The effects of desensitizing agents previously applied during in-office bleaching

Orientador: Luis Alexandre Maffei Sartini PaulilloDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: O objetivo neste estudo, duplo cego de "boca-dividida", foi avaliar, clinicamente, o efeito de dois agentes dessensibilizantes utilizados previamente à aplicação de um gel clareador, a base de peróxido de hidrogênio a 35%, com relação a sensibilidade dental, e se os mesmos interferem na efetividade do clareamento. Para isso foram consideradas duas hipóteses: os géis dessensilizantes iriam reduzir a sensibilidade decorrente do clareamento; os géis dessensibilizantes não iriam influenciar a eficácia do clareamento. Foram utilizados dois agentes dessensibilizantes com diferentes mecanismos de ação, o Flúor Neutro 2% (Flugel, DFL) (FN) que atua através do bloqueio dos canalículos dentinários enquanto o Nitrato de Potássio 5% com Fluoreto de Sódio 2% (Desensibilize KF 2%, FGM) (NP) que atua na transmissão nervosa e no bloqueio. Foram selecionados 30 pacientes, os quais receberam os quatro tratamentos, dois dessensibilizantes e dois placebos, divididos, aleatoriamente, por quadrante. O gel dessensibilizante NP e seu respectivo placebo foram aplicados durante 10 minutos em uma arcada enquanto o gel de FN e seu respectivo placebo foram aplicados por 4 minutos na outra arcada, com o cuidado para que a substância em gel permanecesse nos dentes de cada quadrante. Os dessensibilizantes foram utilizados no inicio de cada sessão, previamente à aplicação do peróxido de hidrogênio 35%. Para o clareamento foram realizadas 3 sessões clinicas, com intervalo de 7 dias entre as mesmas, havendo 3 aplicações do gel clareador por 15 minutos, totalizando 45min por sessão. Os pacientes utilizaram escala analógica de dor de 0-4 para relatarem a sensibilidade, sendo 0 = nenhuma dor, 1 = correspondente a uma dor leve, 2 = moderada, 3 = considerável e 4 = dor intensa. Antes do início de cada sessão, a cor foi registrada de forma objetiva com a utilização de espectrofotômetro (Easyshade, Vident), com o auxilio de uma matriz de silicone para que a medida da cor fosse feita sempre na mesma posição. A variação de cor (?E) foi submetida a ANOVA casual e teste de Tukey (p<0,05). A sensibilidade dental foi avaliada através de ANOVA em esquema fatorial (4x6), sendo que os fatores estudados foram dessensibilizantes e tempo. Dois pacientes desistiram após a primeira sessão de clareamento devido a grande intensidade de dor, e não foram considerados para análise estatística. A alteração de cor após a terceira semana de clareamento apresentou diferença significativa em relação a cor obtida na primeira semana. A intensidade de dor foi estatisticamente significante para os fatores tempo e dessensibilizante, mas não para a interação entre os mesmos. O NP apresentou redução da intensidade de dor quando comparado ao seu placebo, porém a aplicação de FN não diferiu do seu placebo. Com relação ao tempo, a intensidade de dor foi menor durante o clareamento do que nas semanas entre os tratamentos. Pôde-se concluir que a utilização do dessensibilizante a base de nitrato de potássio a 5% e fluoreto de sódio a 2%, aplicado previamente ao clareamento, reduziu a intensidade da sensibilidade dolorosa durante a aplicação do gel clareador, sem alterar a efetividade do clareamentoAbstract: This double blind split-mouth study clinically evaluated the effect of desensitizing agents previously to in-office dental bleaching, evaluating pain intensity and if the desensitizing agents influence the effectiveness of tooth whitening. For this, two following hypotheses were postulated: the desensitizing agent will reduce the soreness resulting from tooth whitening and the desensitizing agent will have no influence on the effectiveness of tooth whitening. The desensitizing agents utilize two mechanisms. Neutral Fluoride 2% (FN) (Flugel, DFL) act obliterate the dentin tubules, and the Potassium Nitrate with 2% sodium fluoride (NP) (Desensibilize KF 2%, FGM) act by blockage of pulp enervation reduction nociceptor sensorial excitability. In total, 30 volunteers were evaluated, and witch one received the four groups of studying, two desensitizing agents and two placebo, randomly distributed between the quadrant. The desensitizing agent corresponding to each group was applied (NP and Placebo I for 10 minutes; FN and Placebo II for 4 minutes) in each arch, with carefully for each substance remained in their quadrant. The desensitizing agents was applied before the bleaching procedure with hydrogen peroxide 35%. Tree sessions was performed for the bleaching, with one week interval between sessions. The gel remained in contact with the teeth for 15 minutes, and was performed three times at each session result in in 45 minutes per session. To evaluate dental sensitivity it was utilizing a numerical scale with intensity scores that ranged from 0 to 4 (0 = no sensitivity, 1 = light sensitivity, 2 = moderate sensitivity, 3 = considerable sensitivity and 4 = intense sensitivity). The color evaluation was performed by an objective analysis utilizing a spectrophotometer (Easyshade, Vivadent) and was made before witch session, with a silicon guide to evaluate the color at different times at the same place. The color variation (?E) were submitted to an analysis of one way variance (ANOVA) and the Tukey test (p<0,05). Pain intensity was submitted to a two-way ANOVA analysis (time and desensitizing agent). Two of the patients discontinued treatment due to hypersensitivity, and they aren¿t including in the statistical analises. The desensitizing products used before the treatment did not influence the final treatment efficacy. The diference of colors ate the third week was significantly different from que diference colors obtained ate the fish week of bleaching. For painful sensations during the treatments a significant difference for desensitizing agent and time was demonstrated, but the interaction of the two factors was not significant. The Tukey test indicated differences between NP and the Placebo I, but there was no significant difference between neutral FN and the placebo II. The pain intensity was lower with the use of the gel during the bleaching compared to the days after treatment, regardless of the desensitizing agent being used. It can be concluded that 5% potassium nitrate with sodium fluoride 2%, applied before in-office bleaching can reduced sensitivity intensity and the use of desensitizing gel prior to bleaching does not alter the effectiveness of whiteningMestradoDentísticaMestra em Clínica Odontológic

The use of fitness apps on customer satisfaction and retention: the fitness centres context

The objective of this study is to analyse the use of fitness centre apps and its influence on customer satisfaction and retention. In this sense, three studies were conducted, one systematic review and two cross-sectional, quantitative studies. The systematic review was carried out using the PRISMA method. The other two studies used the extended unified theory of acceptance and use of technology (UTAUT2) as a base model. All hypothesised relationships used partial least squares structural equation modelling (PLS-SEM), with data from 1,678 fitness customers from Portugal. The results highlighted the importance of the study of technologies in customer retention. The results also support the ability of UTAUT2 in predicting the customer´s intention to use the fitness centre and that the use varies according to customer characteristics. Behavioural intentions are positively related both to the use behaviour of the fitness centre app and to customer overall satisfaction. The suggested that fitness centres invest in the use of a good application, since their use is related to customer overall satisfaction and, thus, indirectly with retention, which benefits the fitness centres

New composite of natural hydraulic lime mortar with graphene oxide

Recent studies show the incorporation of graphene oxide (GO) in cement composites. But these composites are frequently incompatible with original materials for building rehabilitation. To overcome this limitation, natural hydraulic lime mortars were used as matrix, and the influence of GO percentage and type of mixing was investigated. The influence on the microstructure, mechanical and physical properties was assessed. The best results were obtained with dispersed GO at concentrations of 0.05% and 0.1%. A slight improvement of mechanical and physical characteristics was achieved. This could lead to new mortars with improved properties that can be used for building rehabilitation.authorsversionpublishe

Aprendizagens ativas nos domínios da estatística e das probabilidades com recurso a ferramentas digitais

O presente trabalho teve como objetivo o estudo dos módulos 3, 4 (Estatística) e 5 (Probabilidades) incluídos no programa da disciplina de Gestão e Modelação Matemática da Informação. Esta disciplina integra a componente científica do 10º ano do Curso Profissional Técnico de Gestão e Programação de Sistemas Informáticos. Nas sequências didáticas apresentadas são utilizadas as ferramentas digitais, Google Classroom, Google Forms para fornecer aos alunos as atividades a executar, Google Drive para guardar o trabalho em construção e Padlet para publicação do trabalho final. A folha de cálculo Excel e o software de geometria dinâmica GeoGebra foram os recursos digitais utilizados para dar resposta aos trabalhos solicitados e as plataformas Quizizz e Mentimeter serviram para consolidar os conhecimentos adquiridos. A utilização destas ferramentas, permitiu aos discentes desenvolver a autonomia, a motivação e a confiança, adquirindo os conceitos matemáticos envolvidos com sucesso.The present work aimed to study modules 3, 4 (Statistics) and 5 (Probability) included in the program of the discipline Management and Mathematical Modeling of Information. This course integrates the scientific component of the 10th grade of Curso Professional Técnico de Gestão e Programação de Sistemas Informáticos. In the presented didactic sequences, digital tools like Google Classroom, Google Forms are used to give students activities to do and Padlet to submit the final work. The Excel spreadsheet and the dinamyc geometry software GeoGebra, were digital resources used to give answers to the given works. The Quizizz and Mentimeter platforms were used to consolidate the acquired knowledge. The use of these tools allowed students to develop autonomy, motivation and confidence and, finally, successfully acquire the mathematical concepts involved.Mestrado em Matemática para Professore

Describing function analysis of mechanical systems with nonlinear friction and backlash phenomena

This paper analyses the dynamical properties of systems with nonlinear friction and backlash phenomena based on the describing function method. The dynamics is illustrated using the Nyquist and Bode plots and the results are compared with those of standards models.N/

Pole-zero approximations of digital fractional-order integrators and differentiators using signal modeling techniques

A novel strategy to the development of digital pole-zero approximations to fractional-order integrators and differentiators is presented here. The scheme is based in the signal modeling techniques applied to deterministic signals, namely the Padé, the Prony and the Shanks methods. It is shown that the illustrated algorithms yield good results both in the time and the frequency domains. Moreover, they are capable to give superior approximations than other existent approaches, namely the widely used CFE method. Several examples are given that demonstrate the effectiveness of the proposed techniques.N/

Pole-zero approximations of digital fractional-order integrators and differentiators using signal modeling techniques

A novel strategy to the development of digital pole-zero approximations to fractional-order integrators and differentiators is presented here. The scheme is based in the signal modeling techniques applied to deterministic signals, namely the Padé, the Prony and the Shanks methods. It is shown that the illustrated algorithms yield good results both in the time and the frequency domains. Moreover, they are capable to give superior approximations than other existent approaches, namely the widely used CFE method. Several examples are given that demonstrate the effectiveness of the proposed techniques.N/

Least-squares design of digital fractional-order operators

In this paper we develop a method for obtaining digital rational approximations to fractional-order operators of type s^y, where y e R. The proposed method is based on the least-squares (LS) minimization between the impulse response of the fractional Euler/Tustin operators and the digital rational-fraction approximation. We make a comparison with other approaches and the results reveal that the LS method gives superior approximations. The effectiveness of the method is demonstrated both in the time and frequency domains through an illustrative example.N/

Design of Digital Fractional-Order Integrators and Differentiators by Least Squares

First IFAC Workshop on Fractional Differentiation and Its Application - 19-21 July 2004, Enseirb, Bordeaux, France - FDA'04In this paper we develop a method for obtaining digital rational approximations (IIR filters) to fractional-order operators of type sα, where α ∈ . The proposed method is based on the least-squares (LS) minimization between the impulse responses of the digital fractional-order integrator/differentiator and of the rational-fraction approximation. The results reveal that the LS approach gives similar or superior approximations in comparison with other methods. The effectiveness of the method is demonstrated both in the time and frequency domains through an illustrative example