Orientador: Regina Maria Puppin-Rontani / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-17T10:32:18Z (GMT). No. of bitstreams: 1 Castilho_AlineRogeriaFreirede_D.pdf: 4223932 bytes, checksum: d68ac38e0ad424f4cce1e0e952fd0608 (MD5) Previous issue date: 2010 / Resumo: Procedimentos de remoção parcial de cárie, indicados para os dentes com lesão de cárie profunda, utilizam-se do preceito de retirar a dentina mais amolecida e infectada,deixando-se uma fina camada de dentina afetada por cárie, sobre a câmara pulpar, evitandoseassim, exposição pulpar mecânica. Contudo, algumas bactérias cariogênicas podem permanecer na dentina por indeterminados períodos de tempo, podendo ocasionar progressão da lesão. Assim, estudos conduzidos com o propósito de melhorar a propriedade antibacteriana de materiais restauradores, sem, contudo produzir efeitos citotóxicos em células odontoblastóides e capaz de manter as propriedades básicas do material pode ser uma alternativa no tratamento de lesões de cárie profundas, uma vez que não existe um produto comercialmente disponível que associe todas estas características. No intuito de facilitar a apresentação desta Tese, a mesma foi dividida em dois capítulos, como descrito nas proposições seguintes. Capítulo 1: avaliar in vitro as propriedades biológicas (ação antibacteriana contra Streptococcus mutans, Lactobacillus acidophilus, Lactobacillus casei e Actinomyces viscosus, e cito toxicidade em células de linhagem odontoblástica MDPC-23)e mecânicas (resistência à compressão e à tração diametral) de um cimento de ionômero de vidro modificado por resina (Fuji Lining LC), contendo digluconato de clorexidina em diferentes concentrações (0,2%, 0,5%, 1,25% e 2,5%) e assim determinar a concentração terapêutica para utilização desta substância em tratamentos restauradores. Capítulo 2:verificar in vitro o comportamento de um cimento de ionômero de vidro modificado por resina (Fuji Lining LC) contendo hiclato de doxiciclina nas concentrações 1,5%, 3% e 4,5%frente a diferentes patógenos cariogênicos (Streptococcus mutans, Lactobacillusacidophilus, Lactobacillus casei e Actinomyces viscosus), células odontoblástóides MDPC-23 e quando submetidos aos ensaios mecânicos de resistência à compressão e à tração diametral. Os resultados observados em ambos os estudos mostraram que a incorporação de antimicrobianos ao cimento de ionômero de vidro, é capaz de melhorar significativamente efeito inibitório do cimento contra microrganismos criogênicos. A adição de dig luconato de clorexidina a 2,5% promoveu ligeira alteração no metabolismo e morfologia das células MDPC-23. O hiclato de doxiciclina, quando incorporado ao ionômero de vidro mesmo em maiores concentrações, não causou efeitos tóxicos em cultura de células odontoblásticas MDPC-23. Além disso, o cimento de ionômero de vidro contendo digluconato declorexidina a 2,5% apresentou resistência à compressão reduzida, sem alteração da propriedade de resistência a tração diametral do cimento. A adição de hiclato de doxiciclina não alterou as propriedades mecânicas do cimento. Assim, a adição de hiclato de doxiciclina e de digluconato de clorexidina nas concentrações estudadas produziu aumento na atividade antimicrobiana sem efeitos citotóxicos e alteração nas propriedades mecânicas da mistura, exceto para o digluconato de clorexidina a 2,5%, que apresentou o menor resistência a compressão e alterações no metabolismo e morfologia de células pulpares. / Abstract: Partial caries removal approaches are indicated to the management of deep caries. It consists of the incomplete removal of softened carious dentine during cavity preparation, leaving a soft dentine layer over the pulp, so that it is not mechanically exposed. However, some viable cariogenic bacteria have been found in the remaining affected dentine, which may promote caries lesion progression. Therefore, studies aimed to improve inhibitory effect of the restorative materials, without cytotoxic effects on odontoblast cells and able to keep properties of material could be an alternative to the treatment of deep caries lesions. Nevertheless, the disposal-marketed products do not associate all those features. In order to facilitate the accomplishment of this Thesis, it was divided into two chapters, as described on the following descriptions. Chapter 1: to evaluate in vitro biological properties (antibacterial effect against Streptococcus mutans, Lactobacillus acidophilus, Lactobacillus casei and Actinomyces viscosus, and cytotoxicity at odontoblast cell line MDPC-23) and mechanical properties (compressive strength and diametral tensile strength) of a resin-modified glass ionomer cement (Fuji Lining LC) containing different concentrations of chlorhexidine digluconate (0.2%, 0.5%, 1.5% and 2.5%) and, thus to determine the therapeutic concentration of it for using in restorative dental treatment. Chapter 2: to verify in vitro the performance of a resin-modified glass ionomer cement (Fuji Lining LC) containing the antibiotic doxycycline hyclate at 1.5%, 3% and 4.5% against some cariogenic pathogens (Streptococcus mutans, Lactobacillus acidophilus, Lactobacillus casei and Actinomyces viscosus); to analyze it indirect contact with odontoblast-like MDPC-23 cells; and, to reveal the mechanical properties under compressive strength and diametral tensile strength. Results of both studies proved that the incorporation of antimicrobials at adequate proportions into the glass ionomer cement have the ability to become better inhibitory effects of the cement against cariogenic bacteria. The 2.5% chlorhexidine digluconate added to glass ionomer cement promoted slight alteration on the mebolism and morfology of MDPC-23 cells. The incorporation of doxycycline hyclate to glass ionomer cement, even in the highest concentration, did not cause toxic effects on culture of odontoblast-like MDPC-23 cells. In addition, 2.5% chlorhexidine digluconate-containing glass ionomer cement decreased the compressive strength of cement, although there was no difference to diametral tensile strength. The adding of doxycycline hyclate did not alter mechanical properties of cement. It was concluded that doxycycline hyclate and chlorhexidine digluconate in the studied concentrations produced increased antimicrobial activity without cytotoxic effects and changes in mechanical properties of the mixture, except for the 1.25% chlorhexidine digluconate that presented the lowest compressive strength and alterations on metabolism and morphology of pulp cells. / Doutorado / Odontopediatria / Doutor em Odontologia

Orientador: Brenda Paula Figueiredo de Almeida Gomes / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-09T16:41:43Z (GMT). No. of bitstreams: 1 Martinho_FredericoCanato_M.pdf: 2565020 bytes, checksum: d3b12dfab50de25f375d07ea0056245c (MD5) Previous issue date: 2007 / Resumo: O conhecimento das espécies microbianas assim como da suscetibilidade das mesmas à terapia endodôntica é importante para o sucesso do tratamento. Sendo assim, a proposta do presente estudo foi: 1) Analisar a microbiota endodôntica de dentes com necrose pulpar e presença de lesão periapical (C1) e correlacionar com os sinais e sintomas clínicos; 2) investigar mudanças microbiológicas após o preparo químico-mecânico (PQM) (C2); 3) investigar a presença de Entreococcus spp., Candida spp. e enterobactérias na saliva dos pacientes submetidos a terapia endodôntica; 4) quantificar endotoxinas antes (C1) e após PQM (C2); 5) determinar in vitro a suscetibilidade antimicrobiana de algunsmicrorganismos isolados das infecções endodônticas primárias. Amostras microbiológicas foram coletadas da saliva e do canal radicular de 30 pacientes. Foram identificados 182 microrganismos nos canais radiculares, sendo 65,38% anaeróbios estritos. As espécies mais freqüentemente encontradas foram P. micros (63,3%), P. intermedia (50%), S. mitis (30%). Associações positivas foram encontradas entre dor à percussão e E. lentum; dor à palpação e G.haemolysans e E. lentum; fístula e P. micros; exsudato purulento e Bifidobacterium spp. As espécies Peptostreptococcus spp., Fusobacterium spp., Porphyromonas spp., Prevotella spp. foram analisadas e mostraram-se suscetíveis a ação da amoxicilina e da mesma associada ao ácido clavulânico. Maiores concentrações de endotoxinas foram quantificadas nos dentes com sintomatologia clínica. Associação positiva entre LPS e a presença de dor à percussão foi encontrada (p<0,01) Conclusão: A infecção endodôntica primária caracterizou-se ser do tipo mista e polimicrobiana, com predomínio de microrganismos anaeróbios estritos, principalmente bacilos Gramnegativos; a presença de sinais e/ou sintomas clínicos mostrou estar relacionada com determinadas espécies tais como Eubacterium lentum, Gemella haemolysans, Peptostreptococcus micros e Bifidobacterium spp. comumente isoladas em infecções endodônticas primárias; Candida spp. e Enterococcus spp. foram mais freqüentemente isolados da saliva do que as Enterobacteria spp. O isolamento das espécies C. albicans e E. faecalis no canal radicular foram associados com a identificação das espécies na saliva; o PQM dos canais radiculares foi eficaz na redução do número de microrganismos. Mudança na microbiota foi encontrada após PQM. Amoxicilina associada ao ácido clavulânico mostrou ser uma potente combinação contra microrganismos envolvidos na infecção de origem endodôntica. Altas concentrações de endotoxinas nos canais radiculares parecem estar relacionadas com a presença de sintomatologia clínica, particularmente com a dor à percussão. O PQM foi capaz de reduzir a concentração inicial de endotoxinas em todos os canais radiculares, entretanto não foi capaz de eliminá-las / Abstract: Bacteria and their by-products play an important role in the etiology and development of pulp and periapical diseases. The knowledge of endodontic microbiota and its susceptibility to endodontic therapy is important to a successful treatment. Therefore the aims of this study were: 1) to analyse the root canal microbiota in infected teeth with pulp necrosis and periapical lesions (C1) and its correlation with the clinical signs and symptoms; 2) to investigate the variations in the susceptibilities of endodontic microflora to biomechanical procedures (C2); 3) to investigate Candida spp., Enterococcus spp. and enterobacteria in saliva from the patients under endodontic therapy; 4) to quantify endotoxins before (C1) and after chemo-mechanical preparation (CMP) (C2); 5) to determine in vitro the antimicrobial susceptibility rates of the microrganisms recovered from the root canals with primary endodontic infections. Thirty root canals were microbiologically sampled before (C1) and after CMP (C2). At the baseline samples (C1), a total of 182 microrganisms were identified. Strict anaerobic or microphilic species predominated in 65.38%. P. micros (63.3%), P. intermedia (50%), S. mitis (30%) were the most frequent species recovered from the root canals at the baseline samples (C1). Associations between terderness to percussion and the presence of E. lentum; pain on palpation and G. haemolysans and E. lentum; sinus tract and P. micros; Purulent exudate and Bifidobacterium spp. (p<0.05) were found. Peptostreptococcus spp., Fusobacterium spp., Porphyromonas spp., Prevotella spp. were susceptible to amoxicilin and amoxicillin + clavulanate. Higher levels of endodotoxin were detected in teeth with clinical symtphomatology. A positive association was found between the presence of LPS and tenderness to percussion (p<0.01).It was concluded that microbiota from infected root canals with pulp necrosis and periapical lesions was comprised by a mixed and polimicrobial flora, dominated by strict anaerobes, particulary Gram-negative rods. Signs and symptoms seemed to be related to the presence of specific bacteria species Eubacterium lentum, Gemella haemolysans, Peptostreptococcus micros e Bifidobacterium spp.. Candida spp. and Enterococcus were more requently recovered from saliva than Enterobacteria spp. Isolation of C. albicans and E. faecalis from root canals were associated with their identification in the saliva samples. CMP was efficient in reducing the number of microorganisms. Changing in root canal flora was detected after endodontic procedures. Amoxicilin associated with clavulanate was an effective and a strong antimicrobial agent against microorganisms involved in endodontic infections. High contents of LPS seem to be related to the presence of clinical symptomatology, particulary tenderness to percussion. CMP was effective in reducing the initial amount of endotoxin in all root canal samplings but was not able to eliminate it / Mestrado / Endodontia / Mestre em Clínica Odontológica

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / The elimination of bacteria inside the demineralized dentin layer might contribute for a more conservative approach in the restorative treatment of deep dentin caries lesions. This way, this in vitro study aimed to establish safe and effective parameters for using an LED (&#955; = 620-660 nm) associated to the photosensitizer toluidine blue O (TBO) in the disinfection of artificially produced dentin caries lesions. For this, slabs with 25 mm2 of flatted occlusal human dentin were immersed for 5 days in BHI broth inoculated with Streptococcus mutans for caries induction. After demineralization, the slabs were randomly allocated to 10 experimental groups (n=15), as follows Control5; Control10; Control15; TBO; LED5; LED10; LED15; PDT5; PDT10 and PDT15, which were treated with TBO (0.1 mg.ml-1 for 5 min) or 0.9% NaCl solution for 5, 10 or 15 min, and submitted or not to LED irradiation for 5, 10 or 15 min (47, 94, and 187 J/cm2). Dentin samples from caries lesions were collected before and after treatments and bacteria were then cultured for Streptococcus mutans counts. In addition, using a type K thermometer, the temperature inside the pulp and in periodontal area was monitored for the groups PDT5, PDT10 and PDT1510 in 10 teeth with deep occlusal cavities. Paired t test/Wilcoxon matched pairs test (&#61537;=5%) were used to determine differences between microbial population before and after treatments, and ANOVA followed by Tukey test for comparing data of temperature and log reductions. Statistically significant differences in Streptococcus mutans viability were found for the groups: Control15; LED15; PDT5; PDT10 and PDT15. The temperature from intrapulpal and periodontal area were lower than 2oC, being higher inside the pulpal chamber for group PDT15 when compared to group PDT5. Thus, it the experimental conditions used in the study, photodynamic therapy may be a safe and effective treatment to be used for disinfecting carious dentin, however the influence of time of irradiation/exposition it the Streptococcus mutans viability should be better investigated. / A eliminaÃÃo de bactÃrias presentes na camada de dentina desmineralizada poderia contribuir para uma abordagem mais conservadora no tratamento restaurador de lesÃes de cÃrie dentinÃria profundas. Desta forma, este estudo in vitro objetivou estabelecer parÃmetros eficazes e seguros para a utilizaÃÃo de um LED (&#955; = 620-660 nm) associado ao fotossensibilizador azul de orto-toluidina (TBO) na desinfecÃÃo de lesÃes de cÃrie dentinÃria produzidas artificialmente. Para tal, blocos com 25 mm2 de dentina oclusal planificada foram imersos por 5 dias em BHI caldo inoculado com Streptococcus mutans para induÃÃo de cÃrie. Depois da desmineralizaÃÃo, os blocos foram aleatoriamente distribuÃdos em 10 grupos experimentais (n=15), a saber: Controle5; Controle10; Controle15; TBO; LED5; LED10; LED15; TFD5; TFD10 e TFD15, que foram tratados ou nÃo com TBO (0,1 mg.ml-1 por 5 minutos) ou soluÃÃo de NaCl a 0,9% por 5, 10 ou 15 minutos, e submetidos ou nÃo a irradiaÃÃo com LED por 5, 10 ou 15 minutos (47, 94, e 187 J/cm2). Amostras de dentina cariada foram coletadas antes e apÃs os tratamentos e as bactÃrias foram semeadas para contagem de Streptococcus mutans. Adicionalmente, com um termÃmetro tipo K, a temperatura intra-pulpar e da Ãrea periodontal nos grupos TFD5; TFD10 e TFD15 foi monitorada em 10 dentes com cavidades oclusais confeccionadas em dentina profunda. Teste t pareado e ANOVA seguida pelo teste Tukey (&#61537;=5%) foram usados para verificaÃÃo da reduÃÃo microbiana promovida pelos tratamentos, bem como para verificaÃÃo da alteraÃÃo na temperatura durante a irradiaÃÃo. DiferenÃas significativas estatisticamente na viabilidade do Streptococcus mutans entre contagens foram observadas nos grupos: Controle15; LED15; TFD5; TFD 10 e TFD15. A temperatura intra-pulpar e no periodonto foi inferior a 2oC, sendo a no interior da cÃmara pulpar maior para o grupo TFD15 quando comparado ao grupo TFD5. Dessa forma, nas condiÃÃes experimentais atuais, a terapia fotodinÃmica pode ser um tratamento eficaz e seguro a ser usado na desinfecÃÃo de dentina cariada, contudo a influÃncia do tempo de irradiaÃÃo ou exposiÃÃo à soluÃÃo salina na viabilidade do Streptococcus mutans deve ser melhor investigada.

nÃo hà / Este trabalho buscou comparar a eficÃcia anti-cÃrie e antimicrobiana de quatro diferentes substÃncias: carvacrol 20% (CAR), carvacrol 10% em associaÃÃo com o timol a 10% (CAR+THY), clorexidina a 20% (CHX) e fluoreto de sÃdio a 5% (NaF), em crianÃas de alto risco e livres de cÃrie. Cento e vinte crianÃas, entre 36 a 71 meses, foram selecionadas de prÃ-escolas pÃblicas de um bairro do MunicÃpio de Fortaleza (CearÃ), caracterizando-as segundo os critÃrios de risco à carie da Academia Americana de Odontologia PediÃtrica como crianÃas de alto risco. Essas crianÃas foram randomicamente distribuÃdas nos quatro grupos de tratamento. Os antimicrobianos foram manipulados na forma de verniz e aplicados trimestralmente durante um ano. Pacientes foram monitorados trimestralmente, atravÃs de exames clÃnicos periÃdicos para avaliaÃÃo do surgimento de lesÃes de cÃrie. Foram coletadas salivas antes do inÃcio do tratamento (B), apÃs 7 (D7), 30 (D30), 90 (D90), 180 (D180) e 360 (D360) dias de tratamento para detecÃÃo de EGM. Na anÃlise microbiolÃgica as amostras foram cultivadas sobre Agar MSB, incubadas em estufa a 37 C, com atmosfera de microaerofilia, durante 48 horas. As colÃnias foram confirmadas como sendo EGM a partir de provas bioquÃmicas. A contagem bacteriana foi expressa em unidades formadoras de colÃnias (UFC/mL). Dados foram considerados significativos quando p<0.02. Ao comparar os nÃveis de EGM entre B e D7 nÃo observou-se diferenÃa entre os tratamentos (p=0,032). ComparaÃÃes dos percentuais de reduÃÃo de EGM entre os grupos (D30-D90) e demonstrou uma diferenÃa estatisticamente significativa (p=0,002) , havendo diferenÃa entre o CAR versus CAR+THY (p=0,003); CAR +THY versus CHX (p=0,004) e CHX versus NaF, (p=0,014). O CAR+THY apresentou o menor percentual de reduÃÃo e a CHX o maior. Observamos um aumento de EGM nos grupos tratados com CHX e NaF em D360. ComparaÃÃes entre o ceo-s dentro de cada grupo, demonstrou uma diferenÃa significativa entre o ceo-s inicial e o ceo-s do exame realizado 9 meses apÃs o inÃcio dos tratamentos, com exceÃÃo do grupo NaF. Observou-se uma correlaÃÃo positiva significante entre o total de superfÃcies e a idade em todos os tratamentos estudados. NÃo houve diferenÃa significante da densidade de cÃrie entre as vÃrias faixas etÃrias dentro e entre os grupos. NÃo houve diferenÃa no ceo-s entre os grupos (p=0,746). Em conclusÃo, todos os tratamentos produziram significante reduÃÃo de EGM com grandes variaÃÃes dentro e entre os grupos, associada a baixa experiÃncia de cÃrie. / This study aimed to compare the anticaries and antimicrobial efficacy of four different substances: 20% carvacrol (CAR), 10% carvacrol in association with 10% thymol (CAR+THY), 20% chlorhexidine (CHX) and 5% sodium fluoride (NaF), in high-risk, caries-free children. One hundred and twenty children, between 36 and 71-months age, were selected from public preschools from a neighborhood in Fortaleza (CearÃ). Children were classified as a high caries-risk group according to the American Academy of Pediatric Dentistry Guidelines. These children were randomly allocated into four different treatment groups. Antimicrobial agents were made as varnishes and applied every 3 months, during one year. Patients were monitored every 3 months for new caries lesions. Saliva was collected before treatment initiation (B) and after 7 (D7), 30 (D30), 90 (D90), 180 (D180) and 360 (D360) days post-treatment for MS detection. For microbiological analysis, samples were cultivated on MSB agar media and incubated at 37o C under microaerofilic conditions, during 48 hours. Bacterial colonies were confirmed as being MS through biochemical tests. MS counts were expressed in colony forming units (CFU/mL). Data was considered significant when p<0.02. When comparing MS levels between B and D7, no difference was observed between groups (p=0,032). Comparisons of the percentage MS reduction between groups (D30-D90) demonstrated a significant difference (p=0,002), with a difference between CAR versus CAR+THY (p=0.003), CAR+THY versus CHX (p=0.004), and CHX versus NaF (p=0.014). CAR+THY presented the smallest percentage reduction, while CHX presented the greatest. We observed an increase in MS in the groups treated with CHX and NaF at D360. With the exception of the NaF group, comparisons between dmfs within each group, demonstrated a significant difference between the initial dmfs and the dmfs measured 9 months after treatment initiation. A significant positive correlation between the total dental surfaces and the patientâs age was observed in all groups. No significant difference was found between caries density of the different age groups within and between groups. The dmfs scores did not differ between groups (p=0,746). In conclusion, all treatments produced significant MS reduction with great variations within and between groups, associated with low caries experience.

A alveolite seca é uma das complicações pós-operatórias mais comuns e sintomáticas na exodontia, porém, até o momento não possui um protocolo de tratamento definido. A oxitetraciclina (OTC) é um antibiótico de amplo espectro utilizado no tratamento de múltiplas infecções. Entretanto, nos últimos anos as tetraciclinas de primeira geração, tais como a OTC, têm sido evitadas devido ao surgimento de microrganismos resistentes. Afortunadamente, nos últimos anos tem se observado uma tendência contrária graças às medidas de controle no uso de antibióticos. Sistemas de liberação controlada podem evitar o desenvolvimento de resistência bacteriana e diminuir o risco de efeitos adversos. Este estudo teve como objetivo preparar uma nanofibra polimérica de policaprolactona e oxitetraciclina (PCL/OTC), e ainda avaliar suas propriedades físicas e biológicas in vitro e in vivo, visando seu futuro uso no tratamento da alveolite seca. As nanofibras poliméricas carregadas com OTC foram preparadas pelo sistema de eletrofiação, caracterizadas através da microscopia eletrônica de varredura (MEV) e avaliadas sobre seu perfil de liberação do fármaco. A atividade antibacteriana da nanofibra sobre um biofilme misto de Porphyromonas gingivalis, Prevotella intermédia, Fusobacterium nucleatum, Eikenella corrodens, Streptococcus sanguis e Aggregatibacter actinomycetemcomitans foi analisada mediante a contagem das unidades formadoras de colônias viáveis após os tempos de contato de 1, 4, 24, 30 e 48 h. O processo de reparo alveolar induzido pela nanofibra PCL/OTC foi avaliado de forma histomorfológica e histomorfométrica após o tratamento da alveolite seca em molares de ratos, e comparado ao tratamento com nanofibras de PCL pura e Alvogyl®, 7, 14 e 21 dias após a exodontia. Finalmente, foi realizada a identificação e contagem de osteoclastos através da marcação da fosfatase ácida resistente ao tartarato (TRAP), nos mesmos tempos de avaliação. As nanofibras PCL/OTC apresentaram orientação randômica em camadas e morfologia multiforme. O perfil de liberação do sistema apresentou um efeito de explosão nas primeiras 8 horas, seguido por um período de liberação lenta e prolongada da OTC. A nanofibra PCL/OTC (132 ?g de OTC/mL) reduziu mais de 50% das colônias do biofilme nas primeiras horas de liberação, seguido por um período de manutenção em que a porcentagem de colônias bacterianas permaneceu baixa. O grupo tratado com PCL/OTC apresentou a maior porcentagem de tecido conjuntivo no 7º dia (p<0,05) e maior porcentagem de osso neoformado no 14º e 21º dias após a exodontia (p<0,05), em comparação aos outros grupos. O tratamento de alveolite seca com a fibra PCL/OTC permitiu a regeneração tecidual do alvéolo quase em sua totalidade até o 21º dia, sendo que a cronologia de regeneração tecidual com este material foi mais rápida do que com a fibra de PCL pura, e esta última mais rápida que do que o controle positivo Alvogyl®. O grupo PCL/OTC apresentou uma quantidade menor (p<0,05) de osteoclastos por área em relação aos outros grupos nos três tempos experimentais. O perfil de liberação prolongando de OTC e as propriedades biológicas relevantes apresentadas pela nanofibra PCL/OTC, sugerem que esta poderia ser considerada uma alternativa para o tratamento da alveolite seca. / Dry socket is one of the most common and symptomatic postoperative complications in tooth extraction, however, to date, it does not have an established treatment protocol. Oxytetracycline (OTC) is a broad-spectrum antibiotic, employed in the treatment of multiple infections. Nevertheless, in the last few years, first-generation tetracyclines such as OTC, have been avoided due to the development of resistant microorganisms. Fortunately, in recent years there has been a contrary trend thanks to control measures in the use of antibiotics. Controlled release systems can prevent the development of bacterial resistance and decrease the risk of adverse effects. This study aimed to prepare a polymeric nanofiber of polycaprolactone and oxytetracycline (PCL/OTC), and to evaluate its physical and biological properties in vitro and in vivo, aiming its use in the treatment of dry socket at the future. The OTC-charged polymeric nanofibers were prepared by electrospinning, and characterized by scanning electron microscopy (SEM) and drug release profile evaluation. The antibacterial activity of the nanofiber over a mixed biofilm containing Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, Eikenella corrodens, Streptococcus sanguis, and Aggregatibacter actinomycetemcomitans was analyzed by counting the viable colony-forming units after 1, 4, 24, 30 and 48 h of contact. The alveolar repair process induced by the PCL/OTC nanofiber was evaluated histomorphologically and histomorphometrically after the treatment of dry socket in rat molars, and compared to the treatment with plain PCL nanofibers and AlvogylTM, 7, 14 and 21 days after extraction. Finally, the identification and counting of osteoclasts were performed through the tartrate resistant acid phosphatase (TRAP) staining, at the same evaluation time points. PCL/OTC nanofibers presented random orientation in layers and multiform morphology. The release profile of the PCL/OTC system showed a burst effect within the first 8 hours, followed by a prolonged slow release period. The PCL/OTC nanofiber at a concentration of 132 ?g OTC/mL reduced more than 50% of the biofilm colonies in the first few hours of release, followed by a maintenance period in which the percentage of bacterial colonies remained low. The PCL/OTC group presented the highest percentage of connective tissue on the 7th day (p<0.05), and of newly formed bone on the 14th and 21st days (p<0.05) after dental extraction, compared to the other groups. The treatment of dry socket with the PCL/OTC fiber allowed almost complete tissue regeneration up to the 21st day, and the chronology of tissue regeneration with this material was faster than with the plain PCL fiber, and the latter was more rapid than the positive control AlvogylTM. The PCL/OTC group presented a lower amount (p<0.05) of osteoclasts per area than the other two groups in the three experimental periods. The prolonged release profile of OTC and the relevant biological properties presented by the PCL/OTC nanofibers suggest that these may be considered as an alternative treatment of dry socket.

Indiana University-Purdue University Indianapolis (IUPUI) Endodontic Regeneration Graduate Endodontic Department / Introduction: Regenerative endodontic procedures are used to treat immature teeth with pulpal necrosis in order to control infection, enable continued root development and enhance formation of a pulp like tissue in the canal. Canal disinfection is an integral part the regenerative endodontic process. Double antibiotic paste (DAP; i.e., equal parts of ciprofloxacin and metronidazole) has been successfully used for canal disinfection in regenerative endodontics. A comparison of the residual antibacterial effect of dentin treated with various dilutions of DAP pastes on biofilm formation has not yet been investigated thoroughly. Objectives: The aims of this in-vitro study were to investigate how concentration and time of treatment affect the residual antibacterial properties of DAP in preventing E. faecalis biofilm formation on human dentin. Materials and Methods: Extracted human teeth were used to obtain 4x4mm radicular dentin specimens. Each specimen was pretreated for 1 or 4 weeks with the 77 clinically used concentration of DAP (500 mg/mL), low concentrations of DAP (1, 5 or 50 mg/mL) loaded into a methylcellulose system, calcium hydroxide (Ca(OH)2), or placebo paste. After treatment, samples were rinsed and placed in sterile phosphate buffered saline (PBS) for three weeks. Samples were then inoculated with cultured E. faecalis and incubated in anaerobic conditions for three weeks to allow mature biofilm formation. The dentin samples were rinsed and biofilms detached. The detached biofilm cells were then diluted and spirally plated for enumeration on blood agar plates. The plates were then incubated for 24 h and the number of CFUs/mL was determined using an automated colony counter. Data was analyzed using Fisher’s Exact and Wilcoxon rank sum tests were used for statistical comparisons (α=0.05). Results: Dentin pretreatment for 4 weeks with 5, 50 or 500 mg/mL of DAP demonstrated significantly higher residual antibacterial effects and complete eradication of E. faecalis biofilms in comparison to a 1 week pretreatment with similar concentrations. However, dentin pretreated with 1 mg/mL of DAP or Ca(OH)2 did not provide a substantial residual antibacterial effect regardless of the application time. Conclusion: Dentin treated with 500, 50, or 5 mg/mL of DAP for 4 weeks was able to completely prevent the colonization of bacterial biofilm. Four-week treatment of dentin with DAP offers superior residual antibacterial effect in comparison to a one-week treatment. Intracanal application of DAP for 4 weeks during endodontic regeneration may offer an extended residual antibacterial effect.

Indiana University School of Dentistry Department of Endodontics / Introduction: Triple antibiotic paste (TAP, 1000 mg/ml) is composed of equal portions of ciprofloxacin, metronidazole and minocycline and is used as an intracanal dressing to disinfect the infected immature root canal during endodontic regeneration procedures. Lower concentrations of TAP have been recommended to minimize detrimental effects on pulp stem cells. TAP can be retained within the dentin matrix and its continual release confers an antibacterial effect to the dentin. Objective: The aim of this in vitro study was to investigate the residual antibacterial effect of dentin treated with various concentrations of TAP loaded into a gel system. Materials and Methods: Radicular dentin slabs were prepared from human teeth after obtaining IRB approval. The slabs were sterilized and treated with methylcellulose-based TAP of 100 mg/mL, 10 mg/mL, 1 mg/mL, 1.5% NaOCl, placebo paste with no TAP, or a positive control group with pure 1000 mg/mL TAP. Samples in each group were treated with the assigned TAP concentration for three weeks or immersed in 1.5% NaOCl for five minutes (n =18 per group). All samples were then irrigated with sterile water followed by 17% EDTA and incubated in phosphate buffered saline for either 2 or 4 weeks. Samples were then inoculated with Enterococcus faecalis and incubated for an additional 3 weeks. Biofilm formed on each sample was then dislodged and spiral plated to evaluate the bacterial colony-forming units. Data were analyzed using Fisher’s Exact tests and Wilcoxon rank sum tests (α = 0.05). Results: Dentin treated with 10, 100, or 1000 mg/mL of TAP demonstrated significant residual antibacterial effects up to four weeks. However, only 100 mg/mL TAP was able to completely prevent bacterial colonization after four weeks. No considerable residual antibacterial effect was observed in dentin treated with placebo gel, 1 mg/ml TAP or 1.5% NaOCl. Conclusion: At least 10 mg/mL of TAP loaded into a methylcellulose system is required to achieve a substantial residual antibacterial effect for four weeks.

Indiana University-Purdue University Indianapolis (IUPUI) Indiana University School of Dentistry Indiana University Endodontic Department / The residual antibacterial effects of antimicrobials used in endodontic regeneration against biofilm bacteria obtained from immature and mature teeth Jordon C. Jacobs DDS, Richard L Gregory PhD, Ygal Ehrlich DMD, Kenneth Spolnik DDS, MS, Josef S. Bringas DMD, DDS, MS, and Ghaeth Yassen BDS, MSD, PhD We explored the residual antibacterial properties of dentin pretreated with low concentrations of double antibiotic paste (DAP) against biofilm bacteria obtained from different clinical sources. Dentin blocks were sterilized and randomized into 4 treatment groups and 2 control groups (n=20). Blocks from treatment groups were pretreated with DAP (1 or 5 mg/ml) loaded into methylcellulose, calcium hydroxide (Ca(OH)2), or methylcellulose paste. After one week, the treatment pastes were removed and all blocks were immersed in PBS. The dentin blocks from treatment groups and one of the control groups were then inoculated with bacterial isolates obtained from immature or mature teeth with pulpal necrosis(n=10). The remaining control group received no bacteria and was used as a sterile control. Blocks were then incubated anaerobically for 3 weeks. Biofilm disruption assays were conducted for all samples. Two-way ANOVA and pair-wise comparisons were used for statistical analyses. The residual antibacterial effect of dentin pretreated with 5 mg/ml of DAP was significantly higher than all other groups regardless of the source of biofilm. Dentin pretreated with 1 mg/ml of DAP demonstrated significantly higher residual antibacterial effects in comparison to dentin pretreated with placebo paste and Ca(OH)2 only in bacterial isolates obtained from mature teeth with pulpal necrosis. Dentin pretreated with Ca(OH)2 did not demonstrate any residual antibacterial effects. Dentin pretreated with 1 or 5 mg/ml of DAP demonstrated significantly better residual antibacterial effects against biofilm bacteria obtained from mature teeth with pulpal necrosis in comparison to bacterial isolates obtained from immature teeth with pulpal necrosis.

We investigated the antibacterial effect of low concentrations of double antibiotic paste (DAP) loaded into a methylcellulose system against bacterial biofilms obtained from mature and immature teeth with necrotic pulps. Standardized radicular dentin specimens were randomly divided into six experimental groups (n = 20). Group 1: 5mg/mL DAP treatment. Group 2: 1mg/mL DAP treatment. Group 3: Calcium hydroxide (Ca(OH)2) treatment. Group 4: Methylcellulose. Group 5: No treatment. Group 6: No bacteria or treatment. Clinical bacterial isolates were obtained from mature and immature teeth with necrotic pulps indicated for endodontic regeneration or routine endodontic treatment, respectively. Specimens in each group were inoculated with either bacterial isolates (n = 10) and incubated anaerobically for 3 weeks. Specimens were then treated for one week with the assigned group treatment. Treatments were rinsed with sterile saline and biofilms were detached and spiral plated using biofilm disruption assays. Wilcoxon Rank Sum tests followed by pair-wise comparisons were used for statistical analyses. Treatment of infected dentin with 1 mg/ml of DAP, 5 mg/mL of DAP, and Ca(OH)2 demonstrated significant and substantial antibiofilm effects in comparison to untreated control groups or groups treated with placebo paste. Furthermore, 1 mg/mL of DAP caused complete eradication of biofilm obtained from mature tooth with necrotic pulp. However, the same concentration was not able to completely eradicate biofilm obtained from the immature tooth with necrotic pulp. Low concentrations of DAP (1-5 mg/mL) loaded into a biocompatible methylcellulose system demonstrated significant antibacterial effects against biofilm obtained from both mature and immature teeth with necrotic pulps.

Indiana University-Purdue University Indianapolis (IUPUI); Graduate Endodontics, Masters degree thesis / We evaluated the antibacterial stability (shelf life) of a new radiopaque double antibiotic paste (RoDAP) loaded in a methylcellulose system with 30% w/v barium sulfate against biofilm collected from an immature tooth with necrotic pulp. Uniform radicular dentin specimens were infected with bacterial biofilm obtained from an immature tooth with a necrotic pulp and incubated anaerobically for three weeks. These samples were randomly divided into 6 experimental groups (n=7) and treated for 1 week at three time points of aged radiopaque DAP: 0 months, 3 months, and 6 months. Group 1: 1mg/mL RoDAP treatment. Group 2: 10 mg/mL RoDAP treatment. Group 3: Calcium hydroxide (Ca(OH)2) treatment. Group 4: Methylcellulose with barium sulfate. Group 5: No treatment. Group 6: No bacteria or treatment. The samples were rinsed with sterile saline to detach biofilms and then spiral plated using a biofilm disruption assay. Statistical analyses were performed using Wilcoxon rank-sum tests and Wilcoxon signed rank tests with fixed effects for treatment, time, and the treatment-by-time interaction. Treatment of infected dentin with 1 mg/mL RoDAP, 10 mg/mL RoDAP, and Ca(OH)2 demonstrated significant and substantial antibiofilm effects in comparison to untreated control groups or groups treated with placebo paste after 0, 3, and 6 months of aging. Calcium hydroxide, however, showed slightly less antibiofilm activity after 6 months of aging when compared to 0 months and 3 months of aging. This difference was statistically significant (p > 0.05). In conclusion, both concentrations of RoDAP maintained full antibacterial efficacy after 6 months of aging, while calcium hydroxide lost some antibacterial activity after a shelf life of 6 months.