Thickness of the buccal bone wall and root angulation in the maxilla and mandible: an approach to cone beam computed tomography

Background: The objective of this paper is to anatomically describe the bone morphology in the maxillary and mandibular tooth areas, which might help in planning post-extraction implants. Methods: CBCT images (Planmeca ProMax 3D) of 403 teeth (208 upper teeth and 195 lower teeth) were obtained from 49 patients referred to the Dental School of Seville from January to December 2014. The thickness of the facial wall was measured at the crest, point A, 4mm below, point B, and at the apex, point C. The second parameter was the angle formed between the dental axis and the axis of the basal bone. Results: A total of 403 teeth were measured. In the maxilla, 89.4% of incisors, 93.94% of canines, 78% of premolars and 70.5% of molars had a buccal bone wall thickness less than the ideal 2mm. In the mandible, 73.5% of incisors, 49% of canines, 64% of premolars and 53% of molars had <1mm buccal bone thickness as measured at point B. The mean angulation in the maxilla was 11.67±6.37° for incisors, 16.88±7.93° for canines, 13.93±8.6° for premolars, and 9.89±4.8° for molars. In the mandible, the mean values were 10.63±8.76° for incisors, 10.98±7.36° for canines, 10.54±5.82° for premolars and 16.19±11.22° for molars. Conclusions: The high incidence of a buccal wall thickness of less than 2mm in over 80% of the assessed sites indicates the need for additional regeneration procedures, and several locations may also require custom abutments to solve the angulation problems for screw-retained crowns

Análisis de la superficie de cultivo para la producción de bioplásticos

El presente trabajo establece el potencial de mercado de los Bioplásticos (BPL), en tres escenarios: Escenario CB (crecimiento bajo), Escenario CM (crecimiento medio) y Escenario CR (crecimiento rápido). El objetivo final es Obtener las superficies de cultivo necesarias para satisfacer la demanda de las empresas productoras de BPL, según los tres escenarios. Las regiones geográficas estudiadas son: La Unión Europea (UE-27), Estados Unidos (EE.UU) y la región de Asia-Pacífico, entendiéndose, que esta última región comprende la parte del Centro, Este y Sur de Asia, además de Australia y Nueva Zelanda. Son las principales zonas donde se encuentran las empresas productoras de los BPL estudiados. Más del 95% de los BPL son elaborados en estas regiones. Se han realizado tres proyecciones para los años 2010, 2015 y 2020

Identification of Degraded Land in the Canary Islands; Tests and Reviews

Degraded Land is an area that either by natural causes (fires, floods, storms or volcanic eruptions) or more by direct or indirect causes of human action, has been altered or modified from its natural state. Restoration is an activity that initiates or accelerates the recovery of an ecosystem. It can be defined as the set of actions taken in order to reverse or reduce the damage caused in the territory. In the case of the Canary Islands there is a high possibility for the territory to suffer processes that degrade the environment, given that the islands are very fragile ecosystems. Added to this they are territories isolated from the continent, which complicates the process of restoring them. In this paper, the different types of common degraded areas in the Canary Islands are identified, as well as the proposed solutions for remediation, such as afforestation of agricultural land or landfill closure and restoration

Analysis and Potential of Use of Biomass Energy in Canary Islands, Spain

Biomass has always been associated with the development of the population in the Canary Islands as the first source of elemental energy that was in the archipelago and the main cause of deforestation of forests, which over the years has been replaced by forest fossil fuels. The Canary Islands store a large amount of energy in the form of biomass. This may be important on a small scale for the design of small power plants with similar fuels from agricultural activities, and these plants could supply rural areas that could have self-sufficiency energy. The problem with the Canary Islands for a boost in this achievement is to ensure the supply to the consumer centers or power plants for greater efficiency that must operate continuously, allowing them to have a resource with regularity, quality and at an acceptable cost. In the Canary Islands converge also a unique topography with a very rugged terrain that makes it greater difficult to use and significantly more expensive. In this work all these aspects are studied, giving conclusions, action paths and theoretical potentials

Effects of different undersizing site preparations on implant stability

As immediate loading protocols are becoming more frequent, the primary stability of implants has become an essential criterion for the osseointegration of dental implants. Based on this, the objective of this study was to understand the influence of different undersized surgical preparation sites on the insertion torque (IT) and implant stability quotient (ISQ). Four different site-preparation protocols were performed on fresh humid type III bovine bone: one control, the standard protocol recommended by the manufacturer (P1), and three variations of undersized techniques (P2, P3 and P4). The implant used was VEGA by Klockner Implant System. The sample size was n = 40 for each of the four groups. A torquemeter was used to measure the IT, and the ISQ was measured with a Penguin RFA. Both variables showed a tendency to increase as the preparation technique was reduced, although not all the values were statistically significant (p < 0.05) when comparing with the standard preparation. The preparations without a cortical drill, P2 and P4, showed better results than those with a cortical drill. Given the limitations of this study, it can be concluded that reducing the implant preparation can increase both the IT and ISQ. Removing the cortical drill is an effective method for increasing implant stability, although it should be used carefully

Main Cause of the Poloidal Plasma Motion Inside a Magnetic Cloud Inferred from Multiple-Spacecraft Observations

Although the dynamical evolution of magnetic clouds (MCs) has been one of the foci of interplanetary physics for decades, only few studies focus on the internal properties of large-scale MCs. Recent work by Wang et al. (J. Geophys. Res.120, 1543, 2015) suggested the existence of the poloidal plasma motion in MCs. However, the main cause of this motion is not clear. In order to find it, we identify and reconstruct the MC observed by the Solar Terrestrial Relations Observatory (STEREO)-A, Wind, and STEREO-B spacecraft during 19 – 20 November 2007 with the aid of the velocity-modified cylindrical force-free flux-rope model. We analyze the plasma velocity in the plane perpendicular to the MC axis. It is found that there was evident poloidal motion at Wind and STEREO-B, but this was not clear at STEREO-A, which suggests a local cause rather than a global cause for the poloidal plasma motion inside the MC. The rotational directions of the solar wind and MC plasma at the two sides of the MC boundary are found to be consistent, and the values of the rotational speeds of the solar wind and MC plasma at the three spacecraft show a rough correlation. All of these results illustrate that the interaction with ambient solar wind through viscosity might be one of the local causes of the poloidal motion. Additionally, we propose another possible local cause: the existence of a pressure gradient in the MC. The significant difference in the total pressure at the three spacecraft suggests that this speculation is perhaps correct

Forward pi^0 Production and Associated Transverse Energy Flow in Deep-Inelastic Scattering at HERA

Deep-inelastic positron-proton interactions at low values of Bjorken-x down to x \approx 4.10^-5 which give rise to high transverse momentum pi^0 mesons are studied with the H1 experiment at HERA. The inclusive cross section for pi^0 mesons produced at small angles with respect to the proton remnant (the forward region) is presented as a function of the transverse momentum and energy of the pi^0 and of the four-momentum transfer Q^2 and Bjorken-x. Measurements are also presented of the transverse energy flow in events containing a forward pi^0 meson. Hadronic final state calculations based on QCD models implementing different parton evolution schemes are confronted with the data.Comment: 27 pages, 8 figures and 3 table

Search for Doubly-Charged Higgs Boson Production at HERA

A search for the single production of doubly-charged Higgs bosons H^{\pm \pm} in ep collisions is presented. The signal is searched for via the Higgs decays into a high mass pair of same charge leptons, one of them being an electron. The analysis uses up to 118 pb^{-1} of ep data collected by the H1 experiment at HERA. No evidence for doubly-charged Higgs production is observed and mass dependent upper limits are derived on the Yukawa couplings h_{el} of the Higgs boson to an electron-lepton pair. Assuming that the doubly-charged Higgs only decays into an electron and a muon via a coupling of electromagnetic strength h_{e \mu} = \sqrt{4 \pi \alpha_{em}} = 0.3, a lower limit of 141 GeV on the H^{\pm\pm} mass is obtained at the 95% confidence level. For a doubly-charged Higgs decaying only into an electron and a tau and a coupling h_{e\tau} = 0.3, masses below 112 GeV are ruled out.Comment: 15 pages, 3 figures, 1 tabl

Low Q^2 Jet Production at HERA and Virtual Photon Structure

The transition between photoproduction and deep-inelastic scattering is investigated in jet production at the HERA ep collider, using data collected by the H1 experiment. Measurements of the differential inclusive jet cross-sections dsigep/dEt* and dsigmep/deta*, where Et* and eta* are the transverse energy and the pseudorapidity of the jets in the virtual photon-proton centre of mass frame, are presented for 0 < Q2 < 49 GeV2 and 0.3 < y < 0.6. The interpretation of the results in terms of the structure of the virtual photon is discussed. The data are best described by QCD calculations which include a partonic structure of the virtual photon that evolves with Q2.Comment: 20 pages, 5 Figure