To build novel electronic noses for mimicking biological olfactory systems that consist of olfactory receptor arrays with large surface area and massively-diversified chemical reactivity, three dimensional (3D) vertical aligned ZnO nanowire arrays were employed as active materials for gas detection. ZnO nanowire arrays share 3D structures similar to mammalian olfactory receptor arrays, with thousands of vertical nanowires providing a high reception area which can significantly enhance the sensors’ sensitivity. Meanwhile, with different material decorations (such as SnO2, In2O3, WO3 and polymers), each array of nanowires can produce a distinguishable response for each separate analyte, which would provide a promising way to improve the selectivity. Both patterned grown well-aligned and wafer size random-distributed 3D nanowire array sensing devices are investigated. Several different types of gas sensors have been investigated in this dissertation. Metal oxide semiconductor gas sensors based on 3D metal oxides/ZnO vertical nanowire arrays have detected NO2 and H2S down to ppb level, and five gases of NO2, H2S, H2, NH3, and CO have been discriminated. Active self-powered gas sensors based on 3D metal oxides/ZnO vertical nanowire arrays have been successfully fabricated and worked well for H2S and NO2 detection. With the decoration by mixture of PEDOT polymer with metal oxide nanoparticles, ZnO vertical nanowire array gas sensors have fast response and recovery time as well as good sensitivity to volatile organic gases of acetone, methanol and ethanol. A novel ionization sensor also has been built by ZnO vertical nannowire arrays, and this device could be able to ionize air under safety operation voltage.

The accuracy of ozone measurements in the middle atmosphere is of great importance when determining its diurnal variation. A high time resolution of the measured data is desirable and depends on the sensitivity of the receiver used to detect the ozone. This thesis aims to improve the sensitivity of a groundbased 142 GHz microwave radiometer used for measuring atmospheric ozone data. This is done by replacing the previous receiver components with a series of new components and arranging them in different setups for comparison purposes. Mechanics and wiring were changed in order to install the setups along with changes in the optics. Each test setup could be implemented as a first step towards improving the sensitivity of the radiometer. The result show that the optics contribute with an unexpected addition of noise to the measurements and hence the overall performance and improvement of the radiometer could not be determined. Suggestions are made for further work which include improving the optics and performing cryo-measurements.

No / Objectives: Poor knowledge of eye health, concerns about the cost of spectacles, mistrust of optometrists and limited geographical access in socio-economically deprived areas are barriers to accessing regular eye examinations and result in low uptake and subsequent late presentation to ophthalmology clinics. Personal Medical Services (PMS) were introduced in the late 1990s to provide locally negotiated solutions to problems associated with inequalities in access to primary care. An equivalent approach to delivery of optometric services could address inequalities in the uptake of eye examinations. Study design: One-way and multiway sensitivity analyses. Methods: Variations in assumptions were included in the models for equipment and accommodation costs, uptake and length of appointments. The sensitivity analyses thresholds were cost-per-person tested below the GOS1 fee paid by the NHS and achieving breakeven between income and expenditure, assuming no cross-subsidy from profits from sales of optical appliances. Results: Cost per test ranged from £24.01 to £64.80 and subsidy required varied from £14,490 to £108,046. Unused capacity utilised for local enhanced service schemes such as glaucoma referral refinement reduced the subsidy needed. / Yorkshire Eye Research, NHS Leeds, RNIB

O objetivo deste estudo clínico randomizado duplo cego boca-dividida foi avaliar, in vivo, a efetividade do condicionamento ácido prévio do esmalte e de géis clareadores a base de peróxido de hidrogênio (PH) de baixa concentração, associados a fontes de luz híbrida (LH), tendo como variáveis de reposta: sensibilidade dental, fluxo sanguíneo pulpar, grau de mudança e estabilidade de cor ao longo de 6 meses. Trinta e seis voluntários que se encaixaram nos critérios de inclusão e exclusão foram selecionados e randomizados em 3 grupos (n=12), de acordo com o protocolo clareador a ser utilizado. Dentro de cada grupo, um dos hemiarcos foi aleatoriamente selecionado para a realização do condicionamento ácido do esmalte, previamente a aplicação do gel clareador. Os géis que compunham os três protocolos clareadores foram: PH a 10% (experimental) associado a LH a base de LED violeta + laser de diodo (experimental); PH a 15% associado a LH a base de LED azul + laser de diodo; e PH a 35% sem ativação com fonte de luz. A sensibilidade foi avaliada com a escala VAS; a fluxometria pulpar, com o sistema Laser Doppler; e a cor pelo cálculo do ?E via espectrofotômetro. Os dados foram tratados pela análise de variância de medidas repetidas (ANOVA), Tukey e teste de Friedman (p<0,05). Com relação à sensibilidade, foram encontradas diferenças significativas na interação tempo e grupo, mas não com relação ao ácido. Quanto à vascularização pulpar, o efeito de grupo não foi rejeitado, sendo o grupo de PH a 35% o que apresentou as menores medianas para as variações percentuais, porém os efeitos de ácido e tempo não foram significativos. Quanto à cor, diferenças significantes foram encontradas entre os grupos, mas não com relação ao uso do ácido, sendo o PH a 35% o que promoveu maior aumento do ?E. Conclui-se assim que o condicionamento ácido não foi capaz de favorecer a efetividade do clareamento em função do grau de mudança e estabilidade de cor, bem como não aumentou a sensibilidade e o fluxo sanguíneo da polpa dental. A concentração dos agentes clareadores foi determinante para o grau de mudança de cor e demonstrou influenciar a sensibilidade e o fluxo sanguíneo pulpar. / The aim of this double blind split-mouth randomized clinical study was to evaluate, in vivo, the effectiveness of prior acid etching on enamel and low concentration bleaching gels based on hydrogen peroxide (HP) associated with hybrid light (HL) sources, having as response variables: dental sensitivity, dental pulp vascularization and degree of color change and stability over 6 months. Thirty-six volunteers in agreement with the inclusion and exclusion criteria were selected and randomly divided into 3 groups (n = 12) according to the bleaching protocol to be used. Within each group, one of the sides was randomly selected for the execution of acid etching prior to the gel application. The three bleaching gels were: 10% HP (experimental) associated with HL-based violet LED/laser (experimental); 15% HP associated with HL-based blue LED/laser; and 35% HP without light activation. Sensitivity was evaluated with the VAS scale; pulp flowmetry by the use of the Laser Doppler system; and efficacy was evaluated by calculating the ?E via a spectrophotometer. Data were analyzed by analysis of variance for repeated measures (ANOVA), Tukeys and Friedman tests (p<0.05). Regarding sensitivity, significant differences were found in the interaction between the application time and group but not regarding etching. For dental pulp flowmetry, the group effect was not rejected, where the 35% HP showed the lowest medians for the percentile variations, but the effects of etching and time were not significant. For color, significant differences were found between the groups, but not between the sides with and without acid etching, where the 35% HP gel promoted the highest increase in ?E. It is therefore concluded that the etching was not able to favor the effectiveness of whitening due to color variation and stability, as well as not increasing sensitivity or pulp blood flow. The concentration of bleaching agents determined the degree of color change and influenced the sensitivity and blood flow of the dental pulp.

Thesis advisor: Eranthie Weerapana / A chemical-proteomic platform to monitor cysteine sensitivity to transnitrosation Yani Zhou Dissertation advisor: Dr. Eranthie Weerapana Abstract S-nitrosation has emerged as a ubiquitous endogenous protein posttranslational modification that significantly impacts cellular protein function through a variety of mechanisms. Despite the advent of chemical and proteomic methods to study S-nitrosation, the subset of cellular cysteine residues that show uniquely high reactivity to endogenous transnitrosation donors is poorly characterized. To further these existing global studies, a cysteine-reactivity profiling strategy was applied herein to rank ~600 cysteine residues by sensitivity to S-nitrosoglutathione. These proteomic studies revealed several previously uncharacterized sites of S-nitrosation, including Cys58 in HADH2. Further characterization revealed that HADH2 catalytic activity is allosterically regulated by S-nitrosation, and this modification occurs in cells at (patho)physiological levels of nitrosative stress. Functional role of Cys58 and its regulation by S-nitrosation facilitated the identification of RB-21-CA as a potential covalent Cys58 inhibitor. Global analysis of GSNO, S-nitroso-Coenzyme A and Thioredoxin-C73-SNO transnitrosation identified 756 cysteines with different sensitivity to each of three SNO donors. Systematic evaluation on transnitrosation selectivity revealed that specific interaction of transnitrosation donor with its protein target is a key component governing the selective transnitrosation of a specific cysteine residue. Together, these studies illustrated the potential of cysteine-reactivity profiling strategy for evaluating the substrate specificity of transnitrosation donors and enable the identification of previously uncharacterized, functionally relevant sites of S-nitrosation. Another cysteine oxoform, S-glutathionylation, is the disulfide formation of a protein cysteine residue with glutathione. Although glucose starvation is known to induce redox-disturbance, global and individual protein S-glutathionylation in response to glucose metabolism or mitochondrial activity remains largely unknown. By using a clickable glutathione approach, which forms clickable glutathione by the use of a mutant of glutathione synthetase, we found that protein S-glutathionylation is readily induced in response to glucose starvation when mitochondrial reactive oxygen species are elevated in cells, and glucose is the major determinant for inducing reversible glutathionylation. Application of a proteomic mass spectrometry platform identified over 1,300 S-glutathionylated. Confirmation of S-glutathionylation for selected proteins by in gel analysis further validated the mass spectrometry results, and highlights the dynamic change of S-glutathionylation on an individual protein level. In order to expand on the understanding of the functional role of the cysteine residues in biological systems, we evaluated a panel of 1,3,5-triazine- and 4-aminopiperidine-based cysteine-reactive small-molecules on two proteins, apoptosis signal-regulating kinase 1 (ASK1) and peroxiredoxin 1 (Prdx1), between which a intermolecular disulfide forms and results in the activation of mitogen-activated protein kinase pathway. In-gel fluorescence revealed that RB-11-CA and SMC-1, both of which contain an n-octyl group as a diversity element, showed greatest selectivity and potency to ASK1 and Prdx1, respectively. Further mass spectrometry analysis identified cysteine 225 of ASK1 and cysteine 173 of Prdx1 are the sites of covalent probe modification. / Thesis (PhD) — Boston College, 2016. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

Objetivo: Avaliar a Função de Sensibilidade ao Contraste de Luminância Espacial e Temporal, estudar o desenvolvimento destas funções, a contribuição das vias de processamento paralelo para as funções de Sensibilidade ao Contraste e seu respectivo desenvolvimento e, por fim, determinar valores normativos destas funções visando uma aplicabilidade clínica.Método A avaliação psicofísica de sensibilidade ao contraste de luminância espacial e temporal foi realizada em 112 sujeitos divididos em três grupos:GrupoI ( idade média =9,14±2,7 anos),Grupo II ( idade média=23,7 ± 3,4 anos) e Grupo III ( idade média=41,8± 5,5 anos) com o programa PSYCHO for Windows Versão 2.36 (Cambridge Research Systems, CRS-Ltd, UK) acoplado a um microcomputador PC XTC -600. . Os estímulos foram apresentados em um monitor Sony Triniton de 19 polegadas GFD420 (Sony Corporation, USA) com resolução espacial de 800X600 e resolução temporal de 69 Hz Os estímulos eram comandados pela placa gráfica VSG 2/4 (Cambridge Research Systems, CRS-Ltd, UK).Resultados A avaliação psicofísica para a sensibilidade ao contraste espacial e temporal mostraram que esta função já está desenvolvida e em pleno funcionamento em crianças (6 anos) ocorrendo um declínio para as frequências espaciais de 2,0cpg;8,3cpg e 14,5cpg para os grupos II e III.Para a frequência temporal de 2,5Hz o declínio ocorre nos Grupos II e III e para a frequência temporal de 5,0 Hz nas idades mais avançadas(GIII). Para o estudo da contribuição das vias de processamento paralelo (magnocelular e parvocelular) podemos notar uma maior sensibilidade ao contraste para decremento de luz do que para incremento de luz, porém não foi possível determinar a real contribuição dessas vias para a função de sensibilidade ao contraste. Conclusão Avaliamos com sucesso a Sensibilidade ao Contraste Espacial e Temporal para todas as faixas etárias e, assim, conseguimos ter acesso ao desenvolvimento desta função, entre as idades de 6 e 57 anos. Valores normativos para as tais funções foram estabelecidos por metodologia nãoparamétrica.. O estudo da contribuição das vias magnocelular e parvocelular não pode ser conclusivo, porém os achados mostraram uma maior sensibilidade para o decremente de luz o que corrobora com a literatura / Purpose: To analyze the spatial and temporal luminance contrast sensitivity function, to study the development of these functions, the contribution of the parallel processing pathways and to determine the normative values of these functions to order a clinical applicability normative. Methods the psychophysical evaluation of the spatial and temporal luminance contrast sensitivity was performed in 112 subjects divided into three groups: Group I (mean age =9.14±2.7 years), Group II (mean age=23.7 ± 3.4 years) and Group III (mean age=41.8± 5.5 years) with the PSYCHO for Windows Version 2.36 (Cambridge Research Systems, CRS-Ltd, UK) connect to the microcomputer PC XTC -600. The stimuli was showed in a monitor Sony Triniton de 19 inches GFD420 (Sony Corporation, USA) with spatial resolution of the 800X600 and temporal resolution of the 69 Hz. The stimuli was made by the graphics card VSG 2/4 (Cambridge Research Systems, CRS-Ltd, UK).Results The psychophysics evaluation to spatial and temporal contrast sensitivity showed that this function is already developed and full operation in children (6 years old) with a decline to spatial frequencies of 2.0cpg;8.3cpg and 14.5 cpg to the groups II and III. For the temporal frequency of 2.5Hz the decline occur to the groups II and III .and to the temporal frequency of 5.0 Hz the decline occur to the advantage ages(GIII). For the study of the parallel processing pathways (magnocellular e parvocellular) we can see bigger contrast sensitivity to decrement than to increment of light. It was not possible determine the real contribution of these pathways to the contrast sensitivity function. Conclusion We evaluated in a successful way the spatial and temporal contrast sensitivity to all age range and so we could access the development of this function between the ages from 6 to 57 years old. Normatives values to this function were established for non parametric methodology. The study of the contribution of the parvocellular and magnocellular pathways is not conclusive, but the results showed a bigger sensibility to decrement than to increment of light that was similar to the literature

A Hanseníase é uma doença de evolução crônica e lenta causada pelo bacilo Mycobacterium leprae, com inflamação especifica, que acomete o sistema nervoso periférico. A detecção da perda de sensibilidade protetora é importante para identificar pacientes que apresentam neuropatia periférica. O método mais utilizado para medir a sensibilidade das fibras de adaptação lenta é o de estesiometria por monofilamentos de Semmes-Weinstein (SW). Um dos fatores etiológicos da úlcera plantar neuropática é a alta pressão em determinado local na região plantar. O Baropodômetro é um aparelho eficiente para avaliar a pressão plantar tanto na postura estática como na dinâmica. Este estudo teve como objetivo descrever clinico-epidemiologicamente pacientes com hanseníase em tratamento no CRNDS do HCFMRP - USP, correlacionando os respectivos resultados dos testes baropodométricos na postura estática e dinâmica com teste de sensibilidade pelos monofilamentos SW. Foram avaliados 51 pacientes com hanseníase, com idade entre 18 e 60 anos, 30 classificados operacionalmente em multibacilares (MB) e 15 em paucibacilares (PB). 20 sujeitos sem neuropatia foram selecionados para o Grupo Controle (GC). Somente os pacientes com hanseníase foram submetidos à estesiometria. Os resultados demonstraram estatisticamente que o paciente MB e PB apresentaram maiores picos de pressão plantar e maior taxa de alteração de sensibilidade na região do calcanhar. Pacientes MB apresentaram maiores picos de pressão plantar na estática, e o GC na dinâmica. Tanto o grupo PB quanto o MB apresentaram úlceras ou calosidades plantares, sendo que no MB estas ocorreram nas áreas de sensibilidade alterada, enquanto no PB as lesões apresentaram-se em áreas coincidentes de alteração de sensibilidade e picos máximos de pressão. Assim, os resultados evidenciaram que a baropodometria contribui para o melhor entendimento da biomecânica do processo de ulceração plantar, além de ser um método prático e não invasivo para o diagnóstico funcional dos pacientes com neuropatia hansênica em relação à distribuição pressórica plantar. / Leprosy is a disease of chronic evolution that causes specific and slow inflammatory reaction, damaging the peripheral neural system. The detection of the sensibility loss is important to identify patients with peripheral neuropathy, and the standard method for it is the Semmes-Weinstein\'s monofilament sensibility test. One of the etiologic factors of the plantar ulcers on neuropathic feet is the high pressure on determined plantar spot. The Podometry is effective to evaluate the plantar pressure during standing position and gait. The aim of this study was to describe epidemically and clinically leprosy\'s patients through podometric evaluations during gait and static posture, and compare these data with Semmes-Weinstein monofilaments sensitivity tests. Methods: 51 leprosy subjects, 18 to 60 years old, already on treatment at the CRNDS of HCFMRP - USP were evaluated and classified as multibacillary (MB) and paucibacillary (PB). Also, 20 normal subjects performed the podometric test and have their data taken as a control group (GC). The statistical analysis of the data showed that leprosy patients have both greater sensitivity loss and plantar peak pressure on the heel area. The MB group showed higher plantar peak pressures during standing position, as well as GC on gait analysis. Both MB and PB presented plantar callus and ulcer; MB skin damage was found within the areas of sensory loss, and PB\'s within the areas of sensitivity loss plus higher peak pressures. The results showed that podometry offers an important contribution to understanding plantar ulcer\'s biomechanics; besides, it is a practical and non-invasive method to functionally diagnose leprosys neuropathy related to plantar pressure distribution.

Esta tese de doutorado aborda o desenvolvimento de sistemas microfluídicos eletroquímicos ultrassensíveis mediante a integração de eletrodos i) concêntricos e ii) nanoestruturados seletivos à detecção condutométrica sem contato acoplada capacitivamente (capacitively coupled contactless conductivity detection, C4D) e à amperometria, respectivamente. O uso dos eletrodos concêntricos, uma configuração inédita em microdispositivos na qual o filme fino metálico circunda todo o microcanal, se mostrou efetivo na melhora da detectabilidade da C4D para análises em fluxo de soluções padrão de LiClO4. O limite de detecção (LD) para esse sal foi igual a 343 pmol L-1, um valor aproximadamente quatro ordens de grandeza inferior àquele obtido com eletrodos planares. O microchip amperométrico nanoestruturado, por sua vez, consistiu de filmes de Au modificados com nanotubos de carbono de parede única (single-walled carbon nanotubes, SWCNTs) verticalmente alinhados e foi aplicado a padrões do neurotransmissor serotonina. A melhora na detectabilidade do método foi novamente apreciável; os valores de LD foram de 11,8 (Au liso) e 0,2 nmol L-1 (Au modificado com os SWCNTs verticalmente alinhados). Esse último é menor frente à grande maioria dos valores descritos na literatura, para os quais técnicas diversas foram empregadas, incluindo: i) potenciometria com eletrodos modificados (1,0 a 500 nmol L-1), ii) HPLC-MS (18,2 nmol L-1), iii) eletroforese capilar combinada com etapas de extração, empilhamento e préconcentração do analito (7,9 nmol L-1) e iv) sensor químico (200 nmol L-1). Finalmente, objetivando a fabricação de microchips de vidro, condutométricos e amperométricos, incorporando eletrodos concêntricos nanoestrurados, uma nova técnica de selagem foi desenvolvida. Essa técnica, designada como selagem adesiva de sacrifício, baseia-se no uso do resiste negativo SU-8 como camada intermediária de modo a permitir a vedação entre duas lâminas de vidro. Numa etapa posterior, a remoção seletiva do SU-8 sob o microcanal é realizada. Logo, canais microfluídicos com propriedades de superfície similares às do vidro foram obtidos. O protocolo experimental adotado é i) simples, ii) rápido, iii) não envolve níveis de pressão e temperatura elevados e iv) prescinde o uso de salas \"limpas\". Vedações com forças de adesão satisfatórias foram alcançadas, suportando pressões superiores a 4 MPa. / This PhD thesis reports the development of ultrasensitive electrochemical microfluidic systems by integrating concentric and nanostructured electrodes selective to capacitively coupled contactless conductivity detection (C4D) and amperometry, respectively. The use of the concentric electrodes, a new assembly in microdevices with thin films wrapping around the microchannel, showed to be effective towards improvement of the detectability in pressure-driven flow platforms incorporating C4D. The limit-of-detection (LOD) in flow analysis of LiClO4 solutions was 343 pmol L-1, ca. four orders of magnitude lower than to the levels obtained with planar electrodes alone. The nanostructured amperometric microchip, in turn, is related to integration of vertically aligned singlewalled carbon nanotubes (SWCNTs) over Au film. Such platform was applied to determination of serotonin standards. The nanomaterial influenced remarkably the sensitivity and detectability. Our system achieved a LOD of 0.2 nmol L-1, to the best of our knowledge one of the lowest values reported in the literature. Finally, in order to fabricate glass microdevices, conductometric and amperometric, with nanostructured concentric electrodes, we developed a new bonding method. This technique, called as sacrificial adhesive bonding, is based on SU-8 negative resist like intermediate layer so to allow the sealing between two glass slides. Next, the selective removal of the SU-8 under the microchannel is carried out. Thus, microfluidic channels presenting glass-like surface properties were achieved. The experimental protocol is simple and fast. In addition, neither high-pressure and elevated-temperature nor the use of \"clean\" rooms were not required. Bondings with satisfactory adhesion forces were obtained, supporting pressures above 4 MPa.

Resumo: Este estudo propõe-se realizar o mapeamento de sensibilidade ambiental a derramamentos de óleo - Cartas SAO - do Parque Estadual da Ilha do Cardoso e áreas do entorno - SP. Para tanto, foi aplicada a metodologia indicada pelo MMA atualmente utilizada no Brasil. Para o melhor detalhamento da avaliação da sensibilidade das praias arenosas, foi elaborada uma subclassificação do índice de sensibilidade do litoral (ISL) das praias em áreas de erosão, transporte e deposição de sedimentos. Devido a características importantes atualmente não avaliadas para os litorais rochosos, propõe-se um refinamento da classificação da sensibilidade destes destes em função dos parâmetros geomorfológicos (textura da rocha, hidrodinamismo e localização). Elaborou-se uma proposta de integração dos índices de sensibilidade dos ambientes costeiros, estuarinos e fluviais da área estudada, levando-se em consideração os mesmos parâmetros atualmente utilizados para a classificação destes ambientes quanto a sensibilidade a derramamentos de óleo. Foram elaboradas áreas de proteção (áreas onde os esforços de combate e limpeza devem ser priorizados)e áreas de sacrifício (setores onde os esforços podem ser secundarizados ou utilizados para atividades de remoção do óleo). Devido a grande sensibilidade da região a derramamentos de óleo sugere-se a instalação de um Centro de Emergência Ambiental e de um plano de emergência para o combate a acidentes na área. / Abstract: This study purpose is to draw the oil spill environmental sensitivity mapping of Cardoso Island's State park and surrounding regions - SP. Thus, the suggested methodology for MMA, usually used in Brazil, was applied. For a better evaluation of the sensitivity of sandy beaches, a subclassification of the shoreline sensitivity index of beaches in erosion, transport and deposition zones of sediments was formulated. Due to important characteristics, so far not evaluated yet, found in rocky shores, it has been suggested a refined classification of sensitivity of those rocky shores according to geomorphologic parameters (rock grain, wave energy and localization). A suggestion of coastal, estuarine e riverine integration of environmental sensitivity index for the study area proposal was elaborated, taking into account the same parameters currently used to the classification of these environments related to the oil spill sensitivity. Priority zones of protection (sectors where the aactions and clean up must be priorities) and sacrifice zones (sectors where the actions must be retard or used to actions of removal oil) were formulated. Due to the great oil spill sensitivity in this region, the installation of an Environmental Emergency Central and a emergency plan to combat oil spill accidents in the region, is higly suggested. / Orientador: Dimas Dias Brito / Coorientador: João Carlos Carvalho Milanelli / Banca: Paulina Setti Riedel / Banca: Gabriel Henrique da Silva / O Atlas foi elaborado junto ao Grupo de Trabalho de Sensibilidade Costeira no Âmbito do Programa de Formação de Recursos Humanos - PRH 05 da UNESP, Rio Claro / Mestre

Hipersensibilidade dentária (HD) é definida como uma dor decorrente de dentina exposta em resposta a fatores intra-bucais. Porém, o papel do biofilme supragengival (BS) no processo de desencadeamento e/ou aumento da HD não é totalmente esclarecido. Este estudo é um ensaio clínico de braço único cujo objetivo foi o de avaliar se, após 4 dias sem medidas mecânicas de controle do BS, a auto-percepção da hipersensibilidade dentinária é influenciada pela presença daquele. Para isto, 74 participantes (28,1±7,3 anos, 48 mulheres), com saúde gengival e ≥ 5 dentes hígidos por quadrante, foram incluídos se apresentassem recessão (REC) e/ou queixa de HD. No dia 0, avaliou-se REC, escala Schiff (ES), Escala Visual Analógica, sensibilidade tátil por meio da sonda Jay (JAY) e Índice de Sangramento Gengival (ISG). Após, realizou-se profilaxia, para remoção de cálculo e/ou BS e os participantes foram orientados a abster-se do controle mecânico do BS por 4 dias e a realizar 2 bochechos/dia (manhã e noite, 1 minuto) com solução de creme dental fluoretado (1g/9ml). No dia 4, após exame usando o Índice de Placa Visível (IPV), índice de Quigley-Hein (QH), EVA e ISG, foi realizada nova profilaxia. Regressão logística por meio de Equações de Estimação Generalizadas foi conduzida, sendo o dente a unidade de análise. Uma média de 6,00±4,08 dentes/paciente apresentou recessão e/ou queixa de HD. Na totalidade dos dentes (n=444), o acúmulo do BS não determinou aumento na queixa de HD. Quando analisados dentes com Schiff≥1 no dia 0 (n=128), a presença de BS associou-se ao aumento na EVA (OR=4,233; p=0,006) independente da presença ou extensão da REC. Conclui-se que o acúmulo do BS aumenta a auto-percepção de HD. / Dental hypersensitivity (HD) is defined as a pain arising from exposed dentin in response to intra-buccal factors. However, the role of the supragingival biofilm (BS) in the process of triggering and / or increasing HD is not fully understood. This study is a single-arm clinical trial whose objective was to evaluate whether, after 4 days without mechanical measures of BS control, the self-perception of dentin hypersensitivity is influenced by the presence of that. Seventy-four participants (28.1 ± 7.3 years, 48 women) with gingival health and ≥ 5 healthy teeth per quadrant were included if they presented recession (REC) and / or HD complaint. At day 0, REC, Schiff scale (ES), Visual Analog Scale tactile sensitivity by means of the Jay (JAY) probe and Gingival Bleeding Index (GBI) were performed. After that, prophylaxis was performed, for calculation and / or BS removal, and participants were instructed to abstain from BS mechanical control for 4 days and to perform 2 mouthwashes / day (morning and night, 1 minute) with a fluoride toothpaste slurry (1g / 9ml). On day 4, after examination using the Visible Plaque Index (IPV), Quigley-Hein Index (QH), EVA and GBI, a new prophylaxis was performed. Logistic regression using Generalized Estimation Equations was conducted, with the tooth being the unit of analysis. An average of 6.00 ± 4.08 teeth/patient presented recession and / or complaint of HD. In all teeth (n = 444), the accumulation of BS did not increase HD complaint. When teeth with Schiff≥1 on day 0 were (n = 128), the presence of BS was associated with an increase in VAS (OR = 4,233; p = 0.006) regardless of the presence or extent of REC. It is concluded that the accumulation of BS increases the self-perception of HD