Action of food preservatives on 14-days dental biofilm formation, biofilm vitality and biofilm-derived enamel demineralisation in situ

AIMS The aims of this double-blind, controlled, crossover study were to assess the influence of food preservatives on in situ dental biofilm growth and vitality, and to evaluate their influence on the ability of dental biofilm to demineralize underlying enamel over a period of 14 days. MATERIALS AND METHODS Twenty volunteers wore appliances with six specimens each of bovine enamel to build up intra-oral biofilms. During four test cycles of 14 days, the subjects had to place the appliance in one of the assigned controls or active solutions twice a day for a minute: negative control 0.9 % saline, 0.1 % benzoate (BA), 0.1 % sorbate (SA) and 0.2 % chlorhexidine (CHX positive control). After 14 days, the biofilms on two of the slabs were stained to visualize vital and dead bacteria to assess biofilm thickness (BT) and bacterial vitality (BV). Further, slabs were taken to determine mineral loss (ML), by quantitative light-induced laser fluorescence (QLF) and transversal microradiography (TMR), moreover the lesion depths (LD). RESULTS Nineteen subjects completed all test cycles. Use of SA, BA and CHX resulted in a significantly reduced BV compared to NaCl (p < 0.001). Only CHX exerted a statistically significant retardation in BT as compared to saline. Differences between SA and BA were not significant (p > 0.05) for both parameters. TMR analysis revealed the highest LD values in the NaCl group (43.6 ± 44.2 μm) and the lowest with CHX (11.7 ± 39.4 μm), while SA (22.9 ± 45.2 μm) and BA (21.4 ± 38.5 μm) lay in between. Similarly for ML, the highest mean values of 128.1 ± 207.3 vol% μm were assessed for NaCl, the lowest for CHX (-16.8 ± 284.2 vol% μm), while SA and BA led to values of 83.2 ± 150.9 and 98.4 ± 191.2 vol% μm, respectively. With QLF for both controls, NaCl (-33.8 ± 101.3 mm(2) %) and CHX (-16.9 ± 69.9 mm(2) %), negative values were recorded reflecting a diminution of fluorescence, while positive values were found with SA (33.9 ± 158.2 mm(2) %) and BA (24.8 ± 118.0 mm(2) %) depicting a fluorescence gain. These differences were non-significant (p > 0.05). CONCLUSION The biofilm model permited the assessment of undisturbed oral biofilm formation influenced by antibacterial components under clinical conditions for a period of 14 days. An effect of BA and SA on the demineralization of enamel could be demonstrated by TMR and QLF, but these new findings have to be seen as a trend. As part of our daily diet, these preservatives exert an impact on the metabolism of the dental biofilm, and therefore may even influence demineralization processes of the underlying dental enamel in situ.

Estudo do efeito de máscara e do efeito terapêutico de dois colutórios na redução da halitose

Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz

A colocação de implantes em medicina dentária

Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz

A multigene family encoding R-SNAREs in the ciliate Paramecium tetraurelia

SNARE proteins (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) mediate membrane interactions and are conventionally divided into Q-SNAREs and R-SNAREs according to the possession of a glutamine or arginine residue at the core of their SNARE domain. Here, we describe a set of R-SNAREs from the ciliate Paramecium tetraurelia consisting of seven families encoded by 12 genes that are expressed simultaneously. The complexity of the endomembrane system in Paramecium can explain this high number of genes. All P. tetraurelia synaptobrevins (PtSybs) possess a SNARE domain and show homology to the Longin family of R-SNAREs such as Ykt6, Sec22 and tetanus toxin-insensitive VAMP (TI-VAMP). We localized four exemplary PtSyb subfamilies with GFP constructs and antibodies on the light and electron microscopic level. PtSyb1-1, PtSyb1-2 and PtSyb3-1 were found in the endoplasmic reticulum, whereas PtSyb2 is localized exclusively in the contractile vacuole complex. PtSyb6 was found cytosolic but also resides in regularly arranged structures at the cell cortex (parasomal sacs), the cytoproct and oral apparatus, probably representing endocytotic compartments. With gene silencing, we showed that the R-SNARE of the contractile vacuole complex, PtSyb2, functions to maintain structural integrity as well as functionality of the osmoregulatory system but also affects cell division.

Morfometria dos forames mandibular, mentual e infraorbital de Lobo-guará Chrysocyon brachyurus, Illiger, 1815 aplicada a bloqueios anestésicos

CHAPTER II - The Chrysocyon brachyurus is the biggest South American canid which has a high frequency of dental injuries, both in wild and captivity. Thus, veterinary procedures are necessary to preserve the feeding capacity of hundreds of captive specimens worldwide. The aim of this study was to study the mandibular morphometry of maned wolf with emphasis on the establishment of anatomic references to the anesthetic blockage of the inferior alveolar and mental nerves. Therefore, 15 measurements in 22 hemimandibles of C. brachyurus adults were taken. For extra-oral technique of blockage of the inferior alveolar nerve at the level of the mandibular foramen, it is stated that the needle should be advanced, close to the medial surface of the mandibular ramus, by 11.4 mm perpendiculary from the palpable concavity. Alternatively, the needle can be introduced for 30.4 mm from the angular process at 20-25 degrees angle with the ventral margin. For blocking only the mentual nerve, it is recommended the introduction of needle for 10 mm, close to the lateral aspect of the mandibular body, at the level of the lower first premolar. The mandibular foramen showed similars position, size and symmetry in the maned wolfs specimens examined. The comparison of the data with those available for other carnivores reflects the necessity for determining these anatomical references specifically for each species.

Dor de origem endodôntica: caso clínico

O objeto apresenta um caso clínico que demonstra uma situação de evento agudo relacionado à dor de origem endodôntica que seja comum de ocorrer nos atendimentos da Atenção Básica, permitindo que o dentista o conheça com mais detalhes, assim como as providências e encaminhamentos necessários para um atendimento eficaz. Para contextualizar, expõe os acontecimentos que envolvem a dor sentida pela personagem Regina de Souza, cujos motivos de consulta na Unidade de Saúde foram assimetria facial, edema extra-oral no lado direito, febre e dificuldade para abrir a boca. Na apresentação, o dentista inicia uma anamnese buscando a história pregressa, relacionando as doenças pré-existentes, e realiza procedimentos como inspeção visual extra-oral e inspeção intra-oral. O objeto lembra que o atendimento clínico deve ocorrer com anestesia local e isolamento do dente, além de abordar diagnóstico, conduta clínica inicial, encaminhamentos e ações de prevenção. Ao final do estudo, o dentista deve estar apto a realizar o atendimento inicial ao usuário, classificar o grau de comprometimento dos tecidos afetados, realizar o atendimento inicial com medidas locais, prescrição de medicamentos e cuidados pertinentes ao caso, além de realizar o subsequente encaminhamento à unidade especializada. Para instigar a reflexão, expõe perguntas balizadoras que auxiliam a compreensão do tema, auxiliando para que o profissional se sinta preparado para avaliar os sinais de alerta relacionados à dor de origem endodôntica.

Trauma dental: caso clínico

O objeto apresenta um caso clínico com o objetivo de contextualizar um evento agudo relacionado a um trauma dental, contando a história do personagem Tiago de Souza, que, num acidente em casa, tem os dentes frontais superiores quebrados e, devido ao sangramento, vai com a sua mãe, Dona Regina, à Unidade de Saúde. O dentista inicia uma anamnese buscando a história do trauma e o relato de doenças pré-existentes, além do uso de medicação de algum tipo e se há registro de alergias. Em seguida, realiza procedimentos como inspeção visual extra-oral e inspeção intra-oral. O objeto contempla também observações sobre o atendimento clínico, o diagnóstico, a conduta clínica inicial e os encaminhamentos. Ao final do estudo, o dentista deve estar apto a realizar o atendimento inicial ao paciente portador de fratura dental, classificar o grau de comprometimento dos tecidos bucais e dentais afetados e realizar o atendimento inicial com medidas locais e cuidados pertinentes ao caso. Para finalizar, o objeto expõe perguntas balizadoras que auxiliam a compreensão do caso, proporcionando um espaço para reflexão, auxiliando para que o profissional se sinta preparado para avaliar os sinais de alerta relacionados ao trauma dental.

Trauma de face: caso clínico

O objeto apresenta um caso clínico que demonstra uma situação de evento agudo relacionado a trauma de face, permitindo que o dentista conheça com mais detalhes o tema abordado. Para contextualizar, expõe os acontecimentos que envolvem o trauma sofrido por Tiago de Souza, que cai de bicicleta e, devido a um corte profundo no queixo e ao sangramento, é levado por sua mãe às pressas à Unidade de Saúde. O objeto destaca a anamnese, a limpeza e a avaliação da ferida, a inspeção visual extra-oral e a inspeção visual intra-oral, além de abordar o atendimento clínico, o diagnóstico, a conduta clínica inicial e os encaminhamentos referentes ao caso. Ao final do estudo, o dentista deve estar apto a realizar o diagnóstico correto e o atendimento inicial do paciente com fratura de côndilo, além de tomar as medidas necessárias para o seu encaminhamento e acompanhamento. Para finalizar, o objeto expõe perguntas balizadoras que auxiliam a compreensão do tema, auxiliando para que o profissional se sinta preparado para realizar o diagnóstico correto e o atendimento do paciente com a fratura exemplificada.

Dor de origem periodontal e na mucosa: caso clínico

O objeto apresenta um caso clínico com o objetivo de contextualizar um evento agudo relacionado a dor de origem periodontal e na mucosa, contando a história da personagem Mônica da Silveira, recepcionista da Unidade de Saúde, cujo motivo da consulta era dor contínua, espontânea e intensa, localizada próximo à base da mandíbula, além de febre e dificuldade de engolir. O dentista inicia a anamnese e, depois, realiza inspeção visual extra-oral e inspeção visual intra-oral. O objeto orienta que o dentista deve estar preparado para realizar o atendimento do paciente que se apresenta com dor de origem periodontal, sendo capaz de realizar diagnóstico, atendimento inicial com medidas locais e prescrição de medicamentos, além de cuidados pertinentes ao caso e subsequentes encaminhamentos. Para finalizar, o objeto expõe perguntas balizadoras que auxiliam a compreensão do caso, proporcionando um espaço para reflexão, abordando inclusive a indagação sobre procedimentos e orientações que devem ser realizados na Atenção Básica antes de os pacientes com quadros periodontais agudos serem encaminhados para o Centro de Especialidades Odontológicas (CEO) para atenção especializada.

Intra-epithelial CD8+ T cells and basement membrane disruption in oral lichen planus

Background: We investigated basement membrane (BM) disruption and the distribution of mast cells (MCs) and T cell subsets, in oral lichen planus (OLP) and normal buccal mucosa (NBM) using immunohistochemistry. In OLP, there were increased numbers of tryptase(+) MCs in areas of BM disruption (P

Intracranial Hemorrhage, Outcome, and Mortality After Intra-Arterial Therapy for Acute Ischemic Stroke in Patients Under Oral Anticoagulants

Use of intravenous tissue-type plasminogen activator (IV tPA) for acute ischemic stroke is restricted to patients with an international normalized ratio (INR) less than 1.7. However, a recent study showed increased risk of symptomatic intracranial hemorrhage after IV tPA use in patients with oral anticoagulants (OAC) even with an INR less than 1.7. The present study assessed the risk of symptomatic intracranial hemorrhage, clinical outcome, and mortality after intra-arterial therapy (IAT) in patients with and without previous use of OAC.

Oral health conditions among the elderly in Southeastern São Paulo State

OBJECTIVE: This study aimed to asses oral health conditions in a population aged 60 years and over living in Botucatu, Southeastern Brazil. A cross-sectional population-based study was carried out using a random sample (N=372) of the urban population aged 60 years and over from the city of Botucatu, in 2005. World Health Organization criteria and codes for oral health epidemiological surveys were used. Re-examination was carried out in 10% of individuals aiming to evaluate intra-examiner agreement. Statistical analysis was performed by one-way ANOVA or Kruskal-Wallis ANOVA, as applicable. Also, the t-test was used in the absence of homoscedasticity. Fisher's exact test was used for situations where the categories with less than five units were observed. Adjusted residuals and multiple-comparison analysis were conducted to identify associations between variable categories and subgroups. The intra-examiner agreement was 98% and Kappa statistics result was 0.95. Loss component represented 90.68% of DMF-T index, which was 29.85. The prevalence of edentulism was 63.17%. Upper and lower dentures were found in 80% and 58% respectively, with complete denture as the most commonly used. In those studied, 15% required upper and 38% lower dentures. There was more need for complete denture in both jaws. Approximately 20% had soft tissue alterations. For periodontal conditions, most sextants were excluded (81.81%). Periodontal pockets (4 - 5 mm) were seen in 11.29% of the examined individuals. The oral health status of the elderly population in Botucatu is poor, as well as in other Brazilian cities. The results of this study may help planning collective health actions, giving an accurate description of the oral problems among the elderly.

In vitro Fluoride Release and Tensile Bond Strength of a Polymeric Intra-Buccal Bioadhesive

The intra-buccal polymeric bioadhesive systems that can stay adhered to the oral soft tissues for drug programmed release, with the preventive and/or therapeutic purpose has been employed for large clinical situations. A system based on hydroxypropyl methyl cellulose/Carbopol 934`/magnesium stearate (HPMC/Cp/StMg) was developed having the sodium fluoride as active principle. This kind of system was evaluated according to its resistance to the removal by means of physical test of tensile strength. Swine buccal mucosa extracted immediately after animals` sacrifice was employed as substrate for the physical trials, to obtain 16 test bodies. Artificial saliva with or without mucin was used to involve the substrate/bioadhesive system sets during the trials. Artificial salivas viscosity was determined by means of Brookfield viscometer, showing the artificial saliva with mucin 10.0 cP, and the artificial saliva without mucin 7.5 cP. The tensile strength assays showed the following averages: for the group ""artificial saliva with mucin"" - 12.89 Pa, and for the group ""without mucin"" - 12.35 Pa. Statistical analysis showed no significant difference between the assays for both artificial salivas, and it was possible to conclude that the variable mucin did not interfered with the bioadhesion process for the polymeric devices. The device was able to release fluoride in a safe, efficient and constant way up to 8 hours.