Logistic Regression Analysis of the Factors Involved in the Failure of Osseointegration and Survival of Dental Implants with an Internal Connection and Machined Collar: A 6-Year Retrospective Cohort Study.

BACKGROUND: Although the long-term success rate of dental implants is currently close to 95%, it is necessary to provide more evidence on the factors related to the failure of osseointegration and survival. PURPOSE: To establish the risk factors associated with the failure of osseointegration and survival of dental implants with an internal connection and machined collar and to establish a predictive statistical model. MATERIALS AND METHODS: An analytical, retrospective, and observational clinical study of a sample of 297 implants with a follow-up of up to 76 months. Independent variables related to the implant, patient, and surgical and rehabilitative procedures were identified. The dependent variables were failure of osseointegration and failure of implant survival after prosthetic loading. A survival analysis was carried out by applying the Kaplan-Meier model (significance for p < 0.05). The log-rank test and the Cox regression analysis were applied to the factors that presented differences. Finally, the regression logit function was used to determine whether it is possible to predict the risk of implant failure according to the analyzed variables with the data obtained in this study. RESULTS: The percentages of osseointegration and survival were 97.6 and 97.2%, respectively. For osseointegration, there were significant differences according to gender (p = 0.048), and the risk of nonosseointegration was 85% lower in women. Regarding survival, the Cox analysis converged on only two factors, which were smoking and treatment with anticoagulant drugs. The risk of loss was multiplied by 18.3 for patients smoking more than 10 cigarettes per day and by 28.2 for patients treated with anticoagulants. CONCLUSIONS: The indicated risk factors should be considered, but the analysis of the results is not sufficient to create a predictive model.

Candida parapsilosis Colony Morphotype Forecasts Biofilm Formation of Clinical Isolates.

Candida parapsilosis is a frequent cause of fungal bloodstream infections, especially in critically ill neonates or immunocompromised patients. Due to the formation of biofilms, the use of indwelling catheters and other medical devices increases the risk of infection and complicates treatment, as cells embedded in biofilms display reduced drug susceptibility. Therefore, biofilm formation may be a significant clinical parameter, guiding downstream therapeutic choices. Here, we phenotypically characterized 120 selected isolates out of a prospective collection of 215 clinical C. parapsilosis isolates, determining biofilm formation, major emerging colony morphotype, and antifungal drug susceptibility of the isolates and their biofilms. In our isolate set, increased biofilm formation capacity was independent of body site of isolation and not predictable using standard or modified European Committee on Antimicrobial Susceptibility Testing (EUCAST) drug susceptibility testing protocols. In contrast, biofilm formation was strongly correlated with the appearance of non-smooth colony morphotypes and invasiveness into agar plates. Our data suggest that the observation of non-smooth colony morphotypes in cultures of C. parapsilosis may help as an indicator to consider the initiation of anti-biofilm-active therapy, such as the switch from azole- to echinocandin- or polyene-based strategies, especially in case of infections by potent biofilm-forming strains.

Caenorhabditis elegans as a Model System To Assess Candida glabrata, Candida nivariensis, and Candida bracarensis Virulence and Antifungal Efficacy.

Although Candida albicans remains the major etiological agent of invasive candidiasis, Candida glabrata and other emerging species of Candida are increasingly isolated. This species is the second most prevalent cause of candidiasis in many regions of the world. However, clinical isolates of Candida nivariensis and Candida bracarensis can be misidentified and are underdiagnosed due to phenotypic traits shared with C. glabrata Little is known about the two cryptic species. Therefore, pathogenesis studies are needed to understand their virulence traits and their susceptibility to antifungal drugs. The susceptibility of Caenorhabditis elegans to different Candida species makes this nematode an excellent model for assessing host-fungus interactions. We evaluated the usefulness of C. elegans as a nonconventional host model to analyze the virulence of C. glabrata, C. nivariensis, and C. bracarensis The three species caused candidiasis, and the highest virulence of C. glabrata was confirmed. Furthermore, we determined the efficacy of current antifungal drugs against the infection caused by these species in the C. elegans model. Amphotericin B and azoles showed the highest activity against C. glabrata and C. bracarensis infections, while echinocandins were more active for treating those caused by C. nivariensisC. elegans proved to be a useful model system for assessing the pathogenicity of these closely related species.

Synthesis, Physical, Mechanical and Antibacterial Properties of Nanocomposites Based on Poly(vinyl alcohol)/Graphene Oxide-Silver Nanoparticles.

The design of new materials with antimicrobial properties has emerged in response to the need for preventing and controlling the growth of pathogenic microorganisms without the use of antibiotics. In this study, partially reduced graphene oxide decorated with silver nanoparticles (GO-AgNPs) was incorporated as a reinforcing filler with antibacterial properties to poly(vinyl alcohol) (PVA) for preparation of poly(vinyl alcohol)/graphene oxide-silver nanoparticles nanocomposites (PVA/GO-AgNPs). AgNPs, spherical in shape and with an average size of 3.1 nm, were uniformly anchored on the partially reduced GO surface. PVA/GO-AgNPs nanocomposites showed exfoliated structures with improved thermal stability, tensile properties and water resistance compared to neat PVA. The glass transition and crystallization temperatures of the polymer matrix increased with the incorporation of the hybrid. The nanocomposites displayed antibacterial activity against Staphylococcus aureus and Escherichia coli in a filler content- and time-dependent manner. S. aureus showed higher susceptibility to PVA/GO-AgNPs films than E. coli. Inhibitory activity was higher when bacterial cells were in contact with nanocomposite films than when in contact with leachates coming out of the films. GO-AgNPs based PVA nanocomposites could find application as wound dressings for wound healing and infection prevention.

Graphene Oxide-Silver Nanoparticle Nanohybrids: Synthesis, Characterization, and Antimicrobial Properties.

Drug resistance of pathogenic microorganisms has become a global public health problem, which has prompted the development of new materials with antimicrobial properties. In this context, antimicrobial nanohybrids are an alternative due to their synergistic properties. In this study, we used an environmentally friendly one-step approach to synthesize graphene oxide (GO) decorated with silver nanoparticles (GO-AgNPs). By this process, spherical AgNPs of average size less than 4 nm homogeneously distributed on the surface of the partially reduced GO can be generated in the absence of any stabilizing agent, only with ascorbic acid (L-AA) as a reducing agent and AgNO3 as a metal precursor. The size of the AgNPs can be controlled by the AgNO3 concentration and temperature. Smaller AgNPs are obtained at lower concentrations of the silver precursor and lower temperatures. The antimicrobial properties of nanohybrids against Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa, Gram-positive Staphylococcus aureus, and the yeast Candida albicans were found to be concentration- and time-dependent. C. albicans and S. aureus showed the highest susceptibility to GO-AgNPs. These nanohybrids can be used as nanofillers in polymer nanocomposites to develop materials with antimicrobial activity for applications in different areas, and another potential application could be cancer therapeutic agents.

Effect of biomaterials hydrophobicity and roughness on biofilm development.

Most hospitalized patients are carriers of biomedical devices. Infections associated with these devices cause great morbidity and mortality, especially in patients in intensive care units. Numerous strategies have been designed to prevent biofilm development on biodevices. However, biofilm formation is a complex process not fully clarified. In the current study, roughness and hydrophobicity of different biomaterials was analyzed to assess their influences on the biofilm formation of four leading etiological causes of healthcare-associated infections, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus epidermidis and Candida albicans, using a CDC biofilm reactor. Hydrophobic materials allowed the formation of more abundant and profuse biofilms. Roughness had effect on biofilm formation, but its influence was not significant when material hydrophobicity was considered.

Efficacy of Selective Grinding Guided by an Occlusal Splint in Management of Myofascial Pain: A Prospective Clinical Trial.

BACKGROUND: For patients whose centric relation (CR) has not been considered at the start and during treatment, the task of achieving an occlusal scheme that works together with the temporomandibular joint, the muscles, and the structures of the stomatognathic apparatus becomes a major concern. OBJECTIVE: This study aims to describe a reproducible, predictable and to date unreported procedure of selective grinding guided by an occlusal splint and to analyze condylar position (CP) based on the skeletal pattern. METHODS: A total of 72 symptomatic patients (38 females and 34 males) were classified into three groups: hyperdivergent, intermediate and hypodivergent. CP was quantified by mounted casts on a measures condyle displacement (MCD) device. Helkimo index was also performed in order to assess the severity of the temporomandibular joint (TMJ) disorders attending to clinical dysfunction, occlusal state and anamnestic dysfunction. Once the stability had been obtained, the splint was progressively reduced until the maximum intercuspation (MIC) was achieved. RESULTS: The vertical displacement was found to be significantly different between the hyperdivergent and other two groups (p<0.01). Comparisons of MCD analysis before and after the selective grinding procedure identified a statistically significant difference in the horizontal and vertical CP (p<0.01) between the different groups whereas the Helkimo Index showed a clear improvement of TMJ disorders. CONCLUSION: All facial types, specially the hyperdivergent face type, showed a reduction in condylar displacement (CD) and less craniomandibular symptoms using this procedure, making it an excellent technique for clinicians.

Usefulness of the Non-conventional Caenorhabditis elegans Model to Assess Candida Virulence.

Invasive candidiasis is caused mainly by Candida albicans, but other Candida species have increasing etiologies. These species show different virulence and susceptibility levels to antifungal drugs. The aims of this study were to evaluate the usefulness of the non-conventional model Caenorhabditis elegans to assess the in vivo virulence of seven different Candida species and to compare the virulence in vivo with the in vitro production of proteinases and phospholipases, hemolytic activity and biofilm development capacity. One culture collection strain of each of seven Candida species (C. albicans, Candida dubliniensis, Candida glabrata, Candida krusei, Candida metapsilosis, Candida orthopsilosis and Candida parapsilosis) was studied. A double mutant C. elegans AU37 strain (glp-4;sek-1) was infected with Candida by ingestion, and the analysis of nematode survival was performed in liquid medium every 24 h until 120 h. Candida establishes a persistent lethal infection in the C. elegans intestinal tract. C. albicans and C. krusei were the most pathogenic species, whereas C. dubliniensis infection showed the lowest mortality. C. albicans was the only species with phospholipase activity, was the greatest producer of aspartyl proteinase and had a higher hemolytic activity. C. albicans and C. krusei caused higher mortality than the rest of the Candida species studied in the C. elegans model of candidiasis.

Análisis comparativo de la repetibilidad y reproductibilidad de dos métodos de medición de la dimensión vertical en rehabilitación oral: una revisión sistemática / Comparative analysis of the repeatability and reproducibility of two methods for measuring the vertical dimension in oral rehabilitation: a systematic review

El objetivo de este estudio establecer si el método de evaluación de la dimensión vertical mediante cefalometría y el convencional con rodillos de articulación, consiguen resultados sin diferencias estadísticamente significativas. Realización de una revisión sistemática conforme a la metodología PICO del Centro de Medicina Basada en la Evidencia de Oxford. Se formula una pregunta dirigida al objetivo fijado y se elabora una estrategia de búsqueda empleando MeSH key words específicos derivados de la pregunta en la base de datos PubMed hasta 2015 y libros de rehabilitación oral. Se consultan un total de 833 artículos por título, siendo 26 revisados a texto completo. Se analizan trabajos sobre distintos métodos de determinación de la dimensión vertical, haciendo especial hincapié en los basados en métodos cefalométricos. Finalmente 9 artículos cumplen los criterios de inclusión y se realiza una evaluación crítica del nivel de evidencia. No se ha encontrado suficiente evidencia científica que demuestre la repetibilidad de ambos métodos. Es necesario realizar estudios controlados y aleatorizados que comparen ambos métodos para determinar si son repetibles y reproducibles y obtienen resultados sin diferencias estadísticamente significativas.

The objective of this work was to establish if the method of evaluation of the vertical dimension by cephalometry and the common one with joint rollers, obtains results without statistically significant differences. We carried out a systematic review based on the PICO methodology of the Center for Evidence-Based Medicine for Oxford. A question aimed at the objective was made, and a search strategy was developed using specific MeSH key words derived from the question in the Pubmed database up to 2015 and oral rehabilitation books. A total of 833 items were consulted by tittle, and for 26 of these full text was reviewed. Works on different methods for determining the vertical dimension were studied, with special emphasis on those based on cephalometric methods. Finally 9 articles fulfilled the criteria for inclusion and a critical assessment of the evidence level was performed. We did not find sufficient scientific evidence to demonstrate the repeatability of these methods. It is necessary to realize randomized controlled trials comparing both methods to determine if they were statistically repeatable and reproducible.

Influencia del Diseño Micro y Macroscópico de la Región Cervical del Implante en la Preservación de Hueso Marginal Perimplantario: Una Revisión Sistemática / Influence of the Micro and Macroscopic Implant Neck Design in the Preservation of Marginal Bone Level: A Systematic Review

El objetivo de esta revisión sistemática fue evaluar los distintos diseños en el cuello del implante (pulido o tratado, con o sin intercambio de plataforma, o con o sin microespiras) y su posible influencia en la pérdida del hueso marginal periimplantario. Se llevo a cabo una revisión sistemática siguiendo la metodología PICO del Centro de Medicina Basada en la Evidencia de la Universidad de Oxford. La pregunta dirigida a la consecución de los objetivos fue: ¿Es el diseño del cuello del implante un factor crítico en la conservación del hueso marginal periimplantario? Se emplearon MeSH keywords específicos en las bases de datos Pubmed y Cochrane. Tres revisores independientes se pusieron de acuerdo en los estudios finalmente incluidos, obteniendo un índice de concordancia kappa de 0,88. De estos, se realizó una evaluación crítica del nivel de evidencia y también del riesgo de sesgo de los RCT mediante la Herramienta Cochrane. Se consultaron 445 artículos por título, incluyendo finalmente un total de 16 artículos a texto completo. La heterogeneidad de estos estudios impidió realizar un meta-análisis. No se encontró evidencia de que una determinada configuración del cuello del implante sea mejor que otra en la conservación del hueso marginal periimplantario y sin embargo, parece que una posición apico-coronal yuxtaósea del cuello pulido del implante respecto a la cresta ósea receptora pudiera ser crítica a ese respecto. No se encontró suficiente evidencia sobre la efectividad de las diferentes configuraciones de la región cervical del implante en la preservación del hueso marginal periimplantario. Son necesarios estudios clínicos controlados y aleatorizados a largo plazo para valorar los efectos de dichas modificaciones.

The aim of this systematic review was to assess whether different implant neck designs (polished or coated, with or without platform switching, either with or without microthreads) influence marginal bone resorption. A systematic review was conducted following the PICO methodology of the Centre for Evidence-Based Medicine of Oxford University. The question to the achievement of objectives was: Is the design of the implant neck a critical factor in the preservation of marginal bone levels? Specific MeSH keywords were used in the Pubmed and Cochrane databases. Three independent reviewers agreed on the studies ultimately included finding a concordance kappa index of 0.86. Of these articles, acritical evaluation of the level of evidence was performed and also the risk of bias of the RCT using the Cochrane tool. Four hundred forty-five items were reviewed by title, eventually including a total of 16 full-text articles. Heterogeneity of these studies made impossible the performance of a meta-analysis. No evidence that a particular configuration of the implant neck was better than another in preserving the peri-implant marginal bone was found, and yet it seems that an apico-coronal position juxta-osseous of the smooth neck of the implant relative to the bone crest could be decisive. Not enough evidence was found on the effectiveness of different configurations of the cervical region of the implant in the periimplant marginal bone preservation. More randomized controlled trials are needed to assess long-term effects of such modifications.