Predictability of the resonance frequency analysis in the survival of dental implants placed in the anterior non-atrophied edentulous mandible

Background: Dental primary implant stability is considered essential in the success of the osseointegration process. The recent advent of the resonance frequency analysis (RFA) seems to effectively measure primary implant stability, although its relationship with implant survival has to be further established. Patients and Methods: Seventy patients with complete mandibular edentulism underwent dental implant rehabilitation by means of the placement of 68 dental implants within the interforaminal region and subsequent placement of an overdenture. Primary implant stability was measured by means of RFA and it was expressed in terms of implant stability quotient (ISQ) on the day of the implant insertion and at the time of the healing abutment placement in a conventional implant two-stage surgical procedure. Results: Overall implant survival rate was 97.1% at the end of the follow-up period. The mean ISQ value for 3.75 and 4.25 mm diameter implants was 78.4 ± 5.46 and 80.83 ± 5.35 respectively, at the time of the implant placement; and 76.68 ± 4.34 and 78.22 ± 6.87 respectively, at the second surgical stage. No statistical differences were observed in relation to changes in mean ISQ value along the healing process Conclusions: No statistical differences in terms of primary and secondary implant stability measured by RFA exists between 3.75 mm and 4.25 mm diameter implants in the conventional implant two-stage surgical procedure in patients with non-atrophied edentulous mandible being restored with an overdenture. Furthermore, no statistical association between RFA and the implant insertion torque was observed for endosseous dental implant placement at the first surgical stage. © Medicina Oral

Estratigrafía Sísmica de Alta Resolución en las Rías Baixas: Pontevedra y Vigo (NO España)

El estudio detallado de los perfiles de sísmica reflexión de alta resolución, de las rías de Pontevedra y Vigo ha permitido diferenciar 7 unidades sísmicas. Las unidades sísmicas Bg y Bm se interpretan como correspondientes a rocas del basamento, graníticas y metamórficas respectivamente. Las 5 unidades sísmicas restantes corresponden al relleno sedimentario de las rías. La identificación de los límites de secuencia L2 y L3 permiten reconocer tres secuencias sedimentarias (S1, S2 y S3), de más antigua a más reciente, que van marcando una progresiva ampliación de la zona de sedimentación en las rías. En la secuencia más reciente (S3) destaca la presencia de apantallamientos acústicos y/o formas de escape, interpretadas como debidas a la presencia de gas biogénico en los sedimentos.Detailed study of high-resolution seismic reflection profiles of the Ría de Pontevedra and Vigo (NW Spain) has allowed to distinguish 7 seismic units. Seismic units Bg and Bm are interpreted as granitic and methamorphic basement rocks respectively. The other 5 seismic units correspond to the sedimentary infill of the rías. The identification of the sequences boundaries L2 and L3 allow to recognize three sedimentary sequences (S1, S2 and S3), from oldest to youngest, 217 S. García-Gil et al. Estratigrafía sísmica de alta resolución en las Rías Baixas:... that give a progressive enlargement of the rías sedimentary basin. In the most recent sequence (S3) appear acoustic blanking and/or escape features, interpreted as due to the presence of biogenic gas in the sediments of the rías

Temporomandibular joint arthrocentesis. Review of the literature

The treatment of the temporomandibular joint (TMJ) is still controversial. TMJ arthrocentesis represents a form of minimally invasive surgical treatment in patients suffering from internal derangement of the TMJ, especially closed lock. It consists of washing the joint with the possibility of depositing a drug or other therapeutic substance. Resolution of symptoms is due to the removal of chemical inflammatory mediators and changes in intra-articular pressure. Numerous clinical studies regarding this technique have been published. The goal of this paper is to review all clinical articles that have been published with regard to the critique of this technique. 19 articles with different designs fulfilling selection guidelines were chosen. A series of clinical and procedure variables were analyzed. Although the mean of improvement was higher that 80%, further research is needed to determine more homogeneous indications for TMJ athrocentesis

Grindability and combustion behavior of coal and torrefied biomass blends

Biomass samples (pine, black poplar and chestnut woodchips) were torrefied to improve their grindability before being combusted in blends with coal. Torrefaction temperatures between 240 and 300 °C and residence times between 11 and 43 min were studied. The grindability of the torrefied biomass, evaluated from the particle size distribution of the ground sample, significantly improved compared to raw biomass. Higher temperatures increased the proportion of smaller-sized particles after grinding. Torrefied chestnut woodchips (280 °C, 22 min) showed the best grinding properties. This sample was blended with coal (5–55 wt.% biomass). The addition of torrefied biomass to coal up to 15 wt.% did not significantly increase the proportion of large-sized particles after grinding. No relevant differences in the burnout value were detected between the coal and coal/torrefied biomass blends due to the high reactivity of the coal. NO and SO2 emissions decreased as the percentage of torrefied biomass in the blend with coal increased.This work was part of the subcontracted contribution of INCAR to a project carried out by EDP Spain with the financial support from the European Regional Development Fund (ERDF) and acting IDEPA (Economic Development Agency of the Principality of Asturias) as research funding agency (Ref.: IDE/2013/000233). The authors thank A. J. Martín, member of the PrEM group at INCAR-CSIC, for his contribution.Peer reviewe

Aplicación del Sonar de Barrido Lateral a la cartografía de fondos marinos. Ejemplo de la Ría de Pontevedra (Galicia, NO España).

Se realiza una cartografía de detalle de los fondos actuales de la Ría de Pontevedra basándose en los registros de sonar de barrido lateral. El análisis de los sonogramas obtenidos permite diferenciar cuatro patrones de reflectividad. Los datos de muestras directas del fondo obtenidas dentro de la zona que caracteriza a cada patrón establecen la relación directa entre reflectividad-textura. La correlación de las sonografías con la geología de la zona emergida hacen posible distinguir en los registros los dos tipos de basamento (granítico y metamórfico) en función de sus reflectividades y rasgos estructurales (fracturas). El sistema acústico aplicado permite discriminar entre formas sedimentarias (megaripples) y antrópicas (bateas, marcas de arrastre), a la vez que se establece su relación directa con las condiciones hidrodinámicas y rasgos morfológicos de la Ría de Pontevedra.Side scan sonar is used to provide a high resolution mapping of the seafloor of the Ría de Pontevedra. Sonograph analysis allows us to distinguish four backscatter patterns. Bottom samples within each pattern establish a direct relationship between backscatter and sediment texture. Sonograph correlation with land geology permit the differentiation between granitic and metamorphic basement, as well as its structural features (fractures). The side scan sonar is also used for discriminating sedimentary (megaripples) and anthropogenic features (mussel rafts, trawl-marks) and also for establishing the relationship between the hydrodynamic conditions and geomorphology of the Ría

A three-dimensional view of the remnant of Nova Persei 1901 (GK Per)

We present a kinematical study of the optical ejecta of GK Per. It is based on proper motions measurements of 282 knots from ~20 images spanning 25 years. Doppler-shifts are also computed for 217 knots. The combination of proper motions and radial velocities allows a unique 3-D view of the ejecta to be obtained. The main results are: (1) the outflow is a thick shell in which knots expand with a significant range of velocities, mostly between 600 and 1000 km/s; (2) kinematical ages indicate that knots have suffered only a modest deceleration since their ejection a century ago; (3) no evidence for anisotropy in the expansion rate is found; (4) velocity vectors are generally aligned along the radial direction but a symmetric pattern of non-radial velocities is also observed at specific directions; (5) the total Halpha+[NII] flux has been linearly decreasing at a rate of 2.6 % per year in the last decade. The Eastern nebular side is fading at a slower rate than the Western one. Some of the knots displayed a rapid change of brightness during the 2004-2011 period. Over a longer timescale, a progressive circularization and homogenization of the nebula is taking place; (6) a kinematic distance of 400+-30 pc is determined. These results raise some problems to the previous interpretations of the evolution of GK Per. In particular, the idea of a strong interaction of the outflow with the surrounding medium in the Southwest quadrant is not supported by our data.Comment: Accepted for publication in The Astrophysical Journal (19 pages, 17 figures). Higher resolution version of this article (2.5 MB) is available at http://www.aai.ee/~sinope/ApJ89291_liimets.pd

Hemiepifisiodesis femoral distal mediante biomateriales reabsorbibles: Estudio experimental en el conejo

Se valoró experimentalmente un implante triangular compuesto de 3 tornillos metálicos unidos por un filamento de PDS II o Tendofil como método de epifisiodesis. Se utilizaron conejos esqueléticamente inmaduros, divididos en 4 Grupos, según el seguimiento postoperatorio (1,2,3 y 4 meses), subdivididos a su vez en 2 subgrupos según el filamento empleado. Se colocó el implante en la cara lateral de la epífisis femoral distal izquierda. La extremidad posterior derecha sirvió como control practicándose estudios radiológicos, histológicos e histomorfométrico. Las extremidades intervenidas presentaron una desviación en valgo significativa respecto a las control. El implante utilizado consiguió el frenado misario con ambos filamentos. Durante el primer mes, la eficacia del implante reabsorbible fue comparable al metálico. Posteriormente, el metálico resultó más eficaz. Los estudios histológicos e histomorfométrico mostraron un frenado asimétrico de la fisis intervenida. No hubo daños fisarios en relación con la degradación del implante reabsorbible. Nuestros resultados sugieron el diseño de implantes reabsorbibles en la cirugía del cartílago de crecimiento.A triangular implant compound by 3 metallic screws united by a filament (PDS II vs. Tendofil) as method of experimental epiphysiodesis was evaluated. They were used 32 immature rabbits, divided into 4 Groups acoording to the follow-up (1.2.3. and 4 months), and subdivided according to the employed filament. The implant was located at the lateral face of the distal left femoral epiphysis. The right extremity served as control. Radiographic, histologic and histomorphometric studies were performed. The operated legs presented a significant valgus deviation as compared to controls. The epiphysiodesis was achieved with both types of filaments. During the first month, the efficiency of the absorbable implant was comparable to the metallic. Thereafter, the metallic implant results more effective. Histologic and morphometric studies showed the hemiepiphysiodesis. No physeal damaged in relationship to the degradation of the absorbable implant was observed. Our results suggests the use of absorbable implant in growth plate surgery

On the Transverse-Traceless Projection in Lattice Simulations of Gravitational Wave Production

It has recently been pointed out that the usual procedure employed in order to obtain the transverse-traceless (TT) part of metric perturbations in lattice simulations was inconsistent with the fact that those fields live in the lattice and not in the continuum. It was claimed that this could lead to a larger amplitude and a wrong shape for the gravitational wave (GW) spectra obtained in numerical simulations of (p)reheating. In order to address this issue, we have defined a consistent prescription in the lattice for extracting the TT part of the metric perturbations. We demonstrate explicitly that the GW spectra obtained with the old continuum-based TT projection only differ marginally in amplitude and shape with respect to the new lattice-based ones. We conclude that one can therefore trust the predictions appearing in the literature on the spectra of GW produced during (p)reheating and similar scenarios simulated on a lattice.Comment: 22 pages, 8 figures, Submitted to JCA