Salivary factors associated with noncarious cervical lesions: A systematic review.

OBJECTIVE: This study aimed to carry out a systematic review of observational studies searching the association between salivary factors (amount and quality of saliva) and noncarious cervical lesions (NCCL) in individuals with permanent dentition. DESIGN: Cross-sectional, case-control, and cohort studies performed in humans with permanent dentition (population) and considering noncarious cervical lesions (outcome) in association with salivary characteristics (exposure) were included. PubMed, Web of Science, Cochrane, LILACS/BBO, Scopus, Embase, IBCT, NICE, OpenGrey, and Google Scholar were searched, with no language or date restrictions. Of 6561 potentially eligible studies, 142 were selected for full-text analysis. Three reviewers independently selected the studies, performed data extraction, and quality analysis through the Newcastle-Ottawa Scale. RESULTS: Finally, ten references were included in the review, four case-control and six cross-sectional studies. Several salivary parameters were evaluated. Some parameters were considered associated with the presence of noncarious cervical lesions: salivary buffering capacity, salivary pH, citric acid, and calcium and potassium levels. The methodological quality varied across studies, with high heterogeneity among them. CONCLUSIONS: Some associations between saliva and NCCL suggesting protective factors and others risk factors were found. However, the evidence is sparse and comes from a few studies with great heterogeneity. New scientific evidence, with standardized methods, should be encouraged. Understanding salivary parameters that influence the occurrence of NCCL is important to guide dentists in relation to etiological factors that could potentially be neglected. The results may help in the development of new and early diagnostic methods and treatments for noncarious cervical lesions.

Noncarious cervical lesions in the aging population analyzed through digital scanning: occlusal risk factors, dimensions, and morphology.

OBJECTIVES: To evaluate noncarious cervical lesions (NCCL) in older adults by analyzing each lesion's morphology, dimension, and occlusal risk factors using intraoral scanning and clinical evaluation. MATERIALS AND METHODS: Individuals over 60 treated at the School of Dentistry in Minas Gerais, Brazil, were invited to participate in this cross-sectional study. We clinically evaluated 1245 teeth for the presence of NCCL and dentin hypersensitivity (DH) in 53 individuals. Three-dimensional models were obtained using Omnicam, and occlusal risk factors were evaluated through the presence of wear facets, intense occlusal contacts, and interferences. The 3Shape 3DViewer software was used to classify NCCL morphology and to measure their height. NCCL depth, width, and area measurements were determined using ImageJ. Descriptive analyses were performed. The Kolmogorov-Smirnov test showed that quantitative data exhibited non-normal distribution. For bivariate analyses of quantitative data, the Mann-Whitney test was employed. The results were reported with mean, standard deviation, median, minimum, and maximum. For bivariate analyses of categorical data, the Pearson chi-square test was used. The results were reported with frequencies (counts) and percentages. A regression model evaluating the association between occlusal risk factors and the absence/presence of NCCL was built. RESULTS: Most participants were female (58.5%), with a mean age of 66. The frequency of NCCL was 28.27%, corresponding to 352 teeth. Of these, 68.18% exhibited saucer morphology and 31.82% wedge-shaped morphology. The frequency of DH was 13.92% in teeth with NCCL. Saucer NCCL exhibited significantly greater height (p = 0.02), while wedge-shaped lesions showed greater depth (p < 0.001). Also, teeth with NCCL had a higher proportion of wear facets (66.8%; p < 0.001), intense occlusal contacts (39.8%; p = 0.008), and occlusal interferences (21.9%; p = 0.05). The regression model showed that teeth with wear facets were 1.50 times more likely to exhibit NCCL than teeth without wear facets (p < 0.001). Teeth with intense occlusal contact were 1.22 times more likely to exhibit NCCL than teeth without intense occlusal contact (p = 0.031). CONCLUSIONS: NCCL is a common dental condition in the older adults evaluated in this study. Wedge-shaped NCCL exhibited greater depth, while saucer NCCL had more expressive height. Occlusal risk factors may represent a crucial mechanism for the occurrence of NCCL in this population. CLINICAL RELEVANCE: Understanding the mechanisms involved in developing NCCL is helpful in diagnostic and preventive practices. The study showed the importance of dental occlusion and characteristics of different NCCL morphologies that help the clinician in decision-making.

On the Functional Role of Gamma Synchronization in the Retinogeniculate System of the Cat.

Fast gamma oscillations, generated within the retina, and transmitted to the cortex via the lateral geniculate nucleus (LGN), are thought to carry information about stimulus size and continuity. This hypothesis relies mainly on studies conducted under anesthesia and the extent to which it holds under more naturalistic conditions remains unclear. Using multielectrode recordings of spiking activity in the retina and the LGN of both male and female cats, we show that visually driven gamma oscillations are absent for awake states and are highly dependent on halothane (or isoflurane). Under ketamine, responses were nonoscillatory, as in the awake condition. Response entrainment to the monitor refresh was commonly observed up to 120 Hz and was superseded by the gamma oscillatory responses induced by halothane. Given that retinal gamma oscillations are contingent on halothane anesthesia and absent in the awake cat, such oscillations should be considered artifactual, thus playing no functional role in vision.SIGNIFICANCE STATEMENT Gamma rhythms have been proposed to be a robust encoding mechanism critical for visual processing. In the retinogeniculate system of the cat, many studies have shown gamma oscillations associated with responses to static stimuli. Here, we extend these observations to dynamic stimuli. An unexpected finding was that retinal gamma responses strongly depend on halothane concentration levels and are absent in the awake cat. These results weaken the notion that gamma in the retina is relevant for vision. Notably, retinal gamma shares many of the properties of cortical gamma. In this respect, oscillations induced by halothane in the retina may serve as a valuable preparation, although artificial, for studying oscillatory dynamics.

Cárie dentária e lesões cervicais não cariosas em idosos independentes: características individuais, ambientais e salivares / Dental caries and noncarious cervical lesions in independent elderly: individual, environmental, and salivary characteristics

O envelhecimento populacional característico das mudanças demográficas atuais vem sendo acompanhado por maior preservação dentária. Pessoas idosas possuem particularidades que as tornam mais susceptíveis ao desenvolvimento de alterações bucais como cárie dentária e lesões cervicais não cariosas (LCNC). Com a idade avançada, a prevalência da cárie dentária aumenta, e as LCNC tornam-se mais comuns e graves. O objetivo desse estudo foi avaliar a frequência de cárie dentária e de LCNC em idosos independentes, além de investigar associações entre proteínas salivares e a presença de cárie, e entre LCNC e fatores oclusais em dois artigos distintos. Neste estudo transversal, parte dos dados foi coletada usando entrevista estruturada. A experiência de cárie e de LCNC foi determinada pelos índices de Dentes Cariados, Perdidos e Obturados (CPO-D), Raízes Cariadas e Obturadas (CO- R) e Índice de Desgaste Dentário (TWI), coletados em exame clínico. Ao total, foram avaliados 127 indivíduos, com idade entre 60 e 84 anos. A média do CPO-D foi 23,86 e frequência de cárie dentária foi 65,4%. Para LCNC, a frequência de lesões com profundidade superior a 1mm foi 65,4%. Modelos 3D foram obtidos a partir de escaneamento intraoral para análise oclusal, morfologia e morfometria das LCNC, em 53 idosos, totalizando 1245 dentes com frequência absoluta de 352 (28,27%) dentes com LCNC. Lesões arredondadas possuíam maior altura, enquanto lesões anguladas apresentaram maior profundidade. Dentes com LCNC apresentaram maior proporção de facetas de desgaste, contatos oclusais intensos e contatos de interferência oclusal. Saliva em repouso foi coletada durante 5 minutos para quantificação do fluxo, pH, capacidade de tamponamento e proteínas salivares por meio de análise proteômica realizada em 80 participantes. Os indivíduos foram subdivididos em um grupo sem cárie ativa (47,5%) e outros dois grupos com lesões de cárie divididos pela mediana de dentes acometidos: £2 dentes (31,3%) e >2 dentes com cárie ativa (21,3%). Na análise proteômica, foram quantificadas 665 proteínas, envolvidas em processos de imunidade inata, modulação enzimática, atividade dos íons cálcio e adesão celular. Dessas, 68 proteínas demonstraram diferenças significativas de abundância entre os grupos. O conjunto de dados proteômicos foi correlacionado com índice de placa dentária visível, experiência de cárie radicular, fluxo salivar, capacidade tampão, pH e porcentagem de ingestão de açúcar. Com as correlações, 87 candidatos a biomarcadores foram identificados e 19 repetiram a significância da análise anterior. Dessa forma, os resultados deste estudo indicam potenciais biomarcadores e características individualizadas do paciente idoso que podem contribuir para o direcionamento do manejo clínico desse estrato populacional.

Population aging, characteristic of current demographic changes, has been accompanied by greater dental preservation. Older individuals possess particularities that make them more susceptible to the development of oral conditions such as dental caries and noncarious cervical lesions (NCCL). With advanced age, the prevalence of dental caries increases, and NCCL becomes more common and severe. The aim of this study was to assess the frequency of dental caries and NCCL in independent older individuals, as well as to investigate associations between salivary proteins and the presence of caries, and between NCCL and occlusal factors in two distinct articles. In this cross-sectional study, part of the data was collected using a structured interview. Dental caries and NCCL experience were determined by the Decayed, Missing, and Filled Teeth (DMFT) index, Decayed and Filled Roots (DFR) index, and Tooth Wear Index (TWI), collected through a clinical examination. In total, 127 individuals aged between 60 and 84 years were evaluated. The mean DMFT was 23.86, and the frequency of dental caries was 65.4%. For NCCL, the frequency of lesions with a depth greater than 1mm was 65.4%. 3D models were obtained from intraoral scanning for occlusal analysis, morphology, and morphometry of NCCL, in 53 elderly individuals, totaling 1245 teeth with a frequency of 352 (28.27%) teeth with NCCL. Saucer lesions had greater height, while wedge-shaped lesions showed greater depth. Teeth with NCCL presented a higher proportion of wear facets, intense occlusal contacts, and occlusal interference contacts. Unstimulated saliva was collected for 5 minutes to quantify flow, pH, buffering capacity, and salivary proteins through proteomic analysis performed on 80 participants. Individuals were subdivided into a group without active caries (47.5%) and two other groups with caries lesions divided by the median of affected teeth: ≤2 teeth (31.3%) and >2 teeth with active caries (21.3%). In the proteomic analysis, 665 proteins involved in innate immunity, enzymatic modulation, calcium ion activity, and cell adhesion processes were quantified. Of these, 68 proteins showed significant differences in abundance between the groups. The proteomic dataset was correlated with visible dental plaque index, radicular caries experience, salivary flow, buffering capacity, pH, and percentage of sugar intake. Through these correlations, 87 potential biomarker candidates were identified, and 19 replicated the significance of the previous analysis. Thus, the results of this study indicate potential biomarkers and individualized characteristics of elderly patients that may contribute to directing the clinical management of this population stratum.

A multilevel analysis model for dental caries determinants in independently-living elderly

To evaluate the prevalence of untreated caries and its association with biological, individual, and environmental variables in independently-living elderly people. Methods: This cross-sectional study included 72 elderly (≥60 years) patients of a university dental clinic in Belo Horizonte, Brazil. Sociodemographic data, systemic diseases, medications, and free sugar intake were collected. Visible plaque, Decayed, Missing, and Filled Teeth (DMFT), and Decayed and Filled Root (DFR) indexes were assessed through clinical examination. Unstimulated saliva was collected to determine salivary flow, pH, and buffering capacity. Descriptive analysis and multilevel logistic regression analysis were performed following a dental caries theoretical model (p <0.05, 95% CI). Results: The mean DMFT and DFR were 24.44 (SD=4.59) and 3.21 (SD=2.93), respectively. The prevalence of untreated caries was 61.11%. In the adjusted multilevel regression model involving 1639 teeth, untreated dental caries was significantly associated with the presence of biofilm (OR = 1.84; 95% CI: 1.24­2.74), salivary buffering capacity (OR = 0.87; 95% CI: 0.77­0.99) and per capita income (OR = 0.06; 95% CI: 0.004­0.74). Conclusion: The experience of dental caries was widespread among independently-living elderly patients, and its variability was best explained by the presence of biofilm, reduced salivary buffering capacity, and low per capita income. A comprehensive assessment is needed of the biological, individual, and environmental factors related to the presence of dental caries in independently-living elderly people

Bond strength of two universal adhesive systems to human dentin using different strategies / Resistência de união de sistemas adesivos universais à dentina humana usando diferentes estratégias

ABSTRACT The objective of this study was to evaluate the microtensile bond strength (μTBS) to dentin of two universal adhesive systems: Single Bond Universal (SBU) and Ambar Universal , used in different adhesion strategies. Materials and Method: Thirty-six human teeth were prepared (n=6) and treated following different adhesive strategies: G1: SBU-etch-and-rinse, applied on dry dentin; G2: SBUetch- and-rinse, applied on moist dentin; G3: SBU-self-etching; G4: AU-etch-and-rinse, applied on dry dentin; G5: AU-etch-and-rinse, applied on moist dentin; G6: AU-self-etching. The specimens were submitted to μTBS test, failure analysis, and scanning electron microscopy (SEM). Data were analyzed with ANOVA and Tukey's tests (p<0.05). Results: Microtensile bond strength was significantly lower in G1 than G2 and G3. AU adhesive performed worse than the SBU system, except in G5. Cohesive and mixed failures predominated in G1 and G2, while adhesive failures predominated in G3 and G5. Conclusions: Universal adhesives are an interesting innovation, but there are still doubts about their performance, mainly regarding the different protocols provided by the manufacturers. The conventional adhesive strategy on moist dentin demonstrated higher μTBS for both adhesives. The use of the selfetching strategy with the SBU showed promising results.

RESUMO O objetivo deste estudo foi avaliar a resistência de união à microtração (μTBS) de dois sistemas adesivos universais: Single Bond Universal (SBU) e Ambar Universal , utilizados em diferentes estratégias de adesão. Materiais e método: 36 dentes humanos foram preparados (n=6) e tratados seguindo diferentes estratégias adesivas: G1: SBU-condicionamento e enxágue, aplicado sobre dentina seca; G2: SBU-condicionamento e enxágue, aplicado sobre dentina úmida; G3: SBU-autocondicionante; G4: AU-condicionamento e enxágue, aplicado em dentina seca; G5: AU-condicionamento e enxágue, aplicado sobre dentina úmida; G6: AU-autocondicionante. Os espécimes foram submetidos ao teste de μTBS, análise de falhas e microscopia eletrônica de varredura (SEM). Os dados foram analisados com os testes ANOVA e Tukey (p<0,05). Resultados: A resistência de união à microtração de G1 foi significativamente menor que G2 e G3. O adesivo AU teve um desempenho pior que o sistema SBU, com exceção do G5. Falhas coesivas e mistas predominaram em G1 e G2 enquanto G3 e G5 apresentaram predominância de falhas adesivas. Conclusões: Os adesivos universais representam uma inovação interessante, mas ainda há dúvidas sobre seu desempenho, principalmente em relação aos diferentes protocolos fornecidos pelos fabricantes. A estratégia adesiva convencional em dentina úmida demonstrou maior μTBS para ambos os adesivos. O uso da estratégia autocondicionante com a SBU apresentou resultados promissores.

Adjunctive therapies for in vitro carious lesions: Antimicrobial activity, activation of dentin metalloproteinases and effects on dental pulp cells.

BACKGROUND: Adjunctive therapies used before dental restorative procedures may encourage carious tissue removal. Beyond promising antimicrobial properties, treatments could positively modulate the dentin-pulp complex while not interfering with restoration survival. Herein, we evaluated a set of substances and their effects on carious lesions and the underlying dentin or pulp cells. METHODS: Artificial caries lesions were developed in bovine teeth cavities immersed in Streptococcus mutans and Lactobacillus casei co-cultures. The cavities were treated according to the following groups: Phosphate Buffer Saline (PBS), Chlorhexidine (CHX), Papacárie® (Papain gel), Ozone (O3), and antimicrobial Photodynamic Therapy (aPDT). After treatments, samples were cultivated to count isolated microbial colonies. The zymography assay evaluated the activity of dentin metalloproteinases (MMP-2 and MMP-9). Cell viability was indirectly assessed on human dental pulp cells after 24, 72, or 120 h, whereas the odontodifferentiation potential was evaluated after ten days of cell culture. RESULTS: CHX and aPDT led to around 1 log bacterial load reduction. PBS, CHX, and aPDT showed the eventual expression of MMP-2 and MMP-9. Cell viability was reduced (< 30%) after 120 h for all groups compared to the control. CHX, O3, and aPDT induced greater odontodifferentiation (≈ 20% higher) than PBS and papain gel. CONCLUSION: Adjunctive therapies presented little or no biological significance in reducing bacterial load in artificial carious lesions. Although the activation of endogenous metalloproteinases may represent a possible concern for adhesive restorations, some of these treatments may have a positive role in dental pulp tissue repair.

Enhanced mechanical properties, anti-biofilm activity, and cytocompatibility of a methacrylate-based polymer loaded with native multiwalled carbon nanotubes.

OBJECTIVES: We aimed to optimize the mechanical and biological properties of a conventional methacrylate-based dental polymer by loading it with double- and triple-walled carbon nanotubes as growth (DTWCNTG). METHODS: A formulation of bisphenol A-glycidyl methacrylate and triethylene glycol dimethacrylate (mass ratio = 2:1) was mixed with DTWCNTG at concentrations of 0.0% (control), 0.001%, 0.005%, and 0.010%. The concentrations were physicochemical and morphologically evaluated, and antibacterial activity was assessed by seeding a Streptococcus mutans strain (ATCC 25175) on the experimental polymeric surfaces. Cellular survival and osteodifferentiation were evaluated in epithelial (HaCat) and preosteoblast cells (MC3T3-E1). RESULTS: The 0.001% DTWCNTG concentration yielded higher compressive strength, elastic modulus, flexural strength, flexural modulus, water sorption, and solubility than the control. The degree of conversion and color did not significantly change with a low amount of DTWCNTG incorporated into the polymer. Antibacterial activity significantly improved when tested on the 0.001% DTWCNTG discs. No groups showed cytotoxicity in a short-term analysis and adding DTWCNTG favored MC3T3-E1 mineralization over the control, particularly in the 0.001% formulation. SIGNIFICANCE: The micro-addition of 0.001% DTWCNTG confers mechanical resistance, antimicrobial properties, and bioactivity to methacrylate-based polymers without significantly compromising color. Incorporating DTWCNTG improved dental composite properties and could be a biomodified material for minimally invasive procedures.

Bond strength of two universal adhesive systems to human dentin using different strategies.

The objective of this study was to evaluate the microtensile bond strength (µTBS) to dentin of two universal adhesive systems: Single Bond Universal (SBU) and Ambar Universal (AU), used in different adhesion strategies. MATERIALS AND METHOD: Thirty-six human teeth were prepared (n=6) and treated following different adhesive strategies: G1: SBU-etch-and-rinse, applied on dry dentin; G2: SBUetch- and-rinse, applied on moist dentin; G3: SBU-self-etching; G4: AU-etch-and-rinse, applied on dry dentin; G5: AU-etch-and-rinse, applied on moist dentin; G6: AU-self-etching. The specimens were submitted to µTBS test, failure analysis, and scanning electron microscopy (SEM). Data were analyzed with ANOVA and Tukey's tests (p<0.05). RESULTS: Microtensile bond strength was significantly lower in G1 than G2 and G3. AU adhesive performed worse than the SBU system, except in G5. Cohesive and mixed failures predominated in G1 and G2, while adhesive failures predominated in G3 and G5. CONCLUSIONS: Universal adhesives are an interesting innovation, but there are still doubts about their performance, mainly regarding the different protocols provided by the manufacturers. The conventional adhesive strategy on moist dentin demonstrated higher µTBS for both adhesives. The use of the selfetching strategy with the SBU showed promising results.

O objetivo deste estudo foi avaliar a resistência de união à microtração (µTBS) de dois sistemas adesivos universais: Single Bond Universal (SBU) e Ambar Universal (AU), utilizados em diferentes estratégias de adesão. Materiais e método: 36 dentes humanos foram preparados (n=6) e tratados seguindo diferentes estratégias adesivas: G1: SBU-condicionamento e enxágue, aplicado sobre dentina seca; G2: SBU-condicionamento e enxágue, aplicado sobre dentina úmida; G3: SBU-autocondicionante; G4: AU-condicionamento e enxágue, aplicado em dentina seca; G5: AU-condicionamento e enxágue, aplicado sobre dentina úmida; G6: AU-autocondicionante. Os espécimes foram submetidos ao teste de µTBS, análise de falhas e microscopia eletrônica de varredura (SEM). Os dados foram analisados com os testes ANOVA e Tukey (p<0,05). Resultados: A resistência de união à microtração de G1 foi significativamente menor que G2 e G3. O adesivo AU teve um desempenho pior que o sistema SBU, com exceção do G5. Falhas coesivas e mistas predominaram em G1 e G2 enquanto G3 e G5 apresentaram predominância de falhas adesivas. Conclusões: Os adesivos universais representam uma inovação interessante, mas ainda há dúvidas sobre seu desempenho, principalmente em relação aos diferentes protocolos fornecidos pelos fabricantes. A estratégia adesiva convencional em dentina úmida demonstrou maior µTBS para ambos os adesivos. O uso da estratégia autocondicionante com a SBU apresentou resultados promissores.

Associação entre cárie dentária e determinantes biológicos, individuais e ambientais: estudo transversal em idosos não institucionalizados / Association of dental caries and biological, individual and environmental determinants: a cross-sectional study in noninstitutionalized elderly people

A cárie dentária é uma doença multifatorial, cuja etiologia engloba fatores biológicos, individuais e ambientais. A população idosa apresenta risco aumentado para desenvolvimento da cárie coronária e radicular, devido a mudanças alimentares, dificuldade de higienização, exposições radiculares, mudanças salivares e presença de alterações sistêmicas que implicam no uso crônico de medicamentos. O envelhecimento populacional, aliado ao risco aumentado para a ocorrência de cárie dentária em idosos, demanda um exame integrado do processo da doença, incluindo diferentes níveis de fatores para a construção de um modelo de análise mais robusto. O objetivo desse estudo foi avaliar a ocorrência de cárie dentária e sua associação com o biofilme dental, consumo de açúcares livres, alterações sistêmicas e características salivares, sociodemográficas e econômicas em idosos não institucionalizados. O estudo foi aprovado pelo Comitê de Ética em Pesquisa da Universidade Federal de Minas Gerais (CEP/UFMG; CAAE: 12045119.7.0000.5149) e os participantes assinaram um Termo de Consentimento Livre e Esclarecido. Dados sociodemográficos e econômicos, alterações sistêmicas e medicamentos em uso foram coletados usando questionário. A ingestão de açúcares livres foi analisada por meio de recordatório de 24 horas e do Programa de Apoio à Nutrição (NutWin). Índices de placa visível, de dentes cariados, perdidos e obturados (CPO-D) e de raízes cariadas e obturadas (CO-R) foram coletados por exame clínico, feito em cadeira odontológica. Saliva em repouso foi coletada por cinco minutos para determinar fluxo, pelo método volumétrico, pH e capacidade tampão usando tiras colorimétricas (GC America Inc.). Análise descritiva (IBM SPSS Statistics®) e análise de regressão logística multinível (Stata®) das variáveis foram realizadas (p<0,05, IC95%). Participaram do estudo 72 indivíduos, com média de idade igual a 67,29 (DP=6,12). A maioria dos participantes eram mulheres (55,6%), relataram pelo menos uma doença sistêmica (81,9%) e usavam, continuamente, pelo menos um medicamento (79,2%). A média (desvio padrão) do fluxo salivar foi 0,61 (0,34) ml/minuto. As médias (desvio padrão) do pH e da capacidade tampão da saliva foram, respectivamente, 6,9 (0,45) e 7,2 (3,07). O CPO-D médio foi 24,44, CPO-S médio foi 84,32, e o CO-R médio foi 3,21 O número médio de dentes cariados foi de 1,76, sendo 0,75 raízes cariadas por indivíduo. As frequências de cárie dentária e cárie radicular foram 61,11% e 36,11%, respectivamente. No modelo de regressão ajustado, a presença de cárie dentária foi significativamente associada à presença de biofilme (OR=1,840; IC95% 1.237,2.736), que atuou como fator de risco, capacidade tampão salivar (OR=0,874; IC95% 0.769,0.993) e renda per capita (OR=0,0568; IC95% 0.00438,0.738), que atuaram como fatores de proteção. A presença de cárie dentária foi alta entre idosos não institucionalizados, sendo sua variabilidade melhor explicada pela presença de biofilme, capacidade tampão da saliva e renda per capita.

Dental caries is a multifactorial disease, whose etiology includes biological, individual and environmental factors. The elderly population has an increased risk of developing coronary and root caries, due to dietary changes, difficulty in cleaning, root exposures, salivary changes and the presence of systemic diseases that imply the chronic use of medications. Population aging combined with increased risk factors for dental caries in the elderly demands a comprehensive examination of the disease process including different factors levels for the construction of a more robust analysis model. Thus, the objective of this study was to evaluate the occurrence of dental caries and the association with dental biofilm, free sugar intake, systemic factors, salivary, sociodemographic and economic characteristics in noninstitutionalized elderly. The study was approved by the Research Ethics Committee of the Universidade Federal de Minas Gerais (CEP / UFMG; CAAE: 12045119.7.0000.5149) and the participants signed a consent form. Sociodemographic and economic data, systemic diseases, and medications in use were collected using a questionnaire. The intake of free sugars was analyzed using 24-hour recall and a nutrition support software (NutWin). Visible plaque index, decayed, missed and filled teeth (DMFT) and decayed and filled roots (DFR) were collected by clinical examination in a dental chair. Unstimulated saliva was collected for five minutes to determine the flow rate using the volumetric method, and pH and buffering capacity with colorimetric strips (GC America Inc.). Descriptive analysis (IBM SPSS Statistics®) and multilevel logistic regression analysis (Stata®) of the variables were performed (p <0.05, 95% CI). Seventy-two individuals participated, with a mean age of 67.29 (SD = 6.12). Most participants were female (55.6%), had at least one systemic disease (81.9%) and used at least one medication (79.2%). The mean (SD) salivary flow rate was 0.61 (0.34) ml/minute. The mean (SD) salivary pH was 6.9 (0.45) and the mean (SD) salivary buffering capacity was 7.2 (3.07). The mean DMFT and DFR indexes were 24.44 and 3.21, respectively. The mean of decayed teeth was 1.76, with 0.75 decayed roots per individual. The frequencies of dental and root caries were 61.11% and 36.11%, respectively. In the adjusted regression model, the presence of dental caries was significantly associated with the presence of biofilm (OR = 1.840; 95% CI 1.237;2.736), salivary buffering capacity (OR = 0.874; 95% CI 0.769;0.993) and per capita income (OR = 0.0568; 95% CI 0.00438;0.738). The frequency of dental caries was high among noninstitutionalized elderly people, and its variability is better explained by the presence of biofilm, salivary buffering capacity and per capita income.

Molecular interactions and physico-chemical characterization of quercetin-loaded magnetoliposomes.

The bioflavonoid quercetin may prevent magnetoliposomes oxidation, preserving their stability. In this work, the interaction between quercetin and asolectin-based magnetoliposomes was investigated by monitoring the hydration degree, vibrational, rotational and translational mobility parameters of the system as well as its thermodynamic properties. The efficiency of the encapsulation of maghemite magnetic nanoparticles was detected by high resolution-continuum source flame atomic absorption spectrometry (HR-CS FAAS). The magnetic behavior of the system was studied by vibrating sample magnetometry (VSM) technique. The size and surface charge of magnetoliposomes were detected by dynamic light scattering (DLS) and zeta potential (ζ-potential) measurements. The influence of quercetin on the physico-chemical parameters of the magnetoliposomes was evaluated by Fourier transform infrared spectroscopy (FTIR), 31P and 1H nuclear magnetic resonance (NMR) and differential scanning calorimetry (DSC) techniques. In vitro antioxidant and antitumoral assays were also performed for the magnetoliposomes. An insertion of quercetin into magnetoliposomes reduced the efficiency of the encapsulation of maghemite nanoparticles by 11%, suggesting a significant interaction between flavonoid and nanoparticles in a specific region of the system. Quercetin discreetly decreased the saturation magnetization of magnetoliposomes, but did not affect the superparamagnetic behavior of the system. 31P and 1H NMR results showed that quercetin did not alter the inverted hexagonal system phase state but decreased lipid polar head mobility. The flavonoid also seems to reorient the choline group above the bilayer phosphate membrane plane, as indicated by ζ-potential system values. FTIR, NMR and DSC responses showed that quercetin disordered the carbonyl and the methylene regions of the magnetoliposomes. Quercetin, as the nanoparticles, seems to be located in the polar head regions of magnetoliposomes, ordering it and diminishing the lipid intermolecular communication in the membrane carbonyl and non-polar regions. The lipid peroxidation of the magnetoliposomes was prevented 8-fold by the presence of quercetin in the system. Also, the flavonoid was responsible for a 45% reduction in the viability of glioma cells. Location and interactions between quercetin and magnetoliposomes components were discussed in order to be correlated with the results of biological activity, contributing to the design of more stable and efficient magnetoliposomes to be applied as contrast and antitumoral agents.