Assuntos
Cariostáticos/uso terapêutico , Cárie Dentária/prevenção & controle , Fluoretos Tópicos/uso terapêutico , Braquetes Ortodônticos/efeitos adversos , Fluoreto de Sódio/uso terapêutico , Adolescente , Análise de Variância , Criança , Cárie Dentária/etiologia , Testes de Atividade de Cárie Dentária , Feminino , Fluorescência , Humanos , Lasers Semicondutores , MasculinoRESUMO
Objetivo: avaliar a correlação entre as leituras de descalcificação artificial de esmalte in vitro por meio do DIAGNOdent® e pela microscopia óptica com luz polarizada. Metodologia: foram utilizados 25 dentes bovinos que foram expostos a um meio artificial de cáries por uma hora, duas vezes ao dia, por 35 dias. Em seguida, procedeu-se as leituras das fluorescências utilizando o aparelho laser DIAGNOdent®. Foram registradas as leituras das áreas sem descalcificação (para calibração) e as áreas desmineralizadas artificialmente. Após as leituras da fluorescência, as regiões de leitura por laser foram cortadas em secções de aproximadamente 400μm e avaliadas por meio da microscopia de luz polarizada. Resultados: demonstraram que, embora com algum grau de variação, o sistema DIAGNOdent® foi capaz de detectar as descalcificações semelhantemente àqueles reconhecidos por microscopia de luz polarizada, estabelecendo um padrão razoável de equivalência de leituras. Conclusão: os valores médios encontrados para o DIAGNOdent® demonstraram um coeficiente de correlação de Pearson de 0,63 com relação aos valores das leituras microscópicas.
Aim: evaluate the correlation between the artificial in vitro enamel decalcification through DIAGNOdent® laser and through optic microscopic with polarized light. Methodology: for this research, 25 bovine teeth had been exposed to an artificial decay environment during one hour, two times a day, for 35 days. After wards, DIAGNOdent® laser has been used to read the fluorescence from the enemel areas without decalcification (for calibration) and to evaluate the non-mineralized artificially. After the fluorescence readings regions of laser read were cut into sections of about 400μm and evaluated by polarized light microscopy. Results: the results had demonstrated that, even with some degree of variation, the DIAGNOdent® system was capable of recognizing the decalcification, establishing regular equivalence of standard readings such as light polarized microscopy. Conclusion: the average values found for DIAGNOdent® laser had demonstrated a 0,63 coefficient of correlation of Pearson to the values of microscopically readings.
Assuntos
Animais , Bovinos , Cárie Dentária/diagnóstico , Desmineralização do Dente/diagnóstico , Técnicas In Vitro , Lasers , Microscopia de Polarização , Fluorescência , Testes de Atividade de Cárie Dentária/instrumentaçãoRESUMO
Introducao: Ha uma crescente divisao dentro da nossa profissao que sofre com varias controversias perpetua, incluindo aquelas relativas ao tratamento precoce e expansivo, estetica e etica, evidencias e pericia e uma enfase no aspecto economico. Infelizmente, e o publico que deve pagar, em um variado numero de formas, proporcionais ao nivel de dialogo e aviltado casal holandes. Dependencia de depoimentos, direto ao consumidor, publicidade, publicacoes exclusivas, e grande grupo de metodos de treinamento substituindo as regras de evidencia e do metodo cientifico. Objetivo: Revisar o atual estado da arte da especialidade de ortodontia a luz da enfase tanto no consumismo com na evidencia. Conclusao: Cuidadosa avaliacao das necessidades e desejos de nossos pacientes e do nosso negocio deve ser embasada com um tratamento etico e baseado em evidencias.
Introduction: There is a growing schism within our profession that suffers at its core from several perpetual controversies including those of early and expansive treatment, esthetics and ethics, evidence and expertise, and an emphasis on economics. Unfortunately, it is the public that must pay, in a number of ways, commensurate to the level of debased dialogue and double Dutch. Reliance upon testimonials, direct-to-consumer advertising, proprietary publications, and large group awareness training methods are replacing the rules of evidence and the scientific method. If we no longer ask questions, then soon any old treatment will do. Objective: To review the current state of the art of the specialty of orthodontics in light of today's emphasis on both consumerism and evidence. Conclusion: Careful assessment of the wants and desires of our patients and our businesses must be tempered with ethical and evidence-based treatment.
Assuntos
Estatística como Assunto , Odontologia , Ortodontia , ÉticaRESUMO
A prospective examination of 10 consecutively treated orthodontic patients was undertaken to examine the effectiveness of fluoride varnish in reducing enamel demineralization. Pairs of dental quadrants for each patient's mouth (ie, maxillary right and mandibular left; maxillary left and mandibular right) were randomly assigned to an experimental or control group. After placement of resin-bonded orthodontic brackets, fluoride varnish was applied to the 2 experimental dental quadrants for each patient. Subsequent applications were done every 3 months during 12 months of orthodontic treatment. A double-blinded examination of intraoral photographs of the 100 experimental and 100 control teeth was done. The presence of white spot lesions was registered using the enamel decalcification index and the 2 groups were compared using paired Student t tests with a significance level of 5% (P < .05). There was no statistically significant difference between the mean enamel decalcification index for the control and experimental groups before or after treatment, since demineralization increased for both groups. Most importantly, the change in mean enamel decalcification index was significantly smaller for the experimental group (0.34), compared to the control group (0.51). In other words, there was 44.3% (P <.05) less demineralization noted for teeth that had been treated with fluoride varnish during orthodontic treatment.
Assuntos
Cariostáticos/uso terapêutico , Cárie Dentária/prevenção & controle , Fluoretos Tópicos/uso terapêutico , Braquetes Ortodônticos , Adolescente , Cariostáticos/administração & dosagem , Criança , Estudos Cross-Over , Cárie Dentária/patologia , Esmalte Dentário/efeitos dos fármacos , Esmalte Dentário/patologia , Método Duplo-Cego , Feminino , Fluoretos Tópicos/administração & dosagem , Seguimentos , Humanos , Masculino , Fotografia Dentária , Estudos Prospectivos , Cimentos de Resina/química , Fluoreto de Sódio/administração & dosagem , Fluoreto de Sódio/uso terapêutico , Desmineralização do Dente/patologia , Desmineralização do Dente/prevenção & controleRESUMO
The soft tissue changes after the extraction of maxillary first premolars and subsequent anterior tooth retraction were evaluated for 16 Class II, division 1 patients. Pre- and posttreatment lateral head cephalograms were evaluated using superimpositions on Björk-type metallic implants in the maxilla. The patient sample was divided into group I patients, those who did exhibit lip seal at rest in the pretreatment cephalogram and group II patients, those who did not exhibit lip seal at rest in the pretreatment cephalogram. Upper incisor retraction was followed by a similar ratio of upper lip retraction in both the lip seal and nonsealed groups (1:0.75 and 1:0.70 mean ratios, respectively). However, those without lip seal did demonstrate more retraction at stomion (USt). The final upper lip position (Ls) was reasonably correlated with retraction of the cervical maxillary incisor point (cU1) with determination coefficients of 63.6% in the lip sealed and 68.5% in the lip incompetent groups. Although labial and nasolabial angles tended to open after incisor retraction, there was little predictability for this response.
Assuntos
Implantes Dentários , Incisivo , Lábio/anatomia & histologia , Má Oclusão Classe II de Angle/terapia , Técnicas de Movimentação Dentária , Dente Pré-Molar/cirurgia , Cefalometria , Feminino , Humanos , Masculino , Maxila , Desenvolvimento Maxilofacial , Aparelhos Ortodônticos , Tantálio , Extração Dentária , Técnicas de Movimentação Dentária/instrumentação , Técnicas de Movimentação Dentária/métodosRESUMO
OBJECTIVES: To test the hypothesis that fluoride varnish is effective in reducing demineralization (white spot) lesions adjacent to bonded orthodontic brackets. DESIGN: Two similar samples of extracted bovine incisors, with bonded orthodontic brackets, were separated into an experimental group (fluoride varnish was applied) and control group (no fluoride varnish) to examine the preventive effects of fluoride varnish. SETTING AND SAMPLE POPULATION: The dental clinic of the State University of Maringá--UEM (Maringá, Paraná, Brazil). Thirty-eight extracted bovine incisors with bonded orthodontic brackets. EXPERIMENTAL VARIABLE: Fluoride varnish was applied topically to half of the sample of extracted bovine teeth. No varnish was applied to the other half. OUTCOME MEASURE: The depths of enamel demineralization (white spot) lesions were measured from polarized light microscopy images using image analysis software. RESULTS: The teeth in both the experimental and control groups had been exposed to a cariogenic environment twice a day for 35 days. Those teeth that had been treated with two applications of fluoride varnish (one at the outset and another 15 days later) demonstrated about 38% less mean lesion depth than teeth where no varnish had been applied. CONCLUSION: Orthodontists may wish to consider the application of fluoride varnish during fixed orthodontic therapy to help reduce the development of enamel white spot lesions.
Assuntos
Cariostáticos/uso terapêutico , Esmalte Dentário/efeitos dos fármacos , Fluoretos Tópicos/uso terapêutico , Braquetes Ortodônticos , Desmineralização do Dente/prevenção & controle , Animais , Bovinos , Colagem Dentária , Cárie Dentária/prevenção & controle , Processamento de Imagem Assistida por Computador , Laca , Microscopia de Polarização , Saliva Artificial/química , Escovação DentáriaRESUMO
The malarial parasite Plasmodium vivax causes disease in humans, including chronic infections and recurrent relapses, but the course of infection is rarely fatal, unlike that caused by Plasmodium falciparum. To investigate differences in pathogenicity between P. vivax and P. falciparum, we have compared the subtelomeric domains in the DNA of these parasites. In P. falciparum, subtelomeric domains are conserved and contain ordered arrays of members of multigene families, such as var, rif and stevor, encoding virulence determinants of cytoadhesion and antigenic variation. Here we identify, through the analysis of a continuous 155,711-base-pair sequence of a P. vivax chromosome end, a multigene family called vir, which is specific to P. vivax. The vir genes are present at about 600-1,000 copies per haploid genome and encode proteins that are immunovariant in natural infections, indicating that they may have a functional role in establishing chronic infection through antigenic variation.
Assuntos
Genes de Protozoários , Plasmodium vivax/genética , Adulto , Animais , Anticorpos Antiprotozoários/imunologia , Cromossomos Artificiais de Levedura , DNA de Protozoário , Biblioteca Gênica , Variação Genética , Humanos , Malária Vivax/parasitologia , Família Multigênica , Plasmodium falciparum/genética , Plasmodium falciparum/patogenicidade , Plasmodium vivax/imunologia , Plasmodium vivax/patogenicidade , Proteínas de Protozoários/genética , Proteínas de Protozoários/imunologia , Pseudogenes , Reação em Cadeia da Polimerase Via Transcriptase Reversa , TelômeroRESUMO
OBJECTIVES: To determine whether a continuous i.v. infusion of cimetidine, a histamine-2 (H2) receptor antagonist, is needed to prevent upper gastrointestinal (GI) hemorrhage when compared with placebo and if that usage is associated with an increased risk of nosocomial pneumonia. Due to the importance of this latter issue, data were collected to examine the occurrence rate of nosocomial pneumonia under the conditions of this study. DESIGN: A multicenter, double-blind, placebo-controlled study. INTERVENTIONS: Patients were randomized to receive cimetidine (n = 65) as an iv infusion of 50 to 100 mg/hr or placebo (n = 66). SETTING: Intensive care units in 20 institutions. PATIENTS: Critically ill patients (n = 131), all of whom had at least one acute stress condition that previously had been associated with the development of upper GI hemorrhage. MEASUREMENTS AND MAIN RESULTS: Samples of gastric fluid from nasogastric aspirates were collected every 2 hrs for measurement of pH and were examined for the presence of blood. Upper GI hemorrhage was defined as bright red blood or persistent (continuing for > 8 hrs) "coffee ground material" in the nasogastric aspirate. Baseline chest radiographs were performed and sputum specimens were collected from all patients, and those patients without clear signs of pneumonia (positive chest radiograph, positive cough, fever) at baseline were followed prospectively for the development of pneumonia while receiving the study medication. Cimetidine-infused patients experienced significantly (p = .009) less upper GI hemorrhage than placebo-infused patients: nine (14%) of 65 cimetidine vs. 22 (33%) of 66 placebo patients. Cimetidine patients demonstrated significantly (p = .0001) higher mean intragastric pH (5.7 vs. 3.9), and had intragastric pH values at > 4.0 for a significantly (p = .0001) higher mean percentage of time (82% vs. 41%) than placebo patients. Differences in pH variables were not found between patients who had upper GI hemorrhage and those patients who did not, although there was no patient in the cimetidine group who bled with a pH < 3.5 compared with 11 such patients in the placebo group. Also, the upper GI hemorrhage rate in patients with one risk factor (23%) was similar to that rate in patients with two or more risk factors (25%). Of the 56 cimetidine-infused patients and 61 placebo-infused patients who did not have pneumonia at baseline, no cimetidine-infused patient developed pneumonia while four (7%) placebo-infused patients developed pneumonia. CONCLUSIONS: The continuous i.v. infusion of cimetidine was highly effective in controlling intragastric pH and in preventing stress-related upper GI hemorrhage in critically ill patients without increasing their risk of developing nosocomial pneumonia. While the number of risk factors and intragastric pH may have pathogenic importance in the development of upper GI hemorrhage, neither the risk factors nor the intragastric pH was predictive. Therefore, short-term administration of continuously infused cimetidine offers benefits in patients who have sustained major surgery, trauma, burns, hypotension, sepsis, or single organ failure.