A review on the prevention of inflammatory periimplant diseases

Background: An impressive number of dental implants are inserted worldwide. Evolution in dental implants and simplification of surgical techniques allowed a significant increase in the number of dentists involved in implant surgery. Most of them are general dentists, are not always sufficiently formed and experienced, frequently use low-quality implants, do not adopt the proper patient selective criteria, do not adequately monitor and maintain the inserted implants, and do not report their own statistics to the dental community. Consequently, the incidence of inflammatory periimplant diseases (IPDs) has progressively increased to values significantly higher than those previously indicated by the scientific literature. Materials and Methods: Two main literature searches were undertaken in October 2018 in the PubMed Website database. Only articles written in English and published from 2008 onward were considered; 'Clinical Trial,' 'Meta analysis,' 'Observational study,' 'Review,' and 'Validation study' were selected as article type filters. The following keywords were used in the searches: 'Peri implantitis prevention' and 'Dental implant failure prevention.'Results: Preventive measures are analyzed according to the different factors that can favor the occurrence of an infection. The factors are divided into (i) implant dependent, (ii) patient dependent, and (iii) surgeon dependent. Conclusions: Scientific and clinical data confirm that when materials are selected with care, patients are carefully evaluated for factors of risk and attitude to adhere to the necessary maintenance program, and operative protocols and maintenance programs are respected dental implants can be attractive and effective tools for oral rehabilitation. Nevertheless, dentists and patients should have greater awareness that in many cases the decision to utilize dental implants cannot be taken lightly

Towards the Modeling of Neuronal Firing by Gaussian Processes

This paper focuses on the outline of some computational methods for the approximate solution of the integral equations for the neuronal firing probability density and an algorithm for the generation of sample-paths in order to construct histograms estimating the firing densities. Our results originate from the study of non-Markov stationary Gaussian neuronal models with the aim to determine the neuron's firing probability density function. A parallel algorithm has been implemented in order to simulate large numbers of sample paths of Gaussian processes characterized by damped oscillatory covariances in the presence of time dependent boundaries. The analysis based on the simulation procedure provides an alternative research tool when closed-form results or analytic evaluation of the neuronal firing densities are not available.Comment: 10 pages, 3 figures, to be published in Scientiae Mathematicae Japonica

A Community-Structure-Based Method for Estimating the Fractal Dimension, and its Application to Water Networks for the Assessment of Vulnerability to Disasters

AbstractMost real-world networks, from the World-Wide-Web to biological systems, are known to have common structural properties. A remarkable point is fractality, which suggests the self-similarity across scales of the network structure of these complex systems. Managing the computational complexity for detecting the self-similarity of big-sized systems represents a crucial problem. In this paper, a novel algorithm for revealing the fractality, that exploits the community structure principle, is proposed and then applied to several water distribution systems (WDSs) of different size, unveiling a self-similar feature of their layouts. A scaling-law relationship, linking the number of clusters necessary for covering the network and their average size is defined, the exponent of which represents the fractal dimension. The self-similarity is then investigated as a proxy of recurrent and specific response to multiple random pipe failures – like during natural disasters – pointing out a specific global vulnerability for each WDS. A novel vulnerability index, called Cut-Vulnerability is introduced as the ratio between the fractal dimension and the average node degree, and its relationships with the number of randomly removed pipes necessary to disconnect the network and with some topological metrics are investigated. The analysis shows the effectiveness of the novel index in describing the global vulnerability of WDSs

Regulamentações envolvendo agentes microbianos de controle no Brasil.

A importância do controle biológico de organismos nocivos no Brasil tem crescido consideravelmente nas ultimas duas décadas. Um número grande de projetos conduzidos no pais tem resultado em reduções significativas de varias pragas, através da introdução ou manejo de agentes nativos de controle biológico. Um desenvolvimento cada vez maior do controle biológico e esperado diante das demandas internacionais, para o uso de meios mais naturais de produção da agricultura, e pela implementação das normas ISO 14.000. Pesquisa, produção, comercialização uso, importacao e registro de pesticidas em geral são regulamentados no Brasil pela Lei Federal numero 7802, de julho de 1989 e pelo Decreto Presidencial numero 98816, de janeiro de 1990. Uma regulamentação específica para o registro comercial de produtos contendo agentes microbianos de controle, considerando suas características diferentes das partículas químicas, não existe oficialmente no Brasil. Recentemente, foi elaborada uma proposta oficial para os Órgaos de Registros (NARDO et al., 1995), levando em consideração as características intrínsecas dos microrganismos, assim como requisitos para sua avaliação sobre componentes do meio ambiente e da saúde humana, baseada em regulamentações exóticas para fins de controle biológico, o Brasil tem uma serie de regras de intercambio internacional. Permissão para introdução e exploração são necessárias, entretanto não existe nenhuma menção sobre a exportação de agentes microbianos coletados no pais. Atualmente todas essas regulamentações estão sofrendo revisões e adaptações. O Laboratório de Quarentena "Costa Lima",, situado em Jaguariúna, SP, junto ao Centro Nacional De Pesquisa de Monitoramento e Avaliação de Impacto Ambiental (EMBRAPA/CNPMA), e o unido credenciado no país para auxiliar o Ministério da Agricultura e do Abastecimento, quanto as solicitações para a incrementação deste método de controle. Também no âmbito regional dos países do Cone Sul, o Brasil tem participado na elaboração de regulamentações relacionadas com o controle biológico através do COSAVE (COMITÊ DE SANIDADE VEGETAL DO CONE SUL) criado em 1992, com a finalidade de elaborar e harmonizar regulamentações fitossanitárias para os países da região: Argentina, Brasil

New-Concept Gas Turbine Burner Simulation in Moderate Intense Low-Oxygen Combustion Regime

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Probiotic streptococcus salivarius reduces symptoms of denture stomatitis and oral colonization by Candida Albicans

Denture stomatitis (DS) is an inflammatory status of oral mucosae frequently observed in denture wearers, and mainly associated with oral overgrowth of Candida albicans. DS is the cause of multiple visits to the dental office and is thought to enhance the risk of systemic infections. The treatment of DS mainly relies upon improvement of oral hygiene measures and prescription of topical or systemic antifungal agents, and disinfectants that, although effective, are not without drawbacks. Since, in recent years, some probiotics were investigated as a means to contrast oral colonization by Candida spp., this study was designed to preliminarily evaluate the effects of probiotic strain Streptococcus salivarius K12, in subjects affected by DS, and the duration of these effects. Fifty adult denture wearers affected by DS were enrolled and randomly divided into two groups: the experimental group was instructed to perform careful oral and denture hygiene and to assume the probiotic preparation for 30 days; the control group received only oral hygiene instructions. Patients were evaluated for signs of DS at the beginning of the study, at the end of treatment and 30 days later. Microbiological samples were obtained at the beginning of the study and at the end of treatment to quantify Candida albicans cells. Experimental treatment reduced clinical signs and symptoms of DS and the count of C. albicans. The clinical effects of experimental treatment were still evident after 30 days, suggesting that administration of probiotic strain Streptococcus salivarius K12 could be a promising approach in the treatment of DS

In vivo evaluation of operative torque generated by two Nickel-Titanium rotary instruments during root canal preparation

Objectives This in vivo study evaluated the operative torque and preparation time of ProTaper NEXT (Dentsply Maillefer; Ballaigues, Switzerland) and EdgeFile X7 (EdgeEndo; Albuquerque, New Mexico, United States) rotary systems during root canal preparation of maxillary premolars. Materials and Methods Ten double-rooted maxillary premolars with independent canals were selected. Each canal in each tooth was prepared with one of the rotary systems (n = 10), ProTaper NEXT or EdgeFile X7. The instruments were rotated at 300 rpm with maximum torque set at 2 N.cm using an electric motor (KaVo; Biberach, Germany) that automatically recorded torque values at every 1/10th of a second (ds). Statistical Analysis Operative torque (N.cm) and preparation time (s) of the first shaping instrument (size 17/.04) of both rotary systems were recorded and statistically compared using the Mann-Whiney U test with a significance level set at 5%. Results No instrument exhibited flute deformation or underwent intracanal failure. No differences were found between the instruments regarding the maximum (peak) torque values (p > 0.05). EdgeFile X7 17/.04 required significantly less preparation time (3.75 seconds interquartile range [IQR]: 3.2-9.0) than ProTaper NEXT X1 (15.45 seconds IQR: 8.35-21.1) (p < 0.05). The median operative torque values of ProTaper NEXT X1 (0.26 N.cm; IQR: 0.18-0.49) were significantly higher compared with EdgeFile X7 17/.04 (0.09 N.cm; IQR: 0.05-0.17) (p < 0.05). Conclusions Although no difference was found between the median peak torque values of ProTaper NEXT X1 and EdgeFile X7 17/.04 instruments, the operative torque and instrumentation time results were impacted by their different designs and alloys during clinical preparation of root canals

Surgical treatment of a cemental tear-associated bony defect using hyaluronic acid and a resorbable collagen membrane: a 2-year follow-up

Introduction A cemental tear (CeT) is a special type of surface root fracture that may cause periodontal and even periapical tissue destruction. Unfortunately, there is limited knowledge as to how these rare cases can effectively be treated. The present case is believed to be the first reported in the literature treating a bony defect caused by a cemental tear with hyaluronic acid (HA) and a collagen membrane. The aim of this case report is to present a regenerative surgical approach with clinical and tomographic success and stability at 2-year follow-up.Case PresentationA 61-year-old patient presented with spontaneous pain and gingival swelling over his right central maxillary incisor. Radiographically, a radiolucent area was observed in the medial third between both central incisors. The tomographic evaluation showed a buccal bone dehiscence and a bony defect. Once the differential diagnosis with an endodontic-periodontal lesion and root fracture was performed, CeT was the presumptive diagnosis. During the exploratory flap surgery, a small root fragment (CeT) on the mesial side of the tooth was founded and removed. The bony lesion was treated with hyaluronic acid (HA) and a resorbable collagen membrane. At 2-year follow-up clinical, radiographic, and tomographic success was observed.ConclusionA CeT-associated bony defect could be successfully treated after removing cemental fragments and performing a regenerative approach using HA and a resorbable collagen membrane