O objetivo do trabalho foi avaliar a prevalência das lesões dentárias não cariosas e sua relação com processos erosivos. Foram examinados 260 alunos da graduação da Faculdade de Odontologia de Bauru. Os pacientes responderam a um questionário envolvendo identificação, hábitos de higiene bucal, dieta, condição de saúde, etc. Foram realizados, ainda, exames clínicos para a identificação, classificação das lesões e graus de sensibilidade. De posse dos dados de cada paciente, a amostra foi analisada e tabulada no programa Microsoft Office Excel. A análise estatística foi realizada utilizando-se o programa estatístico Sigma Stat, sendo que as variáveis foram pareadas e submetidas ao teste Chi-Quadrado de Pearson, com nível de significância de 5%. Os resultados demonstraram que cerca de 35% dos pacientes avaliados possuíam pelo menos uma lesão dentária não cariosa. Observou-se uma maior prevalência de lesões nos pré-molares, seguido pelos molares, incisivos e caninos. A grande maioria das lesões acometeu a região cervical, principalmente na face vestibular. Não se observou diferença estatisticamente significante na ocorrência de lesões dentárias não cariosas relacionadas com a ingestão de frutas cítricas e refrigerantes, presença de doenças sistêmicas, diferentes fluxos salivares e pH tampão da saliva. Houve uma maior prevalência de lesões sensíveis nos pacientes que consumiam frutas cítricas e refrigerantes, com fluxo salivar intermediário/baixo e nos pacientes com pH tampão > que 5,5. Respeitando as características da população estudada, nenhum dos fatores avaliados pareceu interferir na dinâmica das lesões dentárias não cariosas. / This study aimed to evaluate the prevalence of noncarious dental lesions (NCDL) and their relation to erosive processes. 260 undergraduate students from Bauru School of Dentistry were examined. Patients answered a questionnaire containing identification form, oral hygiene habits, diet and systemic health condition. Thus, clinical examination was carried out to assess the kind and classification of the NCDL and the degree of lesion sensitivity. The data was recorded using a Microsoft Office Excel datasheet. Statistical analysis was performed through Sigma Stat 3.0. The factors were compared and subjected to Pearson Chi-square test, at a 5% level of significance. The results demonstrated that around 35% of the patients evaluated presented at least one NCDL. It was observed that teeth most commonly affected by these lesions were premolars, followed by molars, incisors and canines. Most of the lesions affected the cervical area, mainly the buccal face of the teeth. No significant difference was observed on NCDL in relation to citric fruit and soft drink exposure, systemic diseases, salivary flow and saliva pH buffer. Higher prevalence of hypersensitive lesions was observed in patients that ingested acidic fruits and soft drinks, with intermediate/low salivary flow and in patients with saliva pH buffer > than 5.5. Considering the characteristics of the population studied, none of the factors analyzed seemed to interfere in the dynamics of the NCDL.

O objetivo do trabalho foi avaliar a prevalência das lesões dentárias não cariosas e sua relação com processos erosivos. Foram examinados 260 alunos da graduação da Faculdade de Odontologia de Bauru. Os pacientes responderam a um questionário envolvendo identificação, hábitos de higiene bucal, dieta, condição de saúde, etc. Foram realizados, ainda, exames clínicos para a identificação, classificação das lesões e graus de sensibilidade. De posse dos dados de cada paciente, a amostra foi analisada e tabulada no programa Microsoft Office Excel. A análise estatística foi realizada utilizando-se o programa estatístico Sigma Stat, sendo que as variáveis foram pareadas e submetidas ao teste Chi-Quadrado de Pearson, com nível de significância de 5%. Os resultados demonstraram que cerca de 35% dos pacientes avaliados possuíam pelo menos uma lesão dentária não cariosa. Observou-se uma maior prevalência de lesões nos pré-molares, seguido pelos molares, incisivos e caninos. A grande maioria das lesões acometeu a região cervical, principalmente na face vestibular. Não se observou diferença estatisticamente significante na ocorrência de lesões dentárias não cariosas relacionadas com a ingestão de frutas cítricas e refrigerantes, presença de doenças sistêmicas, diferentes fluxos salivares e pH tampão da saliva. Houve uma maior prevalência de lesões sensíveis nos pacientes que consumiam frutas cítricas e refrigerantes, com fluxo salivar intermediário/baixo e nos pacientes com pH tampão > que 5,5. Respeitando as características da população estudada, nenhum dos fatores avaliados pareceu interferir na dinâmica das lesões dentárias não cariosas. / This study aimed to evaluate the prevalence of noncarious dental lesions (NCDL) and their relation to erosive processes. 260 undergraduate students from Bauru School of Dentistry were examined. Patients answered a questionnaire containing identification form, oral hygiene habits, diet and systemic health condition. Thus, clinical examination was carried out to assess the kind and classification of the NCDL and the degree of lesion sensitivity. The data was recorded using a Microsoft Office Excel datasheet. Statistical analysis was performed through Sigma Stat 3.0. The factors were compared and subjected to Pearson Chi-square test, at a 5% level of significance. The results demonstrated that around 35% of the patients evaluated presented at least one NCDL. It was observed that teeth most commonly affected by these lesions were premolars, followed by molars, incisors and canines. Most of the lesions affected the cervical area, mainly the buccal face of the teeth. No significant difference was observed on NCDL in relation to citric fruit and soft drink exposure, systemic diseases, salivary flow and saliva pH buffer. Higher prevalence of hypersensitive lesions was observed in patients that ingested acidic fruits and soft drinks, with intermediate/low salivary flow and in patients with saliva pH buffer > than 5.5. Considering the characteristics of the population studied, none of the factors analyzed seemed to interfere in the dynamics of the NCDL.

Light scattering-based techniques are being developed for non-invasive diagnostics of inhomogeneous media in various fields, such as medicine, biology, and material characterization. However, as most media of interest are highly scattering and have a complex structure, it is difficult to obtain a full analytical solution of the scattering problem without introducing approximations and assumptions about the properties of the system under consideration. Moreover, most of the previous studies deal with idealized scattering situations, rarely encountered in practice. This dissertation provides new analytical, numerical, and experimental solutions to describe subtle effects introduced by the properties of the light sources, and by the boundaries, absorption and morphology of the investigated media. A novel Monte Carlo simulation was developed to describe the statistics of partially coherent beams after propagation through inhomogeneous media. The Monte Carlo approach also enabled us to study the influence of the refractive index contrast on the diffusive processes, to discern between different effects of absorption in multiple scattering, and to support experimental results on inhomogeneous media with complex morphology. A detailed description of chromatic effects in scattering was used to develop new models that explain the spectral dependence of the detected signal in applications such as imaging and diffuse reflectance measurements. The quantitative and non-invasive characterization of inhomogeneous media with complex structures, such as porous membranes, diffusive coatings, and incipient lesions in natural teeth was then demonstrated.

Indiana University-Purdue University Indianapolis (IUPUI) / Background: Non-cavitated caries lesions form due to acid diffusion and demineralization of enamel subsurface with an intact surface layer (SL). Caries lesions progress when the outcome of demineralization and remineralization processes over time is net mineral loss. Lesions that continue to demineralize are called active, while those that display no evidence of further demineralization are called inactive. Micro-computed-tomography (µCT) analysis provides objective non-destructive measurements of the thickness of the surface layer (SL) and severity of caries lesions. Aims: 1) To investigate if visual/tactile suspected active non-cavitated early white spot lesions present a thinner surface layer than inactive ones; 2) To investigate if there is an association between the thickness of the surface layer (SLT) and caries activity, as determined by QLF during dehydration (△QD); 3) To determine lesion severity by comparing lesion volume and maximum depth correlation with △Q value at 15 s from QLF during dehydration. Materials and Methods: Thirty extracted human premolars exhibiting non-cavitated approximal white spot early lesions stored in 0.1.-percent thymol/4C and treated with 5.0-percent NaOCl/30 min were included in the study. Fifteen active and 15 inactive lesions were determined by visual/tactile examinations by consensus of two experienced examiners. Roughness measurements (Ra) were acquired using non-contact optical profilometry. Two-dimensional minimum (2D-min), maximum (2D-max), average (2D-avg) SL and three-dimensional (3D) analyses, volume and depth of lesions were determined from µCT image analysis. A series of fluorescence images were acquired at baseline (hydrated), at 1 s, at 5 s, at 10 s and at 15 s by QLF. During image acquisition, surfaces were dehydrated with continuous-compressed-air. △Q and △Q/s (△QD) were calculated. Data were analyzed using two-sample t-tests and Pearson correlation coefficients (p < 0.05). Results: Surface roughness of active and inactive lesions was not significantly different (p > 0.08). Overall lesion volume and depth in dentin were significantly larger in active lesions (p = 0.022, p = 0.009). SL thickness of active and inactive lesions was not significantly different (2D = 0.121, 3D = 0.080, 2D-avg = 0.446, 2D-min = 0.197, 2D-max = 0.122). △QD at 1s was significantly larger for active lesions (p = 0.046). ΔQ at 15 s of dehydration had a moderate positive association with lesion volume (r = 0.56). △QD had a weak negative association with SL thickness (2D-avg) and (2D-min). Conclusions: 1) Active and inactive non-cavitated lesions show no difference in SL thickness; 2) QLF during dehydration (△QD) does not correlate well with SL thickness; 3) ΔQ at 15 s of dehydration correlates moderately well with lesion volume and is consistent with caries activity assessed by visual/tactile examination.