Periódicos - Resumos

URI Permanente para esta coleção

Navegar

Submissões Recentes

Agora exibindo 1 - 20 de 390
  • Resumo IPEN-doc 30286
    Performance evaluation of the incorporation of PET/CT procedures in the SUS
    2023 - PRATES, B.; POZZO, L.
    Aim/Introduction: High-complexity technologies, such as PET/ CT, should have their incorporation constantly analyzed and enhanced to support their consolidation. The evaluation of the performance of these equipment commits to the understanding of subjects such as the clinical application effectiveness, the usage of these devices in the patient’s real life, and the impact of this technology in the different regions where they are applied. Therefore, this work aimed to evaluate the performance incorporation PET/CT equipments and procedures by the Brazilian National Health System (SUS) according to admissibility, economic, innovation, and technical criteria, accordant to the Methodological Guideline for the Elaboration of Studies for the Evaluation of EMA (medical-assistance equipment). Furthermore, the demand for the application of this technology was also considered. Materials and Methods: The data collection methodology was based on an active search for information, such as the consultation of bibliographies and websites that presented data of interest, such as ANVISA, DATASUS, CNEN, and RHC. Results: Thirteen records of equipment from seven distinct manufacturers were identified within the validity period. Moreover, there are 110 registrations with at least one PET/CT equipment in the National Registration of Health Facilities (CNES) and 160 registrations of facilities authorized by the National Commission of Nuclear Energy (CNEN). Published by the National Health Fund (FNS), the value proposed for such equipment in 2022 is BRL 6,405,000.00. Regarding approved financing proposals, seven are registered and distributed in the records of five facilities. The applied taxes observed are IPI, PIS, and COFINS. Per procedure, according to the SUS table records, the amount paid was BRL 2,107.22, and the total amount paid since the incorporation of the technology is BRL 348,446,738.37. Conclusion: The development of the work led to the perception that, although there was some difficulty in obtaining some data that permeate the PET/CT technology, the incorporation of this technology took place in a satisfactory manner. There was divergence in results such as the number of devices. This fact was due to the way in which information was made available, as many data are self-declared by interested parties. Because it is the incorporation of a high-complexity technology in full use, few studies evaluating its performance were observed. Based on Consolidation Ordinance No. 1/2017 - which adopts the recommendation of one PET/CT unit per 1.5 million inhabitants, it was found that few Brazilian states have available the number of devices to meet the needs of demand.
  • Resumo IPEN-doc 29895
    Proteolytic activity of secreted proteases from pathogenic leptospires and effects on phagocytosis by murine macrophages
    2023 - AMAMURA, THAIS; COURROL, DANIELLA; BARBOSA, ANGELA; SILVA JÚNIOR, ILDEFONSO; SILVA, TIAGO da; MIDON, LEONARDO; HEINEMANN, MARCOS B.; CHAMBI, ROSA C.; MORGANTI, LIGIA; ISAAC, LOURDES
    Leptospirosis is a zoonosis caused by spirochete bacteria that belong to the genus Leptospira. This disease represents a serious public health problem, especially in developing countries with tropical and subtropical temperatures. Pathogenic leptospires escape from the Complement System, a property that permits them to survive in vitro when in contact with normal human serum (NHS). In a previous study carried out by our group, it was observed that culture supernatants from different pathogenic species of leptospires (SPL) contain proteases that cleave many Complement proteins, including the central molecule C3 and its fragments C3b and iC3b. Our hypothesis is that these proteases, could decrease the phagocytic clearance of leptospires. Using flow cytometry, we observed decreased amounts of CR3 and CR4 in murine peritoneal macrophages treated with SPL for 24 h. By confocal microscopy, we observed reduction in TLR2, CD11b and CD206 levels when these cells were treated with SPL and recombinant thermolysin for 24 h. Furthermore, opsonins such as C3b/iC3b deposited on the surface of pathogenic leptospires were observed to be completely degraded in the presence of SPL or recombinant thermolysin. Finally, we decided to investigate the phagocytosis of pathogenic leptospires by macrophages in the presence of these proteases. We observed an increase of phagocytosis of leptospires opsonized with normal mouse serum even when macrophages were treated with the proteases. However, when opsonized bacteria were also incubated with SPL, recombinant thermolysin and recombinant leptolysin., there was a decline in leptospires phagocytosis. This suggests that the proteolytic activity can affect phagocytosis by peritoneal macrophages mainly through the degradation of opsonins deposited in the membrane of leptospires. These observations lead us to suggest that proteases secreted by pathogenic leptospires could degrade opsonins present in normal serum or deposited in the bacterial membrane as well as cleave or inhibit macrophage surface molecules. Therefore, these proteases could interfere with the recognition and internalization by murine macrophages, favoring the spread of leptospires in the host.
  • Resumo IPEN-doc 29894
    Leptospira interrogans leptolysin displays proteolytic activity against complement proteins
    2023 - COURROL, DANIELLA; SILVA, CRISTIANE F. da; CHAMBI, ROSA C.; MORGANTI, LIGIA; ISAAC, LOURDES; PORTARO, FERNANDA; SILVA, RODRIGO R. da; BARBOSA, ANGELA
    Pathogenic Leptospira species are extremely efficient in disseminating in the host, a fact attributed to their ability to escape complement system activation, and to degrade extracellular matrix and other components of the human plasma. Recently, our group evaluated the proteolytic activity of secreted proteins by leptospires, and exoproteome analyzes of these bacteria allowed the identification of some proteases, including the metalloprotease pappalysin-1 domain protein, which we named leptolysin. In this work we produced and functionally characterized leptolysin from L. interrogans to expand our knowledge on this metalloprotease from Leptospira in the processes of invasion and immune evasion. According to in silico analyzes this protease belongs to the category of short pappalysins, also found in other bacteria. Leptolysin is present in all Leptospira species but is more conserved among pathogenic species of the P1 subclade. A preliminary biochemical characterization of its proteolytic activity was performed using FRET (Free Resonance Energy Transfer) peptides. The enzyme exhibited maximum activity at pH 8.0 and 37 C, was active in the presence of different salts and was strongly inhibited by EDTA and 1,10-phenanthroline. It showed a marked preference for arginine residues in the P1 position. The proteolytic activity of recombinant leptolysin on host molecules was also evaluated in vitro and in vivo. The metalloprotease was active against extracellular matrix proteins (proteoglycans and fibronectin), coagulation cascade molecules (fibrinogen and thrombin) and effector proteins of the human complement system (C2 to C9). A leptolysin knockout strain (Dlic13434) was produced and characterized. This strain showed lower survival in normal human serum (SHN) compared to the wild-type strain. However, in a model of epicutaneous infection in hamsters, no attenuation of virulence was observed with the knockout strain, although the bacterial load in the kidneys of these animals was lower than that observed in animals inoculated with the wild-type strain. Finally, data with sera from leptospirosis patients suggest that leptolysin is produced during natural infections by pathogenic leptospires. The characterization of toxins, their targets and mechanisms of action can help in the development of strategies to combat leptospirosis.
  • Resumo IPEN-doc 29811
    ICC INTERCORR WCO 2021
    2022 - PANOSSIAN, ZEHBOUR; COSTA, ISOLDA; ROSSI, JESUALDO L.
    Brazil, once again, organized one of the world’s most significant corrosion events, the ICC - INTERNATIONAL CORROSION CONGRESS. In 1978, the 7th edition of the congress was held by ABRACO, in Rio de Janeiro, under the direction of our Dr. Aldo Cordeiro Dutra, chairman of the Executive Committee. To intertwine two events, the 21st ICC was held together with the traditional INTERCORR, the most representative corrosion and corrosion prevention event held in Brazil, organized by ABRACO, in its 8th edition, which included the workshop “Corrosion and Green Energy”, an event of the World Corrosion Organization (WCO). Thus, the ICC INTERCORR WCO 2021 was arranged with this strong partnership.The institutions responsible for organizing the ICC INTERCORR WCO 2021 were: the Brazilian Corrosion Association (ABRACO), the International Corrosion Council (ICC), and the World Corrosion Organization (WCO). To overcome a new post-pandemic Covid-19 reality, the event occurred virtually from July 20th to 23rd, 2021.The ICC INTERCORR WCO 2021 has become a reference for developing the industrial sector, being an excellent forum for presenting new technologies, disseminating knowledge, prospecting for brands, business opportunities and expanding relationships. Its main objective was to encourage the exchange of knowledge between researchers, technicians, professionals, and companies, whether nationally or globally.The ICC INTERCORR WCO 2021 program included the presentation of 6 plenary conferences, 19 lectures, and more than 220 technical articles by renowned specialists from different countries such as Germany, India, Egypt, USA, Portugal, Australia, Italy, Sweden, Spain, Brazil, among others.Today´s moment highlights the importance of promoting such an event in the country, aiming to find solutions to contribute to the recovery that the industrial sector needs. Maintaining the integrity of assets and minimizing operating and maintenance costs are highly relevant concerns in our daily lives, directly impacting the productive sector.Therefore, on behalf of the Executive Committee, we would like to thank all participants and members of the local organizing committee and the scientific committee. We also sincerely thank the support team for collaborating before, during and after this highly successful event.
  • Resumo IPEN-doc 29703
    Latin America Optics and Photonics 2022
    2023 - GOMES, ANDERSON S.L.; SOUZA, EUNEZIO T. de; ZEZELL, DENISE M.
    The 2022 Latin America Optics and Photonics Conference (LAOP 2022), the major international conference sponsored byOptica in Latin America, returned to Recife, Pernambuco, Brazil, after its first edition in 2010.Held every two years since (except for 2020), LAOP has the explicit objective to promote Latin American excellence in optics and photonics research and support the regional community. In the 6th edition in 2022, it featured a comprehensive technical program with recognized experts in fields critical to Latin America, highly multidisciplinary, with themes frombiophotonics to2Dmaterials. The 191 attendees of LAOP2022 listened to five plenary speakers, 28 keynotes, 24 invited talks, and 128 presentations, including oral and posters
  • Resumo IPEN-doc 29727
    Projeto e construção de um sistema de aquecimento por micro-ondas de baixo custo para avaliação de susceptores
    2022 - BRANDAO, ULISSES; SPINACE, ESTEVAM V.; SEKO, MURILO H.; FERREIRA, WILLIAM de P.
    Este trabalho consistiu no projeto e construção de um forno de micro-ondas de 2,45 GHz, destinado à avaliação de susceptores a serem utilizados como catalisadores, em temperaturas de 400 a 1.100 ºC. Sua construção baseou-se em simulações feitas em computador, seguida de testes e modificações para sua funcionalização.
  • Resumo IPEN-doc 29677
    Resonance frequency analysis of dental implants after laser therapy
    2010 - MORALES, J.M.G.; TORTAMANO-NETO, P.; TODESCAN, F.F.; ANDRADE JUNIOR, J.C.S. de; MAROTTI, J.; ZEZELL, D.M.
    Background: The importance of primary stability in implant placement for long-term success is well known in the literature. The resonance frequency analysis technique has extensively been used in experimental and clinical research for the last 10 years, for assessing primary stability. The benefits of low-level laser therapy in bone tissue are already consolidated in the literature, however, little is known about its benefits on improvement of stability of dental implants. Aim: The aim of this randomdouble blind clinical study was to investigate whether stability of titanium implants can be enhanced by low-level laser therapy during the osseointegration process when measured by means of resonance frequency analysis. Methods: Thirty implants (n¼30) were placed in the posterior region of partially edentulous mandible of eight adult patients, after following several inclusion criteria and were distributed bilaterally in agreement with the prosthetic requirement. The implants on the experimental side were randomly submitted to low-level laser therapy (830 nm, 86mW, 92.1 J/cm2, 2.57 J, 3 s/ point, at 20 points), and on the control side the laser irradiation was only simulated. The first irradiation was performed in the immediate postoperative period, and it was repeated every 48 h in the first 14 days. The initial implant stability quotient of the implants was measured by means of resonance frequency analyzer (Osstells). New implant stability quotient measurements were made after 10 days, 3, 6, 9 and 12 weeks. ANOVA for repeated measurements and Bonferroni test were used to assess statistically significant differences. Results: The initial implant stability quotient values ranged from 65 to 84, with a mean of 76. The irradiated side showed significant drop in stability from the 10th day until the sixth week only (P¼0.028), and presenting a gradual increase from the sixth to the 12th week. In the control side, the mean implant stability quotient increased up to the third week, decreased in the sixth week, and then began to grow again. The highest stability values were observed in the 10th day in the irradiated group, and the lowest in the sixth week in both groups. No statistical differences were detected among the ISQ means in the two groups for each of the six times observation. Conclusions and clinical implications: No evidence was found of any effect of low-level laser therapy on implants’ stability when measured by resonance frequency analysis. Because high primary stability and good bone quality are of major relevancy for a rigid bone–implant interface, additional low-level laser therapy under these conditions may have little impact macroscopically. Further researches under different bone conditions are necessary for a better understanding of the occurrences at bone/implant interface.
  • Resumo IPEN-doc 29676
    Effect of Er,Cr:YSGG laser and fluoride application on enamel demineralization
    2007 - ANA, P.A.; TABCHOURY, C.P.M.; CURY, J.A.; ZEZELL, D.M.
    This study evaluated the influence of sub-ablative Er,Cr:YSGG laser and topical fluoride application on incipient caries development in vitro. One hundred and sixty human enamel slabs were ramdomly divided into eight equal groups: (1) untreated (control); (2–4) irradiated with Er,Cr:YSGG laser at 0.25, 0.50 and 0.75 W, respectively; (5) treated with acidulated phosphate fluoride (APF; 1.23% F) for 4 min; (6–8) pre-irradiated with Er,Cr:YSGG laser at 0.25, 0.50 and 0.75 W, respectively and subjected to APF application. All groups were submitted to pH-cycling simulating a cariogenic challenge, and after 10 cycles mineral loss ( Δ Z) was measured in enamel. Calcium, inorganic phosphorus (P i ) and fluoride concentrations were also measured in the demineralizing and remineralizing pH-cycling solutions. Data were analyzed by ANOVA ( α = 0.05). No differences in Δ Z were found between laser irradiation at 0.25 W, 0.50 W and controls, while after laser irradiation at 0.75 W (Group 4) and application of APF (Group 5) there was a significant decrease in Δ Z. Laser irradiation at 0.50 and 0.75 W prior to APF application there was a significantly lower Δ Z than in other groups. A significant increase in Ca and P i concentrations was observed in demineralizing solutions compared to the initial concentrations, but no significant changes in Ca and P i concentrations were detected between any groups. A significant decrease in fluoride concentration was observed in pH-cycling solutions of control and 0.25 W laser groups, while the association of laser at 0.50 and 0.75 W with fluoride promoted an increase of fluoride content in remineralizing solutions. In conclusion, Er,Cr:YSGG laser irradiation at 0.50 and 0.75 W, associated with fluoride, seems to be a good alternative for reducing enamel demineralization.
  • Resumo IPEN-doc 29675
    Low fluence CO2 laser (10.6 μm) parameters for caries prevention
    2007 - ESTEVES-OLIVEIRA, M.; ZEZELL, D.M.; VELLOSO, W.F.; MEISTER, J.; FRANZEN, R.; LAMPERT, F.; EDUARDO, C.P.; APEL, C.
    Although CO 2 laser irradiation can decrease enamel demineralization, thermal damage to the surface is a common side effect. The occurrence of fissures and cracks may compromise in vivo application. Therefore, the aim of the present study was to find CO 2 laser (10.6 μm) parameters resulting in maximum caries- preventive effect with the lowest thermal damage. Five low fluences of 0.12, 0.29, 0.39, 0.50 and 0.60 J/cm 2 combined with high repetition rates of 500, 154, 167, 182, 187 Hz, respectively and 10 μs pulse duration were chosen for the experiments. 78 bovine enamel cubes were divided into 5 laser groups and one control. After treatment the samples were submitted to an 8-day pH-cycling regime. Demineralization was assessed by lesion depth measurements with a polarized-light microscope. The temperature rise at the enamel surface and the propagation into deeper layers were calculated using a finite element model. Surface morphology was evaluated by SEM. All laser groups resulted in statistically significant lower lesion depths than the control group (ANOVA; p < 0.05). Morphologically, the two lowest fluences resulted in no surface changes. The calculated temperature rise at 1.5 mm depth was less than 5 ° C in all groups. In the present in vitro study irradiation with 0.12 J/cm 2 , 500 Hz and 2500 pulses of CO 2 laser increased enamel caries resistance without causing undesirable surface damage or excessive temperature rise.
  • Resumo IPEN-doc 29658
    Estudo do mecanismo de conversão ascendente no visível em vidros de telureto codopados com Er3+ e Yb3+
    2007 - AMANCIO, CARLOS T.; JAKUTIS NETO, JONAS; WETTER, NIKLAUS U.; BONFIM JÚNIOR, FRANCISCO A.; KASSAB, LUCIANA R.P.
  • Resumo IPEN-doc 29657
    Emissão de luz azul em amostras de germanato dopadas com Tm:Yb e Tm:Yb:Nd
    2006 - ASSUMPCAO, THIAGO A.A. de; JAKUTIS NETO, JONAS; WETTER, NIKLAUS U.; KASSAB, LUCIANA R.P.
  • Resumo IPEN-doc 29656
    Estudo de processos de conversão ascendente em vidros dopados com Nd3+
    2003 - LIMA, B.L.S. de; COURROL, L.C.; KASSAB, L.R.P.; DEL CACHO, V.D.; GOMES, L.; WETTER, N.U.
  • Resumo IPEN-doc 29655
    Propriedades espectroscópicas de vidros de fluorborato de chumbo dopados com Nd3+ para uso em laser de estado sólido
    2002 - DEL CACHO, VANESSA D.; KASSAB, LUCIANA R.P.; COURROL, LILIA C.; WETTER, NIKLAUS U.
  • Resumo IPEN-doc 29503
    Exploratory analysis of a Brazilian real-world open database applied to prostate cancer
    2022 - MONTEIRO, LUCILENA R.; OLIVEIRA, MERCIA L.; MENEZES, MARIO O.; POZZO, LORENA
    Introduction. Prostate cancer was the second most frequent cancer and the fifth leading cause of cancer death among men in 2020. The incidence rates vary substantially in countries with different Human Development Indexes (HDI), while the mortality rates decrease with improved access to the health system, availability of therapies and earlier detection. Worldwide, population-based cancer registries are important tools for planning and managing health systems. The Fundação Oncocentro de São Paulo (FOSP) is responsible to collect, clean and publicize data from cancer treatment institutions. This study aimed to describe retrospectively the demographic and clinical profile of prostate cancer (PC) in Brazil using this database. It is not an incidence study as data is representative only from specific institutions. Methods. This was a retrospective observational study of the years 2000 to 2020 from analysis of the publicly available FOSP database (http://www.fosp.saude.sp.gov.br). The records were extracted, merged, and cleaned using a fully documented and validated data process. Only patients included on the register with a primary PC diagnosis were considered. Results. From January 2010 to June 2020, there were 943,660 patients diagnosed with C61 in FOSP database for the considered time period. The majority of the FOSP database records are from patients who live and/or were born in SP (91.8 and 58.4%, respectively) orMG(2.8 and 10.5%, respectively). The mean age of PC at baseline was 69 years. Considering the stage of the disease, the mean ages are 55, 70, 67, 66 and 61, for stages 0, 1, 2, 3 and 4, respectively. This cohort was also analyzed in relation to treatments received, and status at the end of treatment (51.3% are disease-free, 18.4% are alive with cancer, and 30.3% are dead). Conclusions. FOSP population-based cancer registries are a powerful tool to obtain information for planning, and improving the management of healthcare services especially for São Paulo.
  • Resumo IPEN-doc 29501
    The effect of tartaric-sulfuric acid (TSA) anodizing on the corrosion resistance of the AA7475-T761
    2022 - ARAUJO, JOAO V.; MILAGRE, MARIANA X.; GABBARDO, ALINE D.; KLUMPP, RAFAEL E.; COSTA, ISOLDA
    The microstructure of the high strength aluminum alloy, AA7475–T761, in the as-received condition was characterized by optical microscopy, scanning electron microscopy and transmission electron microscopy, and statistical analyses of grain size and micrometer precipitates distribution and density were performed. An anodic aluminum oxide (AAO) film was potentiostatically grown on the alloy in tartaric sulfuric acid (TSA). The anodizing behavior of the alloy and the mechanisms of localized corrosion initiation and propagation in bare (not anodized) and anodized conditions were discussed. The alloy corrosion behavior was investigated in sodium chloride solutions using electrochemical techniques (cyclic potentiodynamic polarization) and the morphology and extent of corrosion propagation was investigated through optical microscopy, optical profilometry and scanning electron microscopy analyses. It was observed that the two alloy surface conditions (bare and anodized) play different roles in the propagation of the localized corrosion process. The bare alloy presented lower localized corrosion potentials and the propagation of the localized corrosion was shallower, but more heavily distributed, than in the anodized condition. However, the alloy in the anodized condition presented lower repassivation potentials due to the deeper pits formed. In addition, the variability of pitting potentials for the anodized condition was high, due to the heterogenous structure of the AAO film formed, and dependent on the time and drying storage conditions previous to electrochemical characterizations. The electrochemical results were correlated with the microstructural characteristics of the oxide surface film of the alloy in both conditions, bare (not anodized) and anodized.
  • Resumo IPEN-doc 29208
    Protocolos de associação de flúor e laser de alta potência (Nd:YAG) na prevenção da cárie
    2022 - FONTES-OLIVEIRA, Y.R.; CARAMEL-JUVINO, A.; AVELINO, S.G.; ZEZELL, D.M.
    Avaliar os protocolos publicados para prevenção da cárie utilizando associação de flúor e laser Nd:YAG. Foram utilizadas seis bases de dados: Web-of-Science, PubMed, ResearchGate, Google Acadêmico, LILACS e Scielo. Dos 115 artigos inicialmente coletados, foram excluídas as duplicatas, artigos com dentes bovinos, artigos sem flúor gel ou que abordavam erosão. Foram selecionados 12 artigos. Sobre os efeitos do tratamento, os artigos relataram que a irradiação laser promove fusão e re-solidificação da superfície, tornando-a mais ácido-resistente. Quando associado a fluoretos, este laser aumenta a superfície de contato para a ação do flúor, potencializando os seus efeitos. Analisando os parâmetros utilizados na irradiação, a maior parte (50%) usou 0,6W de potência e 84,9 J/cm² de fluência, seguido pelos valores menores 0,5W e 70,7 J/cm² (16,6%). Estes parâmetros foram considerados seguros em estudos que avaliam a possibilidade de dano térmico à polpa. Dentre os estudos que compararam os efeitos da aplicação de flúor prévia ou posteriormente à irradiação laser, apenas 8,3% relataram que o tratamento sinérgico com laser de Nd:YAG e flúor não foi mais eficaz do que o flúor isolado. Já 33,3% apresentaram melhores efeitos com a aplicação de flúor depois do laser e 8,3% obtiveram melhores resultados com aplicação antes do laser. 8,3% concluíram que o resultado independe da ordem. O protocolo de 0,6W de potência e 84,9 J/cm² de fluência, com aplicação de flúor posterior a irradiação laser, apresentou resultados satisfatórios na prevenção da cárie para a maioria dos estudos.
  • Resumo IPEN-doc 29207
    O uso de fontes de luz em protocolos clareadores: alteração de cor, temperatura, transmitância e irradiância
    2022 - VARDASCA, I.S.; REGIS, M.A.; ZEZELL, D.M.; FRANCCI, C.
    O objetivo do presente estudo foi avaliar as alterações de cor superficial, temperatura, transmitância e irradiância de diferentes fontes de luz em alguns protocolos de clareamento em consultório com peróxido de hidrogênio (PH) de baixa concentração. 90 blocos de esmalte/dentina humanos foram pigmentados e separados em 9 grupos(n=10): SG-SL (sem gel-sem luz), SG-VIO (sem gel, com exposição ao LED violeta), PH35%-SL (sem luz), PH17,5%-SL, PH6%-SL, PH17,5%-AZUL (com exposição ao LED azul), PH6%-AZUL, PH%17,5-VIO (exposição ao LED violeta) e PH6%-VIO. A avaliação da cor foi realizada 7, 14 e 21 dias após o início e 14 dias após o término do protocolo de clareamento com espectrofotômetro, com os valores L*a*b* de reflectância, através do whiteness index (ΔWID ). A análise da temperatura foi realizada com um termopar, a transmitância das luzes com uma esfera integradora e a irradiância das luzes com um powermeter. ANOVA com post-hoc Tukey para as análises de alteração de cor, temperatura e transmitância. O teste de Mann-Whitney foi utilizado para a irradiância. Como resultado, os grupos PH17,5 apresentaram (ΔWID ) similar ao PH35%, independente das fontes de luz. Todos os protocolos irradiados com fontes de luz apresentaram alteração de temperatura maior de 5,5ºC, exceto SG-VIO. A transmitância foi maior no LED azul e no PH17,5%, e a irradiância foi maior no LED azul. Conclui-se que o uso de fontes de luz associadas a géis clareadores de menor concentração não melhoram o resultado estético, porém há um aumento considerável da temperatura, maior no LED Azul que no violeta.
  • Resumo IPEN-doc 29206
    Avaliação da desmineralização superficial do esmalte tratado com flúor e laser utilizando Microscopia Eletrônica de Varredura
    2022 - CARAMEL-JUVINO, A.; FONTES-OLIVEIRA, Y.R.; AVELINO, S.G.; ZEZELL, D.M.
    Avaliar o efeito da aplicação tópica de flúor (12.300 μF-/g) associada a irradiação com laser de Nd:YAG (84 J/cm2) na desmineralização superficial do esmalte, utilizando imagens de Microscopia Eletrônica de Varredura (MEV). Utilizou-se 60 amostras de esmalte humano (CAAE: 02854118.3.0000.0075), divididas em 4 grupos: Controle Negativo, Flúor, Laser e Flúor + Laser (n=15). Após os tratamentos, os grupos foram subdivididos em 3 (n=5), para ciclagem de pH in vitro simulando três condições diferentes: pH 5 (abaixo do pH crítico do esmalte), pH 4,5 (abaixo do pH crítico do esmalte na presença do flúor) e pH 4 (investigativo). Quatro imagens por amostras foram obtidas por MEV a 15 kV, em aumento de 4.000X. As imagens foram classificadas como esmalte hígido, desmineralização leve, moderada ou severa. Para análise estatística, realizou-se uma normalização, onde a classificação de desmineralização severa foi equiparada a 100% de desmineralização, 0 foi equiparado à classificação saudável e as demais classificações foram proporcionais. Em pH 5, os grupos Flúor, Laser e Flúor + Laser não tiveram diferenças significativas entre si (p>0,05). Em pH 4,5, o grupo Flúor + Laser teve o menor percentual de desmineralização (p<0,05). Já em pH 4, não houve diferença significativa entre nenhum grupo. Os dados sugerem que o tratamento de Flúor + Laser tem ação preventiva mesmo em pH abaixo do crítico para esmalte na presença do flúor (pH 4,5). Além disso, indica que possivelmente este tratamento altera o pH crítico da estrutura para valores entre 4,5 e 4, ampliando o poder preventivo do flúor.