Aesthetic dentistry : chromatic appreciation in the clinic and the laboratory

Aesthetic requirement in dentistry is getting more and more important every day. One of its basic principles is the correct selection of colour for the restorations. Colour is a quality which is modulated by a series of factors, environmental and individual, that the clinic must know. Colour measurement by the human eye can induce to an appreciation mistake if it doesn?t follow a correct protocol of light conditions and observation technique, checked by the authors, simplifying it with a practical focusing. Colour measurement instruments have appeared recently, trying to correct the problems of conventional technique

Iturriaga'ren ipuiak

En port: "Euskaltzaleak" argitalduaDialecto : texto en euskera central -- guipuzcoanoS. XX -- Periodo : último euskera modernoEuskalkia : erdialdekoa -- gipuzkeraXX. md. -- Aroa : azken euskara modernoaDigitalización. Vitoria-Gasteiz : Fundación Sancho el Sabio, 2008Rústic

Modeling production functions and economic weights in intensive meat production of guinea pigs

[EN] A profit function for a typical commercial farm of intensive guinea pig production was designed. The simulated farm contained 86 cages with a ratio of 7:1 females/males, with continuous mating. Kits were weaned at 15 days of age and slaughtered for meat production at 90 days of age. The absolute (EW) and relative economic weights of the main traits were calculated. The highest EW were kits produced per kindling (US$25), kits weaned per kindling (US$22), kits born alive per kindling (US$20), and the number of kindlings per female and year (US$12). Profit, returns, and costs per female and year were US$15, 68, and 53, respectively. Returns came from the production of young guinea pigs and discarded reproductive adults for meat production, 90 and 10% of the total returns. The highest costs were feeding and labor, 44 and 23% of the total cost. The EW and profit did not substantially change when simulating variations of ±20% in the prices of kilograms of fattening feed and kilograms of live weight of guinea pig, showing their robustness to future variations in market prices or to variations in prices between countries. The results obtained highlight the importance of the feeding costs in the guinea pig meat production.Pascual, M.; Cruz, DJ.; Blasco Mateu, A. (2017). Modeling production functions and economic weights in intensive meat production of guinea pigs. Tropical Animal Health and Production. 49(7):1361-1367. doi:10.1007/s11250-017-1334-4S13611367497Cartuche, L., Pascual, M., Gómez, E. and Blasco, A., 2014. Economic weights in rabbit meat production, World Rabbit Science, 22, 165–177.Chancay, 2015. Venta de cuyes. http://www.ventadecuyes.com . Accessed 20 Jun 2016.Chirinos, O., Muro, K., Álvaro, W., Otiniano, J., Quezada, J. C. and Ríos V., 2008. Crianza y comercialización del cuy para el mercado limeño, (Esan University, Lima, Peru).Chupin, D., 1995. Rearing unconventional livestock species: a flourishing activity, (Food and Agriculture Organization of the United Nations, Rome, Italy).Espinoza, J., Furushio, E. and Rodríguez, A., 2008. Propuesta de un plan de negocio para una empresa dedicada a la crianza tecnificada de cuyes ubicada en Ñaña y su comercialización al mercado local, (MSc thesis, Peruvian University of Applied Science, Lima, Peru).Humberto-Rodriguez, L., Mabel Palomino, T., Victor Hidalgo, L. and Gustavo Gutiérrez R., 2013. Efectos de factores fijos y al azar sobre el peso al nacimiento y al destete en cuyes de la costa central del Perú. Revista de Investigaciones Veterinarias del Peru, 24, 16–24.Instituto de Investigación Agraria, 1991. Proyecto sistemas de producción de cuyes. https://idl-bnc.idrc.ca/dspace/bitstream/10625/35272/4/104403_v2.pdf . Accessed 02 Sep 2016.Jimenez, A., 2005. Determinación de parámetros productivos y reproductivos de cuyes mejorados con sistemas de crianza en jaula y en poza, (BSc Thesis, Polytechnic School of Chimborazo, Roibamba, Ecuador).Ministerio de Agricultura, Ganadería, Acuacultura y Pesca de Ecuador, 2014. Manual de crianza y producción de cuyes con estándares de calidad. http://www.agricultura.gob.ec/wp-content/uploads/downloads/2015/11/Manual-para-la-crianza-del-cuy.pdf . Accessed 17 Jun 2016.Universidad Nacional Agraria la Molina, 2015. Programa de investigación y proyección social en alimentos. http://www.lamolina.edu.pe/cproducciόn/plantaalimentos/ . Accessed 27 Jan 2015

Relationship between resolution and accuracy of four intraoral scanners in complete-arch impressions

The scanner does not measure the dental surface continually. Instead, it generates a point cloud, and these points are then joined to form the scanned object. This approximation will depend on the number of points generated (resolution), which can lead to low accuracy (trueness and precision) when fewer points are obtained. The purpose of this study is to determine the resolution of four intraoral digital imaging systems and to demonstrate the relationship between accuracy and resolution of the intraoral scanner in impressions of a complete dental arch. A master cast of the complete maxillary arch was prepared with different dental preparations. Using four digital impression systems, the cast was scanned inside of a black methacrylate box, obtaining a total of 40 digital impressions from each scanner. The resolution was obtained by dividing the number of points of each digital impression by the total surface area of the cast. Accuracy was evaluated using a three-dimensional measurement software, using the ?best alignment? method of the casts with a highly faithful reference model obtained from an industrial scanner. Pearson correlation was used for statistical analysis of the data. Of the intraoral scanners, Omnicam is the system with the best resolution, with 79.82 points per mm2, followed by True Definition with 54.68 points per mm2, Trios with 41.21 points per mm2, and iTero with 34.20 points per mm2. However, the study found no relationship between resolution and accuracy of the study digital impression systems (P >0.05), except for Omnicam and its precision. The resolution of the digital impression systems has no relationship with the accuracy they achieve in the impression of a complete dental arch. The study found that the Omnicam scanner is the system that obtains the best resolution, and that as the resolution increases, its precision increases

In vivo evaluation of three-dimensional of volumetric changes using a CAD/CAM chair-side system : technical procedure

An intraoral digital scanner in combination with specialized three-dimensional surface analysis software monitors volumetric changes to soft tissues or dental restorations. This technology can evaluate the success of a specific technique or medium- or long-term clinical outcomes in both clinical and research situations. This article describes how this technology was used to provide immediate chair-side data analysis without the help of specialized laboratory support

Comparative characterization of a novel cad-cam polymer-infiltrated-ceramic-network.

Background: The field of dental ceramics for CAD-CAM is enriched with a new innovative material composition having a porous three-dimensional structure of feldspathic ceramic infiltrated with acrylic resins.The aim of this study is to determine the mechanical properties of Polymer-Infiltrated-Ceramic-Network (PICN) and compare its performance with other ceramics and a nano-ceramic resin available for CAD-CAM systems. Material and Methods: In this study a total of five different materials for CAD-CAM were investigated. A polymer- infiltrated ceramic (Vita Enamic), a nano-ceramic resin (Lava Ultimate), a feldspathic ceramic (Mark II), a lithium disilicate ceramic (IPS-e max CAD) and finally a Leucite based ceramic (Empress - CAD). From CAD-CAM blocks, 120 bars (30 for each material cited above) were cut to measure the flexural strength with a three-point- bending test. Strain at failure, fracture stress and Weibull modulus was calculated. Vickers hardness of each material was also measured. Results: IPS-EMAX presents mechanical properties significantly better from the other materials studied. Its strain at failure, flexural strength and hardness exhibited significantly higher values in comparison with the others. VITA ENAMIC and LAVA ULTIMATE stand out as the next most resistant materials. Conclusions: The flexural strength, elastic modulus similar to a tooth as well as having less hardness than ceramics make PICN materials an option to consider as a restorative materia

Effect of retention design of artificial teeth and implant-supported titanium CAD-CAM structures on fracture resistance

Background: For implant-supported hybrid prostheses, high mastication forces and reduced acrylic resin thickness over a metal substructure often cause failures arising from tooth or resin fractures. To assay fracture resistance of artificial teeth and resin in implant-supported hybrid prostheses in relation to the titanium structure and retention design supporting teeth. Material and Methods: 40 specimens bearing incisors were divided into four groups according to the titanium structure supporting the teeth and the type of load force applied: Group I (Control; n=10): Application of static loading to ten incisors set over a metal structure with internal retention. Group II (Control; n=10): Application of static loading to ten incisors set over a metal structure with external retention. The remaining study specimens (n=20) were subjected to 120,000 masticatory and thermal cycles in a chewing simulator. Afterwards, static loading was applied until the point of fracture using an Instron machine. Group III (Study; n=10): Application of dynamic and static loading to ten incisors set over a metal structure with internal retention. Group IV (Study; n=10): Application of dynamic and static loading to ten incisors set over a metal structure with external retention. Data obtained for the four groups was analyzed and compared, determining the type of fracture (cohesive or adhesive) using a reflected light microscope. Results: Statistical analysis confirmed that there were significant differences in fracture resistance between the four groups. External retention was found to have more fracture resistance than the internal retention. Conclusions: Hybrid prostheses with titanium substructures and external retention obtained significantly better results than samples with internal retention

Effects of the right carotid sinus compression technique on blood pressure and heart rate in medicated patients with hypertension

Objectives: To identify the immediate and middle-term effects of the right carotid sinus compression technique on blood pressure and heart rate in hypertensive patients. Design: Randomized blinded experimental study. Settings: Primary health centers of Cáceres (Spain). Subjects: Sixty-four medicated patients with hypertension were randomly assigned to an intervention group (n = 33) or to a control group (n = 31). Intervention: In the intervention group a compression of the right carotid sinus was applied for 20 sec. In the control group, a placebo technique of placing hands on the radial styloid processes was performed. Outcome measures: Blood pressure and heart rate were measured in both groups before the intervention (preintervention), immediately after the intervention, 5 min after the intervention, and 60 min after the intervention. Results: The intervention group significantly decreased systolic and diastolic blood pressure and heart rate immediately after the intervention, with a large clinical effect; systolic blood pressure remained reduced 5 min after the intervention, and heart rate remained reduced 60 min after the intervention. No significant changes were observed in the control group. Conclusions: Right carotid sinus compression could be clinically useful for regulating acute hypertension

Moduli spaces and formal operads

Let Mg,l be the moduli space of stable algebraic curves of genus g with l marked points. With the operations which relate the different moduli spaces identifying marked points, the family (Mg,l)g,l is a modular operad of projective smooth Deligne-Mumford stacks, M. In this paper we prove that the modular operad of singular chains C?(M;Q) is formal; so it is weakly equivalent to the modular operad of its homology H?(M;Q). As a consequence, the “up to homotopy” algebras of these two operads are the same. To obtain this result we prove a formality theorem for operads analogous to Deligne-Grifiths-Morgan-Sullivan formality theorem, the existence of minimal models of modular operads, and a characterization of formality for operads which shows that formality is independent of the ground field