14 research outputs found
Influence of Drilling Technique on the Radiographic, Thermographic, and Geomorphometric Effects of Dental Implant Drills and Osteotomy Site Preparations
The aim of this comparative study is to analyze the influence of drilling technique on the
radiographic, thermographic, and geomorphometric e ects of dental implant drills and osteotomy site
preparations. One hundred and twenty osteotomy site preparations were performed on sixty epoxy
resin samples using three unused dental implant drill systems and four drilling techniques performed
with a random distribution into the following study groups: Group A: drilling technique performed
at 800 rpm with irrigation (n = 30); Group B: drilling technique performed at 45 rpm without irrigation
(n = 30); Group C: drilling technique performed at 45 rpm with irrigation (n = 30); and Group D:
drilling technique performed at 800 rpm without irrigation (n = 30). The osteotomy site preparation
morphologies performed by the 4.1 mm diameter dental implant drills from each study group were
analyzed and compared using a cone beam computed tomography (CBCT) scan. The termographic
e ects generated by the 4.1 mm diameter dental implant drills from each study group were registered
using a termographic digital camera and the unused and 4.1 mm diameter dental implant drills
that were used 30 times from each study group were exposed to a micro computed tomography
(micro-CT) analysis to obtain a Standard Tessellation Language (STL) digital files that determined the
wear comparison by geomorphometry. Statistically significant di erences were observed between
the thermographic and radiographic results of the study groups (p < 0.001). The e ect of cooling
significatively reduced the heat generation during osteotomy site preparation during high-speed
drilling; furthermore, osteotomy site preparation was not a ected by the wear of the dental implant
drills after 30 uses, regardless of the drilling technique.Odontologí
Implant-Supported Fixed Partial Dentures with Posterior Cantilevers: In Vitro Study of Mechanical Behavior
Rehabilitation with dental implants is not always possible due to the lack of bone quality
or quantity, in many cases due to bone atrophy or the morbidity of regenerative treatments. We
find ourselves in situations of performing dental prostheses with cantilevers in order to rehabilitate
our patients, thus simplifying the treatment. The aim of this study was to analyze the mechanical
behavior of four types of fixed partial dentures with posterior cantilevers on two dental implants
(convergent collar and transmucosal internal connection) through an in vitro study (compressive
loading and cyclic loading). This study comprised four groups (n = 76): in Group 1, the prosthesis was
screwed directly to the implant platform (DS; n = 19); in Group 2, the prosthesis was screwed to the
telescopic interface on the implant head (INS; n = 19); in Group 3, the prosthesis was cemented to the
telescopic abutment (INC; n = 19); and in Group 4, the prosthesis was cemented to the abutment (DC;
n = 19). The sets were subjected to a cyclic loading test (80 N load for 240,000 cycles) and compressive
loading test (100 KN load at a displacement rate of 0.5 mm/min), applying the load until failure
occurred to any of the components at the abutment–prosthesis–implant interface. Subsequently, an
optical microscopy analysis was performed to obtain more data on what had occurred in each group.
Results: Group 1 (direct screw-retained prosthesis, DS) obtained the highest mean strength value
of 663.5 ± 196.0 N. The other three groups were very homogeneous: 428.4 ± 63.1 N for Group 2
(INS), 486.7 ± 67.8 N for Group 3 (INC), and 458.9 ± 38.9 N for Group 4 (DC). The mean strength
was significantly dependent on the type of connection (p < 0.001), and this difference was similar
for all of the test conditions (cyclic and compressive loading) (p = 0.689). Implant-borne prostheses
with convergent collars and transmucosal internal connections with posterior cantilevers screwed
directly to the implant connection are a good solution in cases where implant placement cannot
avoid extensions.Odontologí
Criterios de ordenación temporal de las intervenciones quirúrgicas en patología cardiovascular y endovascular adquirida. Versión 2022
Waiting list management of cardiac surgical procedures is a main concern for all the Spanish autonomic health systems and for our scientific Society. The first statement for optimal timing of patients waiting for cardiac surgery was published in 2000. Since then, after significant changes in the management of some pathologies, new normative frameworks and the current healthcare situation, a review of the timing criteria to offer an adequate and updated standard of care is needed. In this document we aim to review the available literature in the field and stablish a consensus within a working group of the Spanish Society of Cardiovascular and Endovascular Surgery to optimize the priority recommendations in cardiac surgical waiting lists in our country. (c) 2022 Sociedad Espanola de Cirugia Cardiovascular y Endovascular. Published by Elsevier Espana, S.L.U. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ riccuses/by-nc-nri/4.0/)
Estado del arte de la investigación en salud mental en Costa Rica
libro (no arbitrado)--Universidad de Costa Rica, Escuela de Psicología, Instituto de Investigaciones Psicológicas, Escuela de Salud Pública, Centro de Investigaciones en Biología Celular y Molecular, y Escuela de Biología. Escuela de Psicología de la Universidad Nacional. Ministerio de Salud. 2013Esta es una obra que contiene varios capítulos que brindan, en conjunto, un panorama general del estado de la investigación en Salud Mental en Costa Rica. Presentan la contextualización histórica con los eventos más relevantes en la atención de la enfermedad mental. Se muestra la investigación desarrollada en el pasado y las necesidades y líneas de investigación para un futuro cercano, de cara a las políticas públicas en Salud Mental. Se reflexiona y analiza en el concepto de la Salud Mental hacia conceptos más comprensivos como bienestar o calidad de vida, y factores socioambientales asociados. Se aportan nuevos paradigmas y enfoques con el fin de comprender la Salud Mental no sólo desde sus dimensiones físicas y psicológicas, sino considerando sus manifestaciones sociales y culturales.Universidad de Costa Rica y Ministerio de SaludUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Sociales::Instituto de Investigaciones Psicológicas (IIP
The PREDICTS database: a global database of how local terrestrial biodiversity responds to human impacts
Biodiversity continues to decline in the face of increasing anthropogenic pressures
such as habitat destruction, exploitation, pollution and introduction of
alien species. Existing global databases of species’ threat status or population
time series are dominated by charismatic species. The collation of datasets with
broad taxonomic and biogeographic extents, and that support computation of
a range of biodiversity indicators, is necessary to enable better understanding of
historical declines and to project – and avert – future declines. We describe and
assess a new database of more than 1.6 million samples from 78 countries representing
over 28,000 species, collated from existing spatial comparisons of
local-scale biodiversity exposed to different intensities and types of anthropogenic
pressures, from terrestrial sites around the world. The database contains
measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35)
biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains
more than 1% of the total number of all species described, and more than
1% of the described species within many taxonomic groups – including flowering
plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans
and hymenopterans. The dataset, which is still being added to, is
therefore already considerably larger and more representative than those used
by previous quantitative models of biodiversity trends and responses. The database
is being assembled as part of the PREDICTS project (Projecting Responses
of Ecological Diversity In Changing Terrestrial Systems – www.predicts.org.uk).
We make site-level summary data available alongside this article. The full database
will be publicly available in 2015
Influence of Drilling Technique on the Radiographic, Thermographic, and Geomorphometric Effects of Dental Implant Drills and Osteotomy Site Preparations
The aim of this comparative study is to analyze the influence of drilling technique on the radiographic, thermographic, and geomorphometric effects of dental implant drills and osteotomy site preparations. One hundred and twenty osteotomy site preparations were performed on sixty epoxy resin samples using three unused dental implant drill systems and four drilling techniques performed with a random distribution into the following study groups: Group A: drilling technique performed at 800 rpm with irrigation (n = 30); Group B: drilling technique performed at 45 rpm without irrigation (n = 30); Group C: drilling technique performed at 45 rpm with irrigation (n = 30); and Group D: drilling technique performed at 800 rpm without irrigation (n = 30). The osteotomy site preparation morphologies performed by the 4.1 mm diameter dental implant drills from each study group were analyzed and compared using a cone beam computed tomography (CBCT) scan. The termographic effects generated by the 4.1 mm diameter dental implant drills from each study group were registered using a termographic digital camera and the unused and 4.1 mm diameter dental implant drills that were used 30 times from each study group were exposed to a micro computed tomography (micro-CT) analysis to obtain a Standard Tessellation Language (STL) digital files that determined the wear comparison by geomorphometry. Statistically significant differences were observed between the thermographic and radiographic results of the study groups (p < 0.001). The effect of cooling significatively reduced the heat generation during osteotomy site preparation during high-speed drilling; furthermore, osteotomy site preparation was not affected by the wear of the dental implant drills after 30 uses, regardless of the drilling technique
Behaviour of polythionates in the acid lake of poás volcano: Insights into changes in the magmatic-hydrothermal regime and subaqueous input of volatiles
In this chapter, we document an extensive record of concentrations and speciation of polythionates (PTs: S4O6 2−, S5O6 2−, and S6O6 2−), which form in the warm (21–60 °C) and hyper-acidic (pH < 1.8) waters of the crater lake of Poás volcano (Costa Rica) through interaction with gaseous SO2 and H2S of magmatic origin. Our data set, together with earlier published results, covers the period 1980–2006 during which lake properties and behavior were marked by significant variations. Distinct stages of activity can be defined when combining PT distributions with geochemical, geophysical and field observations. Between 1985 and mid-1987, when fumarolic outgassing was centered on-shore, the total concentration of PTs in the lake was consistently high (up to 4,200 mg/kg). Mid-1987 was the start of a 7-year period of vigorous fumarolic activity with intermittent phreatic eruptions from the lake, which then dried out. Concentrations of PTs remained below or close to detection limits throughout this period. After mid-1994, when a new lake formed and fumarolic outgassing shifted to the dome, the total PT concentrations returned to relatively stable intermediate levels (up to 2,800 mg/kg) marking more quiescent conditions. Since early 1995, numerous weak fumarole vents started, opening up at several other locations in the crater area. During short intervals (November 2001–May 2002 and October 2003–March 2005), PTs virtually disappeared. After April 2005, PTs re-appeared in large amounts (up to more than 3,000 mg/kg) until February 2006, one month before the onset of the March 2006–2017 cycle of phreatic eruptions, when concentrations dropped and remained below 100 mg/kg. The observed behavior of PTs records changes in the input and SO2/H2S ratios of subaqueous fumaroles. The prevailing distribution of PTs is S4O6 2− > S5O6 2− > S6O6 2−, which is common for periods when total PT concentrations and SO2/H2S ratios of the gas influx into the lake are relatively high. PTs are virtually absent as a consequence of thermal or sulphitolytic breakdown during periods of strong fumarolic outgassing in response to shallow intrusion of fresh magma or fracturing of the solid envelope around a pre-existing body of cooling magma. They are also low in abundance or undetected during quiescent periods when subaqueous fumarolic output is weak and has low SO2/H2S ratios, resulting in a concentration sequence S5O6 2− > S4O6 2− > S6O6 2−. The onset of phreatic eruptions are preceded by an increase in PT concentrations, accompanied by a change in the dominance from penta- to tetrathionate, and followed by a sharp drop in total PT content, up to several months before. Periods of phreatic eruptive activity that started in 1987 and 2006 followed these PT signals of increased input of sulfur-rich gas, in both cases possibly in response to shallow emplacement of fresh magma or hydrofracturing
Behaviour of polythionates in the acid lake of poás volcano: Insights into changes in the magmatic-hydrothermal regime and subaqueous input of volatiles
In this chapter, we document an extensive record of concentrations and speciation of polythionates (PTs: S4O6 2−, S5O6 2−, and S6O6 2−), which form in the warm (21–60 °C) and hyper-acidic (pH < 1.8) waters of the crater lake of Poás volcano (Costa Rica) through interaction with gaseous SO2 and H2S of magmatic origin. Our data set, together with earlier published results, covers the period 1980–2006 during which lake properties and behavior were marked by significant variations. Distinct stages of activity can be defined when combining PT distributions with geochemical, geophysical and field observations. Between 1985 and mid-1987, when fumarolic outgassing was centered on-shore, the total concentration of PTs in the lake was consistently high (up to 4,200 mg/kg). Mid-1987 was the start of a 7-year period of vigorous fumarolic activity with intermittent phreatic eruptions from the lake, which then dried out. Concentrations of PTs remained below or close to detection limits throughout this period. After mid-1994, when a new lake formed and fumarolic outgassing shifted to the dome, the total PT concentrations returned to relatively stable intermediate levels (up to 2,800 mg/kg) marking more quiescent conditions. Since early 1995, numerous weak fumarole vents started, opening up at several other locations in the crater area. During short intervals (November 2001–May 2002 and October 2003–March 2005), PTs virtually disappeared. After April 2005, PTs re-appeared in large amounts (up to more than 3,000 mg/kg) until February 2006, one month before the onset of the March 2006–2017 cycle of phreatic eruptions, when concentrations dropped and remained below 100 mg/kg. The observed behavior of PTs records changes in the input and SO2/H2S ratios of subaqueous fumaroles. The prevailing distribution of PTs is S4O6 2− > S5O6 2− > S6O6 2−, which is common for periods when total PT concentrations and SO2/H2S ratios of the gas influx into the lake are relatively high. PTs are virtually absent as a consequence of thermal or sulphitolytic breakdown during periods of strong fumarolic outgassing in response to shallow intrusion of fresh magma or fracturing of the solid envelope around a pre-existing body of cooling magma. They are also low in abundance or undetected during quiescent periods when subaqueous fumarolic output is weak and has low SO2/H2S ratios, resulting in a concentration sequence S5O6 2− > S4O6 2− > S6O6 2−. The onset of phreatic eruptions are preceded by an increase in PT concentrations, accompanied by a change in the dominance from penta- to tetrathionate, and followed by a sharp drop in total PT content, up to several months before. Periods of phreatic eruptive activity that started in 1987 and 2006 followed these PT signals of increased input of sulfur-rich gas, in both cases possibly in response to shallow emplacement of fresh magma or hydrofracturing
Digital technique to analyze the wear of screw-retained implant supported metal-ceramic dental prostheses and natural tooth as antagonist: a pilot study
Abstract The aim of this study was to describe a novel digital technique to analyze the wear of screw-retained implant-supported metal-ceramic dental prostheses and natural tooth as antagonist. Materials and methods Ten patients were consecutively included to rehabilitate partial edentulism by dental implants. Both the screw-retained implant-supported metal-ceramic dental prostheses and the natural tooth as antagonist were submitted to a digital impression through an intraoral scan to generate a Standard Tessellation Language digital file preoperatively (STL1), at 3 months (STL2), and 6 months (STL3) follow-up. Afterwards, an alignment procedure of the digital files (STL1-STL3) was performed on a reverse engineering morphometric software (3D Geomagic Capture Wrap) and volume changes at the screw-retained implant-supported metal-ceramic dental prostheses and the natural tooth as antagonist were analyzed using Student’s t-test. Moreover, Gage R&R statistical analysis was conducted to analyze the repeatability and reproducibility of the digital technique. Results Gage R&R showed a variability attributable to the digital technique of 3.8% (among the measures of each operator) and 4.5% (among operators) of the total variability; resulting repeatable and reproducible, since the variabilities were under 10%. In addition, statistically significant differences were shown at the wear volume (μm3) of both the natural tooth as antagonist (p < 0.0001) and the screw-retained implant-supported metal-ceramic dental prostheses between 3- and 6-months follow-up (p = 0.0002). Conclusion The novel digital measurement technique results repeatable and reproducible to analyze the wear of screw-retained implant-supported metal-ceramic dental prostheses and natural tooth as antagonist
Recomendaciones para la creación, cuidado y manejo de los accesos vasculares para hemodiálisis. Documento de Posición del Comité de Nefrología Intervencionista y del Grupo de Consenso para Optimización de Accesos Vasculares de la Sociedad Latinoamericana de Nefrología e Hipertensión
Este documento establece la posición del Comité de Nefrología Intervencionista y del Grupo de Consenso para Optimización de Accesos Vasculares de la Sociedad Latinoamericana de Nefrología e Hipertensión (SALNH) y es el resultado del interés promovido en la sociedad para diseñar un conjunto de recomendaciones, simples, exhaustivas y sobre todo aplicables a la región acerca de la creación, cuidado y manejo de los accesos vasculares para pacientes en hemodiálisis; para ello se seleccionó la información con mayor sustento científico y que mejor se adapta a las necesidades de los pacientes. Este documento intenta poner al alcance de todos los profesionales de la salud y los pacientes las mejores opciones sobre el acceso vascular (AV) para hemodiálisis, desde su planeación, creación y vigilancia hasta la resolución de las complicaciones potenciales