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PANMELLA PEREIRA MACIEL
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Development of experimental varnish containing fluorine-doped
S53P4 glass-ceramic for dental use
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Advisor : PAULO ROGERIO FERRETI BONAN
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Date: Dec 21, 2023
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Time: 08:30
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Show Summary
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Reversing and/or preventing the progression of carious or erosive lesions
poses a significant challenge. Thus, new treatment strategies are sought to facilitate
the action of fluoride in the superficial and underlying layers of these lesions. With
this objective, the aim was to develop an experimental varnish with commercial
potential containing fluoride-doped glass-ceramics. Glass-ceramics of S53P4
composition doped with Fˉ ions (CF) were produced via the sol-gel route. The CF
was characterized by Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD),
and Fourier Transform Infrared Spectroscopy (FTIR). The experimental varnish
(VE), composed of hydrogenated rosin, had 10% and 20% by weight of CF incorporated (0, 5, or 10 mol% Fˉ). The VE was characterized by SEM, Rheology,
Optical Profilometry, and FTIR. The CF and VE were evaluated for ion release,
cytotoxicity against VERO cell line, antimicrobial effect, adhesion, biofilm formation,
and in vitro mineralization test. Data were tabulated and analyzed by One-Way
ANOVA, Kruskal-Wallis test, and two-way ANOVA. The CF presented semicrystalline structure with a sodium-calcium-silicate phase (bioactive phase).
Micrographs showed irregular and porous surface particles. The CF (5 mol% - CF5
and 10 mol% - CF10) demonstrated biocompatibility and minimum inhibitory
concentration (MIC) at concentrations below 10 and 6.25mg/mL, respectively.
Hydroxyapatite formation was observed, especially for CF10. In the 24-hour period,
12 and 35 ppm of Fˉ were released for CF5 and CF10, respectively. Homogeneous
varnishes were obtained without precipitation and with good viscosity. The
incorporation of CF increased the surface roughness of experimental varnishes but
did not interfere with the antibacterial effect. Varnishes with 20% CF demonstrated
biocompatibility and MIC at concentrations below 10 and 3.12mg/mL, respectively,
except for C. albicans. Regarding Fˉ ion release, all varnishes with CF5 and CF10
released more fluoride than the commercial Duraphat varnish. In conclusion,
bioactive glass-ceramics with bio-reactive properties (hydroxyapatite/fluorapatite
formation), especially for CF10, and antimicrobial properties were obtained.
Additionally, when incorporated into the experimental varnish, biocompatibility was
observed in VERO cells and antibacterial effects on S. aureus. The varnish matrix
did not interfere with Fˉ and Ca+2 ion release.
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ISIS MORAIS BEZERRA MUNIZ
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Antimicrobial effect of an experimental mouthwash with
cinnamaldehyde on duo-species biofilm in a root caries model with high glucose
concentration
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Advisor : LEOPOLDINA DE F DANTAS DE ALMEIDA
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Date: Dec 20, 2023
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Time: 13:00
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Show Summary
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Dental caries is still considered one of the biggest public health challenges,
affecting a large portion of the world's population. The topic surrounding root caries has been the subject of studies due to its increased prevalence. The reason
attributed to this fact is the increase in the population's life expectancy, which
consequently means that individuals retain their teeth for longer. In
immunocompromised patients, microbial communities are capable of exacerbating
their virulence factors, triggering adverse consequences for oral health. Diabetic
patients, especially decompensated ones, are more susceptible to certain types of
oral changes, such as salivary changes and tooth decay. The validation of models
that evaluate microbial interactions as well as the effect of substances that help in
the prevention and treatment of caries is necessary, mainly simulating common
clinical conditions, such as diabetes. The in vitro antimicrobial effect of an
experimental mouthwash with cinnamaldehyde on duospecies biofilms was
evaluated in a root caries model with high glucose concentration. Specimens
(n=6/group) of bovine dentin (5×5×1mm) were prepared and an artificial caries
lesion was induced. The inoculum was standardized at 106 and 108 CFU/mL for C.
albicans (ATCC 90028) and S. mutans (UA159), respectively. Specimens were
inserted into 24-well plates and were coated with humam saliva for acquired
pellicle formation (1h). Then, biofilms were seeded using TYE with 1% sucrose.
After 4 hours, the culture medium was removed and TYE with 100 mM glucose
was inserted, simulating salivary concentrations of a diabetic individual. Daily, the
biofilm was exposed to 10% sucrose, three times a day, simulating episodes
feast-famine. At the end of each day, the samples were exposed to to the
following treatments: experimental mouthwash with 1% cinnamaldehyde (CIN),
mouthwash with 0.05% sodium fluoride (NaF). chlorhexidine 0.12% (CHX) (positive
control) and saline 0.9% (growth control). After 96h, the effects of the mouthwash,
as well as the analysis of microbial interactions were evaluated based on cell
viability assays (CFU/mL) on Saburaud Dextrose Agar (ASD) and Mitis Salivarius
Agar (MSA) plates, dosage of soluble and insoluble extracellular polysaccharides
(S- EPS and I-EPS) (µg/mL), dosage of total proteins (TP) (g/dL), phospholipase
activity (Pz value, mm), calcium quantification (mg/mL), analysis of cellular
metabolism using the MTT test, surface roughness using optical profilometry (μm)
and metabolomic analysis. SPSS software was used for data analysis. Calcium Quantification and MTT data were submitted to ANOVA and Tukey tests (α<5%).
CFU/mL, S- EPS and I-EPS Dosage of TP and surface roughness using
profilometry data were submitted to the Kruskal-Wallis and Mann-Whitney tests
(α<5%). Phospholipase activity was evaluated semi-quantitatively and
metabolomics data by partial least squares (PLS-DA) and sparse (S-PLS-DA)
discriminant analysis. It was found that the CFU/mL count in both culture media
(ASD and MSA), dosage of PECs and PECis S- EPS and I-EPS, phospholipase
activity and calcium concentration in the culture medium did not differ statistically
between the groups evaluated (p>0.05). Regarding the dosage of TP, it was found
that the NaF, CIN and CHX groups differed from the growth control (p<0.05), with
no differences between them (p>0.05), showing a reduction in production of
proteins by biofilm. Regarding the MTT test, CHX showed superior activity
compared to the other treatments (p<0.05). The growth control group presented
higher roughness values, being statistically different from all the others (p<0.05).
The PLS-DA analysis demonstrated a slight difference when compared the saline
and NaF with CHX and CIN groups (AcC = 46.00%, R2 = 39.79%,Q2 = -1.47%).
The S-PLS-DA demonstrated a more evident differenciation when conpared the
saline and other groups, in special CHX and CIN groups. The VIP score
demonstrated an important variation among groups. Cinnamaldehyde did not show
a significant antimicrobial effect, compared to NaF, CHX or saline, in a medium
supplemented with a high concentration of glucose. Investigating the potential
effect of cinnamaldehyde seeks to contribute to the development of new strategies
to combat oral infections, providing a better understanding of the therapeutic
benefits of this substance. Knowledge about new antimicrobial substances can
open up a range of alternatives so that new therapies can be developed aimed at
controlling biofilm and its problems.
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THAYANA MARIA NAVARRO RIBEIRO DE LIMA
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Telemonitoring through a mobile app as a strategy for dental care
for children and adolescents with câncer
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Advisor : SIMONE ALVES DE SOUSA
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Date: Dec 11, 2023
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Time: 09:00
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Show Summary
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The use of mobile applications as a telemonitoring tool can be considered
an applicable strategy in Dentistry for the prevention, promotion of oral health, and
assistance in the diagnosis of comorbidities. From the perspective of pediatric
cancer patients, comprehensive dental care is needed in conjunction with the care
provided by the multidisciplinary team. Thus, the objective of this dissertation is to
evaluate the photographic tool of a mobile application to enable subsequent
telemonitoring of dental conditions in children and adolescents with cancer. For this
purpose, two work plans were developed. In the first plan, information on the
accuracy of photos taken with mobile applications for the detection of potentially
malignant lesions and the monitoring of patients was evaluated through a systematic review with meta-analysis. Its results suggest the feasibility of diagnosis
through remote exams with photos taken by applications and indicate the
possibility of using these technologies in regions where access to healthcare
professionals is not guaranteed. The importance of further research on this topic is
also emphasized to ensure the effective incorporation of similar remote exams in
dental clinical practice. In the second plan, the accuracy of remote examination of
oral mucositis through photos taken by the Pediatric Oncology Telemonitoring
(TON) mobile application was assessed. This plan sought to evaluate the
scientifically based remote telemonitoring strategy discussed in the first plan. The
development of TON can be considered one of the major advances in dental care
provided to pediatric patients in the studied oncology hospital, and this application
seems to be a viable option to expand attention both in the hospital environment
and remotely, in the cities where children, adolescents, and their families reside.
The sensitivity, specificity, and accuracy results of TON application for remote
examination of oral mucositis and severe oral mucositis were favorable. Initial
cases of oral mucositis could be identified through photographs, suggesting that
patients with this condition can be remotely guided if this tool is made available for
use.
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ARELLA CRISTINA MUNIZ BRITO
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Effect of alloxan induced diabetes and fluconazole therapy on the pathogenicity of mixed biofilms of Candida albicans and Streptococcus oralis in a murine model
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Advisor : YURI WANDERLEY CAVALCANTI
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Date: Nov 29, 2023
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Time: 14:00
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Show Summary
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Diabetes mellitus and oral candidiasis are diseases that have a high prevalence. Diabetic individuals may have higher rates of fungal colonization and invasion due to their systemic conditions. However, the extent to which this interrelationship can be harmful remains a topic of scientific relevance. The aim of the present study was to evaluate the effect of diabetes mellitus induced by alloxan and treatment with fluconazole on the virulence and pathogenicity of co-infection of mixed biofilms of Candida albicans and Streptococcus oralis in an animal model. Male Wistar rats (n=24) were distributed into: CTR group, non-diabetic, without treatment (n=6), FLU group, non-diabetic, treated with fluconazole (n=6), DCTR group, diabetic, without treatment (n=6), DFLU group, diabetics, treated with fluconazole (n=5) and group C-, negative control (n=1). The diabetic groups received doses of 120 mg/kg to 240 mg/kg of alloxan before the coinfection period. Hyperglycemia was confirmed at 250 mg/dL of fasting glucose. The co-infection protocol followed with doses of prednisolone 100 mg/kg and suspensions of C.albicans and S. oralis inoculated via swab into the oral cavity and administered ad libitum in water. The groups that received treatment with fluconazole received doses of 10 mg/kg every 12 hours. The control groups received administration of 0.9% saline solution. At the end of the experimental period, all animals were euthanized and observed macroscopically for the presence or absence of lesions on the tongue and microscopically using histochemical methods of Hematoxylin- eosin (HE) and Periodic Acid-Schiff (PAS) to evaluate changes in the palate, tongue and pancreas. The extraction and quantification of C.albicans DNA from the tongue was also carried out, as well as gene expression for SAP6 and HWP1 using Real-time RT-qPCR. Data were analyzed by ANOVA one-way e Tukey test (α= 5%). Whitish lesions were observed on the tongues of animals in the DCTR group. With the exception of C-, which did not present macroscopic changes, the other groups presented erythematous areas on the surface. In histological sections, the DCTR group showed more changes in relation to the other groups, with emphasis on epithelial invasion by hyphae and hyperkeratosis on the tongue, as well as epithelial reduction and the presence of an ulcer with dilated vessels on the palate. All diabetic animals showed destruction of the Islets of Langerhans. The quantification of C.albicans DNA in the animals' tongues indicated that there was a difference between the DCTR group and the others (p<0.05), however in the rest of the groups there were no differences (p>0.05). SAP6 gene expression indicated that there was no significant difference in the groups evaluated (p>0.05). Regarding HWP1 gene expression, it was observed that there was a difference between the groups of healthy animals and diabetic animals (p<0.05). The results indicates that the diabetic groups not treated with fluconazole showed a greater number of macroscopic and histological changes, as well as greater quantification of C.albicans and gene expression for HWP1. Treatment with fluconazole was effective in reducing fungal invasion. The findings of the present research may assist further studies that consider alloxan diabetes and treatment with fluconazole to evaluate the effects of oral candidiasis in murine models.
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HUGO VICTOR DANTAS
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Analysis of three types of instrumentation in the modelling of root
canals of permanent maxillary lateral incisors: a study controlling for variations in
root canal anatomy.
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Advisor : FREDERICO BARBOSA DE SOUSA
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Date: Nov 24, 2023
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Time: 14:00
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Show Summary
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Nickel-titanium (NiTi) files are the most suitable for modeling root canals,
but there are no studies on permanent maxillary lateral incisors (ILSP). The
objective of this in vitro study was to test the hypothesis that the type of
instrumentation (NiTi files, in motorized modes and with a new manual adapter,
and conventional stainless steel files) affects the shaping of permanent maxillary
lateral incisor root canals (ILSPs). ). ) when the anatomical variation of the root
canal (estimated by canal angulation, initial root canal volume and ratio between
largest and smallest diameter) is controlled in data analysis. 60 upper lateral
incisor teeth without endodontic treatment, without restoration, without root carious
lesion and with apical angulation between 10° and 30° were selected based on 3D
microcomputed tomography (MicroCT) and then randomly distributed into three
groups (n = 20/group): NiTi files with motor (GMT), NiTi files with manual adapter
(GAD) and conventional files (GAI). Each tooth was instrumented in two sequential
steps, the first with files up to #45 (GMT45, using WaveOne Gold files; GAD45,
using WaveOne Gold files and GAI45, using stainless steel files) and the second
with files up to 80 (GMT80, using MKLife files; GAD80, using MKLife files; and
GAI80, using stainless steel files). MicroCT analysis was performed after each
instrumentation step and the following steps were analyzed in the apical third:
volume increase (AVOL%), surface area increase (ASUR%), structure model index
(SMI), areas not touched (ANT%), canal transport and frequency of apical defects.
Then, the regression test was applied between confounding variables or covariates
and the factor and stage, separately. For the development of the untouched area,
the potential confounder or covariate was the mean AR variable. For the volume increase stage, the potential confounder or covariate was adjusted initial volume.
AVOL% was strongly associated with the initial canal volume in all groups
(coefficient r2 = 0.75-0.86, p< 0.01), so that the adjusted AVOL% (AVOLaj%) was
obtained by the product of AVOL% by the logarithm of the initial volume. There
was a lower AVOLaj% in the GAI45 and GAI80 groups when compared to the
GMT45 (p = 0.03) and GMT80 (p = 0.02) groups, respectively, with no significant
differences between the other groups. The same occurred with the increase in
surface area, which had a strong negative association with the initial volume, and
the increase in adjusted surface area (ASajus) was calculated by the product
between the increase in surface area and the logarithm of the initial channel
volume. . Regarding the frequency of apical errors, the GAI45 group had more
errors than the GAD45 group (p = 0.03; Relative risk of 4.50; 95% CI: 2.62-7.74)
and the GAI80 group had more errors than the GMT80 (p = 0.02; Relative risk of
2.60; 95% CI = 1.11-6.08) and GAD80 (p = 0.01; Relative risk of 3.25; 95% CI =
1,44-7,35). In conclusion, the files showed lower adjusted volume than the
motorized NiTi files and also a higher frequency of apical defects when compared
with the motor and ED File groups, while the motorized and manual adapter NiTi
file groups demonstrated similar performances at all stages.
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SUYENE DE OLIVEIRA PAREDES
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ORAL HEALTH PROMOTION WITHIN THE FAMILY HEALTH STRATEGY: FROM THE NATIONAL PANORAMA TO DAILY WORK IN RURAL AREAS
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Date: Nov 17, 2023
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Time: 14:00
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Show Summary
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To comprehensively grasp the landscape of health promotion within the realm of oral health, encompassing both the national landscape of Oral Health Promotion (OHP) procedures and delving into more profound explorations of OHP practices at the local and regional levels, this study has formulated distinct objectives across three Planes of Analysis (PAs). PA 1 (Article 1) undertook an inquiry into the correlations between sociodemographic variables and municipal coverage provided by Family Health Strategy (FHS) in conjunction with OHP procedures across Brazil. This inquiry assumed the form of a cross-sectional investigation, leveraging secondary data sourced from the Ministry of Health, referring to 2019. Negative binomial regression models were employed to associate outcomes with covariates and to estimate the prevalence ratio (PR) along with corresponding 95% confidence intervals (95%CI). The analytical cohort encompassed 4,913 municipalities. The findings indicated that municipalities characterized by lower income inequality (PR=1.04; 95%CI 1.01-1.08), higher illiteracy rates (PR=1.06; 95%CI 1.00-1.13), and populations ranging from 10,001 to 50,000 inhabitants (PR=1.07; 95%CI 1.02-1.12), as well as populations ranging from 50,001 to 100,000 (PR=1.21; 95%CI 1.12-1.30), exhibited a heightened incidence of individual OHP procedures. Conversely, a reduced frequency was associated with lower susceptibility to poverty (PR=0.83; 95%CI 0.78-0.89) and diminished Oral Health Teams (OHT) coverage (PR=0.39; 95%CI 0.33-0.45). Regarding collective procedures, diminished frequency was correlated with lower income inequality (PR=0.91; 95%CI 0.87-0.95), lower HDI values (PR=0.53; 95%CI 0.35-0.80) for both low and medium HDI levels (PR=0.79; 95%CI 0.71-0.87), and lower per capita income (PR=0.84; 95%CI 0.81-0.88). PA 2 (Article 2) delved into an examination of the nexus between sociodemographic and professional profiles, coupled with workrelated factors, and the effectiveness of OHP strategies. This phase of investigation adopted a cross-sectional, quantitative, descriptive, and analytical framework. The study cohort comprised 211 dentists selected through snowball sampling, all of whom were affiliated with OHT operating in Paraíba. Employing Poisson regression, the study established associations between the aforementioned factors and the desired outcomes, estimating the prevalence ratios (PRs) along with their corresponding 95% confidence intervals (95%CI), with statistical significance determined at p<0.05. Enhanced effectiveness of OHP strategies was notably linked with OHTs classified as "mixed" (urban and rural coverage area) (RP=1.54; 95%CI 1.154-2.076), where dentists held temporary contracts (RP=1.67; 95%CI 1.2402.250). PA 3 aimed to achieve an in-depth comprehension of the activities of FHS dentists operating within rural OHTs in Paraíba, particularly from the standpoint of OHP and their daily responsibilities. Adopting a cross-sectional and qualitative approach, this phase of investigation encompassed interviews with fourteen professionals. Thematic content analysis was employed as the methodology to understand and systematize the gathered data (Articles 3 and 4). The narratives emerging from this analysis unveiled imprecise conceptualizations of Health Promotion, wherein the scope of these concepts was often confined to the prevention of oral diseases. Disparities were evident regarding support units, and certain rural populations were devoid of specialized oral health services. Noteworthy engagement in outreach practices and initiatives targeting pregnant women was observed among professionals. However, the establishment of cohesive groups faced challenges, and intersectoral actions primarily revolved around collaborations between the healthcare and education domains. Discrepancies were evident in terms of managerial support. The narratives underscored the potential of OHP endeavors to bolster self-esteem and enhance quality of life, premised upon principles of comprehensive care, solidarity, and humanization (Article 3). Positive sentiments were associated with the significance of their work and the favorable interactions with communities. These professionals encountered adversities encompassing socioeconomic and emotional requisites, geographical remoteness, infrastructural limitations, disparities in accessibility and organization, and complexities in harmonizing collective and individual initiatives. The biomedical care model and dental extractions were ingrained within the rural context, while dissatisfactions were attributed to remuneration and infrastructure. The repercussions of the COVID-19 pandemic were evidenced through heightened biosecurity measures and the curtailment of collective activities (Article 4). In summation, the municipal sociodemographic variables (income inequality, illiteracy populations ranging, susceptibility to poverty, HDI and per capita income) and OHT/FHS coverage influence the performance of OHP procedures in Brazil. In the Paraíba, the greater effectiveness of OHP strategies can be influenced by professionals who work in urban and rural territorial segments, and with temporary contracts. In understanding the rural territories of Paraíba, the singularities of these locations result in challenges for OHP practices and the daily work of dentists.
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MARIA LETÍCIA BARBOSA RAYMUNDO
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Oral Health of Traditional Peoples and Communities in Brazil: Scope Review and Epidemiological Survey in Quilombola Territory in the City of João Pessoa-PB
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Advisor : YURI WANDERLEY CAVALCANTI
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Date: Nov 13, 2023
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Time: 14:00
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Show Summary
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Traditional Peoples and Communities (PCT) in Brazil are affected by health inequities, including oral health. Gathering epidemiological information about the oral health status is the initial step in making the epidemiological situation visible. The objective of this dissertation was to elucidate the health condition of PCT, and for this purpose, two work plans were developed. The first work plan involved designing and developing a scoping review protocol with the aim of mapping the available evidence on oral health research among Traditional Peoples and Communities (PCT) in Brazil through primary studies, addressing the following question: "What evidence is available regarding oral health surveys of Traditional Peoples and Communities in Brazil?". The scoping review was conducted following the Problem, Concept, and Context strategy, as established by the Joanna Briggs Institute. The search strategy included Medical Subject Headings terms, synonyms, and relevant free terms related to epidemiological surveys on oral health and PCT in Brazil, across the MEDLINE/PubMed, LILACS, Scopus, Web of Science, and Embase databases. The bibliographic searches were updated until July 2023. In the first stage of the study selection process, a total of 401 citations were found. Among these 401 studies, 211 were removed due to duplication. Based on the title, abstract, and keywords, 136 studies were excluded because they reported secondary data or were non-specific and non-representative of PCT. In the second selection stage, 61 studies were read in full, and 39 were included in the review. Two studies were manually added. The included studies were published between 1968 and 2023. Of these, 31 studies investigated the oral health condition of indigenous peoples, 7 were about quilombola communities, and 3 were about riverine peoples. No studies about Romani communities were found in the search. All studies were cross-sectional in nature, with the majority located in the Northeast region of the country (n=12), assessing dental caries as the primary oral health issue (n=13) through clinical examinations (n=25), with a high prevalence observed among PCT (n=11). The review conducted reveals that in Brazil, studies on the oral health of PCT are ongoing, albeit in an isolated and independent manner, indicating a considerably high prevalence of oral health problems in these communities. In the second work plan, a population-based cross-sectional epidemiological survey was conducted in a quilombola territory in the municipality of João Pessoa, Paraíba, with children aged 4 to 8 years. The objective was to assess the prevalence of dental caries through intraoral examinations and its associated factors, including sociodemographic and socioeconomic factors and nutritional factors measured through the cariogenic potential of the diet. The ceo-s (decayed, extracted, filled surfaces) and CPO-S (decayed, missing due to caries, filled surfaces) indices were used, along with the pufa/PUFA index, which quantifies the prevalence and severity of untreated dental caries-related oral conditions. Examinations were conducted on 146 children in the quilombola territory. Among the families who participated in the study, only 46.3% (n=62) self-identified as quilombolas. Regarding skin color, 63.2% (79) of the children were of mixed race. In terms of socioeconomic status, 69.7% (n=83) had income below the minimum wage, 67.4% (n=95) received government assistance, and the average household size was 4 (±1.38) individuals. In the Poisson multilevel regression model, with the child's age, sex, and skin color, and receipt of government assistance as the clustering factor, the factors associated with dental caries experience, untreated dental caries prevalence, and the PUFA index were examined. Children from quilombola families with incomes below the minimum wage had a 6.35 times higher prevalence of dental caries experience (PR=6.35, 95% CI 3.36 to 11.98). Those from quilombola families with cariogenic diets had a 3.26 times higher prevalence of untreated caries (PR=3.26, 95% CI 1.57 to 6.78), and children from families with incomes below the minimum wage had a 4.69 times higher prevalence of pulpal involvement (PR=4.69, 95% CI 1.06 to 20.65). Thus, children from quilombola families with low incomes and cariogenic diets have a higher prevalence of dental caries experience and untreated dental caries, highlighting the influence of social factors on oral health. Furthermore, more studies on quilombola communities are needed to bring visibility to this group.
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WILSON JOSE DE MIRANDA LIMA
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Murinometric, histological, and immunohistochemical study of the
influence of obesity on the development of experimental bisphosphonate-induced
osteonecrosis.
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Date: Sep 29, 2023
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Time: 14:00
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Show Summary
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Osteonecrosis is a disease characterized by the death of bone
constituents. Some compounds, such as bisphosphonates that act by inhibiting
bone resorption, can induce osteonecrosis. When the disease occurs in the jaws
and is induced by the use of bisphosphonates, it's called BRONJ - BisphosphonateRelated Osteonecrosis of the Jaws. Obesity is considered a public health problem
and is related to other oral diseases, such as cavities and periodontitis. This study is
pioneering in identifying the relationship between obesity and bisphosphonateinduced osteonecrosis. The work aimed to analyze the influence of obesity on the
development of bisphosphonate-induced osteonecrosis through histological,
immunohistochemical, and morphometric analyses. The experiment consisted of 24
male Wistar rats (Rattus Norvegicus) with an approximate age and weight of 30
days and 180g. They were randomly and simply divided into four groups: healthy,
osteonecrosis, obese, and obese with osteonecrosis. Osteonecrosis was induced
using zoledronic acid in injectable solution at 4mg/5mL intraperitoneally, at a dose of
250 µg/kg, once a week for eight weeks, combined with bone trauma (extraction of
the lower left first molar). Obesity was induced using a high glycemic index diet.
Each group was qualitatively and quantitatively evaluated regarding: obesity model
development, osteonecrosis model development, macroscopy and microscopy of
maxillary lesions. The results were expressed as the mean percentage and
standard deviation and statistically analyzed using one-way analysis of variance
(ANOVA) followed by Tukey's post-test. Animals in the osteonecrosis group and the
obese with osteonecrosis group presented larger areas of necrosis (averages:
172.83 ± 18.19 µm² and 290.33 ± 15.77 µm², respectively) (p < 0.0001). Bone
sequestration, hepatic steatosis, and increased adipocyte size were observed in the
obese group (average: 97.75 ± 1.91 µm²) and the obese with osteonecrosis group
(average: 98.41 ± 1.56 µm²), indicating greater tissue damage in these groups (p < 0.0001). Regarding immunohistochemical analyses, the healthy and obese groups
showed intense extracellular matrix deposition. TNF-β showed intense and
multifocal labeling in the osteonecrosis (27.59 ± 7.65 µm²) and obese (25.52 ± 8.31
µm²) groups. For TGF-β, labeling was also intense and multifocal, especially in the
obese with osteonecrosis group (44.98 ± 3.93 µm²). Collagen I labeling was more
intense in healthy animals (26.73 ± 8.29 µm²), while in other groups, it was discreet
and focal. The establishment and standardization of the obesity and osteonecrosis
induction model in Wistar rats were confirmed based on murinometric parameters
evaluation (weight evolution, nasoanal length, Lee index, body mass index,
abdominal and thoracic circumferences, adiposity index, and liver weight). Possible
influences of obesity and osteonecrosis on weight evolution and murinometric
parameters were observed. The study suggests that TNF-alpha and TGF-β may
play important roles in bone tissue damage and repair, possibly in association with
obesity and inflammatory processes related to osteonecrosis. The potential
interaction between TGF-β, TNF-alpha, and collagen I in bone tissue could be
crucial for understanding bone remodeling, disease prevention, and treatment.
However, further studies are needed to explore the underlying mechanisms.
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ISIS DE ARAUJO FERREIRA MUNIZ
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Development of a teleconsultation application in
temporomandibular disorders
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Advisor : PAULO ROGERIO FERRETI BONAN
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Date: Aug 23, 2023
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Time: 08:00
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Show Summary
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Introduction: Teleconsultation is a subdivision of teledentistry in which it
allows the management of the patient by one or more professionals who can discuss
the case report and conduct it remotely, synchronously, in real time, or
asynchronously. In this way, it represents the solution for the continuity of dental
practice using information technology. Aim: To develop a teleinterconsultation
application for diagnosing TMD and to evaluate its usability, viability, usefulness and
diagnostic agreement. Materials and methods: The application was developed
using the App Glide (GoogleTM) as a basis and was evaluated by five TMD expert judges, who tested the application for a week regarding feasibility, usability, and
usefulness. The answers were according to the Likert scale, with values from 1
(totally disagree) to 5 (totally agree). The instrument used for the evaluation
corresponded to a questionnaire adapted from Google Forms. To assess the
diagnostic agreement, the percentage of absolute inter-examiner agreement was
used between the TMD diagnosis given in person and by the consultants through
the application and determined through the division between the number of
agreements and the total number of evaluations. Results: The tool developed
consists of a main screen with the concept of TMD, the purpose of the application,
information about privacy and legality, instructions on its use, and guidelines on filling
out the DC/TMD forms, and all this information contains images or instructional
videos. The application also features a menu bar with interchangeable screens
containing the professionals' registration, case reports, consultant's opinion,
DC/TMD forms, and face-to-face assistance with the services available for
assistance. The application is available and can be installed through the link:
https://dtmapp.glideapp.io. The evaluation of the tool by the expert judges was
satisfactory, being considered viable, useful, and easy to understand and use by
professionals. The evaluation of the tool by the expert judges was satisfactory, being
considered viable (80%), easy to use (90%) and useful (93%) for professionals. Of
the 11 reports of diagnosed cases, 9 presented diagnostic agreement representing
81.8% of absolute agreement. Conclusion: Given the results of this research, it is
possible to conclude that the developed application can be used to assist the dental
surgeon in the diagnosis and management of the patient with TMD.
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YURI VICTOR DE MEDEIROS MARTINS
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Continuing Education in Health and its relationship with the work
processes in Dental Specialty Centers
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Date: Aug 17, 2023
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Time: 14:00
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Show Summary
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The National Policy of Continuing Education in Health, instituted in Brazil
in 2004, emerged as a theoretical and methodological basis of instructions for the
training and development of health workers, as well as guidelines and devices for
its implementation. It understands the qualification of workers as primarily based
on health needs and the local reality, and aims to reformulate professional
practices and the very organization of work. The structuring of work processes
must be based on the problematization of practice. Thus, Continuing Education in
Health responds to the social character of the educational action carried out at
work allied to multidisciplinary teamwork and seeks to achieve a primordial
technical training. The general objective of this thesis was to know how the actions
of Permanent Health Education are inserted within the work routine in the medium
complexity attention in Dentistry. The specific objectives were: a) to analyze the
relationship of the actions of Continuing Education in Health with the work process
and the impact on integrality in the routines of medium complexity attention in
Dentistry; b) to analyze the actions of Continuing Education in Health and its
association with the integrality of the work process within the routines of medium
complexity attention in Dentistry and its impacts on primary care; c) to verify the
impact that the actions of Continuing Education in Health can generate in the oral
health care facilities of a municipality, when considering and using the opinion of
users in their planning and d) to verify the importance of self-assessment for the
production and certification of the Dental Specialty Centers. This is an exploratory
cross-sectional study based on secondary data from the 2nd Cycle of the National
Program for Improving Access and Quality of Dental Specialty Centers. Logistic
regression models obtained through bivariate analysis were adjusted, which
assumed a statistical significance level of 5%. Results showed that where there is
matriciamento or support actions, there is a 26 times greater chance of continuing
education actions, as well as the presence of a manager trained in Collective
Health, incentives, bonuses or financial awards given to professionals for
performance, periodically organized planning and evaluations, and the practice of
self-assessment increase the chance of these education actions happening. The
analysis showed that in the centers where the Continuing Education in Health is carried out in an integrated way with primary care professionals, there is 2 times
more chance of having a joint construction of therapeutic projects and 3 times
more chance of having discussions and constructions of clinical protocols. This
study evidenced the relationship between the actions of Continuing Education in
Health and the strengthening of comprehensive care in dental care of medium
complexity practiced in the Centers for Dental Specialties and its influence on
primary care, in addition to strengthening social control.
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ALDELANY RAMALHO FREIRE
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SOCIOECONOMIC DETERMINATION AND HEALTH UTILITY ANALYSIS FOR ORAL CANCER
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Date: Jun 16, 2023
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Time: 14:00
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Show Summary
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The elucidation of the role of socioeconomic factors on the involvement of individuals by oral cancer can support the implementation of public policies for social protection. Health economics studies are useful to ensure the rational use of resources, given the social contexts of users, making implemented policies more effective. The objective was to investigate the influence of socioeconomic factors on oral cancer rates, in addition to performing a health valuation analysis about the disease. This is a quantitative, analytical study, with five analysis plans (AP). AP 1 evaluated the effect of socioeconomic factors on the frequency of diagnoses of oral mucosa alterations and the number of hospitalizations for oral and oropharyngeal cancer in Brazil. AP 2 assessed the influence of socioeconomic indicators and investments on oral cancer mortality rates in Latin America. AP 3 verified the effect of coverage of public oral health services and socioeconomic indicators on the frequency of hospitalizations and cancer mortality in Brazil. AP 4 assessed the impact of socio-demographic characteristics on the prevalence of oral cancer at an advanced clinical stage in Brazil. In these ecological studies, the data came from official information systems, with public access. Significant associations between independent variables and outcomes were calculated using multivariate logistic regression models, considering p<0,05 and 95%CI. AP 5 consisted of a field study of health utility analysis for oral cancer, verifying the influence of socioeconomic context e oral health status, through Standard Gamble (SG) and Willingness to Pay (WTP). Multivariate Poisson and Negative Binomial regressions were developed, considering p<0.05 and 95%CI. Results of AP 1 demonstrated a higher frequency of diagnoses of mucosal changes and hospitalization of patients with oral cancer in more developed cities (B=11,298; p<0,001) and with greater inequality (B=11,614; p<0,001) in Brazil, while cities with greater inequality (B=8,159; p<0,001), higher proportion of inadequate basic sanitation (B=0,09; p=0,001), lower expectation of years of schooling (B=-0,718; p <0,001) and higher illiteracy rates (B=0,191; p<0,001) had a higher frequency of hospitalized patients with oral and oropharyngeal cancer. In AP 2, male individuals, aged 60 years or older (PR=14,7), residing in countries with greater inequality (PR=1,05), higher per capita health spending (PR = 1,09) and higher investments in research and development (PR = 1,81), were associated with a higher mortality rate from oral cancer in Latin America. The AP 3 verified that Brazilian cities with larger population and Human Development Index, more unequal and with lower coverage of oral health services had a higher risk of occurrence of cases and frequency of deaths from oral cancer. Regarding AP 4, a higher prevalence of oral cancer in advanced clinical stage in Brazil was observed in individuals with higher education, no partner and older (p<0,001). For health utility analysis of oral câncer (AP 5) younger participants (B=-0,250; p=0,023) and those with less schooling (B=-0,767; p<0,001) showed lower SG for a possible treatment. For WTP, male individuals (B=-1,821; p<0,001) with lower income (B=-1,396; p=0,016) and greater impact of oral health on quality of life (B=0,066; p<0,001) would be willing to pay less for a treatment. It is concluded that socioeconomic factors are strongly associated with oral cancer, with inequality, low education, gender and age being relevant factors. In addition, the individual and socioeconomic context influences the health utility for oral cancer.
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BASILIO RODRIGUES VIEIRA
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Effect of chemical agents on stain removal from carious dentin
lesions remineralized with silver diamino fluoride
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Date: May 12, 2023
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Time: 14:00
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Show Summary
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Introduction: Silver diamino fluoride (SDF) is an effective alternative for
arresting caries lesions, including those with dentinal involvement. However, it can
lead to dental staining, which may contraindicate its use. Objectives: to evaluate
the effect of three different chemical agents on stain removal and remineralization of
artificial dentin caries (ADC) lesions treated with silver diamine fluoride (SDF).
Methodology: Baseline L*a*b* values were determined in polished human dentin
blocks, and ADC lesions were induced with an acid gel for 1 week. Samples were
assigned into four groups, each receiving the application of 30% SDF for 3 minutes.
Half of each sample was subjected to a bleaching treatment protocol using garlic
extract (group I), bentonite (group II), or 35% hydrogen peroxide (group III), while
the other half was left untreated (before bleaching). A negative control group (group
IV) of samples with one SDF-treated half and one half without SDF was also tested.
Colour changes (DE) were measured by spectrometry, and transversal microradiography was used to quantify integrated mineral loss (ΔZ) 24h after
treatment (SDF or SDF+bleaching). Results: A two-way mixed ANOVA was applied.
30% SDF application remineralized ADC (p =0.001). The type of chemical agent
evaluated (p<0.0001), time (p=0.01) and their interaction (p<0.0001) bleached the
ADC treated with SDF. However, 35% hydrogen peroxide was the only compound
with a bleaching effect (p < 0.001), without returning to baseline colour. None of the
compounds altered the remineralizing properties of SDF (p = 0.30). Conclusion:
This study provides evidence of the in vitro remineralizing effect in ACD within 24h
after SDF application, as well as the ability of hydrogen peroxide to partially remove
(reduction of 24%) the staining caused by SDF treatment without affecting
remineralization.
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DEBORAH ELLEN WANDERLEY GOMES FREIRE
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WILLINGNESS TO PAY FOR DENTAL PROCEDURES: BIBLIOMETRIC STUDY AND ANALYSIS OF ASSOCIATED FACTORS
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Advisor : YURI WANDERLEY CAVALCANTI
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Date: Apr 27, 2023
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Time: 09:00
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Show Summary
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Economic assessments play an important role so that resources can be used more rationally and efficiently, and should be directed to the needs and attributes that most matter to service users. Among the methods to assess the valuation of health in relation to dental treatments, willingness to pay (WTP) stands out, which represents the strength of an individual's preference for a given intervention and the maximum amount of money that would be sacrificed for that intervention. The aim of this study was to carry out a bibliometric study of WTP in Dentistry and to evaluate the WTP by oral health procedures and associated factors. Initially, a quantitative and analytical study was carried out, with a crosssectional observational design, on WTP due to dental procedures. 280 individuals participated in this study, using digital forms on the Google Forms platform, collecting socioeconomic data, oral disease burden, oral health complaints, preference for oral health care attributes, in addition to willingness to pay for dental procedures. Multiple regressions were generated between the independent variables and WTP for dental procedures, considering a p value <0.05 and a 95% confidence interval as significant. A bibliometric study was also carried out, in which a systematic search was used in order to identify publications that analyzed the WTP in the area of dentistry. Searches were conducted in PubMed, Web of Science and Scopus databases. Studies were selected by two independent researchers and inconsistencies decided by a third researcher. The results showed that, for socioeconomic factors, income and insertion level in Dentistry were the variables that were associated with a higher WTP. Compared to people with an income of 5 minimum wages (SM) or more, individuals with lower income (up to 2 SM) had lower WTP for routine consultation (PR=0.732, p<0.01), anterior tooth restoration (PR =0.785, p<0.01), simple extraction (PR=0.763, p<0.01) and prophylaxis (PR=0.812, p<0.01). Compared to dentistry professionals and students, people not connected to dentistry had lower WTP for anterior tooth restoration (PR=0.774, p<0.01), extraction (PR=0.769, p<0.01) and prophylaxis (PR= 0.742, p<0.01). Regarding the attributes of choice, for a package of basic procedures, consisting of routine consultation, anterior tooth restoration, extraction and prophylaxis, it was observed that a higher WTP was associated with the choice of scheduled appointment or appointment reflected in higher WTP (PR=1.529, p<0.01), performed by a specialist dentist (PR=1.529, p<0.01) or a general practitioner (PR=1.530, p<0.01). For a package of more complex procedures (basic procedures + root canal treatment + prosthetic rehabilitation), a higher WTP was observed among individuals who would choose treatment at a private clinic without health insurance (PR=1.1965, p<0.01) and consultation by appointment (PR=1.173, p<0.01). For bibliometric analysis, 66 studies were included, most of which were published between the Years 2021 and 2022 (n=20, 30%), whose study location was the United Kingdom (n=18, 27%) and which used the contingent valuation technique (n=46, 70%). This utility study, using the WTP, observed that the most relevant socioeconomic factor for users to choose a service is their family income. In addition, professional training and the type of appointment are the attributes most valued by service users. Thus, this study provides important information that can support the planning and organization of dental services.
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BEATRIZ FERNANDES DE SOUZA
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Analysis of polymorphisms and DNA methylation in the DNMT1, DNMT3A and DNMT3B genes in pediatric oncology patients with chemo-induced oral mucositis.
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Date: Mar 30, 2023
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Time: 14:00
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Show Summary
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Oral mucositis is a common side effect of anticancer treatment and is characterized by an inflammatory condition that affects areas such as mucosa of the lips, tongue, floor of the mouth and soft palate. In severe cases (severe oral mucositis), the reddened areas can quickly evolve into painful and bloody ulcers that significantly affect the quality of life of patients as well as the prognosis of the treatment. The main mechanism responsible for the pathophysiology of chemoinduced oral mucositis is the cytotoxic effect of antineoplastic drugs. In turn, methotrexate, widely used in the treatment of hematological tumors, causes stomatotoxicity, causing adverse effects even at low doses. Studies have shown that individual's genetics can influence the development of oral mucositis. In the present study, we investigated the association between Single Nucleotide Polymorphisms (SNPs) in DNMT1 (rs2228611), DNMT3A (rs7590760) and DNMT3B (rs6087990) genes and the methylation profile of the enzymatic family of DNA methyltransferases (Dnmts) with oral mucositis in children and adolescents with hematologic malignancies treated with methotrexate (MTX), in an attempt to define whether the DNMT gene family can be used as a biomarker for inflammation or exposure. The population consisted of healthy and oncopediatric patients aged between 4 and 19 years. The assessment of oral conditions was performed using the Oral Assessment Guide. Demographic, clinical, hematological and biochemical data were obtained from the medical records. The genomic DNA of the epithelial cells of the oral mucosa was used for the analysis of the polymorphisms of DNMT1 (rs2228611), DNMT3A (rs7590760) and DNMT3B (rs6087990), (n=102), through the technique of PCR-Restriction Fragment Length Polymorphism (PCR-RFLP) and for DNA methylation (n=85) Methylation Specific PCR (PCR-MSP) was used. The allele and genotype frequencies of SNPs did not reveal differences between patients with and without oral mucositis. An increase in the frequency of methylation for DNMT1 was detected in patients recovered from mucositis. The methylated profile of DNMT3A associated with the CC genotype (SNP rs7590760) appeared to be linked to higher values of creatinine, while the unmethylated profile of DNMT3B associated with the CC genotype (SNP rs6087990) appeared to be related to higher values of creatinine. We conclude that the DNMT1 methylation profile is associated with the post-mucositis period and the genetic and epigenetic profiles of DNMT3A and DNMT3B are associated with creatinine level.
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HERRISON FELIX VALERIANO DA SILVA
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REPRODUCIBILITY OF MANUAL AND COMPUTERIZED
METRIC METHODOLOGIES IN FORENSIC ANTHROPOLOGY
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Date: Mar 16, 2023
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Time: 15:00
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Show Summary
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Osteometric methodologies in Forensic Anthropology are essential in the reconstruction of
an individual's biological profile, being crucial that there is a correct execution and precision
in the measurements, given the damage that inconsistencies may cause in the process of
human identification. Therefore, the objective was to evaluate the reproducibility of manual
and computerized osteometric methodologies, used in estimating population affinity, sex and
height. To this end, the study had the participation of 15 dental students, who carried out 88
measurements recommended by the methods of estimating ancestry (AncesTrees®), gender
(DSP2® and Wasterlain and Cunha, 2000) and height (Mendonça, 2000), in bone specimens
from two different bones. Measurements were performed on dry bone and on tomographic
images. At first, the measurements were performed only with the aid of a descriptive and
illustrated manual. Subsequently, all measurements were redone, after theoretical-practical
training. For the tomographic images, a theoretical-practical training was carried out on the
handling of the image measurement software. Data were submitted to the respective
estimation methods and subsequently compared. Shapiro-Wilk tests were performed for
normality; 1-group and paired T tests, Intraclass Correlation Coefficient (ICC) and Kappa,
for analysis of significance, analysis of inter- and intra-examiner agreement and comparison
with the gold standard, in addition to the Bland-Altman test, for comparison between methods. For all analyses, a significance level of 5% was adopted. Among the examiners, in
both bones, there was no statistically significant improvement in measurements after training.
The intra-examiner agreement varied randomly regarding the bone analyzed. In the skull,
before and after training, the same degree of agreement was obtained in only 02
measurements (FOL, DKB). Agreement was almost perfect in only 1 measurement (GOL)
(4.0%), in bone 1, and in 22.0%, in bone 2. In the coxal bone, the predominant degree of
agreement was median, with 70%, in frame 2, almost perfect was obtained in 20% of the
measurements, in frame 1. In both frames, 20.0% of the measurements obtained insignificant
agreement. In the long bones, differences were observed in the concordance of measurements
related to sex and height. In terms of sex, there was a predominance of moderate and
substantial degrees in bones 1 and 2, respectively. For height, the almost perfect degree of
agreement was not observed and the PHLF and PLF measurements were not concordant in
bone 2. The results of the analyzes of the estimation methods showed an improvement in the
agreement between examiners, after training, in both bones, in ancestry and sex, with no
difference for height. Accuracy was insignificant for ancestry and sex in bone frame 1 and
median and almost perfect, respectively, in bone frame 2. Statistically significant differences
were observed between manual and digital methods. It is concluded that basic anatomical
knowledge has not proved to be synonymous with expertise in Forensic Anthropology,
requiring a more rigorous leveling procedure so that the execution of metric methodologies
is reliable, taking into account the anatomical nuances and taphonomic processes. In this
sense, the inconsistencies between manual and digital measurements indicate the need for
studies that develop specific parameters for measurements in tomographic images.
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JOSÉ MARIA CHAGAS VIANA FILHO
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Influence of genetic and epigenetic markers on the occurrence of
chemoinduced oral mucositis in oncopediatric patients
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Date: Mar 2, 2023
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Time: 14:00
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Show Summary
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Chemoinduced oral mucositis (OM) is a tissue inflammatory response to the
biochemical action of chemotherapy, commonly observed in patients using
Methotrexate (MTX). This drug, in turn, is related to an alteration of inflammatory
cytokines, such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), and
an oxidative imbalance, which can reduce the activity of antioxidant enzymes
superoxide dismutase (SOD) and catalase (CAT). In addition, vitamin D levels were
also associated with the occurrence of OM. Studies have shown that the mechanism of MTX toxicity is related to genetic alterations, such as single
nucleotide polymorphisms, and in the epigenetic profile of patients, especially with
regard to DNA methylation. Therefore, the objective was to analyze the influence of
genetic and epigenetic modifications in genes that encode the vitamin D receptor
and genes involved in inflammatory mechanisms and oxidative stress. We analyzed
whether the BsmI G>A (rs1544410), FokI C>T (rs2228570) and TaqI T>C
(rs731236) polymorphisms in the VDR gene, as well as the methylation profile in the
VDR, CAT, SOD3, IL-6 and TNF-α were associated with the occurrence of
chemoinduced oral mucositis in pediatric oncopediatric patients treated with MTX.
To this end, a study was carried out with 123 patients (5 to 19 years old), of which
102 were from the Hospital Napoleão Laureano (João Pessoa-PB) and had a
diagnosis of leukemia or lymphoma and were treated with MTX, and 21 were
selected healthy individuals. private dental clinic. OM was assessed using the
modified Oral Assessment Guide. Demographic, clinical, hematological and
biochemical data were collected from medical and dental records. Samples of
buccal epithelial cells were obtained by mouthwash and genomic DNA was
extracted for analysis of polymorphisms by the PCR-RFLP technique (Polymerase
Chain Reaction Restriction Fragment Length Polymorphism) and for analysis of
DNA methylation by MSP (Methylation Specific PCR). Statistical analysis was
performed using Chi-square, Fisher's exact, Mann-Whitney U, Dwass-SteelCritchlow-Fligner tests for multiple comparisons and Hard-Weinberg balance
(p<0.05). The study of polymorphism in the VDR gene included 102 oncopediatric
patients, in which a prevalence was observed in males (57.8%) and mean age was
10.3 years (±4.7). OM affected 84.3% of the patients, of which 53.1% developed the
severe form of the disease (MOG). There was an association between the CT
genotype of the FokI C>T polymorphism (rs2228570) (OR=1.81; CI=0.585.66;
p=0.038), as well as the G allele of the BsmI G>A polymorphism (rs1544410)
(OR=2.27; CI=1.015.11; p=0.040) with MOG. The study of methylation in the VDR,
CAT, SOD3, IL-6 and TNF-α genes involved 85 individuals, 21 healthy individuals
and 64 pediatric oncopediatric patients. Females predominated (54.1%), with a
mean age of 11.1 years (±4.3) and diagnosis of acute lymphoblastic leukemia
(56.5%). Most cancer patients (75.0%) developed OM. There was a difference in the
methylation profiles of the TNF-α gene between the groups (p=0.004), with the nonmethylated profile being more frequent in patients who had recovered from
mucositis when compared in isolation with patients who had mucositis in the time of
sample collection (p=0.049). Therefore, it is concluded that both genetic and
epigenetic modifications are associated with oral mucositis. The FokI C>T
(rs2228570) and BsmI G>A (rs1544410) polymorphisms in the VDR gene increase
the chance of severe oral mucositis and the TNF-α methylation profile is associated
with the post-mucositis period in pediatric oncology patients.
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MARIA DO DESTERRO ANDRÊZZA SOUZA COSTA
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Evaluation of usability and satisfaction with the
teleinterconsultation application in stomatology in Paraíba.
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Date: Feb 24, 2023
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Time: 14:00
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Show Summary
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With the aim of redirecting clinical practice through interconsultation, stimulating the
sharing and discussion of cases, the application Teleinterconsultation in
Stomatology in Paraíba was created as a specialized support strategy for
professionals working in the Unified Health System (SUS). The objective of the study
was to evaluate the usability and satisfaction with the application by oral health
professionals. To meet the objective, the dissertation was divided into two work plans
developed as follows: 1- An exploratory study, through a scope review that gathered evidence available in the databases: PubMed, Scopus, Web of Science, Lilacs,
Embase , Livivo and Google Scholar, in order to analyze how the use of applications
has helped in the clinical practice of dentists. 2- A cross-sectional and observational
study, with dental surgeons in the State of Paraíba, with active registration in the
application, evaluating usability and satisfaction. In the scope review, 289 studies
were identified, 63 of which were read in full. The evaluated studies mostly
addressed applications in the field of stomatology (63%) and were mainly focused
on training health professionals, supporting clinical practice and providing guidance
regarding the treatment of choice. It was observed that the use of applications can
subsidize the dental clinical practice, guaranteeing speed, security and resolution in
the consultations. In the usability evaluation, the Teleinterconsultation in
Stomatology Application was satisfactory (91.25), the data show that the tool is well
accepted by users. According to the satisfaction assessment, the professionals
(62.4%) were optimistic about the application and the theoretical and clinical support
available. It was concluded that clinical dental practice has used mobile applications
aimed at presenting clinical protocols, in addition to capturing videos and intraoral
photographs that provide acceptable subsidies for correct diagnoses and treatments,
endorsing the application of teledentistry as a tool for qualifying the assistance
offered by dentists. The application Teleinterconsultation in Stomatology in Paraíba
presents satisfactory usability, classified by users as very necessary. It is a
complementary and accessible alternative for dental public health since it enables
support for diagnosis, treatments, brings professionals closer and qualifies
assistance, in addition to being easy to use, meeting the needs of professionals,
guaranteeing support, resolution and guarantee of care.
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MANOEL PEREIRA DE LIMA
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GENERAL DATA PROTECTION LAW: ADJUSTMENTS OF DENTAL SERVICES IN BRAZIL
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Date: Feb 15, 2023
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Time: 09:00
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Show Summary
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Introduction: The General Data Protection Law (GDPL), 13.709/2018, in force since 2020, deals with the management and protection of personal data by companies, public agencies and individuals in Brazil, aiming to guarantee the right to freedom and privacy. In health, as well as in other sectors, the processing of patients' personal data must occur with the consent of the holder and in accordance with the new law. Objective: To verify and understand the security in the management of personal data by clinics and dental offices in Brazil, regarding the adaptations to the GDPL. Methods: Methodology: This is a cross-sectional study, approved by the Ethics and Research Committee - ERC (CAAE: 60717822.4.0000.5188), made available to dentists throughout the country through the Google Forms platform, through a structured questionnaire. A sample size of 374 dentists was defined, through the calculation carried out on the online platform OpenEpi (https://www.openepi.com/), adopting a 95% confidence interval and the design effect (deff) of 2.0. After obtained, the data were exported and tabulated in an Excel spreadsheet, and submitted for analysis in the IBM SPSS®️ software (25.0, IBM Corporation, Armonk, New York, USA). Descriptive and exploratory analysis was initially carried out to determine absolute and relative frequencies. Then, statistically significant associations were evaluated using the chi-square test and Pearson correlation. Results: 512 responses to the questionnaire were obtained, showing that 63.1% (n=323) of professionals are linked only to the private network. About 86% (n=441) claimed to know what personal data is, but 71.5% (n=366) cannot distinguish their difference between sensitive personal data. The improper collection of personal data of minors was observed in 16.5% of the responses obtained and 40.9% of professionals reported making some term of consent available to parents and/or guardians. About the data security mechanisms, 72.1% reported that the service was unprotected, not meeting GDPL standards and with risks of failure and information leakage. It was also observed that 54.8% of dentists use some social network to share images of patients, with WhatsApp being the largest of them (32%). Approximately 68% use access to reports and radiographic images, through the clinic's website (28%), Idoc 49.9% and Cfaz.net (5%). Statistically significant associations (p=<0.05) were observed in twelve of the questions asked, when associated with the administrative sphere. Conclusion: With the realization of the study it was possible to observe that most dentists know little about the existence of the GDPL and its applicability within dentistry, that most services lack measures for the protection of data and personal information, in addition to demonstrating the importance of the law for society, especially health-related services.
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ITALO DE LIMA FARIAS
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Synthesis and characterization of a cement based on
hydroxyapatite doped with niobium oxide for use in bone regeneration procedures
-
Date: Feb 8, 2023
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Time: 09:30
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Show Summary
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The use of grafts in bone regeneration procedures is a common clinical
practice in dentistry, in order to ensure bone formation to support soft tissues, or to
enable reconstructive procedures in the bucomaxillofacial complex. For this
purpose, several types of biomaterials can be used, with synthetic hydroxyapatite
being an alternative at a reduced price. Characteristics such as biocompatibility,
bioactivity and osteoconduction allow its use for this purpose. However, its use in
direct clinical procedures is hampered by its low mechanical resistance and low
radiopacity. Under this bias, the objective of this study was to develop a cement
based on hydroxyapatite and doped with niobium oxide as a radiopacifying
material to be used in dental procedures for bone regeneration. For this purpose,
hydroxyapatite was synthesized by the wet precipitation method, to which niobium
oxide was added and a hydrogel matrix based on carboxymethylcellulose, calcium silicate, glycerin and water. The products were characterized in terms of
morphology, physicochemical characteristics by means of X-ray diffraction, infrared
spectroscopy with Fourier transform, setting time, workability and fluidity,
radiographic analysis, pH and microstructure by scanning electron microscopy.
The results showed that it was possible to obtain a cement based on
hydroxyapatite and niobium, without changing the initial phases of the reagents,
with radiopacity, good workability and fluidity to be used by means of devices such
as syringes. In addition, the material presented a basic pH that favors possible
antimicrobial activity and cell growth. Morphologically, microscopic analysis
revealed a porous microstructure that may allow cell growth and nutrient transport
in vivo. The cement obtained showed promising results in order to be applied in
surgeries through minimally invasive procedures, being a moldable material
indicated for filling irregular bone defects, with the possibility of radiographic clinical
follow-up, as well as use in tissue engineering.
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ANA BEATRIZ RODRIGUES MOURA
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Factors associated with mortality of oncopediatric patients in
Brazil based on cancer hospital records
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Date: Jan 27, 2023
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Time: 08:30
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Show Summary
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Cancer is the main cause of death from disease in the age group
between one and nineteen years old in Brazil. The need for a greater
understanding of death records from pediatric cancer in the country is highlighted
in order to optimize health strategies in this segment. The objective of this study
was to evaluate the possible factors associated with the mortality of children and
teenagers due to cancer in Brazil. This is a cross-sectional study with secondary
data through the analysis of cancer electronic health records (EHRs), whose
population consisted of patients aged 0 to 19 years, of both sexes, diagnosed with
malignant neoplasms, in the period from 2000 to 2019. Of the total of 46,526
cases, those that exceeded 365 days to start treatment after the date of diagnosis
and those that presented loss of information regarding the variables of interest
were excluded. After applying the eligibility criteria, 31,954 cases were
descriptively and inferentially analyzed using logistic regressions (α=5%). A
statistical model was designed for each of the 15 histological types analyzed.
Death cases accounted for 22.8% (n=7,288) of the sample. There was a higher
prevalence of death in males (56.97%), aged 0 to 4 years (32.17%), self-declared
as brown (47.63%), living in the Northeast region (38 .57%), with solid tumors
(53.13%), referred by the Sistema Único de Saúde (SUS) [Brazilian public health
system] (80.64%), treated at the Oncology Pediatrics clinic (39.74%) and
histological type lymphoblastic leukemia or lymphoid (28.96%). Patients with
lymphoblastic or lymphoid leukemia were less likely to progress to death when not
referred by the SUS (OR=0.93) and residing in the Northeast (OR=0.96), Midwest (OR=0.90) regions. and South of the country (OR=0.91), while their chances of
death increased in the age groups of 10 to 14 years (OR=1.09) and 15 to 19 years
(OR=1.21), when treated in clinics Clinical Oncology (OR=1.06) and Clinical
Hematology (OR=1.03) and with more than one tumor (OR=1.15). Children and
teenagers with nephroblastoma were less likely to die when not referred by the
SUS (OR=0.90) and residents of the southern region of the country (OR=0.92),
and their chances increased when they had more than one tumor (OR=1.31).
Patients with Ewing's sarcoma had a lower chance of death when treated at the
Radiotherapy clinic (OR = 0.69) and higher chances in the age groups 10 to 14
years (OR=1.16) and 15 to 19 years (OR= 1.17), while patients with germ cell
tumors, trophoblastic tumors and gonad neoplasms were less likely when living in
the southern region of the country (OR=0.91) and when treated at the radiotherapy
clinic (OR=1.06). ). The chances of death were lower for patients with malignant
glioma (OR=0.84) and astrocytoma (OR=0.86) when not referred by the SUS and
for those with neuroblastoma (OR=0.86), retinoblastoma (OR= 0.78), when
residing in the southern region of the country. Furthermore, it was observed that
individuals with medulloblastoma with more than one tumor were more likely to die
(OR=1.77). Therefore, through the present study, it was possible to outline a profile
of deaths of Brazilian children and teenagers due to cancer, highlighting the
difficulties that still exist in the public health system for referring treatment to this
segment of the population. Knowing the panorama of mortality from pediatric
cancer is essential for better planning strategies for controlling and preventing the
disease, as well as expanding health services.
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THAUANY VASCONCELOS SOARES DA SILVA
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INFLUENCE OF REHABILITATION WITH COMPLETE DENTURE ON QUALITY OF LIFE, NUTRITIONAL STATUS AND MASTICATION FUNCTION OF FRAGILE AND NON-FRAGILE ELDERLY
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Advisor : YURI WANDERLEY CAVALCANTI
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Date: Jan 26, 2023
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Time: 14:00
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Show Summary
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The current scientific literature lacks clinical studies that contribute to clinical decision-making in the face of frail elderly people. Although frailty is a condition that is associated with dependence on activities of daily living, it appears that free elderly people in the community can also have a profile of frailty. It is suggested that frailty can interfere with the quality of life related to health, nutritional status, among other parameters that can affect the individual's general health status and interfere with the rehabilitation process with conventional complete dentures. This dissertation was divided into two work plans. Initially, we sought to identify the influence of frailty on the health status of free elderly in the community through. A second study was designed to verify the influence of rehabilitation with complete dentures made using the simplified method on the general health status of free elderly people in the community. A non-randomized clinical study was carried out, in which 49 elderly people participated. Among them: 21 frail elderly, 7 pre-frail elderly and 21 non-frail elderly. The classification of the groups was based on the self-reported instrument for identifying the frailty syndrome. Completely edentulous elderly in need of replacement of complete dentures were included based on a clinical examination performed by trained researchers. Elderly people who presented neurological and/or cognitive alterations were excluded, through the application of the Mini Mental State Examination questionnaire. The following parameters were evaluated: Lean mass; BMI; fat percentage; hand strength; assessment of nutritional status with the questionnaire (MNA); and analysis of masticatory efficiency through colorimetric analysis of chewing gum; self-perception of quality of life in relation to health, using the SF-12 questionnaire (Short-Form Health Survey); evaluation of the impact of oral health on the quality of life of edentulous people, using the OHIP-EDENT questionnaire (Oral Health Impact Profile);. Differences between frail, pre-frail and non-frail groups were investigated in study 1. For study 2, the elderly were rehabilitated and reassessed 90 days after the final adjustment of the new prostheses. In this last analysis, 8 returns were obtained so far. Data were tabulated and analyzed in the Jamovi Desktop software (The Jamovi project, v. 2.3.21, Sydney, Australia). Descriptive and inferential statistical analyzes were performed using Wilcoxon tests, paired t test, ANOVA and Kruskall-Wallis, considering p<0.05. Regarding the influence of frailty on the general state of health, it was found that the general quality of life differed statistically between the frail and non-frail groups (p=0.013). The pre-frail group does not differ statistically from the frail (p=0.137) and non-frail (p= 0.857) groups. There was a difference in MNA between the non-frail and pre-frail groups (p=0.031), as well as between the non-frail and frail groups (p=0.003). The pre-frail and frail groups did not differ from each other (p=0.961). The parameters: hand strength, fat percentage, BMI, lean body mass, impact of oral health on quality of life and masticatory efficiency showed no difference between groups (p>0.05). Regarding the influence of rehabilitation, there was a statistically significant reduction in the percentage of fat (p=0.031 MD= 2.475), an increase in the MNA score (p=0.010 MD= -2.375) meaning an improvement in nutritional status, greater impact negative in quality of life related to oral health (p=0.010 MD= -33.750) and improvement in masticatory efficiency (p=0.014 MD= 0.261). No differences were observed for variables: lean body mass; BMI and self-perception of quality of life in relation to health. This study allows us to conclude that frail elderly people have a worse health-related quality of life and a worse nutritional score. The data obtained in the present study corroborate the findings in the literature, making it possible to identify the improvement in the nutritional status and masticatory efficiency of individuals after rehabilitation. The negative impact on oral health on quality of life may be related to the prosthetic adaptation phase.
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QUEMUEL PEREIRA DA SILVA
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α-TOCOPHEROL AND CINNAMALDEHYDE NANOSSYSTEMS: DEVELOPMENT, CHARACTERIZATION AND ANTIMICROBIAL ACTIVITY
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Advisor : PAULO ROGERIO FERRETI BONAN
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Date: Jan 25, 2023
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Time: 09:00
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Show Summary
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Introduction: The topical use of α-tocopherol (α-toc) and cinnamaldehyde (CNM) together in the oral cavity is still little explored, but it would add the antioxidant and proliferative characteristics of α-toc with the antiinflammatory, analgesic and antimicrobial of the CNM. The encapsulation of these in nanosystems coated with chitosan can enhance their therapeutic effects, promoting mucoadhesion and better permeability. Objective: to evaluate in silico the anti-inflammatory potential of CNM and α-toc and antimicrobial potential of CNM, as well as to develop and characterize nanocapsules and nanostructured lipid carriers (CLN) with these actives and evaluate their antimicrobial potential in vitro. Methodology: The anti-inflammatory activity of CNM and α-toc and antimicrobial activity of CNM were evaluated in silico using molecular docking. Subsequently, the composition analysis of the oils was carried out using gas chromatography coupled to mass spectrometry (GC-MS). The development of the nanocapsules was carried out using the thermosensitive technique of poloxamer 407 and the particle size (D), polydispersion index (PDI) and zeta potential (PZ) were determined, as well as being submitted to infrared spectroscopy by Fourier transform (FTIR), carried out studies of properties of the sol-gel phases, stability, rheological tests and antimicrobial activity. The CLN were developed through hot emulsification followed by ultrasonic sonication, pre-formulation studies, BoxBehnken type design for selection of an optimized formulation, development and analysis of the D, PDI and PZ of the optimized formulations were carried out with CNM and α-toc, evaluating its in vitro antimicrobial activity. Results: The results demonstrated in silico, from molecular docking, a prediction of CNM and α-toc affinity for all evaluated targets, increasing the probability of success in antiinflammatory and antimicrobial activities. GC-MS revealed CNM as the main constituent of CNM oil and α-toc acetate as the main constituent of α-toc oil. In the dispersions of nanocapsules, particles with size ranging from 135.7 to 1997 nm and zeta potential with values between -3.76 to +11.1 were observed; FTIR confirmed the encapsulation of assets in dispersions; the sol-gel phase transition occurred at temperatures between 20°C and 30°C and remained in the form of a solution when stored at room temperature for a time that varied between 15.9 to 47.27 s, they also demonstrated stability in terms of pH, homogeneity , odor and coloration; in the rheological analyses, it was seen that the dispersions of nanocapsules have a pseudoplastic behavior, which facilitates their application due to the decrease in viscosity with effort, as well as, they present better antimicrobial activity in vitro than the encapsulated CNM (MIC from 3.12 µg/mL ) when compared to free CNM (MIC from 39 µg/mL) against strains of Escherichia coli, Staphylococcus aureus and Candida albicans. The pre-formulation study of the CLN allowed the analysis of variables that based the Box-Behnken type design, which provided the concentrations considered ideal for the components after statistical evaluation (25mg/ml of chitosan, 50mg/ml of precirol and 100mg/ ml of CNM and/or α-toc), in order to provide an optimized production of them. Antimicrobial assays showed increased and synergistic action of the actives encapsulated in this system (MIC from 8 µg/mL for CNM, 6 µg/mL for α-toc and 8 µg/mL for chitosan) when compared to the free forms (MIC from 39 µg/mL for CNM, α-toc without activity at the highest concentration tested (50 mg/ml) and 260 µg/mL for chitosan) against strains of Escherichia coli, Staphylococcus aureus and Candida albicans. Conclusion: With this, it is seen that the actives presented in silico, in the molecular docking analysis, a prediction of CNM and α-toc affinity for all evaluated targets. It was also possible to develop both systems with good characteristics and potentiated antimicrobial activities, although the use of CLN is seen as more promising in the oral mucosa.
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MARIA HELOÍSA DE SOUZA BORGES GRISI
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INFLUENCE OF BLOOD PLASMA ON THE DEVELOPMENT AND ACTIVITY OF FUNGAL-BACTERIAL BIOFILM VIRULENCE FACTORS
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Advisor : LEOPOLDINA DE F DANTAS DE ALMEIDA
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Date: Jan 24, 2023
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Time: 10:00
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Show Summary
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Denture stomatitis is a prevalent infection in users of removable complete and/or partial dentures, presenting itself as an inflammation in the palate region juxtaposed to the prosthesis. Candida albicans is the main microorganism involved in the pathogenic biofilm. However, it is a fungal-bacterial infection, where Streptococcus mutans presents a strong synergism with Candida albicans. Blood plasma from the inflammatory exudate of the disease increases the virulence of the Candida albicans biofilm, influencing the progression and pathogenesis of the disease. However, the role of plasma in fungal-bacterial biofilms is not described in the literature. Therefore, the objective of the study was to evaluate the influence of blood plasma on the development and activity of virulence factors in uni-species and duo-species biofilms of Candida albicans (SC5314) and Streptococcus mutans (UA159). Acrylic resin specimens (n=8/group) were used as a substrate for the proliferation of biofilms, which were initially subjected to salivary pellicle formation (1h), being divided into groups with only saliva and groups with saliva supplemented with 5% blood plasma. Inoculums were prepared with BHI medium + 1% sucrose, added with 10% saliva. And for the groups corresponding to blood plasma supplementation in the salivary pellicle formation stage, there was supplementation of 1% blood plasma in the inoculum. The biofilms were incubated for 24h and 96h at 37°C in microaerophilic conditions, with a change of medium for the 96h biofilm. Afterwards, the count of colony forming units (CFU/mL), quantification of soluble extracellular polysaccharides (PECs) and insoluble (PECi) by means of the phenol-sulfuric method, the cellular metabolism of biofilms by means of the MTT assay and the activity of phospholipase. The data were analyzed by the Mann-Whitney test (α=5%), using the comparison between the biofilms (without and with blood plasma) within each time and comparing them between the times. Blood plasma increased the colony forming unit count (CFU/mL) only in the C. albicans uni-species biofilm at 96h (p<0.05). For the dosage of extracellular polysaccharides, a statistically significant difference was observed in the PECis of the duo-species biofilm at 24h, where the biofilm with blood plasma showed a higher production of PECis when compared to the biofilm without blood plasma (p<0.05). For cellular metabolism, the uni-species biofilm of C. albicans in the 24h time with blood plasma showed higher cellular metabolism when compared to that without blood plasma (p<0.05). In the S. mutans singlespecies and duo-species biofilms, at both times (24h and 96h), the biofilm with blood plasma showed greater cellular metabolism compared to that without blood plasma (p<0.05), with a statistically significant difference between the times (p<0.05), where the 24h biofilm with blood plasma showed higher cellular metabolism compared to the 96h biofilm with blood plasma (p<0.05). Phospholipase activity was not altered in the presence of blood plasma in biofilms at both times (p>0.05). It is concluded that blood plasma increases the production of insoluble extracellular polysaccharides and increases the metabolism of Candida albicans and Streptococcus mutans biofilms.
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RAIMUNDO EUZÉBIO DA COSTA NETO
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ANTIFUNGAL ACTIVITY OF NATURAL PRODUCTS AND THEIR DERIVATIVES USING ANIMAL MODEL OF ORAL CANDIDIASIS: A SYSTEMATIC REVIEW
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Date: Jan 24, 2023
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Time: 09:00
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Show Summary
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Introduction: Oral candidiasis is one of the most common fungal infections in clinical dental practice and its establishment is due to factors related to the immune status of the host and to conditions attributed to the fungus, such as its virulence factors. Candida albicans is the most prevalent species of the genus. Several natural products and their derivatives are studies in the control of fungal infections in vitro and few of these studies have advanced to studies in in vivo models. The need to study new antifungals is supported by the increasing isolation of strains with low sensitivity and others with a resistance profile to the available antifungals for oral candidiasis conventional treatment. Objectives: To carry out a systematic review of the literature, seeking to evaluate the antifungal action of natural products as possible candidates for oral candidiasis alternative treatments, with emphasis on the use of animal models of infection, as well as to investigate the cytotoxic effects of these bioactive compounds. Methods: A systematic search was carried out in accordance with PRISMA guidelines in six databases, using a pre-established search strategy, with three hundred and thirty references retrieved after removing duplicates. Two reviewers performed the screening of articles included in the final review according to eligibility criteria, risk of bias assessment - SYRCLE tool. Data extraction was performed independently and when there was any disagreement between the pairs, another reviewer was consulted. Results: Twenty-two articles were included in the qualitative analysis. The isolated compounds were the most studied (13 articles, 50%), followed by the associated isolated compounds (5 articles, 19%) and the crude extracts (4 articles, 15%), fractionated extracts (2 articles, 8%) and the essential oils (2 articles, 8%). Only five studies among the 22 included performed cytotoxicity tests. The compounds showed low MIC values and therapeutic effects in the animal model tested. Conclusion: The most promising compounds with antifungal activity were ellargic acid associated with 2-hydroxypropyl-β-cyclodextrin, caffeic acid phenethyl ester, the ethyl acetate fraction of the Eugenia uniflora extract, the Punica granatum extract and the nanoencapsulated extract of Erodium glaucophyllum.
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MARIA VITORIA OLIVEIRA DANTAS
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Development and antimicrobial evaluation of in situ gels loaded with essential oil of Lippia sidoides Cham.
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Date: Jan 23, 2023
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Time: 14:00
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Show Summary
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INTRODUCTION: Surgical Site Infections (SSIs) are considered a recurrent problem in surgical interventions. In situ gel formulations with antimicrobial release can contribute to minimize the problem. OBJECTIVE: The objective of this work is to develop, carry out morphological and physicochemical characterizations and evaluate the antimicrobial activity of in situ gels of Poloxamer (P407) and Chitosan loaded with essential oil of Lippia sidoides Cham. (OELS) for delivery controlled. METHODOLOGY: Gas chromatography coupled to mass spectroscopy (GC-MS) was performed to experiment with the chemical composition of the oil. The minimum inhibitory concentration (MIC) against strains of Staphylococcus aureus (ATCC 15656), Escherichia coli (ATCC 25922) and Candida albicans (ATCC 76485) was determined. In situ gels of P407 loaded with OELS at concentrations of 1%, 0.5% and 0.25% (PLS1, PLS0.5, PLS0.2) and P407+Chitosan gels with OELS at the same concentrations (PLSQ1, PLSQ0.5, PLSQ0.2). Gels formulated with only the polymers (P and PQ) and 0.9% saline were used as negative controls. Chlorhexidine 0.12% and Nystatin were used as positive controls. The gels were characterized by fourier transform infrared spectroscopy (FTIR), size analysis, polydispersion index (PDI), zeta potential (PZ), evaluation of Sol-Gel transition properties (Tsol-gel), rheological analysis, stability study for 30 days and antimicrobial activity. RESULTS: The chromatographic analysis of OELS showed thymol as the major component (57,85%), followed by pcymene (13,73%). The OELS showed MIC of 256, 128 and 128 µg/mL against strains of S. aureus, E. coli and C. albicans, respectively. FTIR confirmed the incorporation of OELS to the gels. The mean particle size and the PDI values of the microcapsules of the groups formulated without Chitosan (P, PLS1, PLS0.5, PLS0.2) (134.35±24.49nm; PDI 0.295±0.045) were adopted smaller when compared with the formulated groups containing Chitosan (PQ, PLSQ1, PLSQ0.5, PLSQ0.2) (429.15±72.47 nm; PDI 0.57±0.09). Only formulations with Chitosan showed positive PZ values (+5.995±1.288). The formulations adopted as temperatures (Tsol-gel) between 20 ± 1 °C to 28 ± 1 °C, with times (Tsol-gel) at 37° ranging from 18.76 ± 1.24 s to 46.46 ± 8.89 s. According to the rheological analysis, the in situ gels have a pseudoplastic behavior, which facilitates their application due to the decrease in viscosity with effort. In addition, all compositions with OELS were thermally stable in the analyzed temperature range (25-40 °C), showing a tendency to solid behavior and maintenance of the gel structure. The gels were stable, with no phase separation being observed in the centrifugation test, as changes in the pH values of the formulations were less than 6% in all storage forms. No changes in odor were observed. Only the oven-baked gels from the PSL1, PSL0.5 and PSL0.2 groups showed darkening in color. The gel containing the OELS showed a MIC of 5 µg/mL against the tested strains. CONCLUSION: The in situ gels of P407 and Chitosan loaded with OELS showed stable characteristics, with promising antimicrobial action for application in the oral mucosa.
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PAULA LIMA NOGUEIRA
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Evaluation in silico and in vitro of the antifungal activity of a new coumarin derivative on Candida species
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Date: Jan 23, 2023
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Time: 09:00
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Show Summary
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Introduction: The treatment of oral candidiasis is a challenge in Dentistry due to the resistance and toxicity resulting from antifungal therapy and, therefore, the prospection of new therapeutic agents is necessary. Objective: This study aimed to determine in silico and in vitro antifungal activity against Candida species and cytotoxicity against human cells of a coumarin derivative. Methodology: The interaction of the compound with fungal cell targets was analyzed through molecular docking. Molecular dynamics simulations were performed to evaluate the flexibility and stability of interactions in the presence of factors such as solvent, ions, pressure and temperature in binding with 1,3β-glucan synthase, squalene epoxidase and 14-α-desmethylase targets. The in vitro activity against Candida species, the possible mechanisms of action, the time required for the inhibition of fungal growth and the association of the compound with nystatin, the standard antifungal in dentistry, were evaluated by the checkerboard method. The cytotoxicity of the compound on human keratinocytes (HaCat) was investigated in vitro. Results: The docking study indicated affinity for all evaluated targets, 1,3β-glucan synthase (1EQP), squalene epoxidase (4MAI), δ-14-sterol reductase (4QUV), 14-α-desmethylase (5TZ1) and thymidylate synthase (5UIV), with the respective binding energy values -100.39; -81.20; -88.15; -73.15 and 74.80 Kcal/mol. Molecular dynamics simulation showed that in the presence of temperature, pressure, solvent and ions, the compound proved to be able to establish strong bonds and remained in the active site of the evaluated targets. Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC) values ranged from 67.16 μM (15.6 μg/mL) to 537.28 μM (125.0 μg/mL) according to each species of Candida. Regarding the mechanism of action, the MIC did not change in the presence of sorbitol, unlike the presence of ergosterol, the MIC increased its value, indicating the ergosterol of plasma membrane as one of its possible targets. The MIC - 125 µg/mL (538.1 µM) and MICx2 - 250 µg/mL (1076 µM) of the compound did not allow fungal growth in a period of at least 24 h, and the death kinetics indicated that the MIC of the compound was able to to inhibit growth for up to 36 h (p < 0.0001). From that moment on, the cells multiplied. MICx2, in turn, maintained growth inhibition throughout the analysis period (p < 0.0001). The association with nystatin was indifferent for antifungal action (ICIF=1.25). The compound had an IC50a of 100µM indicating little cytotoxic activity at this concentration for human keratinocytes according to the literature. Conclusion: The compound 7-(Pentyloxy)-2H-chromen-2-one showed antifungal activity in the in silico test, being confirmed in the in vitro tests, in addition to showing little cytotoxicity for keratinocytes, showing promising results for a possible alternative in the treatment of oral candidiasis
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