Search

El exceso de herbivoría causa graves problemas de erosión, desertificación y pérdida de biodiversidad. Los vallados han sido ampliamente utilizados para controlar este problema, aunque se ha comprobado que estos vallados tienen a medio plazo tanto efectos positivos, como efectos negativos e indeseados. Sin embargo, no existen trabajos que evalúen su eficacia a medio-largo plazo. En este trabajo hemos seleccionado 6 especies de flora amenazada (localizadas en las Sierras de Cazorla, Segura y las Villas y Sierra de Mágina) que presentan poblaciones valladas y sin vallar. En estas poblaciones se tomaron en campo datos de las especies amenazadas y de distintos parámetros del hábitat. De esta forma se comprobó que los vallados disminuían en general la presencia y actividad de ungulados, pero en algunas ocasiones los individuos de las poblaciones valladas producían un menor número de flores y frutos. Las zonas valladas experimentaron un aumento significativo en la cobertura, aumentando la competencia interespecífica para las especies amenazadas. No hubo cambios drásti- cos en el suelo, aunque sí un incremento en algunos parámetros indicadores de exceso de herbivoría en algunas poblaciones no valladas. La conclusión más clara de este trabajo es que el efecto de los vallados, positivo o negativo, no es uniforme, sino que varía entre especies y entre poblaciones de la misma especie. Narcissus, Atropa y Glandora se vieron beneficiadas, mientras que Aquilegia, Euonymus y Gera- nium no recibieron un beneficio claro. Se pone de manifiesto la necesidad de evaluar periódicamente la eficacia de los vallados, así como la necesidad de ensayar y evaluar métodos alternativos (vallados individuales, temporales,etc.).

Effective, unbiased, high-throughput methods to functionally identify both class II and class I HLA-presented T cell epitopes and their cognate T cell receptors (TCRs) are essential for and prerequisite to diagnostic and therapeutic applications, yet remain underdeveloped. Addressing this bottleneck, we established T-FINDER (T cell Functional Identification and (Neo)-antigen Discovery of Epitopes and Receptors), a platform that rapidly deconvolutes CD4 and CD8 TCR reactivities to targets physiologically processed and presented by an individual’s unmanipulated, complete HLA haplotype. By using a highly sensitive TCR signaling reporter capable of detecting even low-affinity TCR:ligand interactions, T-FINDER not only robustly identifies unknown peptide:HLA ligands from complex antigen libraries, but also rapidly screens and functionally validates the specificity of complex TCR libraries against known or predicted targets. To demonstrate its pan-HLA presentation capacity, we apply the platform to multiple TCR-based applications, including glioma, celiac disease, and rheumatoid arthritis, providing unique biological insights and showcasing T-FINDER’s potency and versatility.

The Special Collection of articles on the Science Projects of the EOSC Future project, funded by the European Commission, refers to one of the essential components of the project. This editorial article explains how the Science Projects fit to the EOSC Future, the way their concept has been developed and evolved during the preparation and the implementation of the project and it also makes an introduction to the templates developed by the Science Projects as a plan to carry out their activities.

Parasitic plants, among many other parasitic organisms, are shifting in their geographic distribution in response to global change, establishing novel interactions with susceptible but previously unexposed host plants. Projections of future species assemblages in increasingly changing environments frequently overlook the strong capacity of these parasites to transform ecological systems, and host switching is considered a mere change of partner with no subsequent impact on ecosystem properties. We explore the ecological consequences of parasite host shifts analysing the growth and reproductive responses of two host trees that share a different interaction‐history with the parasitic plant Viscum album: recent in the case of Pinus sylvestris subsp. nevadensis and longstanding in that of Pinus nigra. We quantified growth by measuring primary (bud elongation) and secondary (dendrochronology) tree growth, and reproduction by quantifying cone crops, cone size, seed production, seed weight, seed germination, and emergence success. Pinus nigra registered a minor effect on reproduction but a major reduction in biomass, clearly reflected in lower primary and secondary tree growth, smaller cones and lighter seeds. On the contrary, P. sylvestris subsp. nevadensis underwent a strong decline of its reproductive capacity with no effects on growth, manifested in smaller cone crops, less seed production, and lower germination and emergence success. Synthesis. Mistletoe parasitism unleashes contrasting responses in taxonomically close host species with sharply different consequences for the forest ecosystem. While old hosts tolerate better the effect of parasitism, minimizing the impact on reproduction at the expense of their growth, recent hosts undergo greater effects of parasitism, suffering reproductive collapse with no perceptible loss of growth. We conclude that the increasing phenomenon of parasite host switching is not just a mere change of partner, but a driver of a new ecosystem organization. These results highlight the importance of considering the specific effects of newly established interactions when predicting future species assemblages, as these can trigger different ecological organizations from those we currently know.

Providing fruit, nectar, leaves and litter, mistletoes represent important resources for many organisms, linking above‐ground patterns with below‐ground processes. Here, we explore how mistletoe litter affects arthropod availability, especially those taxa preferentially consumed by ground‐feeding insectivorous birds, a group that has undergone widespread declines. We estimated the influence of mistletoe on arthropod occurrence by sampling arthropod communities beneath infected and uninfected trees with pit‐fall traps. Then, we experimentally isolated direct effects of mistletoe litter on arthropods with a litterbag study. Soil arthropod communities beneath infected trees had consistently greater abundance and biomass – total arthropods and the subset of arthropods preferentially consumed by ground‐foraging insectivores – compared to otherwise comparable uninfected trees. Arthropods showed a weak response to litter addition, with maximum abundances recorded from bags with low mistletoe litter, significantly lower abundances associated with higher mistletoe fractions and pure tree litter (after 5 months). Our findings confirm that mistletoe occurrence has a significant positive impact on arthropod availability, especially on those preferred by ground‐foraging bird insectivores. However, only a minor part of this impact is due to the direct, short‐term effects of mistletoe litter, which suggests that additional mistletoe‐mediated effects (e.g. local changes in structural or microclimatic factors, cumulative effects over multiple years) play significant roles. By altering arthropod assemblages within leaf litter and increasing the heterogeneity of resource availability on forest floors, mistletoe plays an important role in improving habitat quality for declining insectivores.

Climate change will alter the biotic and abiotic environment and dissipate ecological barriers, reorganising maps of current distribution of parasites and their hosts. In this study, we analyse the population dynamics of the parasitic plant Viscum album subsp. austriacum and explore key biotic (host availability and seed dispersal) as well as abiotic (temperature) factors influencing elevational distribution. The study was conducted along an elevational gradient of a Mediterranean mountain, covering the distribution belts of three potential pine hosts: Pinus halepensis (1300-1500 m), P. nigra (1300-1900 m) and P. sylvestris var. nevadensis (1600-2000 m). Along this gradient, we measured multiple variables of mistletoe population (prevalence, abundance and demographic profile) and different factors that might define the current mistletoe distribution (host suitability and availability, temperature and seed dispersal services). We found a decline in mistletoe prevalence and abundance with increasing elevation, detecting larger values of both variables at lower elevations of the most suitable host (Pinus nigra). Pinus sylvestris var. nevadensis was a suboptimal but suitable host for the parasite at high elevations. Mistletoe found suitable temperatures and seed dispersal services all along the gradient, being able to recruit at any site. With warming temperatures, the presence of suitable vectors for parasite dispersion, and the presence of a sub-optimal host (P. sylvestris var. nevadensis) at the mountain top, mistletoe currently has a window of opportunity to expand its present geographic distribution to the summits.

Summary 1. The capacity of parasitic plants in structuring natural communities is increasingly recognized. These plants can affect the structure, composition and productivity of plant communities by modifying the competitive balance between hosts and non-host species and by altering the quantity and quality of resources entering the soil. Despite the progress made in this field, there is still a lack of integrative studies showing the structuring capacity of parasitic plants in forest ecosystems, where their effect may be less detectable due to the long lifespan of the system. 2. In this study we evaluate the long-term impact of Viscum album subsp. austriacum on the woody-plant community of a Mediterranean pineland. This mistletoe remains several years on the same host, exerting long-lasting, spatially concentrated effects on community and ecosystem characteristics. Mistletoe concentrates zoochorous seeds and induces changes in the soil fertility and light availability beneath the canopy of parasitized trees, which have the potential to facilitate zoochorous-plant colonization, recruitment, and growth at the same time as it weakens the host. Here, we analyse whether mistletoe-driven changes could result in a nucleus of zoochorous woody plants nourished by the abundant organic detritus accumulated under the host. We also analyse whether mistletoe effects can expand after host death. 3. We selected unparasitized, parasitized, and dead parasitized Pinus nigra trees, in which we studied the joint effect of mistletoe-mediated changes in soil nutrient and light availability, with the seed rain, seed predation, seedling establishment, plant recruitment, and plant growth. Light- and soil-nutrient resources were greater under parasitized trees, and intensified after host death. The seed rain was maximum under parasitized trees, where seedling recruitment proved more likely. Sapling density, richness, and growth increased with the development of parasitism. 4. Our findings show that Viscum album exerts a strong and lasting impact on the structure and dynamics of Mediterranean pinelands, with parasitized trees acting as centres for the establishment and growth of colonizing fleshy-fruited woody species, which, over the long term, promote vegetation shifts by limiting dominant pine trees and facilitating less represented fleshy-fruited shrubs. This article is protected by copyright. All rights reserved.

The ability of plants to tolerate freezing limits their geographical distribution. Therefore, winter warming may shift a species’ occurrence northwards and/or to higher altitudes. In Europe, the hemiparasitic vascular plant Viscum album (mistletoe) has two common and widespread subspecies: V. a. ssp. album and V. a. ssp. austriacum. The former has a more northern geographic distribution than the latter. Therefore we hypothesised that seeds of V. a. ssp. album are more tolerant to freezing than those of V. a. ssp. austriacum. From these two mistletoe subspecies V. a. ssp. austriacum is, in some managed forest areas, considered a novel threat to tree growth and forest health. Berries of V. a. ssp. album were collected from Sweden, Poland and Switzerland and berries of V. a. ssp. austriacum were collected from Poland, Switzerland and Spain. After storage at −3 °C, seeds were extracted from the pulp of berries and exposed to eight different temperatures between −8 °C and −30 °C, with the storage temperature serving as the control. After freezing treatments, germination of seeds was monitored. In addition, differential thermal analysis was used to measure freeze tolerance of seeds. The seeds of V. a. ssp. album tolerated lower temperatures than seeds of V. a. ssp. austriacum. The temperature at which 50% of seeds lost their ability to germinate (LT50) was −15 °C in V. a. ssp. austriacum and between −15 °C and −19 °C in V. a. ssp. album. The results of differential thermal analysis to determine the freezing point of seeds supported these findings. The freezing tolerance of mistletoe seeds was relatively well coupled with the winter climate at the edge of their current geographic distribution. Based on our results, the warming of winters may eliminate the abiotic barrier that has thus far limited mistletoes’ expansion, opening a window of opportunity for these parasites to increase their abundance and shift their distribution range towards higher latitudes and altitudes. Although mistletoes play important ecological roles in forest ecosystems, their recent increase has raised concern among forest managers, because they may cause a substantial reduction in tree growth in single species dominated stands. Increasing tree species diversity might be an effective method for limiting future mass infestations in homogeneous managed forests.

The city of Barcelona, ​​like other cities in the world, suffers strong internal socio-economic inequalities. Numerous works have sought to detect, quantify, characterize and / or map existing intra-urban differences, almost always based on quantitative methodologies. With this contribution, we intend to illuminate the complementary role that qualitative methodologies can play in studies on urban socio-environmental vulnerability. We consider aspects that are not quantifiable but that may be inherent to many such vulnerable spaces, both in the constructed environment and in the social ambit. These questions are considered through selected neighborhoods of Barcelona which have been shown (in prior works, mainly studies of quantitative manufacturing) to possess elements of vulnerability including a high presence of immigrants from less-developed countries, low per capita income, aging populations, or low educational levels. The results reveal the multidimensionality of vulnerability in the neighborhoods analyzed, as well as the essential complementarity among methodologies that detect and support possible public actions aimed at reducing or eliminating intra-urban inequalities.

Summary Biota plays a central role as sources of spatial heterogeneity, having great potential to define ecological processes and patterns in the landscape. Mistletoes are fleshy-fruited parasitic plants that dwell in forest canopies showing a strong aggregated spatial distribution. Parasitized trees potentially concentrate frugivore activity on their canopy, where birds find food, places to perch and protection against predators. Thus, seed-deposition patterns generated from the canopy are expected to reflect the heterogeneity associated with the parasite. This becomes especially important in generalist dispersal systems; however, so far, we do not know the implications of mistletoe spatial heterogeneity on the seed-dispersal pattern of other plants with which they simultaneously fruit. In a Mediterranean pineland, we analyse the impact of Viscum album subsp. austriacum on the seed-deposition pattern of a zoochorous plant community, taking into consideration the spatial and temporal variability of environmental factors influencing the frugivore's habitat use, such as fruit availability and forest tree density. For four consecutive years, we studied 55 pairs of trees parasitized and unparasitized by mistletoe, analysing zoochorous fruit availability, frugivore visits and the zoochorous seed rain in selected trees. As expected, frugivorous birds responded to mistletoe heterogeneity by visiting parasitized trees preferentially to unparasitized ones, generating a differential deposition of mistletoe seeds on tree branches while dispersing seeds of co-fruiting species under the host canopy. Availability of understory fruits remained similar in patches of parasitized and unparasitized trees, but showed strong temporal fluctuations reflected in the seed rain. On the other hand, mistletoe proved more copious in patches of parasitized trees and their fruit crops varied little between years, making mistletoes reliable food resources likely to lead to consistency in fruit-deposition patterns. In conclusion, mistletoes, by patchily growing on the canopy layer and concentrating zoochorous seeds underneath, can shape the spatial seed-deposition pattern of fleshy-fruited plants in the forest. Moreover, as seeds constantly reach the same deposition sites over long periods, the soil beneath the host canopy could become hotspots for community regeneration. In degraded areas, such mistletoe effects might be critical, possibly promoting recolonization and vegetation recovery through the frugivore's activity.

The aim of the present study is to analyze the electrochemical behavior of five different dental alloys: two cobalt-chromium alloys (CoCr and CoCr-c), one nickel-chromium-titanium alloy (NiCrTi), one gold-palladium alloy (Au), and one titanium alloy (Ti6Al4V), and the galvanic effect when they are coupled to titanium implants (TiG2). It was carried out by electrochemical techniques (open circuit measurements, potentiodynamic curves and Zero-Resistance Ammetry) in artificial saliva (AS), with and without fluorides in different acidic conditions. The studied alloys are spontaneously passivated, but NiCrTi alloy has a very narrow passive domain and losses its passivity in presence of fluorides, so is not considered as a good option for implant superstructures. Variations of pH from 6.5 to 3 in artificial saliva do not change the electrochemical behavior of Ti, Ti6Al4V, and CoCr alloys, and couples, but when the pH of the artificial saliva is below 3.5 and the fluoride content is 1000 ppm Ti and Ti6Al4V starts actively dissolving, and CoCr-c superstructures coupled to Ti show acceleration of corrosion due to galvanic effects. Thus, NiCrTi is not recommended for implant superstructures because of risk of Ni ion release to the body, and fluorides should be avoided in acidic media because Ti, Ti6Al4V, and CoCr-c superstructures show galvanic corrosion. The best combinations are Ti/Ti6Al4V and Ti/CoCr as alternative of noble gold alloys.

Parasitic plants rely on host plants for nutrition. The number of host species varies largely between groups, from single species or genus to hundreds of species. Relative abundance of the host and evolutionary history are the main requisites for parasitic plants to develop specificity to abundant hosts. In the present study, we suggest a novel mechanism by which a hemiparasitic mistletoe can develop local specificity mediated by its host. First, we describe a novel interaction in which a woodboring beetle (Hypothenemus obscurus) preys on mistletoe seeds (Psittacanthus plagiophyllus) attached to tree branches. This beetle preys more frequently on seeds deposited on branches of non-host species than on branches of its unique local host species (53 percent on average vs. 26 percent respectively). We hypothesize that local host specificity for this mistletoe could be partly mediated by beetle-host incompatibility, since the host offers a predation-free space in which mistletoes have better chances to grow. Furthermore, that the exceptional gum exudates produced by this unique host species minimize beetle attacks on branches, thus reducing predation of mistletoe seeds. This novel tritrophic interaction opens an avenue for research on macroscopic host-specificity mechanisms that occur at the level of the host bark and that have been poorly studied by plant ecologists. Resumo Plantas parasitas dependem de seus hospedeiros para se nutrirem. O numero de especies hospedeiras parasitadas pode variar enormemente entre os grupos, desde uma especie de hospedeiro ate centenas deles. A abundância relativa e a historia evolutiva sao os principais requisitos para que plantas parasitas desenvolvam especificidade pelos hospedeiros mais abundantes. Neste estudo nos sugerimos um novo mecanismo pelo qual uma especie de erva-de-passarinho pode desenvolver especificidade local mediada pelo seu hospedeiro. Primeiro, nos descrevemos uma interacao nova em que uma especie de besouro brocador (Hypothenemus obscurus) consome sementes da erva de passarinho Psittacanthus plagiophyllus fixadas aos galhos de arvores. Esta especie de besouro consome mais frequentemente sementes depositadas em galhos de especies de arvores nao hospedeiras do que em galhos do seu unico hospedeiro local (53% em media vs. 26%, respectivamente). Nos levantamos a hipotese de que essa especificidade local por ser parcialmente mediada pela incompatibilidade entre o besouro e o hospedeiro, visto que o hospedeiro oferece um espaco livre de predacao onde a erva-de-passarinho tem melhores chances de estabelecimento. Adicionalmente, propomos que a grande producao de goma pelo hospedeiro minimiza o ataque pelos besouros em seus galhos, reduzindo a predacao das sementes da erva-de-passarinho. Essa nova interacao tritrofica abre uma grande oportunidade para pesquisas sobre mecanismos macroscopicos de especificidade entre plantas parasitas e seus hospedeiros, que ocorrem no nivel da casca do hospedeiro, mas que tem sido pouco estudados pelos ecologos.

Etiological treatment of peri-implantitis aims to reduce the bacterial load within the peri-implant pocket and decontaminate the implant surface in order to promote osseointegration. The aim of this literature review was to evaluate the efficacy of different methods of implant surface decontamination. A search was conducted using the PubMed (Medline) database, which identified 36 articles including in vivo and in vitro studies, and reviews of different decontamination systems (chemical, mechanical, laser and photodynamic therapies). There is sufficient consensus that, for the treatment of peri-implant infections, the mechanical removal of biofilm from the implant surface should be supplemented by chemical decontamination with surgical access. However, more long-term research is needed to confirm this and to establish treatment protocols responding to different implant characterics. Key words:Peri-implantitis, treatment, decontamination, implant surface, laser.

Parasitic plants are important drivers of community and ecosystem properties. In this study, we identify different mechanisms by which mistletoe (Viscum album subsp. austriacum) can affect soil chemical and biological properties at different temporal stages of parasitism. We quantified the effect of parasitism on host growth and the number of frugivorous mutualists visiting the host canopy. Then we collected, identified, and weighed the organic matter input underneath tree canopies and analyzed its nutrient content. Simultaneously, we analyzed soil samples under tree canopies and examined the chemical properties, microbial abundance, and functional evenness of heterotrophic microbial communities. Mistletoe increased the amount, quality, and diversity of organic matter input beneath the host canopy, directly through its nutrient-rich litter and indirectly through a reduction in host litterfall and an increase in bird-derived debris. All these effects gave rise to enriched hotspots able to support larger and more functionally even soil microbial communities beneath parasitized hosts, the effects of which were accentuated after host death. We conclude that mistletoe, together with the biotic interactions it mediates, plays a key role in intensifying soil resource availability, regulating the functional evenness, abundance, and spatial distribution of soil microbial communities.

Cardiovascular disease is the leading cause of death worldwide, but its spatial distribution is not homogeneous. The objective of this study is to analyze the spatial pattern of mortality from these diseases for men and women, in the populated urban area (AUP) of the municipality of Madrid, and to identify spatial aggregations.An ecological study was carried out by census tract, for men and women in 2010. Standardized Mortality Ratio (SMR), Relative Risk Smoothing (RRS) and Posterior Probability (PP) were calculated to consider the spatial pattern of the disease. To identify spatial clusters the Moran index (Moran I) and the Local Index of Spatial Autocorrelation (LISA) were used. The results were mapped.SMR higher than 1.1 was observed mainly in central areas among men and in peripheral areas among women. The PP that RRS was higher than 1 surpassed 0.8 in the center and in the periphery, in both men and women. Moran's I was 0.04 for men and 0.03 for women (p0.05 in both cases).Sex differences were observed in the spatial distribution of mortality cases. RME RRS and PP maps showed a heterogeneous pattern in men, whereas in women a clearer pattern was detected, with a relatively higher risk in peripheral areas of the AUP. The LISA method showed similar patterns to those previously observed.

Fundamentos: Las enfermedades cardiovasculares son la principal causa de muerte en el mundo, aunque su distribución espacial no es homogénea. El objetivo del estudio fue analizar el patrón espacial de la mortalidad por enfermedades cardiovasculares en el área urbana poblada (AUP) del municipio de Madrid así como identificar agregaciones espaciales. Métodos: Se realizó un estudio ecológico, por sección censal, para hombres y mujeres durante 2010. Se calculó la Razón de Mortalidad Estandarizada (RME), Riesgo Relativo Suavizado (RRS) y Probabilidad Posterior (PP) de que el RRS fuera mayor que 1. Para identificar clusters espaciales se utilizó el índice de Moran (I Moran) y el Índice Local de Autocorrelación Espacial (LISA). Los resultados fueron representados cartográficamente. Resultados: En el caso de los hombres se observó una RME mayor de 1,1 especialmente en áreas centrales y en en el grupo de las mujeres ocurrió en la periferia. LA PP de que el RRS fuera mayor que 1 superó el 0,8 en el centro para los hombres y en la periferia en mujeres. El I Moran fue de 0,04 para hombres y de 0,03 para mujeres (p, Background: Cardiovascular disease is the leading cause of death worldwide, but its spatial distribution is not homogeneous. The objective of this study is to analyze the spatial pattern of mortality from these diseases for men and women, in the populated urban area (AUP) of the municipality of Madrid, and to identify spatial aggregations. Methods: An ecological study was carried out by census tract, for men and women in 2010. Standardized Mortality Ratio (SMR), Relative Risk Smoothing (RRS) and Posterior Probability (PP) were calculated to consider the spatial pattern of the disease. To identify spatial clusters the Moran index (Moran I) and the Local Index of Spatial Autocorrelation (LISA) were used. The results were mapped. Results: SMR higher than 1.1 was observed mainly in central areas among men and in peripheral areas among women. The PP that RRS was higher than 1 surpassed 0.8 in the center and in the periphery, in both men and women. Moran’s I was 0.04 for men and 0.03 for women (p

Mistletoes constitute instructive study cases with which to address the role of generalist consumers in the study of plant–animal interactions. Their ranges of safe sites for recruitment are among the most restricted of any plant; therefore, frugivores specializing in mistletoe have been considered almost indispensable for the seed dispersal of these parasitic plants. However, the absence of such specialists in numerous regions inhabited by many mistletoe species raises the question of whether unspecialized vectors may successfully disperse mistletoe seeds to narrowly defined safe sites. Using the European mistletoe Viscum album subsp. austriacum as a study case, we recorded a broad range of 11 bird species that disperse mistletoe seeds. For these species, we studied the mistletoe-visitation rate and feeding behavior to estimate the quantity component of dispersal effectiveness, and the post-foraging microhabitat use, seed handling, and recruitment probabilities of different microhabitats as a measure of the quality component of effectiveness. Both endozoochory and ectozoochory are valid dispersal mechanisms, as the seeds do not need to be ingested to germinate, increasing seed-dispersal versatility. Thrushes were the most effective dispersers, although they were rather inefficient, whereas small birds (both frugivores and non-frugivores) offered low-quantity but high-quality services for depositing seeds directly upon safe sites. As birds behave similarly on parasitized and non-parasitized hosts, and vectors have broad home ranges, reinfection within patches and the colonization of new patches are ensured by an ample assemblage of generalist birds. Thus, a parasitic plant requiring precision in seed dispersal can rely on unspecialized dispersers.

Osteoporosis is very common, particularly in post-menopausal women and is characterized by a decrease in bone mass and strength. Osteoporosis also affects the jawbone and it is considered a potential contraindication to placement of dental implants. The present paper reviews the literature regarding the effect of osteoporosis on osseointegration of implants. Experimental models have shown that osteoporosis affects the process of osseointegration, which can be reversed by treatment. However, studies in subjects with osteoporosis have shown no differences in survival of the implants compared to healthy individuals. Therefore, osteoporosis cannot be considered a contraindication for implant placement. Oral bisphosphonates are the most commonly used pharmacological agents in the treatment of osteoporosis. Although there have been cases of osteonecrosis of the jaw in patients treated with bisphosphonates, they are very rare and it is more usually associated with intravenous bisphosphonates in patients with neoplasms or other serious diseases. Nevertheless, patients treated with bisphosphonates must be informed in writing about the possibility of this complication and must give informed consent. Ceasing to use bisphosphonates before implant placement does not seem to be necessary.

The increased prevalence of diabetes mellitus has become a public health problem. Hyperglycaemia entails a rise in the morbidity and mortality of these patients. Although a direct relationship with periodontal disease has already been shown, little is known about the results of dental implants in diabetics. The present paper reviews the bibliography linking the effect of diabetes on the osseointegration of implants and the healing of soft tissue. In experimental models of diabetes, a reduced level of bone-implant contact has been shown, and this can be reversed by means of treatment with insulin. Compared with the general population, a higher failure rate is seen in diabetic patients. Most of these occur during the first year of functional loading, seemingly pointing to the microvascular complications of this condition as a possible causal factor. These complications also compromise the healing of soft tissues. It is necessary to take certain special considerations into account for the placement of implants in diabetic patient. A good control of plasma glycaemia, together with other measures, has been shown to improve the percentages of implant survival in these patients.