Interação dos cimentos do ProRoot MTA, MTA branco, MTA Bio e Portland branco com a dentina

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde. Programa de Pós-graduação em OdontologiaOs objetivos deste estudo foram analisar a quantidade e a composição química do precipitado formado pelos cimentos ProRoot MTA, MTA Branco, MTA BIO e Portland branco, após imersão em tampão fosfato salino (PBS); avaliar a interface cimento-dentina e, paralelamente, analisar o pH e a liberação de íons cálcio a partir dos cimentos empregados. As coroas de 28 dentes humanos foram removidas e o terço médio das raízes cortados transversalmente para a obtenção de discos radiculares com 2 mm de espessura. Em cada secção, o espaço do canal foi ampliado a fim de obter uma cavidade padronizada com 2 mm de diâmetro. As secções foram divididas aleatoriamente em 5 grupos, sendo as cavidades preenchidas com: ProRoot MTA (Grupo 1), MTA Branco (Grupo 2), MTA BIO (Grupo 3), CP1: Cimento de Portland branco com 20% de óxido de bismuto (Grupo 4), e CP2: Cimento de Portland branco com 20% de óxido de bismuto e 10% cloreto de cálcio (Grupo 5). Em seguida, as amostras foram colocadas em recipientes plásticos contendo 15 mL de PBS e levadas à estufa (37ºC) por um período de 2 meses. A solução tampão foi substituída a cada 5 dias. A cada substituição, os precipitados foram colhidos, lavados, dessecados e pesados. Aos 5, 15, 25 e 35 dias, a solução foi coletada para medição do pH e da concentração de íons cálcio. Ao final dos 2 meses, as amostras foram processadas para avaliação, em MEV, da interface cimento-dentina. Os dados foram analisados estatisticamente em um nível de significância de 5%. Em todas as amostras foi observada a formação de precipitados de apatita carbonatada e a presença de uma intercamada na interface cimento-dentina. A partir da intercamada, foram observados prolongamentos penetrando nos túbulos dentinários. O ProRoot MTA e o MTA BIO formaram maior quantidade de precipitados, geraram os valores de pH mais altos e a maior concentração de íons cálcio em todos os períodos de avaliação. O ProRoot MTA, o MTA Branco, o MTA BIO e o cimento Portland branco têm a capacidade de dissolver alguns de seus componentes e propiciar a precipitação de apatita carbonatada, promovendo a formação de uma intercamada com prolongamentos que penetram nos túbulos dentinários. The aim of this study was to analyze the amount and the chemical composition of the precipitate formed by ProRoot MTA, White MTA, MTA BIO and white Portland cements, after immersion in phosphate buffered saline (PBS), to evaluate the cement-dentine interface and to analyze the pH and the calcium ions release. The crowns of 28 human teeth were removed and the middle third of the roots was sectioned transversally in order to obtain 2mm-thickness sections. In each section, the space of the canal was enlarged to obtain 2mm-diameter standardized cavities. The samples were randomly divided in 5 groups, and the cavities filled with: ProRoot MTA (Group 1), White MTA (Group 2), MTA BIO (Group 3), white Portland cement with 20% of bismuth oxide (CP1) (Group 4), and white Portland cement with 20% of bismuth oxide and 10% calcium chloride (CP2) (Group 5). The samples were immediately placed in plastic vials containing 15 mL of PBS for 2 months at 37ºC. The PBS solution was collected and replaced every 5 days. After each replacement, the precipitates were collected, washed, desiccated and weighed. Calcium ions release and pH of the collected solution were monitored at 5, 15, 25 e 35 days. The samples were processed for SEM observation. Data obtained were statistically analyzed with 5% level of significance. Precipitates of carbonated apatite were observed in all the samples, along with the presence of an interfacial layer between the cement and the dentinal wall. Tags reproducing demineralized tubular dentin were observed from the interfacial layer. ProRoot MTA and MTA BIO cements produced the overall highest amount of precipitates, reached higher pH values, and released more calcium ions at all time intervals. ProRoot MTA, White MTA, MTA BIO and white Portland cements have dissolved, releasing some of their major components, promoting the precipitation of carbonated apatite and the formation of an interfacial layer with tags

Análise da sinalização molecular da resposta inflamatória e do processo de biomineralização promovidos pela implantação de proroot MTA e hidróxido de cálcio em tecido subcutâneo de camundongos

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Programa de Pós-graduação em Odontologia, Florianópolis, 2009O objetivo deste estudo foi avaliar a resposta tecidual e a biomineralização que ocorre após a implantação, em tecido subcutâneo de camundongos, de tubos de dentina preenchidos com ProRoot MTA ou pasta de hidróxido de cálcio (HC). Tubos de dentina com 5,3 mm de diâmetro externo, 1,3 mm de diâmetro interno e 5,0 mm de comprimento foram confeccionados a partir de 83 dentes humanos. Os tubos foram divididos aleatoriamente e preenchidos com ProRoot MTA, HC ou mantidos vazios. Quatro sítios de implantação foram realizados no tecido subcutâneo dorsal de 55 camundongos. Em 3 desses sítios foram implantados um tubo preenchido com MTA, um tubo preenchido com HC ou um tubo vazio. O quarto sítio foi utilizado para observar a resposta inflamatória induzida pelo ato cirúrgico (Sham). Decorridos 12h, 1, 3, 7, 15, 30 e 60 dias, foi realizada a eutanásia dos animais. Os tecidos subcutâneos foram removidos para dosagem de citocinas teciduais, análise histológica e imunoistoquímica e os tubos de dentina foram processados para avaliação em MEV. Os dados foram analisados estatisticamente por meio de ANOVA de duas vias seguido pelo teste de Bonferroni em um nível de significância de 5%. Os achados mostraram que em 12h e nos dias 1 e 3, os níveis teciduais das citocinas TNF-a, IL-1ß e IL-10 apresentaram-se elevados nos tecidos em contato com tubos de dentina preenchidos com MTA ou HC, quando comparados com os em contato com o tubo vazio ou o Sham. Em 12h o MTA estimulou uma expressão significativamente maior de TNF-a, quando comparado ao HC. A análise imunoistoquímica mostrou que a maior expressão de MPO, NF- B, COX-2, iNOS e VEGF foi no dia 1 para todos os grupos. O MTA estimulou, no dia 1, uma expressão significativamente maior de COX-2 quando comparado ao HC. Na visualização em MEV, foi possível observar a presença de aglomerados similares à apatita depositados sobre as fibras colágenas a partir de 12h pós-implantação. A deposição de precipitados aumentou ao longo do tempo, formando uma camada compacta de apatita já aos 7 dias pós-implantação. Na análise da interface MTA-dentina, a mineralização intratubular foi observada a partir das primeiras 12h pós-implantação, sendo que os prolongamentos de apatita se tornaram maiores e mais compactos ao longo do tempo. O HC promoveu um processo de mineralização intratubular com a formação de prolongamentos mais curtos e em menor densidade. Foi possível concluir que o MTA e o HC induzem um ambiente pró-inflamatório e pró-reparo, sendo mais precoce com o MTA. Simultaneamente à resposta inflamatória aguda, o processo de biomineralização ocorreu na interface biomaterial-dentina-tecido, promovendo a formação de uma camada de apatita que permitiu a integração do biomaterial ao ambiente receptor

Inmunoexpresión de ALDH1A1, FGFR2, CD44 y Caspasa-3 en Carcinoma Oral de Células Escamosas y Leucoplasias: un estudio piloto

ABSTRACT: Current research highlighted the importance to recognize feasible biomarkers for early diagnoses and treatment in oral cancer. Our study analyzed the expression and spatial distribution of ALDH1A1, FGFR2, caspase-3, and CD44 in Oral Squamous Cell Carcinoma (OSCC) and leukoplakia with and without oral mucosal dysplasia. Paraffin-embedded samples of OSCC (n=5), leukoplakia with (n=5) and without (n=5) dysplasia obtained by incisional biopsies were processed using conventional histochemical techniques. Immunohistochemistry was performed using antibodies against ALDH1A1, FGFR2, caspase-3, and CD44. Images of the immunohistochemically stained tissue sections were analyzed according to the intensity of the immunostaining of each marker and classified in Scores. The Kruskal-Wallis test was performed (p≤0.05). Our results demonstrated a statically difference in the expression of all immunomarkers between OSCC and leukoplakia without dysplasia, being more significant in FGFR2 and ALDH1A1. Within the limitations of this study, our data showed that all biomarkers were overexpressed in OSCC and leukoplakia with oral mucosa dysplasia, suggesting that the presence of dysplasia is a significant clinic-pathologic predictor for malignant transformation.RESUMEN: La actual evidencia científica enfatiza la importancia de reconocer biomarcadores viables para el diagnóstico y tratamiento temprano del cáncer oral. Nuestro estudio piloto analizó la expresión y distribución espacial de ALDH1A1, FGFR2, caspasa-3 y CD44 en carcinoma oral de células escamosas (COCE) y en leucoplasia con o sin displasia de la mucosa oral. Las muestras incluidas en parafina de COCE (n=5), con (n=5) y sin (n=5) displasia fueron obtenidas mediante biopsias incisionales, las cuales se procesaron utilizando técnicas histoquímicas convencionales. El análisis inmunohistoquímico se realizó utilizando anticuerpos contra ALDH1A1, FGFR2, caspasa-3 y CD44. Las imágenes de las secciones de cada muestra fueron analizadas según la intensidad de inmunoexpresión de cada marcador y se clasificaron en diferentes escalas (scores). Se realizó la prueba de Kruskal-Wallis (valores de p<0,05). Nuestros resultados demostraron una diferencia estadística en la expresión de todos los inmunomarcadores entre COCE y las muestras con leucoplasia sin displasia, siendo más significativa en FGFR2 y ALDH1A1. Considerando las limitaciones de este estudio, los datos sugieren que la presencia de displasia en la mucosa oral es un importante predictor clínico-patológico de transformación maligna.Universidad de Costa Rica/[440-B9-300]/UCR/Costa RicaUCR::Vicerrectoría de Docencia::Salud::Facultad de Odontologí

Mineral Trioxide Aggregate and Calcium Hydroxide Promotes In Vivo Intratubular Mineralization

Literature showed that the interaction of Mineral Trioxide Aggregate (MTA) with dentin in phosphate-buffered saline (PBS) promotes a biomineralization process that leads to the formation of an interfacial layer with mineralized structures at the cement-dentin interface. Thus, we investigated the in vivo biomineralization process promoted by MTA and Ca(OH)² with dentin. Human dentin tubes filled with ProRoot MTA, Ca(OH)²  or kept empty were implanted in subcutaneous tissues in the back of mice. After 12h, 1, 3, 7, 15, 30 and 60 days, the dentin tubes were processed for Scanning Electron Microscope (SEM) observations. SEM examination showed the presence of apatite-like clusters on collagen fibrils over the surface of tubes containing the biomaterials. This mineral deposition was more extensive and compact through time. At day 7, a compact layer of apatite was formed. The MTA/Ca(OH)² -dentin interface showed intratubular mineralization as early as 12h post-implantation. MTA and Ca(OH)²  in an in vivo environment promoted a biomineralization process with dentin, simultaneously to the acute inflammatory response. MTA triggered an earlier and denser interfacial layer.

Análisis de diferentes protocolos de irrigación y su efecto en la permeabilidad y selle radicular de piezas tratadas endodónticamente: estudio ex vivo

Seminario de graduación (licenciatura en odontología)UCR::Vicerrectoría de Docencia::Salud::Facultad de Odontologí

Social inequality in incidence and mortality of malignant neoplasms of lip, oral cavity and pharynx: Is Costa Rica an international paradox?

Objectives: Low socioeconomic position (SEP) has been associated with higher incidences and mortality of lip, oral cavity and pharynx (LOP) cancers in the vast majority of countries with available data. The origins of health inequalities in cancer are socioeconomic, although they vary by time and country. Evidence from Low-and Middle-income Countries (LMICs) remains scarce. This study aims to identify and describe socioeconomic inequalities in LOP cancers incidence and mortality in Costa Rica. The hypothesis tested is that people leaving in low-SEP districts in Costa Rica have greater incidence and mortality rates of lip, oral cavity and pharynx cancers. Methods: The 10th revision of the International Classification of Diseases (ICD-10) was used to define cancer sites. Data come from a national population-based Cancer Registry with 100% completeness to study incidence. Incidence rate included all new cases of LOP cancer diagnosed from January 1, 2011, and December 31, 2015, for a total of 2 798 517 individuals, 13 832 524 years of follow-up and 601 LOP cases. Mortality rate was extracted from the National Death Index, including 2 739 733 individuals, 23 950 240 person-years of follow-up and 586 LOP cancer deaths, from January 1, 2010, to December 31, 2018. The 2011 Census (with 94% of Costa Rican inhabitants) was used to characterize the urbanicity and wealth of 477 districts. Survival models were performed for both incidence and mortality, allowing to consider existing competitive risks. Cox models were used for incidence, and parametric survival models based on a Gompertz distribution for mortality. Results: The study found that people who lived in the most socioeconomically disadvantaged areas had lower probabilities of developing LOP cancers than people in the richest districts. The same pattern for mortality, however, was not significant. Conclusions: The hypothesis that incidence and mortality of LOP cancers will show a positive social gradient was not confirmed in this study, contradicting the existing literature. This could be explained by the social distribution of risky health behaviours, more frequent in socially advantaged populations.Universidad de Costa RicaUCR::Vicerrectoría de Docencia::Salud::Facultad de OdontologíaUCR::Vicerrectoría de Docencia::Salud::Facultad de Medicina::Escuela de Salud PúblicaUCR::Vicerrectoría de Docencia::Salud::Facultad de Medicina::Escuela de Medicin

Push-Out Bond Strength, Characterization, and Ion Release of Premixed and Powder-Liquid Bioceramic Sealers with or without Gutta-Percha

Objective. To evaluate the push-out bond strength of premixed and powder-liquid bioceramic sealers with or without gutta-percha (GP) cone. Materials and Methods. Radicular dentin samples were prepared from 80 single-rooted human teeth. After root canal preparation using ProTaper® and irrigation with NaOCl and EDTA, teeth were divided according to the root canal sealer (n=20): AH Plus®, EndoSequence® BC Sealer™, ProRoot® Endo Sealer, and BioRoot™ RCS. Samples were randomly divided into two subgroups (n=10): GP-S: root canal filling using the single-cone technique, or S: filling with only sealer. Specimens were kept at 37°C and 100% humidity in calcium-free PBS for 30 days. The push-out bond strength was measured in MPa. Fractured specimens were observed at 25x to evaluate the type of failure. pH and calcium ion release were measured at different experimental periods. Raman and SEM-EDAX analyses were performed for root canal sealers. Data were analysed using three-way analysis of variance (ANOVA) and post hoc Tukey test at a significance of P<0.05. Results. Push-out bond strength was greater for samples obturated with only sealers (S) than samples obturated with the single-cone technique (GP-S) (P<0.05). BioRoot™ RCS had greater bond strength than EndoSequence® BC Sealer™. Adhesive failures between cement and gutta-percha cone (87.5%) were predominant in the GP-S. Cohesive failures were predominant for S (80%). BioRoot™ RCS and ProRoot® ES presented higher alkalinization potential than the premixed sealer (EndoSequence® BC Sealer™). Powder-liquid bioceramic sealers (BioRoot™ RCS and ProRoot® ES) released the highest cumulative amount of calcium (28.46 mg/L and 20.05 mg/L). Conclusion. Push-out test without gutta-percha cone presents higher bond strength for bioceramic sealers. Powder-liquid calcium silicate-based sealers present greater bioactivity related to alkalinization potential and calcium ion release

Efficacy of Endodontic Treatment on the Persistence of Selected Endodontic Pathogens and on Radiographical Periapical Healing

The objective of this clinical study was to evaluate by polymerase chain reaction (PCR) the antimicrobial efficacy and the outcome of an endodontic protocol treatment (EPT) performed by under-graduated dental students on infected root canals associated with periapical lesions. Fifty-six patients attending for treatment of pulp necrosis and apical periodontitis were included. A specific EPT approach was performed and DNA extracts were taken at the baseline (S1), after a disinfection-neutralization procedure (S2), post-chemomechanical preparation (S3) and after Intracanal medication (S4) for the presence of specific bacteria. The outcome of the EPT was assessed radiographically using the Periapical Index-system (PAI) after 18-month follow-up. An intergroup evaluation shows that when comparing S1 to S3, S1 to S4, S2 to S3, and S2 to S4, the presence of bacteria were significantly reduced (P &lt; 0.05). Finally, S4 was not significantly reduced when compared with S3 (P &gt; 0.05). The most prevalent species in their respect order were Actinomyces Israelii &gt; Enterococcus Faecalis &gt; Fusobacterium Nucleatum/Prevotella Nigrescens &gt; Phorphyromonas Endodontalis. After the 18-month follow-up, the overall success rate of root canal – treated teeth was of 88% (PAI 1 or 2). This In Vivo study demonstrated that EPT significantly reduced the number of cases with positive results for the studied bacteria, showing a profound positive impact in the outcome of endodontic treatment of teeth diagnosed with Pulp Necrosis and Apical Periodontitis.