Placas maxilo-dentárias em Rincossauros Hyperodapedon Huxley, 1859. Histologia e morfogênese maxilo-dental: nova abordagem.

O estudo das estruturas da placas maxilo-dentárias dos rincossauros Hyperodapedon Huxley, 1859, do Triássico da Formação Santa Maria, em nova abordagem histológica e ontogênica resultou na identificação da natureza do esmalte aprismático verdadeiro, de variados elementos histológicos dentinários e osteológicos, e de um centro de ossificação periosteal primário. Também foram encontradas evidências histológicas dos mecanismos de fusionamento maxilo-dentinário e amelo-maxilar. Com estes elementos, inferimos os modelos de organogênese dental, da ontogênese maxilar e dos mecanismos de fusionamento maxilodental. Encontrou-se uma singular e raríssima coroa dental, imatura e ainda não erupcionada, na região posterior da placa dental e assim evidenciou-se a correta posição da margem odontogenicamente ativa. Adicionalmente inferiu-se a localização da posição da lâmina dentária embrionária. Constatou-se a não formação de alvéolos dentários, de cemento radicular e do espaço necessário à formação do ligamento periodontal e, assim, se deduziu a não formação do folículo dental embriônico. As presenças de especiais elementos anatômicos e histológicos nos tecidos ósseos periapicais evidenciam o crescimento radicular contínuo, enquanto a forma e o fusionamento radicular imediato depõe a favor de uma função dentária fisiológica diferenciada para as baterias dentárias maxilares dos Rincossauros do gênero Hyperodapedon. Os mecanismos que possibilitaram o controle embriônico para a deposição das lamelas de tecido ósseo coronal e seu preciso fusionamento sobre o esmalte dentário, declinam por modificações nas funções tardias do órgão reduzido do esmalte e pela presença de uma membrana oral com funções osteogênicas e também protetivas, situada nas porções posteriores da placa maxilo-dentária em desenvolvimento. Mudanças heterocrônicas no tempo de diferenciação das células da crista neural embriônica e em seus derivados, como a lâmina dentária e órgãos dentários embrionários ou correlacionadas com a organogênese das placas maxilo-dentárias e seus anexos periodontais, todos como condições plesiomórficas para Diápsidas Triássicos, poderiam ser as causas responsáveis pela origem e evolução deste estranho aparelho estomatognático nos clados de Hyperodapedon sp..

Efeito de diferentes posologias do verniz de clorexidina a 1% nos níveis de estreptococos do grupo mutans na saliva e no biofilme dental

Não há concordância em relação ao número total e intervalo entre as aplicações do verniz de clorexidina (CLX) a 1%. Além disso, os resultados quanto ao período de redução dos níveis de estreptococos do grupo mutans (EGM) na saliva ou biofilme dental são controversos. O objetivo do presente trabalho foi avaliar, através de um estudo clínico randomizado e controlado, o efeito de diferentes posologias do verniz de CLX a 1% nos níveis de EGM. Pacientes com níveis de EGM ≥ 105 UFC/ml saliva, 11-16 anos, foram distribuídos em 4 grupos: grupo A (n=14): 1 aplicação do verniz de CLX; grupo B (n=14): 1 aplicação diária do verniz CLX, em 3 dias consecutivos; grupo C (n=15): 3 aplicações do verniz CLX com intervalo de 4 dias entre cada aplicação; grupo D (n=12): 1 aplicação diária do verniz placebo, em 3 dias consecutivos. Amostras de saliva e biofilme dental foram coletadas no início do estudo e 1, 4 e 8 semanas após o término das aplicações e foram cultivadas para avaliação dos níveis de EGM e bactérias totais. Os dados foram avaliados através do teste ANOVA (medidas repetidas) e teste de Tukey. Após 1 semana, observou-se uma leve redução nos níveis salivares de EGM nos grupos A, B e C (-0,70; -0,90; -0,41 log10 UFC/ml saliva; respectivamente), significativa somente nos grupos A e B (p < 0,05). Não foram observadas diferenças nos níveis salivares de EGM entre os grupos experimentais nos diferentes períodos do experimento. No biofilme dental, 1 semana após o término do tratamento, foi observado um aumento significativo nos níveis de bactérias totais em todos os grupos experimentais e uma redução significativa nos níveis de EGM apenas no grupo A. O verniz de CLX a 1% resultou em uma leve e curta redução nos níveis de EGM. Este estudo demonstrou que repetidas aplicações do verniz de clorexidina a 1% não aumentam o seu efeito na redução dos níveis de EGM.

Estudo de utilização de heparinas para profilaxia de tromboembolia venosa em procedimentos cirúrgicos realizados no Hospital de Clínicas de Porto Alegre

Introdução: Ensaios clínicos comprovam que, na ausência de profilaxia, a incidência média de trombose venosa profunda (TVP) pode chegar a 19% em pacientes cirúrgicos. Apesar da existência de recomendações que orientam a prescrição de esquemas profiláticos, estudos mostram que apenas um terço dos pacientes recebem profilaxia adequada. Objetivo: Avaliar a utilização de heparinas para profilaxia cirúrgica em pacientes do Hospital de Clínicas de Porto Alegre (HCPA), comparando a prescrição com recomendações pré-estabelecidas pela Comissão de Protocolos do HCPA e recomendações descritas na literatura. Metodologia: O alvo dessa pesquisa foram pacientes com idade superior a 12 anos, de ambos os gêneros, submetidos a colecistectomias, curetagens uterinas, histerectomias, transplantes renais ou cirurgias de quadril no ano de 2003. Os prontuários foram localizados no Serviço de Arquivo Médico em Saúde (SAMIS). Foram analisadas as indicações e as prescrições de heparinas feitas para esses pacientes, comparando-as com as preconizadas pelas recomendações interna e externa. Para análise estatística, foi desenvolvido banco de dados no programa EpiInfo 6.0. Resultados: A amostra foi composta por 333 pacientes, predominantemente do sexo feminino (80,8%), com idade média de 42,8 (12-92) anos. Duzentos e cinqüenta e um (75,4%) apresentaram indicação para uso de profilaxia, dos quais 114 apresentaram paralelamente contra-indicação para essa prescrição. Apenas 95 (28,5%) pacientes fizeram uso de anticoagulantes. O fármaco mais utilizado foi heparina não-fracionada, na dose de 5.000 UI, com intervalo de 12 horas. A duração média da profilaxia foi 4,5 dias (1 a 20 dias). O seguimento da recomendação interna (esquema + indicação) ocorreu em 33,3% dos casos e da recomendação externa, em 25,2%. Momento de início da profilaxia foi o item do esquema de administração em que houve maior inconformidade. O uso de métodos profiláticos não-farmacológicos foi menor que o preconizado. Discussão e Conclusão: Os resultados encontrados estão de acordo com os de estudos semelhantes publicados na literatura e demonstram que, apesar do conhecimento existente, a prática de prescrição ainda não reflete os avanços da área. Para adequar a profilaxia, é de fundamental importância maior detalhamento e divulgação das recomendações entre os prescritores.

Efetividade da doxiciclina na profilaxia contra letptospirose

Leptospirosis is a worldwide zoonosis of considerable medical and economical importance that affects humans in both urban and rural contexts, as well as domestic animals and wild fauna. Leptospira interrogans is the causative agent and is transmitted to humans by indirect contact with contaminated soil or water. The clinical syndromes include sub clinical infection, self-limited anicteric febrile illness, and severe and potentially fatal illness, known as Weil´s syndrome. In developed countries, leptospirosis is related to occupational or recreational activities while in developing countries, outbreaks occur during floods. In those regions, traditional strategies to prevent the transmission are difficulties to be implemented because of costs and lack of community acceptance. In addition, no efficient vaccine is available for human use. Several studies have suggested that chemoprophylaxis with doxycycline pre and post-exposure may be effective to prevent leptospirosis. Leptospirosis has been reported in rural areas of the State of Rio Grande do Norte, Brazil since 1985 in rice farmers who present the anicteric illness. The disease cause great social and economics impact. The study was conducted in São Miguel where an epidemic of leptospirosis in rice farmers was reported. The main objective was to determine the efficacy of doxycycline in preventing Leptospira exposure. A taxa de soroprevalência de leptospirose na população estudada antes e após a colheita foi de 14,2% (n=22) e de 16.6% (n=27) respectivamente. Anti-Leptospira serology was determined for 61 subjects in two instances, pre and post-exposure to potential contaminated water. There was an increased risk of 29.0 per cent in acquiring infection for individuals that did not use doxycycline. In addition, an increased risk of 30.0 % observed in farmers who did not use protection when exposed to Leptospira. The adhesion to preventive chemoprophylaxis was 55.7%. Therefore doxycycline, under specific circunstances appears to be an effective alternative to protect against leptosprirosis infection. A large sample composed of individuals to adhere to preventive therapy is needed to define time, dosage and length of use of doxycycline in this area

Novos monômeros obtidos a partir do metacrilato de glicidila, bisfenol A e 4, 4 isopropilidenodicicloexanol : síntese, caracterização estrutural e propriedades de compósitos para utilização em resinas de restauração dental

Nowadays, composite resins are the direct restorative materials more important in dental clinical performance, due to their versatility and aesthetic excellence. Bis-GMA (2,2-bis[4(2-hydroxy-3-metacryloxypropoxy)phenil]propane) is the base monomer more frequently used in restorative composite resins. However, this monomer presents some disadvantages, such as high viscosity and two aromatic rings in its structure that can promote allergic reactions to the humans. In this work, the main purpose was to synthesize new monomers from glycidyl methacrylate to use in dental restorative materials. Structural characterization of the monomers was carried out through FTIR and NMR 1H, and eight composites were produced from the new monomers, by addition of silane-treated alumino silicate particles (inorganic filler) and a photocuring system (camphorquinone and ethyl 4-dimethylaminebenzoate). The composites were analyzed by environmental scanning electronic microscopy and the water sorption and solubility, compressive strength and elastic modulus were determined. A commercial composite resin [Z100 (3M)] was used to comparison effect. The new composites presented general characteristics similar to the commercial ones; however, they didn t present the properties expected. This behavior was attributed to the lower degree of monomer reaction and to the granulometry and size distribution of the mineral filler in the polymeric matrix

Determinação da idade dental de crianças brasileiras nordestinas: novos valores de conversão de maturidade dental para população específica

Since Demirjian's system of estimating dental maturity was first described, many researchers from different countries have tested its accuracy among diverse populations. Some of these studies have pointed out a need to determine population-specific standards. In Brazil, the Northeast region is the one that most suffers the negative impact of exodus, specially related to the increase of abandoned children in the cities. The aim of this study was to test the accuracy of Demirjian's system for assessing the dental maturity of northeastern Brazilian children, so as to present a scale for maturity score conversion into dental age developed specifically for this population. This could be used for forensic, anthropological and legal matters, and also as a model for other countries attempting to formulate their own conversion scales. Panoramic radiographs of 1,491 children (821 females and 670 males), aged 7 to 13 years, from Ceará state, northeast Brazil, were assessed by a single observer to determine dental age (DA) according to Demirjian's system. The mean percentage of intra-observer agreement was 86.6%, with a mean Cohen's Kappa coefficient of 0.67 (substantial agreement). The DA was compared by paired t-test to subjects' chronological age (CA). The differences between CA and DA in all age groups were statistically significant (p<0.0001), demonstrating a great advancement in DA among Brazilians. Scatter plots were drawn for both genders, and the data were fitted to a growth curve, y = 100/ (1 + e-a(x b)). Graphs corresponding to the 50th percentile curves were produced. A table with new values for the conversion of maturity score into dental age for northeastern Brazilian children is presented. The great advancement in DA, as obtained by Demirjian's system in this population, justified the determination of specific scores for dental maturity assessment

Isolation of Pseudomonas aeruginosa strains from dental office environments and units in Barretos, state of São Paulo, Brazil, and analysis of their susceptibility to antimicrobial drugs

Uma ampla variedade de patógenos oportunistas tem sido detectadas nos tubos de alimentação de água dos equipos odontológicos, particularmente no biofilme formado na superfície do tubo. Entre os patógenos oportunistas encontrados nos tubos de água, Pseudomonas aeruginosa é reconhecida como uma das principais causadoras de infecções nosocomiais. Foram coletadas 160 amostras de água e 200 amostras de fomites em quarenta clinicas odontológicas na cidade de Barretos, São Paulo, Brasil, durante o período de Janeiro a Julho de 2005. Setenta e seis cepas de P. aeruginosa, isoladas a partir dos fomites (5 cepas) e das amostras de água (71 cepas), foram analisadas quanto à susceptibilidade à seis drogas antimicrobianas freqüentemente utilizadas para o tratamento de infecções provocadas por P. aeruginosa. As principais suscetibilidades observadas foram para a ciprofloxacina, seguida pelo meropenem. A necessidade de um mecanismo efetivo para reduzir a contaminação bacteriana dentro dos tubos de alimentação de água dos equipos odontológicos foi enfatizada, e o risco da exposição ocupacional e infecção cruzada na prática odontológica, em especial quando causada por patógenos oportunistas como a P. aeruginosa foi realçado.

Genetic relatedness of commensal strains of Candida albicans carried in the oral cavity of patients' dental prosthesis users in Brazil

The aim of this study is to describe the degree of yeast-colonization in diabetic and hemodialysed-users of dental prostheses. Individuals (306) were examined using an oral rinse technique in order to evaluate the incidence of yeast-carriage, and genotype of C. albicans. Yeasts were isolated from 68.4% (91/133) individual's dental prostheses users. Dental prostheses were found to be a significant factor for the yeast colonization (P < 0.05). Overall, the intensity of carriage was higher in diabetic patients as compared with health and hemodialysed individuals (P < 0.05). The isolation rates were: C. albicans (51.7%), C. parapsilosis (20.9%), C. tropicalis (14.3%), C. glabrata (6.6%), C. krusei (3.3%), C. rugosa (1.1%), and Pichia (Pichia ohmeri, 2.2%). Ready-To-Go RAPD Analysis Beads were used and primer OPJ 6 distinguished the C. albicans isolates found in prostheses users. All the isolates were grouped into 11 RAPD profiles in four main clusters and, the average S (AB) for the entire collection of 47 C. albicans isolates were 0.779 +/- 0.178. Over 85% of isolates had a similarity level higher than or equal to 0.8 reinforcing the idea that the use of dental prostheses, independently of the host's clinical condition, probably provides the necessary conditions for these strains to gain a growth-specific advantage over others.

Surface dental enamel lead levels and antisocial behavior in Brazilian adolescents

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação clínica da relação entre o índice de placa, índice gengival, alinhamento dental, mucosa ceratinizada, tipo de periodonto e distúrbios oclusais com a ocorrência de recessão gengival

This study clinically evaluated the relationship of gingival recessions with the periodontal index of gingival and plaque, dental alignment, keratinized mocous, type of periodontal, and occlusal disorders. Study participants were individuals aged between 19 and 33 years. The evaluations were performed by using questionnaires and clinical examinations. In subjects examined, the teeth were assessed and divided into groups (Molars, premolars, canines and incisors). The gingival recession were measured in the central region of the teeth and individuals were subject to disclosure to the plate and observing the poll of plaque and gingival index, respectively. 558 teeth were examined, with 24.1%, 135 had gingival recession greater than or equal to 1mm. Through the combination of tests used to evaluate the average of the recession and its relationship with the variables studied, we observed that the degree of recession of the elements assessed dental showed, almost for the most part, when higher values associated with the index plaque (p = 0.101), Gingival Index (p = 0.053), dental alignment (p = 0.962), width of keratinized mocous (p = 0.004) and type of periodontium (p = 0.033), however statistically significant difference could only be considered when related the recessions in the keratinized mocous and the type of the periodontium. Although we identify, when we evaluate the whole set of teeth that occlusal disturbances (p = 0.002) were more strongly associated with cases of gum recession that the gingival index (p = 0.006), however, these two conditions were correlated with the cases of recession, contributing to its occurrence

Recovery of silver residues from dental amalgam

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Qualidade de vida, eficiência mastigatória e presença de disfunção temporomandibular em usuários de prótese parcial removível com arco dental curto inferior

Even nowadays there is in Brasil a large number of edentulous and a precarious financial condition of most of the population. In addition, World Health Organization aims for oral health, which consists on the maintenance of a natural dentition, functional and aesthetic composed of at least 20 teeth, without need of prosthetic intervention throughout life. From this and considering the lack of researches about the permanence of edentulous spaces in the oral cavity, and also avoiding overtreatment, this research has been proposed. Thus, the aim was to evaluate the effect of different lengths of the shortened lower dental arch in the presence or absence of a removable partial denture (RPD) on masticatory function, quality of life and occurrence of temporomandibular dysfunction. To achieve this goal, we compared the masticatory efficiency (colorimetric test), the oral comfort through the analysis of the impact of oral health in quality of life (OHIP-14), the presence of temporomandibular dysfunction (RDC/TMD) and the general quality of life (WHOQOL) of patients with shortened dental arches (SDA) (n=60), which is an arch with a reduction of teeth starting posteriorly, and patients with complete dental arch (Complete DA) (n = 34). The group of patients whit SDA was divided among PPR wears (PPD + SDA) (n = 17) and non-wears (n = 43). The population of this study consisted on patients who received or looked for treatment at the clinics of the Department of Dentistry of UFRN, from clinical analysis and records. The sample was chosen by convenience. For statistical analysis, it was a database in SPSS 17.0, followed by descriptive analysis with frequencies, absolute values, tests of central tendency and variability. The statistical tests used were chi-squared and analysis of variance as well as Tukey s post test, when applicable, all with a 95% confidence level. The results shown a prevalence of TMD of 47,1% among patients using PRP and 69,8% among those who didn t, but this result wasn t statistically significant. The mean of the results of masticatory efficiency, WHOQOL and OHIP didn t show association to the presence or absence of PPR and to the lower number of occlusal units of the patients (0, 1, 2 or more occlusal). The association only occurred among the different groups of SDA and the patients with complete dental arch. Taking into account the results, it could be observed that studied patients with low posterior support using lower PRP didn t have better masticatory efficiency, general quality of life, less impacts of their oral conditions in quality of life or not even less temporomandibular dysfunction or better masticatory efficiency when compared to those who didn t use the prosthesis

Avaliação clínica longitudinal do periodonto de dentes pilares e não pilares de próteses parciais removíveis

The literature has shown a relation between periodontics and the removable partial denture (RPD), with progressive destruction observed in the support structures. The aim of this study was to clinically assess periodontal condition in users of removal partial denture (RPD), and compare right abutments teeth, indirect abutments and controls before installation and after 1 year, in addition to comparing tooth-supported and tooth mucosa-supported abutments. A total of 50 patients, 32 women and 18 men, mean age of 45 years, took part in the study. The patients were examined by a single examiner at prosthesis installation and after 3, 6, 9 and 12 months. The following were verified at each examination: Probe Depth (PD), Plaque Index (PI), Gingival Index (GI), the amount of Keratinized Mucosa (KM), Gingival Recession (GR) and Dental Mobility (DM); in addition patients received oral hygiene orientation, accompanied by prophylaxis, periodontal scaling and root planing (PSRP), when necessary. Analysis of Variance (ANOVA) with Tukey-Kramer post test was used to assess the dependent variables (PD, PI, KM, GR) of the three groups over time while Friedman s test was used for GI. To assess the outcomes of prosthesis type in the right abutment group, a confidence interval-based analysis was performed. The results showed that the control group was the least compromised in all the variables studied. With respect to development of the groups over time, it was verified that the measures for GR, PD, GI and KM increased from initial examination to 1 year of use in all the groups, but only PI showed a significant increase. There was a non-discriminatory low prevalence of dental mobility. The tooth mucosa-supported prosthesis had significantly higher values for GR, GI and PI and significantly lower ones for KM when compared to tooth-supported. Over time, both types of prostheses showed no significant differences from initial to final examination for the variables GR, PD, KM and GI, with PI significant only for tooth-supported. The results showed that the teeth most involved in RPD design had greater potential of periodontal damage, probably because of greater dental biofilm accumulation. Abutments elements adjacent to the free extremities had less favorable periodontal condition than those adjacent to interpolated spaces, but the use of RPD did not worsen the initial condition

Finite-Element Analysis of Stress on Dental Implant Prosthesis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Wear resistance of experimental titanium alloys for dental applications

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)