Spatiotemporal variation in risk of Shigella infection in childhood: a global risk mapping and prediction model using individual participant data.

BACKGROUND: Diarrhoeal disease is a leading cause of childhood illness and death globally, and Shigella is a major aetiological contributor for which a vaccine might soon be available. The primary objective of this study was to model the spatiotemporal variation in paediatric Shigella infection and map its predicted prevalence across low-income and middle-income countries (LMICs). METHODS: Individual participant data for Shigella positivity in stool samples were sourced from multiple LMIC-based studies of children aged 59 months or younger. Covariates included household-level and participant-level factors ascertained by study investigators and environmental and hydrometeorological variables extracted from various data products at georeferenced child locations. Multivariate models were fitted and prevalence predictions obtained by syndrome and age stratum. FINDINGS: 20 studies from 23 countries (including locations in Central America and South America, sub-Saharan Africa, and south and southeast Asia) contributed 66 563 sample results. Age, symptom status, and study design contributed most to model performance followed by temperature, wind speed, relative humidity, and soil moisture. Probability of Shigella infection exceeded 20% when both precipitation and soil moisture were above average and had a 43% peak in uncomplicated diarrhoea cases at 33°C temperatures, above which it decreased. Compared with unimproved sanitation, improved sanitation decreased the odds of Shigella infection by 19% (odds ratio [OR]=0·81 [95% CI 0·76-0·86]) and open defecation decreased them by 18% (OR=0·82 [0·76-0·88]). INTERPRETATION: The distribution of Shigella is more sensitive to climatological factors, such as temperature, than previously recognised. Conditions in much of sub-Saharan Africa are particularly propitious for Shigella transmission, although hotspots also occur in South America and Central America, the Ganges-Brahmaputra Delta, and the island of New Guinea. These findings can inform prioritisation of populations for future vaccine trials and campaigns. FUNDING: NASA, National Institutes of Health-The National Institute of Allergy and Infectious Diseases, and Bill & Melinda Gates Foundation.

Associations Between Eight Earth Observation-Derived Climate Variables and Enteropathogen Infection: An Independent Participant Data Meta-Analysis of Surveillance Studies With Broad Spectrum Nucleic Acid Diagnostics.

Diarrheal disease, still a major cause of childhood illness, is caused by numerous, diverse infectious microorganisms, which are differentially sensitive to environmental conditions. Enteropathogen-specific impacts of climate remain underexplored. Results from 15 studies that diagnosed enteropathogens in 64,788 stool samples from 20,760 children in 19 countries were combined. Infection status for 10 common enteropathogens-adenovirus, astrovirus, norovirus, rotavirus, sapovirus, Campylobacter, ETEC, Shigella, Cryptosporidium and Giardia-was matched by date with hydrometeorological variables from a global Earth observation dataset-precipitation and runoff volume, humidity, soil moisture, solar radiation, air pressure, temperature, and wind speed. Models were fitted for each pathogen, accounting for lags, nonlinearity, confounders, and threshold effects. Different variables showed complex, non-linear associations with infection risk varying in magnitude and direction depending on pathogen species. Rotavirus infection decreased markedly following increasing 7-day average temperatures-a relative risk of 0.76 (95% confidence interval: 0.69-0.85) above 28°C-while ETEC risk increased by almost half, 1.43 (1.36-1.50), in the 20-35°C range. Risk for all pathogens was highest following soil moistures in the upper range. Humidity was associated with increases in bacterial infections and decreases in most viral infections. Several virus species' risk increased following lower-than-average rainfall, while rotavirus and ETEC increased with heavier runoff. Temperature, soil moisture, and humidity are particularly influential parameters across all enteropathogens, likely impacting pathogen survival outside the host. Precipitation and runoff have divergent associations with different enteric viruses. These effects may engender shifts in the relative burden of diarrhea-causing agents as the global climate changes.

The Role of Molecular Testing in Pediatric Meningitis Surveillance in Southern and East African Countries, 2008-2017.

BACKGROUND: As part of the global Invasive Bacterial Vaccine-Preventable Diseases Surveillance Network, 12 African countries referred cerebrospinal fluid (CSF) samples to South Africa's regional reference laboratory. We evaluated the utility of real-time polymerase chain reaction (PCR) in detecting and serotyping/grouping Haemophilus influenzae, Neisseria meningitidis, and Streptococcus pneumoniae (HNS). METHODS: From 2008 to 2017, CSF samples collected from children <5 years old with suspected meningitis underwent routine microbiology testing in-country, and 11 680 samples were submitted for HNS PCR at the regional reference laboratory. Unconditional logistic regression, with adjustment for geographic location, was performed to identify factors associated with PCR positivity. RESULTS: The overall HNS PCR positivity rate for all countries was 10% (1195 of 11 626 samples). In samples with both PCR and culture results, HNS PCR positivity was 11% (744 of 6747 samples), and HNS culture positivity was 3% (207 of 6747). Molecular serotype/serogroup was assigned in 75% of PCR-positive specimens (762 of 1016). Compared with PCR-negative CSF samples, PCR-positive samples were more often turbid (adjusted odds ratio, 6.80; 95% confidence interval, 5.67-8.17) and xanthochromic (1.72; 1.29-2.28), had elevated white blood cell counts (6.13; 4.71-7.99) and high protein concentrations (5.80; 4.34-7.75), and were more often HNS culture positive (32.70; 23.18-46.12). CONCLUSION: PCR increased detection of vaccine-preventable bacterial meningitis in countries where confirmation of suspected meningitis cases is impeded by limited culture capacity.

Reliability of ICDAS to Detect Occlusal Caries among Master's Degree students of Dentistry / Confiabilidade do ICDAS para Detectar Cárie Oclusal Entre Mestrandos de Odontologia

The objective of this study was to investigate the reproducibility of the International System for the Detection and Evaluation of Caries (ICDAS) for the diagnosis of caries by students of the Master's Degree in Dentistry (n = 25). The occlusal surfaces of human third molars (n = 14) were evaluated by twenty-five (n = 25) students using the ICDAS index and later a questionnaire was applied on demographic and professional context data. The dental crowns were sectioned in mesial to distal direction to obtain slices of 1mm in thickness which were observed in a stereomicroscope (40X) to identify the greatest extension of caries lesion. Data were analyzed by the Chi-Square, Fisher's Exact and Spearman's Correlation Coefficient at a significance level of 5%. There was an influence in the diagnosis of caries among students and teeth, where the majority of those who declared themselves to be safe missed the diagnosis. There was variability between the diagnosis and the proposed treatment for caries, with a better diagnosis for tooth VII and less for X; greater fit for treatment of teeth XIII, XIV and lower for IV, VI. The histological cut showed that the teeth were more affected by caries than the ICDAS. It was concluded that the ICDAS reproducibility was partially satisfactory when the occlusal surface was evaluated by the master's degree students. (AU).

Este trabalho teve o objetivo de investigar a reprodutibilidade do Sistema Internacional de Detecção e Avaliação de Cárie (ICDAS) para o diagnóstico da cárie, por estudantes de curso de Mestrado em Odontologia (n=25). As superfícies oclusais de terceiros molares humanos (n=14) foram avaliadas por vinte e cinco (n=25) estudantes, utilizando o índice ICDAS, e posteriormente foi aplicado questionário sobre dados demográficos e de contexto profissional. As coroas dentárias foram seccionadas no sentido mésio distal para obter fatias de 1 mm de espessura, que foram observadas em estereomicroscópio (40X) para identificar a maior extensão da lesão de cárie. Os dados foram analisados pelos Testes Qui-Quadrado, Exato de Fisher e Coeficiente de Correlação de Spearman, em nível de significância de 5%. Houve influência do grau de instrução dos estudantes no diagnóstico da cárie em relação ao dente avaliado e a maioria que se declarou segura errou o diagnóstico. Houve variabilidade entre o diagnóstico e o tratamento proposto para a cárie, com maior acerto para diagnóstico do dente VII e menor para o X; maior acerto para tratamento dos dentes XIII, XIV e menor para IV, VI. O corte histológico mostrou que os dentes estavam mais comprometidos pela cárie que o ICDAS. Concluiu-se que a reprodutibilidade do ICDAS foi satisfatória quando a superfície oclusal foi avaliada pelos mestrandos. (AU).

Potential Diarrheal Pathogens Common Also in Healthy Children in Angola.

BACKGROUND: Globally, diarrhea kills almost 1500 children daily. In diagnostics, molecular methods are replacing traditional assays. We aimed to investigate enteropathogens in children with and without diarrhea in Luanda, the capital of Angola. METHODS: One hundred and ninety-four stool samples from 98 children with acute diarrhea and 96 children without diarrhea were investigated for 17 enteropathogens with multiplex real-time polymerase chain reaction. RESULTS: The median age of children was 10.5 months. Enteropathogens, bacteria, viruses and parasites were detected in 91%, 78%, 50% and 25%, respectively. A positive finding was significantly (P = 0.003) more common in diarrhea when testing for all pathogens combined, for bacteria alone and for viruses alone. More than one pathogen was found more frequently in diarrhea than in non-diarrhea stool samples, in 87% and in 59% (P < 0.0001), respectively. The median number (interquartile range) of pathogens detected was 3 (2) versus 1.5 (2; P < 0.0001), respectively. When age was taken into account, diarrhea was found to be associated with enterotoxigenic and enteroaggregative Escherichia coli, Shigella, Campylobacter, rotavirus, sapovirus and Cryptosporidium. CONCLUSIONS: Multiplex polymerase chain reaction detected enteropathogens in almost all stool samples of children in Luanda, albeit this occurred more often in diarrhea. Children with diarrhea showed more mixed infections than children without diarrhea.

Linear setting expansion of different gypsum products

Introduction:Stone casts are used in dentistry to allow the confection of indirect restorations. Thus, gypsum dimensional stability is fundamental in order to achieve a precise fit between dental structure and restorative material.Objective: The purpose of the present study was to evaluate the hygroscopic linear expansion of commercially available gypsum products. Material and methods: Fifteen dental stones were analyzed (4 type II, 5 type III, 4 type IV and 2 type V), with n = 5. One hundred grams of each gypsum product were mixed following the respective manufacturers' recommendations for powder/water ratio and poured into a V-shape mold, connected to an expansion-measuring device. The hygroscopic expansion was evaluated during 120 min and the collected data was converted into percentage and compared to initial dimensions of the specimen. Results: All type II and V dental stones showed expansion values compatible to the ADA and ISO recommendations. Considering type III stones, only Rutenium 3 was compatible with the recommendations. For type IV, only Durone IV showed expansion values higher than that recommended by ADA, but lower than that of ISO recommendations.Conclusion: The hygroscopic linear expansion of gypsum products should be periodically controlled in order to ensure their precision and reliability to dental practice.

Abrasive wear of two glass ionomer cements after simulated toothbrushing

Introduction and objective: Glass ionomer cement, which was first introduced in Dentistry in 1972, presents good qualities such as aesthetics, fluoride release and adhesion to dental tissues. Because of its preventive characteristics regarding to dental caries, glass ionomer cement has been used for Atraumatic Restorative Treatment (ART), as reported by Frencken and Holmgren 6, meeting the principles announced by the World Health Organization (WHO) for application to large population groups without regular access to dental care. Material and methods: In this present study, the abrasive wear strength of two glass-ionomer cements (Vidrion R® and ChemFlex®) was evaluated through toothbrushing machine. Classic® toothbrushes with soft bristles and Sorriso® dentifrice were also used for the study. Results: Student-t test showed significant difference between both groups, with tobs value = 9.4411 at p < 0.05. Conclusion: It can be concluded that the wear rate caused by toothbrush/dentifrice was higher for Vidrion R® (52.00 mg) than ChemFlex® (5.57 mg).

Técnica mista: clareamento dentário e microabrasão: relato de caso clínico / Mixed technique: tooth bleaching and microabrasion: clinical xase report

O objetivo deste trabalho é apresentar a resolução estética do caso clínico de um paciente com dentes escuros e manchas de fluorose, em que foi realizado o clareamento dentário em consultório, associado à microabrasão do esmalte. O clareamento foi efetuado nos dentes de ambas as arcadas, exceto nos molares. Após condicionamento do esmalte, o agente clareador à base de peróxido de hidrogênio a 35 por cento (Lase Peroxide Sensy, DMC Equipamentos Ltda.) foi aplicado e ativado duas vezes de 3 minutos com aparelho de luz híbrida de LED/laser de diodo terapêutico (Whitening Lase II, DMC Equipamentos Ltda.). Esse processo foi repetido cinco vezes, na mesma sessão, seguido de polimento, laserterapia e aplicação do gel dessensibilizante por 4 minutos. Em uma segunda sessão de clareamento, os caninos e pré-molares receberam mais duas aplicações do gel clareador ativado com luz híbrida. Ao final do procedimento, o paciente ainda apresentava manchas brancas nos dentes superiores, sendo realizada, no final da sessão, a microabrasão do esmalte. Ao final do tratamento, pode-se constatar resultado estético satisfatório alcançado por meio do clareamento dos dentes e remoção das manchas hipocalcificadas.

The objective of this paper was to present the esthetics resolution of a clinical case of a patient with discolored teeth and fluorosis which performed in-office tooth whitening plus enamel microabrasion. Bleaching was done in the teeth of both arches, except the molars. After etching enamel with phosphoric acid at 37% for 15 seconds, the whitening agent with 35% of hydrogen peroxide (Lase Peroxide Sensy, DMC Equipamentos Ltda) was applied twice and activated for three minutes with a hybrid LED/Laser light appliance (Whitening Lase II, DMC Equipamentos Ltda). This process was repeated five times in the same session, followed by polishing, laser therapy and application of desensitizing gel for 4 minutes. In a second session of bleaching, canines and premolars received two more applications of the whitening gel activated with hybrid light. At the end of the procedure, the patient still had white spots on the upper teeth, being held at the end of the session, the microabrasion of the enamel. At the end of treatment, one can see satisfactory final result achieved by means of teeth whitening and removal of hipocalcified stains

Resistência à tração de coroas de NiCr cimentadas sobre munhões de liga de titânio, com 4 diferentes tipos de cimentos / Tensile strength of NiCr crowns cemented upon usinated titanium alloy abutments with 4 different types of cements

Neste trabalho de resistência à tração foi avaliada a eficiência de 4 agentes cimentantes (fosfato de zinco S. S. White, ionômero de vidro Ketac Cem Easymix, resina composta/ionômero de vidro RelyX Luting 2 e resina acrílica especial Panavia 21 TC) usados para fixar coroas totais de NiCr a munhões tronco-cônicos, usinados em liga de Ti-6Al-4V. Foram utilizados 40 munhões, distribuídos em grupos de 10, para cada material. Os ensaios mecânicos foram realizados em uma máquina universal MTS 810, na velocidade de 0,5 mm/min. A respectiva Análise de Variância (ANOVA) apontou existir diferença significante entre os grupos e o teste de Tukey (p < 0,05) também mostrou diferenças significantes entre eles, exceto nas comparações fosfato versus RelyX e fosfato versus Ketac Cem. O melhor desempenho foi apresentado pela resina Panavia 21 (1.127,996 N); a resina composta/ionômero de vidro RelyX (478,197 N) mostrou comportamento similar apenas ao do fosfato (430,662 N), o qual apresentou desempenho semelhante ao ionômero de vidro Ketac Cem (227,705 N).

In this work of tensile strength was evaluated the efficacy of 4 cements (S. S. White zinc phoshate, Ketac Cem Easymix glass ionomer, RelyX Luting 2 composite resin/glass ionomer and Panavia 21 TC special acrylic resin) used to fix NiCr crowns to usinated titanium alloy abutments. Were used 40 abutments distributed in groups of 10 elements, to each material. The mechanical essays were developed at a MTS 810 universal machine, adjusted to a 0.5 mm/m velocity. The ANOVA applied to data pointed out the existence of significant differences between groups; the subsequent Tukeyïs test (p<0.05) also detected significant differences, except at comparisons of phosphate versus RelyX and phosphate versus Ketac Cem. The better performance was presented by Panavia 21 (1,127.996 N); RelyX (478.197 N) showed itself similar only to phosphate (430.662 N), wich had a performance similar to that of Ketac Cem (227.705 N).

Cimentação de coroas com fosfato de zinco sobre munhões de liga de titânio, irradiados ou não por laser / Cimentation of crowns with fosfat of zinc on abutments of titanium alloy, radiated or not for laser

Por meio de tração, coroas totais de NiCr foram removidas de munhões pré-fabricados, compostos por uma liga de Ti6Al-4V. Num total de 20 munhões, 10 foram usados com sua superfície original e 10 com sua superfície modificada por laser, ambos cimentados com fosfato do zinco. O teste mecânico foi executado em uma máquina universal MTS 810 ajustada a uma velocidade de 0,5 mm/min. A análise estatística foi feita pelo teste de Levene, o qual mostrou homogeneidade de variâncias entre os grupos (F = 2,21; p < 0,1). O subsequente teste "t" de Student mostrou haver diferenças significantes entre os grupos. A modificação da superfície dos munhões através do laser causou um aumento na resistência à tração das coroas cimentadas com fosfato de zinco, de 430,66 para 1.514,87 N.

By means of tensile strength, NiCr total crowns were removed from machine-made conical abutments composed by an Ti-6Al-4V alloy. In a total of 20 abutments, 10 were used with it surface presenting high smoothness and 10 abutments had its surfaces modified by laser both cemented with zinc phosphate. The mechanical test was performed at a MTS 810 universal machine adjusted to a speed of 0.5 mm/m. The statistical analysis was done by Levene's test, which showed homogeneity of variances among groups (F =2.21; p < 0.1). "Student t test" showed that significant differences were found between groups. The modification of the abutment surface through laser caused an increase in pull-out resistance of crowns cemented with zinc phosphate from 430.66 N to 1.514,87 N.

Avaliação da perda de peso, da rugosidade de superfície de placas de titânio, esmalte bovino, resina acrílica para base de prótese convencional e sobre implantes e PMMA após teste de abrasão por escovação simulada / Evaluation of weight loss and surface roughness of titanium plates, bovine enamel, acrylic resin for conventional and implant-supported prostheses and PMMA after abrasion test by simulated brushing

O objetivo deste estudo foi avaliar a resistência ao desgaste de placas de titânio submetidos a um teste de escovação simulada. Os materiais empregados foram o titânio, esmalte bovino e resina acrílica termopolimerizável. Para o teste de abrasão, uma máquina de escovação simulada com escovas de cerdas macias, uma solução de dentifrício e água deionizada. Foram realizados 200.000 ciclos de escovação simulada. A perda de massa foi verificada através da diferença em porcentagem entre a massa inicial (antes da escovação) e massa final (após a escovação) através de uma balança analítica Sartorius. A alteração de rugosidade superficial foi determinada pela diferença em percentagem entre as médias de rugosidade inicial e final, após 5 leituras aleatórias por espécime realizado pelo rugosímetro Hommel Tester T 1000 antes e depois do teste de abrasão. A análise estatística demonstrou que todos os materiais do estudo apresentaram perda de massa e aumento significante de rugosidade. Todos os materiais apresentaram perda de massa em relação à pasta comercial. Entre as placas de titânio, apresentaram a menor perda de massa quando escovada pela pasta teste. Os blocos de esmalte apresentaram a maior alteração de massa com diferenças estatísticas quando comparado ao titânio. Quanto à rugosidade superficial, os blocos de esmalte se tornaram mais rugosos quando escovados pela pasta comercial, porém sem diferenças estatísticas entre si. A resina acrílica escovada pela marca comercial apresentou a maior alteração de rugosidade após o teste de escovação simulada.

The aim of this study was to evaluate the wear’s resistance of titanium plates after simulated brushing. We tested titanium plates, bovine enamel and thermo-activated acrylic resin. Soft bristles toothbrushes and a toothpaste slurry were used in an automated brushing machine, which performed 200,000 strokes. Weight loss was measured by the percent difference between initial (before brushing) and final (after brushing) specimens’ mass, using an analytical scale Sartorius. Surface roughness alterations were determined by the percent differences between initial and final roughness, which was obtained after 5 random readings/specimen by the profilometer Hommel Tester T1000, before and after the abrasion test. Statistical analyses revealed that all the materials tested presented a significant decrease in weight and increase in roughness. All the materials showed weight loss in relation to the commercial toothpaste. Titanium plates presented lower weight loss when brushed with the test toothpaste. Enamel blocks had significantly higher weight loss when compared to titanium plates. Regarding surface roughness, enamel blocks became more rough when brushed with the commercial toothpaste, but this was not statistically significant. Acrylic resin brushed with the commercial toothpaste also showed higher alterations in surface roughness after toothbrushing.

Resistência ao cisalhamento por puncionamento de três agentes cimentantes analisados em dois diferentes períodos / Punch-shear strength of three luting cements evaluated at two differents periods

O cisalhamento por puncionamento é um método simples e eficaz para avaliar a resistência de um material por meio de uma carga axial aplicada para deslocar um ou vários materiais entre si. Dessa forma, o objetivo deste trabalho foi avaliar três agentes cimentantes (fosfato de zinco, ionômero de vidro e cimento resinoso), em relação ás resistências ao cisalhamento por puncionamento. Para o ensaio, foram confeccionados espécimes em uma matriz em forma de anel com dimensões de 14 mm de diâmentro interno de 1,5 mm de altura, que permitia obter um corpo de prova em formato de disco. Um conjunto matriz-cimento foi posicionado num dispositivo próprio para o teste. Dez espécimes de cada material foram avaliados em dois períodos de uma hora e 24 horas. Os resultados foram tratados estatisticamente com Análise de Variância a dois critérios (ANOVA), seguida do teste comparativo de Tukey, em nível de significância de 5 por cento. Dentre os agentes cimentantes avaliados nos dois períodos, o cimento resinoso apresentou os maiores valores de resistência ao puncionamento, e o cimento de ionômero de vidro, os menores

Clareação de dentes polpados em consultório com e sem condicionamento ácido prévio do esmalte: relato de caso clínico / Pulped teeth in-office dental bleaching with and without previous enamel acid etching: clinical case report

Este caso clínico avaliou o efeito do condicionamento prévio do esmalte com ácido fosfórico a 37%, na clareação em consultório realizada com gel de peróxido de hidrogênio a 35% e ativado com fonte de luz híbrida (led + laser terapêutico), em função da efetividade, tempo de tratamento e grau de mudança de cor. Após avaliação inicial, exame clínico e profilaxia supragengival completa, a cor foi avaliada visualmente com escala VITA Bleachedguide 3D-MASTER (VITA), quantitativamente com espectrofotômetro VITA Easyshade (VITA) e foi realizada a documentação fotográfica digital (Nikon D70s). Para efeito de comprovação, apenas os hemiarcos do lado direito receberam o condicionamento ácido prévio por 15 segundos. O gel clareador foi manipulado e aplicado sobre os dentes e, após 1 minuto, o gel foi ativado com luz híbrida durante 3 minutos. Após 1 minuto, nova ativação com luz por mais 3 minutos foi realizada. A princípio, 4 aplicações do gel foram realizadas, mas, ao final dessas, pôde-se observar que o grau de mudança de cor dos dentes nos hemiarcos do lado direito era maior que do lado esquerdo. Uma quinta aplicação foi realizada somente nos hemiarcos superior e inferior esquerdos. Pôde-se observar no hemiarco direito, no qual se realizou o ataque ácido, uma redução do número de aplicações do gel clareador. O paciente não relatou sensibilidade durante e após a clareação (24 horas e 1 semana). Após 1 semana, pôde-se verificar a efetividade da técnica em consultório empregada, além da efetividade do condicionamento ácido prévio na aceleração do procedimento clareador.

Chronic maxillary sinusitis associated with dental impression material.

A 62-year-old man was referred for routine treatment of hyperplasia of the mucosa in the anterior lower jaw. An oroantral fistula was detected in the right superior alveolar ridge. The patient had no complaints. Plain radiographs showed a radiopaque foreign body in the posterior region associated with opacification of the maxillary sinus. Computed tomography showed the same hyperdense foreign body located in the posterior lower part of the sinus and an abnormal soft tissue mass in the entire right maxillary sinus. When asked about sinusitis, the patient mentioned occasional episodes of pus taste and intermittent crises of headache lasting for one week. The patient has been edentulous for 20 years. Sinus debridement was performed and the oroantral fistula was closed. The clinical suspicion of the presence of zinc oxide-eugenol paste was confirmed by microscopical and chemical analysis. After 6 months of follow-up, the fistula continued to be closed and sinusitis did not recur. This clinical case of maxillary chronic sinusitis illustrates a different odontogenic origin.

Chronic maxillary sinusitis associated with dental impression material

A 62-year-old man was referred for routine treatment of hyperplasia of the mucosa in the anterior lower jaw. An oroantral fistula was detected in the right superior alveolar ridge. The patient had no complaints. Plain radiographs showed a radiopaque foreign body in the posterior region associated with opacification of the maxillary sinus. Computed tomography showed the same hyperdense foreign body located in the posterior lower part of the sinus and an abnormal soft tissue mass in the entire right maxillary sinus. When asked about sinusitis, the patient mentioned occasional episodes of pus taste and intermittent crises of headache lasting for one week. The patient has been edentulous for 20 years. Sinus debridement was performed and the oroantral fistula was closed. The clinical suspicion of the presence of zinc oxide-eugenol paste was confirmed by microscopical and chemical analysis. After 6 months of follow-up, the fistula continued to be closed and sinusitis did not recur. This clinical case of maxillary chronic sinusitis illustrates a different odontogenic origin (AU)

Influence of different cantilever extensions and glass or polyaramide reinforcement fibers on fracture strength of implant-supported temporary.

In long-term oral rehabilitation treatments, resistance of provisional crowns is a very important factor, especially in cases of an extensive edentulous distal space. The aim of this laboratorial study was to evaluate an acrylic resin cantilever-type prosthesis regarding the flexural strength of its in-balance portion as a function of its extension variation and reinforcement by two types of fibers (glass and polyaramid), considering that literature is not conclusive on this subject. Each specimen was composed by 3 total crowns at its mesial portion, each one attached to an implant component (abutment), while the distal portion (cantilever) had two crowns. Each specimen was constructed by injecting acrylic resin into a two-part silicone matrix placed on a metallic base. In each specimen, the crowns were fabricated with either acrylic resin (control group) or acrylic resin reinforced by glass (Fibrante, Angelus) or polyaramide (Kevlar 49, Du Pont) fibers. Compression load was applied on the cantilever, in a point located 7, 14 or 21 mm from the distal surface of the nearest crown with abutment, to simulate different extensions. The specimen was fixed on the metallic base and the force was applied until fracture in a universal test machine. Each one of the 9 sub-groups was composed by 10 specimens. Flexural strength means (in kgf) for the distances of 7, 14 and 21 mm were, respectively, 28.07, 8.27 and 6.39 for control group, 31.89, 9.18 and 5.16 for Kevlar 49 and 30.90, 9.31 and 6.86 for Fibrante. Data analysis ANOVA showed statistically significant difference (p<0.05) only regarding cantilever extension. Tukey's test detected significantly higher flexural strength for the 7 mm-distance, followed by 14 and 21 mm. Fracture was complete only on specimens of non-reinforced groups.

Effect of cervical relining of acrylic resin copings on the accuracy of stone dies obtained using a polyether impression material.

The purpose of this study was to evaluate the accuracy of the respective dies after polyether elastomeric procedure in the presence or absence of cervical contact of the acrylic resin shell with the cervical region, establishing a comparison to dies obtained with stock trays. This study consisted of three groups with 10 specimens each: 1) acrylic copings without cervical contact, (cn); 2) acrylic copings with cervical contact (cc); 3) perforated stock tray, (st). The accuracy of the resulting dies was verified with the aid of a master crown, precisely fit to the master steel die. ANOVA test found statistically significant differences among groups (p<0.001). Tukey's test found that the smallest discrepancy occurred in group cn, followed by cc, while the st group presented the highest difference (cc x cn: p=0.007; st x cn: p<0.001; st x cc: p<0.001).

Influence of different catilever extensions and glass or polyamaramid reinforcement fibers on fracture strength of implant-supported temporary

In long-term oral rehabilitation treatments, resistance of provisional crowns is a very important factor, especially in cases of an extensive edentulous distal space. The aim of this laboratorial study was to evaluate an acrylic resin cantilever-type prosthesis regarding the flexural strength of its in-balance portion as a function of its extension variation and reinforcement by two types of fibers (glass and polyaramid), considering that literature is not conclusive on this subject. Each specimen was composed by 3 total crowns at its mesial portion, each one attached to an implant component (abutment), while the distal portion (cantilever) had two crowns. Each specimen was constructed by injecting acrylic resin into a two-part silicone matrix placed on a metallic base. In each specimen, the crowns were fabricated with either acrylic resin (control group) or acrylic resin reinforced by glass (Fibrante, Angelus) or polyaramide (Kevlar 49, Du Pont) fibers. Compression load was applied on the cantilever, in a point located 7, 14 or 21 mm from the distal surface of the nearest crown with abutment, to simulate different extensions. The specimen was fixed on the metallic base and the force was applied until fracture in a universal test machine. Each one of the 9 sub-groups was composed by 10 specimens. Flexural strength means (in kgf) for the distances of 7, 14 and 21 mm were, respectively, 28.07, 8.27 and 6.39 for control group, 31.89, 9.18 and 5.16 for Kevlar 49 and 30.90, 9.31 and 6.86 for Fibrante. Data analysis ANOVA showed statistically significant difference (p<0.05) only regarding cantilever extension. Tukey's test detected significantly higher flexural strength for the 7 mm-distance, followed by 14 and 21 mm. Fracture was complete only on specimens of non-reinforced groups.

Abrasive wear of conventional glass ionomer cements / Desgaste abrasivo de cimentos de ionômetro de vidro convencionais

Este trabalho tem por finalidade avaliar a resistência abrasiva de 3 diferentes marcas de cimento de ionômero de vidro (CIV) restauradores, do tipo convencional, disponíveis no mercado nacional. Para isso foi utilizado o teste de agressividade, onde um disco dinâmico revestido com porcelana desgasta, em condições adequadamente estabelecidas, um disco estático revestido com o material restaurador estudado. Neste método valores menones de agressividade indicam maior resistência ao desgaste abrasivo. Foram confeccionados 24 corpos de provas, sendo 8 para cada marca. As marcas de CIV avaliadas foram: Vidrion R (fabricado pela empresa brasileira SSWhite), Ketac Fil Plus (fabricado pela empresa americana 3M ESPE) e Fuji IX GP (fabricado pela empresa japonesa GC), que posteriormente foi substituído pela marca Vitro Fill (fabricado pela empresa brasileira DFL Indústria e Comércio Ltda.). Os materiais foram confeccionados de acordo com as instruções dos respectivosfabricantes. Os testes foram executados em duas etapas: na primeira não houve controle do tempo de exposição ao ambiente, e as análises dos dados revelaram grande influência desta exposição na propriedade de resistência ao desgaste abrasivo. Em uma segunda etapa, o tempo de exposição foi rigidamente controlado, assim como a umidade do ar e a temperatura ambiente, desde a confecçãodos corpos de prova até a finalização dos ensaios, otendo-se assim os resultados desejados. Deste modo, além da classificação de cada marca de acordo com a resistência ao desgaste abrasivo, também foi mostrado que o tempo de exposição deste material ao ar ambiente deve receber atenção especial em trabalhos que versem sobre propriedades mecânicas do cimento de ionômero de vidro.

An evaluation was made of the abrasive strenght of three different brands of conventional glass ionomer cement (GIC) for dental restoration available on the Brazilian market. The evaluation was based on an agressiveness assay in which, under pre established conditions, a disk coated with porcelain wears down a static disk coated with the restorative material under study. According to this method, low agressiveness values indicate high abrasive wear resistance...

Influence of different cantilever extensions and glass or polyaramid reinforcement fibers on fracture strength of implant-supported temporary fixed prosthesis

In long-term oral rehabilitation treatments, resistance of provisional crowns is a very important factor, especially in cases of an extensive edentulous distal space. The aim of this laboratorial study was to evaluate an acrylic resin cantilever-type prosthesis regarding the flexural strength of its in-balance portion as a function of its extension variation and reinforcement by two types of fibers (glass and polyaramid), considering that literature is not conclusive on this subject. Each specimen was composed by 3 total crowns at its mesial portion, each one attached to an implant component (abutment), while the distal portion (cantilever) had two crowns. Each specimen was constructed by injecting acrylic resin into a two-part silicone matrix placed on a metallic base. In each specimen, the crowns were fabricated with either acrylic resin (control group) or acrylic resin reinforced by glass (Fibrante, Angelus) or polyaramide (Kevlar 49, Du Pont) fibers. Compression load was applied on the cantilever, in a point located 7, 14 or 21 mm from the distal surface of the nearest crown with abutment, to simulate different extensions. The specimen was fixed on the metallic base and the force was applied until fracture in a universal test machine. Each one of the 9 sub-groups was composed by 10 specimens. Flexural strength means (in kgf) for the distances of 7, 14 and 21 mm were, respectively, 28.07, 8.27 and 6.39 for control group, 31.89, 9.18 and 5.16 for Kevlar 49 and 30.90, 9.31 and 6.86 for Fibrante. Data analysis ANOVA showed statistically significant difference (p<0.05) only regarding cantilever extension. Tukey’s test detected significantly higher flexural strength for the 7 mm-distance, followed by 14 and 21 mm. Fracture was complete only on specimens of non-reinforced groups.