The aim of the present study was to evaluate bone loss at implants connected to abutments coated with a soda-lime glass containing silver nanoparticles, subjected to experimental peri-implantitis. Also the aging and erosion of the coating in mouth was studied. Five beagle dogs were used in the experiments. Three implants were placed in each mandible quadrant: in 2 of them, Glass/n-Ag coated abutments were connected to implant platform, 1 was covered with a Ti-mechanized abutment. Experimental peri-implantitis was induced in all implants after the submarginal placement of cotton ligatures, and three months after animals were euthanatized. Thickness and morphology of coating was studied in abutment cross-sections by SEM. Histology and histo-morphometric studies were carried on in undecalfied ground slides. After the induced peri-implantitis: 1.The abutment coating shown losing of thickness and cracking. 2. The histometry showed a significant less bone loss in the implants with glass/n-Ag coated abutments. A more symmetric cone of bone resorption was observed in the coated group. There were no significant differences in the peri-implantitis histological characteristics between both groups of implants. Within the limits of this in-vivo study, it could be affirmed that abutments coated with biocide soda-lime-glass-silver nanoparticles can reduce bone loss in experimental peri-implantitis. This achievement makes this coating a suggestive material to control peri-implantitis development and progression.
Both materials favour the closure of the defects provoked. In both cases, a synergistic effect with the collagen membrane is observed. DBB remains integrated in the bone matrix, while BTCP displays a pattern of highly developed progressive resorption with an outstanding bone fraction development.
The present study compares the behaviour of an anorganic bone matrix material and a synthetic β-Tricalcium phosphate employed as grafting materials in a sinus floor augmentation two step protocol in humans. In order to estimate the initial occupation level for the two materials, an ‘in vitro’ simulation has been performed to analyse macroporosity created due to particle packing in terms of porosity and interparticle distances. Grafting in the sinus floor augmentation was performed by filling the defects only with pure grafting materials without autogenous bone addition. The new-bone generated is 100% based on the osteoconductive properties of the grafted materials in contact with physiological fluids. The implants were placed 8 months after the grafting procedure. All the implanted positions were biopsied and embedded in methacrylate resin. Histomorphometric analyses were done over thin film undecalcified sections. Packing simulations allow establishing a comparison of the resorbed volumes related to the initial occupancy of the grafting materials inside the defect. The nature of this interconnected pore network is very alike for either material so new-bone generated was similar (~35 vol.%).
Mergers have become the most widely accepted formula for business growth among many different sectors. However, these processes do not always contribute to obtaining the expected results, particularly from an economic viewpoint. In light of these reflections, this study attempts to establish whether mergers carried out between Spanish agrifood cooperatives during the period 1995-2005 have contributed to reaching some of the objectives they were set out to achieve: improving the economic-financial situation of the companies involved, increasing income and reducing costs. To do so, mergers that took place during this period were analyzed in four autonomous communities (Andalusia, Navarra, La Rioja and the Basque Country). Despite the considerable variability observed following the time-based analysis of the economic-financial situation of cooperatives prior to and after merger, statistically significant differences were only found in four of the fifteen variables studied. These were operating profit (a 99% reduction), financial income (an increase of 240%), extraordinary income (400% increase) and cost of goods sold (16% reduction), of all of which are calculated with respect to production value. The results obtained generally indicate that the objectives that were originally the motivation for initiating the merger processes have not been reached, as the financial situation of the cooperatives has not, by and large, undergone any significant improvement, nor have average unit costs been reduced. Performance and profitability have not improved either and the firms involved have found themselves at lower levels than the average for the sector.Additional key words: costs, integration, synergies.
ResumenLos procesos de fusión de cooperativas agroalimentarias y sus efectos: de las expectativas a los resultados.
Un estudio empírico en cuatro comunidades autónomas españolasLa fusión se ha consolidado como la fórmula de crecimiento empresarial más extendida entre los diferentes sectores empresariales. Sin embargo, no siempre estos procesos contribuyen a los resultados esperados, especialmente en el plano económico. Ante estas cuestiones este trabajo pretende establecer si las fusiones llevadas a cabo entre cooperativas agroalimentarias españolas en el período 1995-2005 han contribuido a lograr algunos de los objetivos con los que se postularon: mejorar la situación económico-financiera de las sociedades implicadas, incrementar sus ingresos y reducir sus costes. Para ello, se han analizado las operaciones de fusión realizadas en el periodo indicado en cuatro comunidades autónomas (Andalucía, Navarra, La Rioja y El País Vasco). A pesar de la considerable variabilidad observada tras el análisis temporal de la situación económico-financiera pre/post fusión de las cooperativas, úni-camente se han obtenido diferencias estadísticamente significativas en cuatro de las quince variables estudiadas, siendo éstas el resultado de explotación (disminución del 99%,), resultado financiero (aumento del 240%), resultado extraordin...
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