A novel flow cytometric protocol for assessment of yeast cell adhesion

Microbial adhesion is a field of recognized relevance and, as such, an impressive array of tools has been developed to understand its molecular mechanisms and ultimately for its quantification. Some of the major limitations found within these methodologies concern the incubation time, the small number of cells analyzed, and the operator's subjectivity. To overcome these aspects, we have developed a quantitative method to measure yeast cells' adhesion through flow cytometry. In this methodology, a suspension of yeast cells is mixed with green fluorescent polystyrene microspheres (uncoated or coated with host proteins). Within 2 h, an adhesion profile is obtained based on two parameters: percentage and cells-microsphere population's distribution pattern. This flow cytometry protocol represents a useful tool to quantify yeast adhesion to different substrata in a large scale, providing manifold data in a speedy and informative manner

Effect of Gutta-percha Solvents on the Bond Strength of Sealers to Intraradicular Dentin: A Systematic Review

Introduction: The aim of our systematic review was to assess the impact of gutta-percha solvents on the bond strength of endodontic sealers to intraradicular dentin using the push-out bond test. Methods and Materials: The literature was searched in databases (PubMed, Web of Science and Scopus) up to September 2020, using the following search terms: (bond strength AND solvent* AND sealer* AND (tooth root OR dentin OR retreatment OR root canal). No date limits were implemented, and English languages were included. The question research was constructed based on the PICO (Population, Intervention, Comparison, and Outcome) strategy: “Does gutta-percha solvents effect the bond strength of sealers to intraradicular dentin?”. The studies were analyzed by two reviewers and were included if they utilized extracted permanent human teeth with completely formed apices, as well as assessed the influence of gutta-percha solvents on the bond strength of sealers to intraradicular dentin using push-out bond test. Review articles, case reports and studies that included immature, bovine or artificial teeth were excluded. The risk of bias was evaluated based on the Cochrane criteria adopted to in vitro studies.  Results: Thirty-two papers were analyzed, seven accomplished the eligibility criteria and were selected for our systematic review. The global risk of bias was high. Due to variations in the methodological variables, a meta-analysis could not be performed. Conclusion: Our systematic review highlighted the adverse effect of chloroform, which decreased the bond strength of different sealers, and the generally higher bond strength of epoxy resin-based sealers, detected with the push-out bond test. We recommend the standardization of methods in future studies to obtain a more definitive conclusion about the influence of solvents on the bond strength of sealers to intraradicular dentin

Avaliação da qualidade de tratamentos endodônticos realizados por estudantes de Medicina Dentária

Objectives: To assess radiographically the technical quality of root fillings placed by undergraduate students at the Faculty of Dental Medicine of the University of Porto. Methods: The records of 318 patients were assessed, of which 225 radiographs of root canal fillings in single-rooted teeth were selected. The radiographs were examined using the VixWin Platinum v1.1 Imaging Software (Gendex, USA). The quality of root canal filling was graded as "acceptable" when both length and density were adequate. Procedural errors were registered. Chi-square tests were used for statistical analysis, considering a 0.05 significance level. Results: Root canal fillings were considered acceptable in 53.3% of the cases. There was a greater percentage of adequate density (70.7%) than adequate length (64%). There was a statistically significant association between the quality of the filling and the type of tooth, with maxillary anterior teeth presenting higher quality (p=0.027). The most common reason for inadequate length was short-filling (33%). There was a statistically significant relationship between the academic year and the density of the fillings (p=0.009). Overall procedural errors occurred in 3.6% of the cases, with the most common being ledge formation and apical transportation. Conclusions: The quality of root canal fillings in single-rooted teeth performed by junior dental students at the University of Porto was considered acceptable in 53.3% of cases.Objetivos: Avaliar radiograficamente a qualidade das obturações de tratamentos endodônticos realizados por estudantes do Mestrado Integrado da Faculdade de Medicina Dentária da Universidade do Porto. Métodos: Foram avaliados os registos de 318 pacientes, dos quais foram selecionadas 225 radiografias periapicais de dentes monorradiculares. As radiografias foram examinadas utilizando o software de imagem VixWin Platinum v1.1 (Gendex, EUA). A qualidade do tratamento endodôntico foi classificada como "aceitável" quando o comprimento e a densidade estavam adequados. Os erros iatrogénicos foram registados. O teste qui-quadrado foi utilizado para análise estatística, considerando um nível de significância de 0,05. Resultados: O tratamento endodôntico foi considerado aceitável em 53,3% dos casos. Houve uma maior percentagem de densidade adequada (70,7%) do que comprimento adequado (64%). Verificou-se uma associação estatisticamente significativa entre a qualidade da obturação e o tipo de dente, sendo os dentes anteriores superiores a apresentar maior qualidade (p = 0,027). A razão mais comum para o comprimento inadequado foram as obturações curtas (33%). Verificou-se uma relação estatisticamente significativa entre o ano letivo e a densidade da obturação (p = 0,009). Erros iatrogénicos ocorreram em 3,6% dos casos, sendo os mais comuns a formação de degraus e o transporte apical. Conclusões: A qualidade dos tratamentos endodônticos em dentes monorradiculares realizados por estudantes de Medicina Dentária da Universidade do Porto foi considerada aceitável em 53,3% dos casos.- (undefined

Microbes and cancer: friends or faux?

Cancer is one of the most aggressive and deadly diseases in the world, representing the second leading cause of death. It is a multifactorial disease, in which genetic alterations play a key role, but several environmental factors also contribute to its development and progression. Infections induced by certain viruses, bacteria, fungi and parasites constitute risk factors for cancer, being chronic infection associated to the development of certain types of cancer. On the other hand, susceptibility to infectious diseases is higher in cancer patients. The state of the host immune system plays a crucial role in the susceptibility to both infection and cancer. Importantly, immunosuppressive cancer treatments increase the risk of infection, by decreasing the host defenses. Furthermore, alterations in the host microbiota is also a key factor in the susceptibility to develop cancer. More recently, the identification of a tumor microbiota, in which bacteria establish a symbiotic relationship with cancer cells, opened a new area of research. There is evidence demonstrating that the interaction between bacteria and cancer cells can modulate the anticancer drug response and toxicity. The present review focuses on the interaction between microbes and cancer, specifically aiming to: (1) review the main infectious agents associated with development of cancer and the role of microbiota in cancer susceptibility; (2) highlight the higher vulnerability of cancer patients to acquire infectious diseases; (3) document the relationship between cancer cells and tissue microbiota; (4) describe the role of intratumoral bacteria in the response and toxicity to cancer therapy.This research was funded by National Funds through FCT—Fundação para a Ciência e a Tecnologia, I.P., within CINTESIS, R&D Unit, grant number UIDB/4255/2020

The precision of propex Pixi with different instruments and coronal preflaring procedures

Objective:This study aimed to evaluate the influence of the instrument regarding the apical fit and type of the alloy and coronal preflaring procedures in the accuracy of Propex Pixi.Methods: A total of 40 extracted human single-rooted permanent teeth with apical diameters of 200 mu m were selected. A #10 K-file was inserted in the root canal until its end could be observed by a dental microscope to obtain the actual working length (WL). Electronic measurements were performed using Propex Pixi to the root apex ("0.0"). Different file alloys (stainless steel [SS] and nickel titanium [NiTi]) and sizes (#10, #15, and #20) were used before and after coronal flaring. Statistical analysis was performed by a factorial analysis of variance (P <= 0.05).Results: Results showed that the measurements of electronic length (EL) were closer to the actual working length (WL) after coronal flaring (P<0.05). A significant intraclass correlation was observed between EL and WL. In addition, results showed no significant differences between files with different sizes or alloys.Conclusion: Under the conditions of this study, Propex Pixi demonstrated adequate precision. Its accuracy was enhanced by coronal preflaring procedures regardless of the instrument type used (SS or NiTi) and the apical fit.- (undefined

Morel-Lavallée Lesion

Morel-Lavallée lesion is a closed degloving injury that results of separation of skin and subcutaneous tissue from the underlying fascia. This lesion is more common on the thigh and trauma is the most frequent cause. MRI is the preferred imaging technique for its evaluation. Early detection is important to avoid complications such as bacterial growth or extensive skin necrosis.The authors report two cases of Morel-Lavallée lesions, one in a patient with a painless mass on the thigh after a traffic accident and another in a young football player with a painful swelling on the thigh with fluctuation

Complicações que podem surgir durante o Uso do Hipoclorito de Sódio no Tratamento Endodôntico

ResumoA solução de hipoclorito de sódio, em diferentes concentrações, é o irrigante mais utilizado durante o tratamento endodôntico. Embora a sua utilização seja geralmente segura, sequelas graves podem ocorrer quando da sua extrusão para além do apex do canal radicular, afectando os tecidos periapicais.Neste artigo procura-se alertar o Médico Dentista (e outros profissionais de Saúde Oral) para os principais acidentes que podem ocorrer com o uso do hipoclorito de sódio durante o tratamento endodôntico.AbstractSodium hypochlorite is the most common irrigant used in endodontic practice. Usually, the use of sodium hypochlorite is safe, although severe sequelae may occur if this solution is extruded beyond the root apex. This article's aim is to draw the Dentist's attention (and other oral health professionals) to the principal accidents that may occur with the use of sodium hypochlorite during the endodontic treatment

Simulated root canals preparation time, comparing ProTaper Next and WaveOne Gold systems, performed by an undergraduate student

The aim of this study was to compare the WaveOne Gold and ProTaper Next systems regarding the time spent preparing simulated canals performed by an inexperienced student. 0 simulated L-shaped canals were randomly divided into two groups (n = 40) and numbered in order of instrumentation. Canals were instrumented with WaveOne Gold (group 1) and ProTaper Next (group 2) systems. The effective instrumentation time and the number of instrumentation cycles were recorded. All procedures were performed by the same operator. Statistical analysis was obtained by the Mann - Whitney, Kruskal - Wallis test with significance of p<0.05. There were no statistically significant differences regarding the mean instrumentation time between the two instrumentation systems. The instrumentation time decreased over the experimental period, regardless of the technique used. Through a short learning curve, an inexperienced operator can prepare simulated canals in a very predictable time. Time spent was similar in a multi-file instrument system (ProTaper Next) and a single-file system (WaveOne Gold)