Induction of root development and apical closure in permanent mandibular molar with irreversible pulpitis through total pulpotomy with application of mineral trioxide aggregate / Inducción del termino de desarrollo radicular y cierre apical en molar mandibular permanente con pulpitis irreversible a través de pulpotomía total con aplicación de agregado de trióxido mineral

Loss of teeth vitality when root formation is incomplete, results in weaker structures leaving them prone to fractures and unfavourable long-term prognosis. Apexogenesis is currently the treatment of choice in immature teeth and is indicated in vital teeth without pulpal pathologies. The treatment aims to eliminate the causal agent of the damage, and provide the necessary conditions to preserve vitality in the tooth and induce apical root closure. A 6-year-old male patient was treated at the Endodontics Clinic, Universidad de La Frontera upon complaining of acute pain in tooth 30. The tooth presented incomplete root development due to dental caries with pulp exposure and a diagnosis of irreversible symptomatic pulpitis. Total pulpotomy was performed with the application of Mineral Trioxide Aggregate and controlled at 1, 4, 6, 7 and 12 months, achieving root development and apical closure in the permanent molar. The result was comparable with studies that support this therapy in teeth with irreversible pulpitis. This work seeks to contribute to the existing evidence on the management of immature permanent teeth with irreversible pulpitis to induce root development and apical closure, and maintain pulp vitality.

La pérdida de vitalidad en dientes con formación radicular incompleta trae como resultado el debilitamiento de estos, dejándolos propensos a fracturas con un desfavorable pronóstico a largo plazo. Las terapéuticas actuales de regeneración pulpar en dientes inmaduros estan principalmente indicadas en cuadros de pulpitis irreversible y buscan eliminar el agente causal de daño y brindarle al diente las condiciones y estímulos necesarios para preservar vitalidad e inducir el cierre apical radicular. Un paciente de 6 años de edad y de sexo masculino, acude a la Clínica de Especialidad de Endodoncia de la Universidad de la Frontera, consultando por un dolor agudo en diente 4.6 el cual presentaba un desarrollo radicular incompleto producto de una caries con exposición pulpar con diagnóstico de Pulpitis Irreversible Sintomática. Se realiza una pulpotomia total con aplicación de Mineral Trioxide Aggregate y se controla a los 1, 4, 6 y 7 meses obteniendo un interesante resultado comparable con estudios que avalan dicha terapeutica en dientes con pulpitis irreversible. Este trabajo busca contribuir a la evidencia existente sobre el manejo de dientes permanentes inmaduros con cuadros de pulpitis irreversible para inducir el desarrollo radicular, cierre apical y mantener vitalidad pulpar.

Influence of pregnancy on the inflammatory process following direct pulp capping: a preliminary study in rats

Abstract The purpose of this study was to evaluate the inflammatory process following direct pulp capping during pregnancy. This experimental study involved 48 maxillary first molars of female Wistar rats. The procedures were performed in pregnant and non-pregnant animals (n =20 each). Direct pulp capping with mineral trioxide aggregate (MTA) and restoration with a light-cured resin composite was performed in half of exposed pulp specimens. In the other half of specimens, light-cured composite was placed directly on the exposed pulp. In the control groups (n=4 each), no intervention was performed. Animals were euthanized at 3 and 7 days. All sections (three per slide) were viewed under an optical microscope. One previously calibrated pathologist performed descriptive analysis and assigned scores for inflammatory response and tissue organization adjacent to the pulp exposure. The Kappa value for intra-examiner variability was 0.91. At 3 days, in animals treated with MTA, inflammatory infiltrate was absent in non-pregnant animals while mild inflammatory infiltrate was observed in some pregnant animals. The inflammatory response ranged from mild to severe in both groups treated with composite alone. At 7 days, the inflammatory response was more intense in pregnant than in non-pregnant animals treated with MTA; while this difference were not evident in animals treated with composite alone. In conclusion, pregnancy may not influence the inflammatory process following direct pulp capping with light-cured resin composite, which was always harmful to the pulp; while the tissue response after the direct pulp with MTA were more favorable in non-pregnant animals.

Resumo O objetivo deste estudo foi avaliar o processo inflamatório do tecido pulpar após o capeamento pulpar direto, realizado durante a gestação. Este estudo experimental envolveu 48 primeiros molares superiores de ratos Wistar fêmeas. Os procedimentos foram realizados em animais prenhes e não prenhes (n=20). Após as exposições pulpares, o capeamento pulpar direto foi efetuado com agregado trióxido mineral (MTA) ou restauração direta com resina composta. Nos grupos controle (n=4), nenhuma intervenção foi realizada. Os animais foram submetidos à eutanásia após 3 e 7 dias. Todos os cortes foram avaliados através de um microscópio ótico. Um patologista previamente calibrado realizou analise histológica descritiva e estabeleceu escores para intensidade da resposta inflamatória e para o grau de organização tecidual na região adjacente à exposição pulpar. O valor de Kappa intra-examinador foi 0,91. No período experimental de 3 dias, nos animais tratados com MTA, o infiltrado inflamatório estava ausente nos não prenhes, enquanto infiltrado inflamatório moderado estava presente nos animais prenhes. A resposta inflamatória variou de moderada a severa em ambos os grupos tratados apenas com resina composta. Após o periodo experimental de 7 dias, a resposta inflamatória foi mais intensa nos animais prenhes que nos não prenhes do grupo do MTA, enquanto esta diferença não foi tão evidente nos animais que receberam capeamento pulpar direto com resina composta. Pode-se concluir, que a gestação pode não exercer influência no processo inflamatório do tecido pulpar após proteção pulpar direta com resina composta; a qual foi sempre danosa aos tecidos pulpares. No entanto, a resposta tecidual ao capeamento pulpar com MTA foi mais favorável nos animais não prenhes.

Experimental Calcium Silicate-Based Cement with and without Zirconium Oxide Modulates Fibroblasts Viability

The aim of this study was to verify whether the use of zirconium oxide as a radiopacifier of an experimental calcium silicate-based cement (WPCZO) leads to cytotoxicity. Fibroblasts were treated with different concentrations (10 mg/mL, 1 mg/mL, and 0.1 mg/mL) of the cements diluted in Dulbecco's modified Eagle's medium (DMEM) for periods of 12, 24, and 48 h. Groups tested were white Portland cement (WPC), white Portland cement with zirconium oxide (WPCZO), and white mineral trioxide aggregate Angelus (MTA). Control group cells were not treated. The cytotoxicity was evaluated through mitochondrial-activity (MTT) and cell-density (crystal violet) assays. All cements showed low cytotoxicity. In general, at the concentration of 10 mg/mL there was an increase in viability of those groups treated with WPC and WPCZO when compared to the control group (p<0.05). A similar profile for the absorbance values was noted among the groups: 10 mg/mL presented an increase in viability compared to the control group. On the other hand, smaller concentrations presented a similar or lower viability compared to the control group, in general. A new dental material composed of calcium silicate-based cement with 20% zirconium oxide as the radiopacifier showed low cytotoxicity as a promising material to be exploited for root-end filling.

Resumo O objetivo deste estudo foi verificar se o uso do óxido de zircônia como radiopacificador de um cimento experimental à base de silicato de cálcio (WPCZO) levou a citotoxicidade. Os fibroblastos foram tratados com diferentes concentrações (10 mg/mL, 1 mg/mL e 0,1 mg/mL) dos cimento diluídos em meio Eagle modificado por Dulbecco (DMEM) durante períodos de 12, 24, e 48 horas. Os grupos testados foram: cimento Portland (WPC), cimento Portland branco com óxido de zircônio (WPCZO) e MTA Angelus branco (MTA). No grupo controle as células não foram tratadas. A citotoxicidade foi avaliada por meio da mitocondrial-atividade (MTT) e ensaio de densidade celular (cristal violeta). Todos os cimentos apresentaram baixa citotoxicidade. Em geral, na concentração de 10 mg/mL, houve um aumento na viabilidade desses grupos tratados com WPC e WPCZO quando comparado com o grupo controle (p <0,05). Um perfil semelhante para os valores de absorvância foi observado entre os grupos: 10 mg/mL apresentaram um aumento da viabilidade em relação ao grupo controle. Por outro lado, as concentrações menores apresentaram uma viabilidade semelhante ou inferior em comparação com o grupo controle, em geral. Um novo material odontológico composto de cimento à base de silicato de cálcio com 20% de óxido de zircônio, como o radiopacificador, apresentou baixa citotoxicidade e pode ser explorado como um material promissor para retrobturações.

Regenerative Endodontic Treatment as a Retreatment Option for a Tooth with Open Apex - A Case Report

Abstract: Treatment of non-vital immature teeth with apical periodontitis has always been a challenge in Endodontics. Regenerative endodontic treatment (RET) has been successfully used for the management of these cases. The aim of this study is to present a case of RET used for the retreatment of a previously endodontically treated permanent tooth with an open apex. A 14-year-old boy with a poor endodontic treatment done on his maxillary right central incisor developed symptomatic apical periodontitis. Radiographically, incomplete root development with thin dentinal walls and an open apex were evident. After accessing and removing previous filling materials, the canal was copiously irrigated with 2.5% sodium hypochlorite. A triple antibiotic paste was placed inside the canal and left for 15 days. After removal of the antibiotic mixture, bleeding was induced into the canal by passing a hand file out of the apex. A collagen membrane barrier was placed over the blood clot, followed by sealing with mineral trioxide aggregate. Access was sealed with permanent filling materials. Clinical examination at 12, 24 and 36 months revealed no symptoms. Radiographic examination showed resolution of the periapical lesion and apical closure. Sensitivity tests with cold and an electric pulp test elicited a negative response at all recall periods. On the basis of long-term results, RET may be an effective option for the retreatment of an immature permanent tooth with a failed previous treatment and periapical periodontitis.

Root Reconstructed with Mineral Trioxide Aggregate and Guided Tissue Regeneration in Apical Surgery: A 5-year Follow-up

Apical surgery should be considered as the last treatment option and employed when conventional endodontic treatment does not provide the expected result. In teeth undergoing apical surgery, the type of retrograde filling material is one of the factors interfering with the repair of periapical tissues. The material in intimate contact with the periapical tissues plays a fundamental role in the repair process. Several materials have been studied and indicated for use in apical surgery procedures, but the mineral trioxide aggregate (MTA) is still the most frequently used one. Guided tissue regeneration (GTR) techniques have been proposed as an adjunct to apical surgery to enhance bone healing. Here is reported a clinical case in which apical surgery was performed in conjunction with MTA-based root reconstruction of the maxillary right second incisor. After the apical surgery, a root-end cavity was prepared at the vestibular face of the involved tooth and filled with MTA. A bovine bone graft and a cortical collagen membrane were placed on the bone defect. After 5 years, clinical and radiographic assessments showed that the treatment was successful. It may be concluded that MTA presents favorable characteristics in adverse conditions and can be used in conjunction with GTR in cases involving root reconstruction.

A cirurgia apical deve ser considerada como a última opção de tratamento, e realizada quando o tratamento endodôntico convencional não proporciona o resultado esperado. Em dentes submetidos à cirurgia apical, o tipo de material retro-obturador é um dos fatores que interferem no reparo dos tecidos periapicais. O material em íntimo contato com os tecidos periapicais desempenha um papel fundamental no processo de reparo. Vários materiais têm sido estudados e indicados para o uso em procedimentos de cirurgias apicais, entretanto o agregado de trióxido mineral (MTA) ainda é o mais frequentemente utilizado. A regeneração tecidual guiada (GTR) tem sido proposta como um auxiliar na cirurgia apical para melhorar a formação óssea. Aqui é relatado um caso clínico em que a cirurgia apical foi realizada em conjunto com a reconstrução radicular do incisivo lateral superior esquerdo com MTA. Após a cirurgia apical, foi preparada uma retro-cavidade na parede vestibular e o dente envolvido foi obturado com MTA. Um enxerto de osso bovino e uma membrana de colágeno cortical foram colocados no defeito ósseo. Após 5 anos, avaliações clínica e radiográfica mostram que o tratamento foi bem sucedido. Pode-se concluir que o MTA apresenta características favoráveis em condições adversas e que pode ser usado em conjunto com GTR em casos envolvendo reconstrução radicular.

Apical Barrier Formation After Incomplete Orthograde MTA Apical Plug Placement in Teeth with Open Apex - Report of Two Cases

Two cases are reported in which incomplete placement of 4 mm mineral trioxide aggregate (MTA) plug was performed unintentionally at the apical third of permanent immature teeth with open apex and apical periodontitis. As confirmed radiographically, there were gaps between MTA and dentinal walls along the MTA-dentin interface. After setting of MTA was confirmed, endodontic treatment was completed and access was sealed with composite resin. At 6 to 16 months follow-up examinations, formation of dentin in contact with the MTA surface, as well as apical closure and periapical healing were ideied radiographically for both cases. The results of these cases showed that apical barrier formation and complete periapical healing is possible despite the incomplete apical placement of the MTA plug. This might be due to the biological properties of the MTA. Even so, an incomplete three-dimensional placement of the filling material is not advocated.

Efeito do silício na intensidade da cercosporiose e na nutrição mineral de mudas de cafeeiro / Effect of silicon on the intensity of brown eye spot and on the mineral nutrition of coffee seedlings

O presente trabalho objetivou estudar o efeito do silício na intensidade da cercosporiose e na nutrição mineral de mudas de cafeeiro. No experimento 1, testou-se seis doses de ácido silícico (0, 0,5; 1; 2; 4 e 6 g kg­1 de solo) em mudas da cultivar Catuaí Vermelho IAC 99 inoculadas com o fungo Cercospora coffeicola. No experimento 2, foram realizadas microanálises de raios-X para a avaliação de nutrientes presentes nas folhas das mudas de cafeeiro das cultivares Topázio MG1190 e Icatu Precoce IAC 3282, inoculadas e não inoculadas com C. coffeicola, com e sem silicato de cálcio (1 g kg-1 de solo). Com o aumento das doses de ácido silícico observou-se redução na área abaixo da curva de progresso do número de lesões por folha (AACPNLF), redução linear nos teores foliares de magnésio e fósforo e aumento nos teores de enxofre e cobre. Os teores foliares de boro apresentaram comportamento quadrático, diminuindo com o aumento das doses de ácido silícico e aumentando a partir da dose de 4 g kg-1 de solo. Em microanálise de raio X, mudas de cafeeiro com cercosporiose apresentam menores picos de potássio e cálcio, independente da cultivar utilizada.

Our objective was to verify the effect of silicon on the intensity of brown eye spot and on the mineral nutrition of coffee seedlings. In the first experiment, 6 doses of silicic acid (0, 0.5, 1, 2, 4 and 6 g kg-1 soil) were tested using a complete randomized block design with 4 replicates with 6 coffee seedlings cultivar Catuaí Vermelho IAC 99 inoculated with the fungus Cercospora coffeicola. In the second experiment, X-ray microanalysis in a scanning electron microscope was performed on 2 coffee cultivars (Topazio MG1190 and Icatu Precoce IAC 3282), inoculated and non-inoculated with C. coffeicola, treated and untreated with calcium silicate (1 g kg-1 of soil). With the increase of the silicic acid doses, there was observed a reduction in the area under the disease progress curve of the number of lesions per leaf (AUPCNLL), coupled with a linear reduction in the foliar contents of magnesium and phosphorus as well as an increase in the contents of sulfur and copper. The foliar contents of boron presented a quadratic behavior, decreasing with the increase of silicic acid and increasing with the dose of 4 g kg-1 of soil. In X-ray microanalysis, coffee seedlings with brown eye spot presented lower peaks of potassium and calcium, regardless of the cultivar used.