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- The 2018 periodontitis case definition improves accuracy performance of full-mouth partial diagnostic protocolsPublication . Botelho, João; Machado, Vanessa; Proença, Luís; Mendes, José JoãoWe aimed to compare the accuracy performance of the new 2018 periodontitis case definition by the European Federation of Periodontology (EFP)/ American Association of Periodontology (AAP) with Centers for Disease Control (CDC)/AAP 2012 in full-mouth partial recording protocols (PRP). Retrospective data from NHANES 2011-2012 and 2013-2014 were analyzed. For each case definition, full-mouth diagnostic was defined as the reference standard. Patients were diagnosed for the presence of periodontitis and staging for each PRP. Sensitivity, specificity, accuracy and precision, through several indicators, were determined. Performance measurement was assessed through binary and multiclass ROC/AUC analyses. Our performance analysis shows that the new 2018 classification outperforms the 2012 classification regarding the diagnosis and staging of periodontitis on full-mouth PRPs. This recent case definition has strengthened the utility of PRPs and its improvements certainly explain the observed findings. Also, our findings contribute to the reliability of PRPs and its use in future worldwide epidemiological surveys.
- 3D assessment of mandibular buccal shelf geometry for optimal micro-implant placement site in Portuguese individuals : a retrospective cone-beam computed tomography studyPublication . Borga, Joana; Bugaighis, Iman; Proença, Luís; Pereira, François Durand; Costa, Helder Nunes; Pereira, Pedro MarianoObjectives: To determine the most favourable Micro-Implant (MI) insertion site along the mandibular buccal shelf (MBS), using Cone Beam Computed Tomography (CBCT). Methods: This retrospective study assessed CBCT scans from 90 Portuguese patients (32 males and 58 females, aged 14 to 40 years). Paired MBS sites were determined. Comparative and correlation analyses were performed at p < 0.05. Results: A significant increase in MBS width was observed from the mesial to the distal direction (p < 0.001). Conversely, both the MBS steepness and cortical bone thickness significantly decreased from mesial to distal (p < 0.001). Significant negative correlation was also found between age and cortical bone thickness adjacent to the distobuccal cusp and distal tangent of both mandibular second molars (r ≤ −0.373, p ≤ 0.007). Furthermore, significant asymmetric differences were identified between the right and left MBS steepness as well as in the paired cortical bone thickness at the mesiobuccal cusp, buccal groove, and distobuccal cusp of the mandibular second molar (p ≤ 0.016). Conclusions: The results indicate that although there are sufficient MBS width and cortical bone thickness, vestibular to the mandibular second molar for MI insertion, the sites towards the distal root of the mandibular second molar are more favourable when considering MBS steepness. These findings are consistent for both sexes and apply to young and old individuals.
- 3D assessment of the relationship of the mandibular buccal shelf with the mandibular canal : a CBCT retrospective studyPublication . Feliciano, Jéssica; Pereira, Pedro Mariano; Proença, Luís; Borga, Joana; Bugaighis, ImanObjective: This study aimed to evaluate the micro-implant safest insertion site on the mandibular buccal shelf (MBS) without compromising the integrity of the mandibular canal (MC). Methods: This retrospective investigation included cone-beam computed tomography (CBCT) of 96 Portuguese patients (58 females and 38 males, average age of 25.5±10.2 years). Measurements were taken in four bilateral MBS sites buccal to the mandibular second molar; tangent to the distal surface (7D), distobuccal cusp tip (7CD), buccal groove (7S) and mesiobuccal cusp tip (7CM). The transversal MBS midpoint was also determined, and the maximum angulation from the transversal MBS midpoint was extracted relative to the true vertical plane. Subsequently, the distance from the MBS midpoint to the MC was calculated at this angulation. Descriptive and inferential statistical analyses were performed at p<0.05 Results: Significant correlations were observed among several variables and age, sex and bilateral asymmetry (p<0.05). The MBS transversal width and the distance from the MBS midpoint to the MC progressively increased in the posterior direction while the angulation decreased. Conclusion: The most appropriate micro-implant insertion location compared to the other MBS investigated sites, in the absence of impacted third molars, is adjacent to the distal surface of the second molar. This finding is consistent across all age groups, sexes, and insertion sides. However, due to the demonstrated variability, taking a CBCT scan prior to mini-implant insertion might be considered to minimize the risk of injury to the inferior alveolar nerve.
- 3D bioprinting of novel κ-carrageenan bioinks : an algae-derived polysaccharidePublication . Marques, Diana M. C.; Silva, João C.; Serro, Ana Paula; Cabral, Joaquim M. S.; Sanjuan-Alberte, Paola; Ferreira, Frederico C.Novel green materials not sourced from animals and with low environmental impact are becoming increasingly appealing for biomedical and cellular agriculture applications. Marine biomaterials are a rich source of structurally diverse compounds with various biological activities. Kappa-carrageenan (κ-c) is a potential candidate for tissue engineering applications due to its gelation properties, mechanical strength, and similar structural composition of glycosaminoglycans (GAGs), possessing several advantages when compared to other algae-based materials typically used in bioprinting such as alginate. For those reasons, this material was selected as the main polysaccharide component of the bioinks developed herein. In this work, pristine κ-carrageenan bioinks were successfully formulated for the first time and used to fabricate 3D scaffolds by bioprinting. Ink formulation and printing parameters were optimized, allowing for the manufacturing of complex 3D structures. Mechanical compression tests and dry weight determination revealed young’s modulus between 24.26 and 99.90 kPa and water contents above 97%. Biocompatibility assays, using a mouse fibroblast cell line, showed high cell viability and attachment. The bioprinted cells were spread throughout the scaffolds with cells exhibiting a typical fibroblast-like morphology similar to controls. The 3D bio-/printed structures remained stable under cell culture conditions for up to 11 days, preserving high cell viability values. Overall, we established a strategy to manufacture 3D bio-/printed scaffolds through the formulation of novel bioinks with potential applications in tissue engineering and cellular agriculture.
- 3D printing for dental applicationsPublication . Figueiredo-Pina, Célio Gabriel; Serro, Ana Paula
- ABC traffic light: a health education toolPublication . Dias, Maria do Rosário; Correia, Paula Grade; Correia, Patrícia RodriguesIt is during the childhood period of one’s life trajectory that the exponential increase of vocabulary acquisition occurs. In Portugal, language disorders are the most frequently seen child development impairments, affecting 3 to 15 per cent of children under six years. Because delays in the acquisition of basic vocabulary can compromise inter-peer relational communication, a timely therapeutic assessment and intervention becomes all the more crucial. A speech therapy ludic-pedagogic intervention tool—the ABC Traffic Light—was created so as to aid in promoting basic vocabulary acquisition in children aged between three and six years. It consists in a traffic light with three built-in pouches, each of which containing cards suggestive of activities of varying difficulty levels. The empirical range of the proposed tool in the context of speech therapy assessment and intervention sessions should be highlighted.
- Abcesso epidural – uma complicação anestésicaPublication . Carvalho, Inês; Tomé, Sara; Neto, Miguel; Dinis, Isabel"Os abcessos epidurais são infeções muito graves do Sistema Nervoso Central. Constituem lesões focais confinadas ao crânio ou coluna vertebral que exercem compressão cerebra lou medular causando sintomas severos e complicações permanentes. Este caso clínico constitui a descrição de uma complicação pós-operatória após uma artroplastia total do joelho.Embora seja uma entidade rara, tem-se vindo a verificar um aumento de incidência nos últimos 30 anos que se deve, não só aos avanços tecnológicos no campo da imagiologia,mas também ao envelhecimento progressivo da população e ao acréscimo do número de anestesias regionais. A chave para o tratamento desta complicação é o seu reconhecimento precoce, pelo que a hipótese diagnóstica deverá ser colocada, especialmente em casos de doentes imunocomprometidos submetidos a técnicas anestésicas regionais, sob pena de comprometer a cura completa e levar ao desenvolvimento de sequelas graves."
- About the effect of eye blinking on drug release from pHEMA-based hydrogels: an in vitro studyPublication . Galante, Raquel; Paradiso, Patrizia; Moutinho, Maria Guilhermina; Fernandes, Ana Isabel; Mata, José; Matos, António; Colaço, Rogério; Saramago, Benilde; Serro, Ana Paula"The development of new ophthalmic drug delivery systems capable of increasing the residence time of drugs in the eye and improve its bioavailability relatively to eyedrops has been object of intense research in recent years. Several studies have shown that drug loaded therapeutic soft contact lenses (SCLs) constitute a promising approach, with several potential advantages as compared with collyria. The main objective of this work is to study the effect of repetitive load and friction cycles caused by the eye blinking, on the drug release from hydrogels used in SCLs which, as far as we know, was never investigated before. Two poly-2-hydroxyethylmethacrylate based hydrogels, pHEMA-T and pHEMA-UV, were used as model materials. Levofloxaxin was chosen as model drug. The hydrogels were fully characterized in what concerns structural and physicochemical properties. PHEMA-UV revealed some superficial porosity and a lower short range order than PHEMA-T. We observe that the load and friction cycles enhanced the drug release from pHEMAUV hydrogels. The application of a simple mathematical model, which takes into account the drug dilution caused by the tear flow, showed that the enhancement of the drug release caused by blinking on this hydrogel may be relevant in in vivo conditions. Conversely, the more sustained drug release from pHEMA-T is not affected by load and friction cycles. The conclusion is that, depending on the physicochemical and microstructural characteristics of the hydrogels, blinking is a factor that may affect the amount of drug delivered to the eye by SCLs and should thus be considered."
- About the sterilization of chitosan hydrogel nanoparticlesPublication . Galante, Raquel; Rediguieri, Carolina F.; Kikuchi, Irene Satiko; Vasquez, Pablo A. S.; Colaço, Rogério; Serro, Ana Paula; Pinto, Terezinha J. A.In the last years, nanostructured biomaterials have raised a great interest as platforms for delivery of drugs, genes, imaging agents and for tissue engineering applications. In particular, hydrogel nanoparticles (HNP) associate the distinctive features of hydrogels (high water uptake capacity, biocompatibility) with the advantages of being possible to tailor its physicochemical properties at nano-scale to increase solubility, immunocompatibility and cellular uptake. In order to be safe, HNP for biomedical applications, such as injectable or ophthalmic formulations, must be sterile. Literature is very scarce with respect to sterilization effects on nanostructured systems, and even more in what concerns HNP. This work aims to evaluate the effect and effectiveness of different sterilization methods on chitosan (CS) hydrogel nanoparticles. In addition to conventional methods (steam autoclave and gamma irradiation), a recent ozone-based method of sterilization was also tested. A model chitosan-tripolyphosphate (TPP) hydrogel nanoparticles (CS-HNP), with a broad spectrum of possible applications was produced and sterilized in the absence and in the presence of protective sugars (glucose and mannitol). Properties like size, zeta potential, absorbance, morphology, chemical structure and cytotoxicity were evaluated. It was found that the CS-HNP degrade by autoclaving and that sugars have no protective effect. Concerning gamma irradiation, the formation of agglomerates was observed, compromising the suspension stability. However, the nanoparticles resistance increases considerably in the presence of the sugars. Ozone sterilization did not lead to significant physical adverse effects, however, slight toxicity signs were observed, contrarily to gamma irradiation where no detectable changes on cells were found. Ozonation in the presence of sugars avoided cytotoxicity. Nevertheless, some chemical alterations were observed in the nanoparticles.
- Accidental father-to-son HIV-1 transmission during the seroconversion periodPublication . Ezeonwumelu, Ifeanyi; Bártolo, Inês; Martin, Francisco; Abecasis, Ana; Campos, Teresa; Romero-Severson, Ethan O.; Leitner, Thomas; Taveira, NunoA 4-year-old child born to an HIV-1 seronegative mother was diagnosed with HIV-1, the main risk factor being transmission from the child's father who was seroconverting at the time of the child's birth. In the context of a forensic investigation, we aimed to identify the source of infection of the child and date of the transmission event. Samples were collected from the father and child at two time points about 4 years after the child's birth. Partial segments of three HIV-1 genes (gag, pol, and env) were sequenced and maximum likelihood (ML) and Bayesian methods were used to determine direction and estimate date of transmission. Neutralizing antibodies were determined using a single cycle assay. Bayesian trees displayed a paraphyletic–monophyletic topology in all three genomic regions, with the father's host label at the root, which is consistent with father-to-son transmission. ML trees found similar topologies in gag and pol and a monophyletic–monophyletic topology in env. Analysis of the time of the most recent common ancestor of each HIV-1 gene population indicated that the child was infected shortly after the father. Consistent with the infection history, both father and son developed broad and potent HIV-specific neutralizing antibody responses. In conclusion, the direction of transmission implicated the father as the source of transmission. Transmission occurred during the seroconversion period when the father was unaware of the infection and was likely accidental. This case shows how genetic, phylogenetic, and serological data can contribute for the forensic investigation of HIV transmission.