PurposeThe present study describes the requirements specification, design, implementation, and evaluation of the Ubiquitous Reflective E-Portfolio Architecture, a solution proposed to support the development of systems based on mobile and wired access for both online and offline operation.MethodsWe have implemented a prototype named Professional Practice Module to evaluate the Ubiquitous Reflective E-Portfolio Architecture; the module was based on requirements observed during the professional practice, the paper-based portfolio in use, and related learning meetings in the Medicine Course of a Brazilian University. The evaluation of the system was carried out with a learning group of 2nd year students of the medicine course, who answered to extensive evaluation questionnaires.ResultsThe prototype proved to be operational in the activities of the professional practice of the Medicine Course object of the study, including homework tasks, patient care, data sharing, and learning meetings. It also demonstrated to be versatile with respect to the availability of the computer network that, many times, was not accessible. Moreover, the students considered the module useful and easy to use, but pointed out difficulties about the keyboard and the display sizes of the netbook devices, and about their operational system. Lastly, most of the students declared preference for the electronic Professional Practice Module in internal and in group activities, and for the paper-based version while in patient attendance.ConclusionsThere is evidence that the environment where the professional practice takes place influences the usage of the e-portfolio. Mobile devices were able to support students in their professional practice; however, these devices present characteristics that must be judiciously selected, otherwise, they may limit the execution of important tasks. The main shortcoming identified during the evaluation tests was about the use of the module, and of the access device, during patient attendance. For this reason, we have envisioned a new version of the Professional Practice Module that shall follow a twofold requisite: by one side, it will include all the features of the module, to be used at the university or in the students’ homes; from the other side, it will include only the features that are essential for the practice of patient attendance.     

The energy cost of shuttle running

The aim of this study was to: (1) determine directly the energy cost of shuttle running (C _Sh) and (2) compare it to the values indirectly estimated from kinematic data. C _Sh over distances of ≈10 or ≈20 m was determined on 65 subjects (group 1) from gas exchange measurements over 155 trials, or indirectly estimated on 10 subjects (group 2) from the time course of the speed as follows. (1) The cost to accelerate from zero to peak speed was estimated assuming a 25 % efficiency and added to that of constant-speed running, as obtained on subjects of group 1. (2) Since (i) accelerated running on flat terrain is equivalent to running uphill at constant speed, on a slope dictated by the forward acceleration (di Prampero et al. in J Exp Biol 208:2809–2816, 2005), and (ii) the energy cost of running uphill is known, C _Sh was obtained from the time course of the acceleration. C _Sh increased with the average speed, at any given speed being significantly greater for the shorter distances; e.g., at ≈4 m/s over 10 m, it amounted to ≈14 J/(kg m), i.e., 3.5-fold larger than that at constant speed. The two indirect methods yielded results not significantly different from C _Sh over the longer (≈20 m), but underestimated it over the shorter (≈10 m) distances. From our results, over ≈20 m C _Sh can be obtained with sufficient accuracy from actual measurements of peak speed alone, thus, greatly simplifying the experimental procedure. The so-obtained data can then be utilized to assess the athletic status of any subject, as well as to plan appropriate training strategies.     

Disorder in Ho2Ti2−xZrxO7: pyrochlore to defect fluorite solid solution series

Pyrochlore (A₂B₂O₇) is an important, isometric structure-type because of its large variety of compositions and structural derivatives that are generally related to different disordering mechanisms at various spatial scales. The disordering is key to understanding variations in properties, such as magnetic behavior or ionic conduction. Neutron and X-ray total scattering methods were used to investigate the degree of structural disorder in the Ho₂Ti_2−xZr_xO₇ (x = 0.0–2.0, Δx = 0.25) solid solution series as a function of the Zr-content, x. Ordered pyrochlores (Fd$\bar{3}$m) disorder to defect fluorite (Fm$\bar{3}$m) via cation and anion disordering. Total scattering experiments with sensitivity to the cation and anion sublattices provide unique insight into the underlying atomic processes. Using simultaneous Rietveld refinement (long-range structure) and small-box refinement PDF analysis (short-range structure), we show that the series undergoes a rapid transformation from pyrochlore to defect fluorite at x ≈ 1.2, while the short-range structure exhibits a linear increase in a local weberite-type phase, C222₁, over the entire composition range. Enthalpies of formation from the oxides determined using high temperature oxide melt solution calorimetry support the structural data and provide insight into the effect of local ordering on the energetics of disorder. The measured enthalpies of mixing are negative and are fit by a regular solution parameter of W = −31.8 ± 3.7 kJ mol⁻¹. However, the extensive short-range ordering determined from the structural analysis strongly suggests that the entropies of mixing must be far less positive than implied by the random mixing of a regular solution. We propose a local disordering scheme involving the pyrochlore 48f to 8a site oxygen Frenkel defect that creates 7-coordinated Zr sites contained within local weberite-type coherent nanodomains. Thus, the solid solution is best described as a mixture of two phases, with the weberite-type nanodomains triggering the long-range structural transformation to defect fluorite after accumulation above a critical concentration (50% Ti replaced by Zr).

Combined neutron and X-ray total scattering with calorimetric measurements of the solid solution series Ho₂Ti_2−xZr_xO₇ reveals a complex order–disorder transition across short, intermediate, and long length scales induced by chemical substitution.     

Pediatrician performed point-of-care ultrasound for the detection of ingested foreign bodies: case series and review of the literature

PurposeForeign body (FB) ingestions represent a common problem in children. History and physical examination are commonly not enough to diagnose a foreign body ingestion; therefore, conventional radiography is routinely used to detect them. Point-of-care ultrasound is widely used in the emergency department for several diagnostic applications but there are few articles describing the possibility to use point-of-care ultrasound to detect ingested foreign bodies, and the necessary training to get competent in this application. The main objective of this paper is to illustrate the use of point-of-care ultrasound (POCUS) to detect ingested foreign bodies. The secondary objective is to describe a limited training, necessary for emergency pediatricians, to obtain this skill.MethodsThis is a case series of eight pediatric patients who presented to the pediatric Emergency Department (ED), with suspected ingestion of FB, and were assessed with POCUS. Physician sonographers were two pediatricians and three residents in pediatrics working in two Italian Pediatric EDs. All sonographers participated in a 2-day POCUS workshop which included the most common pediatric POCUS applications.ResultsPOCUS, performed by emergency pediatricians who participated to a limited training, allowed to always identify the foreign bodies ingested.ConclusionsWe demonstrate that an appropriate and limited training allows pediatric emergency physicians to correctly identify foreign body in the esophagus or stomach. Point-of-care ultrasound in foreign body ingestion in the Emergency Department may allow to prioritize the escalation of care in children and it can contribute to reduce the time to endoscopic management when needed.Electronic supplementary materialThe online version of this article (10.1007/s40477-020-00452-z) contains supplementary material, which is available to authorized users.     

Influence of foraminal enlargement on the apical extrusion of filling material: Volumetric analysis using micro‐computed tomography

The aim of this study was to compare the root canal instrumentation techniques that involve foraminal enlargement versus those not involving it, in regard to the apical extrusion of filling material, using micro‐computed tomography (micro‐CT). Twenty‐two premolars with single canals were instrumented using the ProTaper Universal System and then randomly divided into two groups (n = 11): Group NFE, without foraminal enlargement, and Group FE, with foraminal enlargement. Instrumentation was performed up to 1 mm short of the apical foramen, and foraminal patency was maintained at each instrument change in both groups. Prior to obturation, the apical portion of the specimens was wrapped in adhesive paper to ensure complete separation between apex and extruded material. The canals were filled according to the continuous wave of condensation technique. The apically extruded material was collected and measured using micro‐CT. Extrusion in Group FE was significantly higher than in Group NFE (0.928 mm³ vs. 0.148 mm³; P < 0.001).     

Effects of cachaça,a typical Brazilian alcoholic beverage,on submandibular glands of rats: a histomorphometric and biochemical study

Objective

This study aimed to evaluate the effects of chronic consumption of cachaça, a Brazilian beverage containing alcohol, on submandibular glands (SM) of rats by using histomorphometric and biochemical parameters.

Materials and methods

Twenty-four male rats (40 days of age) were assigned into the following four groups (n = 6): two control groups for 75 days (C75) and 105 days (C105), and two experimental groups of cachaça ingestion with ascending concentrations for consecutive 75 days (CA75) and 105 days (CA105). On the right SM glands, the striated, granular and acini ducts were processed for histomorphometric analysis. The left SM glands were weighed and stored at − 80 °C, to evaluate through biochemical tests carried out by spectrophotometric methods, the functional activity of total acid phosphatase (TAP), tartrate-resistant acid phosphatase (TRAP), and alkaline phosphatase (ALP) and to determine the mucin levels.

Results

The absolute and relative weights of the SM glands in both experimental groups were reduced in relation to the controls (p < 0.05). The histomorphometric analysis showed a significant reduction of the acini area (p < 0.05) and non-relevant reduction of striated ducts (p > 0.05). The granular ducts did not show a significant increase of the area (p > 0.05). The TAP and TRAP activities were significantly decreased in the experimental groups (p < 0.05), while the ALP functional activity decreased moderately (p > 0.05). Mucin levels also had a significant reduction when compared with the control groups (p < 0.05).

Conclusions

Chronic consumption of cachaça can cause morphological changes associated with glandular atrophy, loss of biochemical functionality of phosphatases, and the reduction of mucin synthesis.

Clinical relevance

The consumption of cachaça can compromise the functions of the submandibular glands by altering their morphology and enzymatic activity.