Hypertension is not consistently associated with postoperative cardiovascular morbidity and therefore not considered a major peri-operative risk factor. However, hypertension may predispose to peri-operative haemodynamic changes known to be associated with perioperative morbidity and mortality, such as intra-operative hypotension and tachycardia. The objective of this study was to determine whether pre-operative hypertension was independently associated with haemodynamic changes known to be associated with adverse peri-operative outcomes. We performed a five-day multicentre, prospective, observational cohort study which included all adult inpatients undergoing elective, noncardiac, non-obstetric surgery. We recruited 343 patients of whom 164 (47.8%) were hypertensive. An intra-operative mean arterial pressure of 100 beats per minute) occurred in 126 (38.9%) patients, of which 61 (48.4%) were hypertensive. Multivariable logistic regression did not show an independent association between the stage of hypertension and either clinically significant hypotension or tachycardia, when controlled for ASA physical status, functional status, major surgery, the duration of surgery or blood transfusion. There was no association between pre-operative hypertension and peri-operative haemodynamic changes known to be associated with major morbidity and mortality. These data therefore support the recommendation of the Joint Guidelines of the Association of Anaesthetists of Great Britain and Ireland (AAGBI) and the British Hypertension Society to proceed with elective surgery if a patient’s blood pressure is < 180/110 mmHg.

MSc(Eng), Faculty of Engineering and the Built Environment, University of the Witwatersrand, 2010

An increasing number of countries worldwide is becoming water-stressed, sub-Saharan Africa being one of the most recurrent regions within this discourse. Tanzania, one of the countries in the region, is no exception: large population growth has increased pressure on its precious water resources. The largest city, Dar es Salaam, has a poorly maintained and dimensioned water supply and wastewater system. However, as this system expands and more people are given access to the water network, the water consumption of the city is expected to increase. This is problematic for the whole city; however, peri-urban areas suffer the most from its consequences, e.g. periodical water shortages. This report seeks to investigate the potential for saving water in one of these peri-urban areas, Kibondemaji, by looking at fields of application and techniques for reuse of wastewater from showers. This is done via a literature review and interviews in the field in order to analyse and compare the different systems – reuse for tap water, irrigation and toilet flushing. The interviews showed that there is wide acceptance within the community for water reuse for toilet flushing but not for tap water or irrigation. Reuse for toilet flushing also requires less treatment than other fields of application, thus being the most promising technique for implementation in Kibondemaji.

ABSTRACT  Purpose The aim of the present study was to evaluate the clinical outcomes of implant-supported restorations of zirconia.   Materials and methods This retrospective study included all patients rehabilitated with implant-supported fixed prostheses made of zirconia in a dental clinical private practice, based on data from patients’ dental records. Implant/prosthesis failure, marginal bone loss, and technical complications were the outcomes analyzed. Survival analyses were used to evaluate the associations between clinical covariates and the outcomes. Univariate and multiple linear model analyses analyzed the association of the marginal bone level (MBL) between the independent variables.   Results Ninety-four patients that received 244 implants supporting 143 fixed prostheses made of zirconia. The implants and the prostheses were followed up for a mean 26 and 20 months, respectively. Only one implant failed, placed in a fresh extraction socket, 27 days after installation. None of the prostheses failed. The most prevalent technical complication was loss/fracture of implant access hole sealing. Restoration chipping occurred in five veneered zirconia restorations, and none in monolithic zirconia prostheses. The cumulative survival rate with regards to restoration chipping was of 92.2% after 4 years. None of the nine independent variables presented a statistically significant hazard ratio (HR) in relation to restoration chipping in the univariate Cox proportional hazard models. Despite the univariate linear models suggesting that some of the independent variables might have an influence on the MBL over time, the results of the multiple linear regression model suggested that none of these predictor variables had a statistically significant influence on MBL.   Conclusions Implant-supported zirconia fixed dental prostheses showed a 100% survival rate in this short-term retrospective study. The cumulative survival rate (CSR) for restoration chipping was 92.2% after 4 years, with all the cases occurring in veneered zirconia restorations, although no variable presented a statistically significant HR on this outcome. None of the predictor variables had a statistically significant influence on MBL.

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Syftet med studien var att undersöka det histopatologiska utseendet hos humana periimplantit-lesioner i relation till lesionens kliniska utseende. Periimplantit-vävnad lokaliserad runt 15 implantat avlägsnades kirurgiskt från 13 individer. De 15 kirurgiskt avlägsnade vävnadsproverna skiljde sig betydligt i utseende kliniskt och delades in i två grupper beroende på om de var inkapslade och välavgränsade mot omgivande vävnad eller mer diffust avgränsade. Vävnaderna preparerades histokemiskt (MAYERS HTX) och immunohistokemiskt (MACH 4 Universal HRP-Polymer Detection System). De celler som undersöktes med immunohistokemiska metoder var T-celler (CD3+), B-celler (CD20+), plasmaceller (CD138+), M1-makrofager (CD68+) och M2-makrofager (CD163+). Förekomsten av neutrofila granulocyter identifierades morfologiskt med rutininfärgning. Därefter scannades och analyserades proverna kvalitativt och kvantitativt. Ingen statistiskt signifikant skillnad kunde påvisas mellan tätheten av infiltrerade lymfocyter (P=0,613) och neutrofila granulocyter (P=0,336) samt arean av inflammationsinfiltratet (P=0,613) mellan de två studerade grupperna. Vidare kunde inget samband observeras mellan den histologiska sammansättningen av de studerade cellerna och det kliniska utseendet vilket dock kan förklaras av otydliga kliniska kriterier. Däremot kan det konstateras att en skillnad föreligger mellan proverna utifrån den histologiska bilden. Däribland varierar antalet plasmaceller avsevärt mellan proverna samt förekomst av fibrös bindvävszon mot benet. Ytterligare studier behövs för att förklara skillnaden i det kliniska och histologiska utseendet. / The purpose of this study was to examine the histopathological composition of human peri-implantitis lesions in relation to the clinical appearance of the lesion. Peri-implantitis tissue located around implants was surgically removed from 13 individuals. The surgically removed tissue samples differed significantly in appearance clinically and were divided into two groups, depending on whether they were encapsulated and well-bound to surrounding tissue or more diffusely delimited. The tissues were histochemically prepared (MAYERS HTX) and immunohistochemical (MACH 4 Universal HRP-Polymer Detection System). The cells examined by immunohistochemical methods were T cells (CD3 +), B cells (CD20 +), plasma cells (CD138 +), M1 macrophages (CD68 +) and M2 macrophages (CD163 +). The presence of neutrophilic granulocytes was examined morphologically by routine staining. The samples were then scanned and analyzed qualitatively and quantitatively. No statistically significant difference could be detected between the density of infiltrated lymphocytes (P = 0.613) and neutrophil granulocytes (P = 0.336) and the area of ​​the inflammatory infiltrate (P = 0.613) between the two studied groups. Furthermore, no relationship could be observed between the histological composition of the cells studied and the clinical appearance, which however, can be explained by unclear clinical criteria. The results indicated that there was a difference between the samples based on the histological composition, including the number of plasma cells which varied considerably between the samples and the presence of fibrous connective tissue zone close to the bone. Further studies are required to explain the difference in the clinical and histological appearance.

Little is known about the microbiome composition associated with peri-implantitis in developing countries. A recent study found a high prevalence of peri-implantitis in a group of Moroccan patients. We hypothesized that a distinct microbiome may be associated with this disease in Moroccan subjects, and the aim of this study was to investigate the composition of the microbiome in peri-implantitis sites and sites without peri-implantitis. The study material consisted of 35 dental patients with dental implants: 22 of these had peri-implantitis, and 13 were without peri-implantitis. Among these subjects, dental plaque samples were collected from 50 peri-implant sites as follows: in the peri-implantitis subjects, 22 samples were from peri-implantitis sites (peri-implantitis patient diseased sites) and 15 samples from sites without peri-implantitis (peri-implantitis patient control sites); and 13 samples from implants from subjects without peri-implantitis (non-peri-implantitis patient control sites). The samples were sequenced for the V1-V3 region of the 16S rRNA gene, and the resultant sequences were classified at the species level using a previously described Blastn-based algorithm. Downstream analysis of the data was performed with Phyloseq, Microbiome, Vegan and MaAsLin packages in R, using a false discovery rate (FDR) cutoff of 0.25. Fifty-six species and 30 genera were identified per sample on average. No significant differences were found between the groups in terms of species richness and alpha diversity. However, beta diversity analysis by PERMANOVA (Adonis) identified a statistically significant difference (FDR=0.024) between the peri-implantitis patient diseased sites and non-peri-implantitis patient control sites. Compared to non-peri-implantitis patient control sites, diseased but not control sites in patients with peri-implantitis showed significantly higher levels of Peptostreptococcus stomatitis and Mogibacterium spp. However, both diseased and control sites in patients with peri-implantitis had higher abundance of Olsenella uli, Atopobium spp. and Actinomyces spp. compared to non-peri-implantitis patient control sites. No differences at FDR ≤ 0.25 were found between diseased and control sites in patients with peri-implantitis, but Porphyromonas endodontalis tended to be elevated in diseased sites while Veillonella parvula tended to increase in control sites. These findings suggest a distinct dysbiotic microbiome is associated with peri-implantitis sites in Moroccan patients. / Oral Biology

Este trabalho avaliou o comportamento eletroquímico de três ligas de níquel-cromo e duas de cobalto-cromo in vitro e in vivo. Nos estudos in vitro foram fabricados eletrodos de trabalho a partir destas ligas. Estes eletrodos ficaram imersos em meio de NaCl 0,15 mol.L-1 a 36,5°C e foram submetidos às técnicas do potencial de circuito aberto, polarização potenciostática anódica e cronoamperometria. Para os estudos in vivo foram selecionados quinze pacientes com implantes já osseointegrados e aguardando a instalação das próteses. Esses pacientes foram distribuídos aleatoriamente em cinco grupos, correspondentes às cinco ligas diferentes. Deste modo, as estruturas protéticas dos implantes foram fundidas utilizando as cinco ligas. Foi utilizada a microscopia eletrônica de varredura (MEV) e a espectroscopia por dispersão de energia (EDS) como métodos de análise das superfícies linguais metálicas das próteses, antes da instalação em ambiente oral e após seis meses de permanência. Vistas por MEV, as ligas duas de cobalto-cromo Starloy C e Remanium 2001 e duas de níquel-cromo Wiron 99 e Remanium CSe apresentaram superfícies heterogêneas caracterizadas por uma fase semelhante à matriz da liga e a outra fase, composta por elementos de maior densidade atômica, correspondente à fase interdendrítica. Após seis meses, não houve sinais de corrosão e alterações significativas na composição destas ligas. As ligas de Co-Cr avaliadas, sob o ponto de vista eletroquímico, indicam comportamento catódico quando unidas ao implante sendo um fator indicativo de proteção à corrosão. Dentro dos limites dos estudos in vitro, as ligas de Ni-Cr apresentaram um filme passivo com ampla faixa de potencial em que se mantêm passiva e ausência de corrosão localizada. A liga de níquel-cromo Dan Ceramalloy apresentou a superfície heterogênea com quatro áreas distintas (área 1 rica em titânio; área 2 rica em níquel; área 3 correspondente à matriz; área 4 rica em molibdênio). Após seis meses, as três próteses metalo-cerâmicas apresentaram as regiões correspondentes à fase 2, rica em níquel, com depressões em baixo relevo, sugerindo a oxidação com a liberação de íons níquel. Nos estudos in vitro a liga Dan Ceramalloy apresenta potencial de corrosão mais negativo, uma faixa passiva de potencial mais estreita e um filme menos protetor, quando comparada com as demais ligas estudadas. Apesar de não ter sido observado clinicamente o processo de corrosão das ligas, os estudos in vitro e in vivo deste material, permitiram verificar o seu comportamento eletroquímico e sugerir a descontinuidade do seu emprego em estruturas protéticas de implantes orais. Os estudos in vitro e in vivo apresentaram concordância para todos os materiais estudados. / In this study, the electro-chemical behavior of three nickel-chrome and two cobalt chrome alloys was studied in vitro and in vivo. In the in vitro studies, working electrodes made of these alloys were fabricated. These electrodes were immersed in a medium of NaCl 0.15 mol.L-1 at 36.5°C and were submitted to the open circuit potential, anodic potentiostatic polarization and chronoamperometry techniques. For the in vivo studies, 15 patients whose implants had osseointegrated, and who were waiting for dental implant placement, were selected. These patients were randomly distributed into five groups, corresponding to the five different alloys. Thus the prosthetic implant superstructures were cast, using the five alloys. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used as methods to analyze the metal lingual surfaces of the prostheses, before they were placed in the oral environment, and after six months in place. Visualized by SEM, the two cobalt-chrome alloys Starloy C and Remanium 2001, and two types of nickel-chrome - Wiron 99 and Remanium Cse - presented heterogeneous surfaces characterized by a phase similar to that of the alloy matrix, and the other phase composed of elements of greater atomic density, corresponding to the interdendritic phase. After six months, there were no signs of corrosion and significant alterations in the composition of these alloys. The Co-Cr alloys evaluated, from an electrochemical point of view, indicated a cathodic behavior when united to the implant, this being a factor indicative of protection against corrosion. Within the limits of the in vitro studies, the Ni-Cr alloys presented a passive film with an ample range of potential in which they remained passive, with absence of corrosion due to pitting. The nickel-chrome alloy Dan Ceramalloy presented a heterogeneous surface with four distinct areas (Area 1 rich in titanium; Area 2 rich in nickel; Area 3 corresponding to the matrix; Area 4 rich in molybdenum). After six months, the three metal-ceramic dental prostheses presented the regions corresponding to Phase 2, rich in nickel, with depressions in low relief, suggesting oxidation with nickel ion release. In the in vitro studies, the alloy Dan Ceramalloy presented a more negative corrosion potential, a narrower range of passive potential and a less protective film, when compared with the other alloys studied. In despite of the process of corrosion of the alloys not having been clinically observed, the in vitro and in vivo studies of this material allowed verification of its electrochemical behavior, and suggest that its use in prosthetic superstructures for oral implants should be discontinued. The in vitro and in vivo studies were shown to be in agreement for all the materials studied.