Experimental nano calcium aluminate/tri calcium silicate root repair: Synthesis, physical and mechanical properties compared to mineral trioxide aggregate and Biodentine / Reparo radicular experimental de nano aluminato de cálcio/silicato de tri cálcio: Síntese, propriedades físicas e mecânicas em comparação com agregado de trióxido mineral e Biodentine

Objective: Endodontic perforation is a challenging mishap that should be repaired with a biocompatible material, Mineral trioxide aggregate (MTA) and Biodentine are the most commonly used repair materials. However, these materials are expensive, (MTA) has prolonged setting time and difficult manipulation. The purpose of this study is to prepare the experimental nano calcium-aluminate/tri-calcium-silicate (CA/C3S) material and comparing its physical properties with biodentine and MTA, to evaluate the experimental material eligibility to compete the commercial repair materials. And to perform part two (animal study) that will evaluate the cytotoxicity, the biocompatibility and the efficacy of (CA/C3S) in furcal perforation repair compared to diode laser. Material and Methods: A mixture of calcium carbonate and aluminum oxide was used to formulate calcium aluminate phase (CA), tri-calcium-Silicate phase (C3S) was formulated by firing of calcium carbonate and quartz. The produced powders were investigated by X-ray diffraction, then (CA) and (C3S) mixed with water.(CA/ C3S) compared with MTA and biodentine for setting-time, micro-hardness, dimensional-stability and solubility. Results: Mean setting time of (CA/C3S) was (32.70±0.75min) which is significantly higher than MTA and Biodentine. The Mean microhardness of (CA/C3S) was (56.50±7.41VHN) which has no statical difference with MTA and Biodentine. Solubility results showed weight increase for (CA/C3S) as following (6.29±3.05)and loss of weight for MTA and Biodentine. The percentage of change in dimensions for(CA/C3S) increased as following (0.64±0.78) while decreased for MTA and Biodentine. Conclusion: The experimental (CA/C3S) material showed good microhardness, dimensional stability and acceptable setting time that could be improved in further work (AU)

Objetivo: A perfuração endodôntica é um percalço desafiador que deve ser reparado com um material biocompatível, Agregado de trióxido mineral (MTA) e Biodentina são os materiais de reparo mais comumente usados. No entanto, esses materiais são caros, (MTA) tem tempo de presa prolongado e difícil manipulação. O objetivo deste estudo é preparar o material experimental de nano aluminato de cálcio/silicato tricálcico (CA/C3S) e comparar suas propriedades físicas com biodentina e MTA, para avaliar a elegibilidade do material experimental para competir com os materiais de reparo comerciais. E realizar a segunda parte (estudo animal) que avaliará a citotoxicidade, a biocompatibilidade e a eficácia do (CA/C3S) no reparo de perfuração de furca em comparação ao laser de diodo.Material e Métodos: Uma mistura de carbonato de cálcio e óxido de alumínio foi usada para formular a fase de aluminato de cálcio (CA), a fase tri-cálcio-silicato (C3S) foi formulada por queima de carbonato de cálcio e quartzo. Os pós produzidos foram investigados por difração de raios X, em seguida (CA) e (C3S) misturados com água. (CA/ C3S) comparados com MTA e biodentina para tempo de presa, microdureza, estabilidade dimensional e solubilidade. Resultados: O tempo médio de presa de (CA/C3S) foi (32,70±0,75min) que é significativamente maior que MTA e Biodentine. A microdureza média de (CA/C3S) foi (56,50±7,41VHN) que não tem diferença estática com MTA e Biodentine. Os resultados de solubilidade mostraram aumento de peso para (CA/C3S) conforme a seguir (6,29±3,05) e perda de peso para MTA e Biodentine. A porcentagem de mudança nas dimensões para (CA/C3S) aumentou como segue (0,64±0,78), enquanto diminuiu para MTA e Biodentine. Conclusão: O material experimental (CA/C3S) apresentou boa microdureza, estabilidade dimensional e aceitável tempo de presa, que pode ser melhorado em trabalhos futuros (AU)

Fracture resistance of simulated immature teeth reinforced with different mineral aggregate-based materials

Abstract This study assessed the fracture resistance of simulated immature teeth reinforced with calcium aluminate cement (CAC) or mineral trioxide aggregate (MTA) containing calcium carbonate nanoparticles (nano-CaCO3). The microstructural arrangement of the cements and their chemical constitution were also evaluated. Forty-eight canines simulating immature teeth were distributed into 6 groups (n=8): Negative control - no apical plug or root canal filling; CAC - apical plug with CAC; CAC/nano-CaCO3 - apical plug with CAC+5% nano-CaCO3; MTA - apical plug with MTA; MTA/nano-CaCO3 - apical plug with MTA+5% nano-CaCO3; and Positive control - root canal filling with MTA. The fracture resistance was evaluated in a universal testing machine. Samples of the cements were analyzed under Scanning Electron Microscope (SEM) to determine their microstructural arrangement. Chemical analysis of the cements was performed by Energy Dispersive X-ray Spectroscopy (EDS). The fracture resistance of CAC/nano-CaCO3 was significantly higher than the negative control (p<0.05). There was no significant difference among the other groups (p>0.05). Both cements had a more regular microstructure with the addition of nano-CaCO3. MTA samples had more calcium available in soluble forms than CAC. The addition of nano-CaCO3 to CAC increased the fracture resistance of teeth in comparison with the non-reinforced teeth. The microstructure of both cements containing nano-CaCO3 was similar, with a more homogeneous distribution of lamellar- and prismatic-shaped crystals. MTA had more calcium available in soluble forms than CAC.

Resumo Este estudo avaliou a resistência à fratura de dentes imaturos simulados reforçados com cimento de aluminato de cálcio (CAC) ou trióxido agregado mineral (MTA) contendo nanopartículas de carbonato de cálcio (nano-CaCO3). O arranjo microestrutural dos cimentos e sua constituição química também foram avaliados. Quarenta e oito caninos simulando dentes imaturos foram distribuídos em 6 grupos (n=8): Controle negativo - sem plug apical ou obturação do canal radicular; CAC - plug apical com CAC; CAC/nano-CaCO3 - plug apical com CAC + 5% nano-CaCO3; MTA - plug apical com MTA; MTA/nano-CaCO3 - plug apical com MTA + 5% nano-CaCO3; e Controle positivo - obturação dos canais radiculares com MTA. A resistência à fratura foi avaliada em máquina universal de ensaios. Amostras dos cimentos foram analisadas em Microscópio Eletrônico de Varredura (MEV) para determinar seu arranjo microestrutural. A análise química dos cimentos foi realizada por Espectroscopia de Energia Dispersiva de Raio-X (EDS). A resistência à fratura de CAC/nano-CaCO3 foi significativamente maior do que o controle negativo (p<0,05). Não houve diferença significativa entre os outros grupos (p>0,05). Ambos os cimentos apresentaram microestrutura mais regular com a adição de nano-CaCO3. As amostras de MTA apresentaram mais cálcio disponível em formas solúveis do que CAC. A adição de nano-CaCO3 ao CAC aumentou a resistência à fratura dos dentes em comparação aos dentes não reforçados. A microestrutura de ambos os cimentos contendo nano-CaCO3 foi semelhante, com uma distribuição mais homogênea de cristais de formato lamelar e prismático. MTA apresentou mais cálcio disponível nas formas solúveis do que CAC.

Simvastatin-enriched macro-porous chitosan-calcium-aluminate scaffold for mineralized tissue regeneration

Abstract The present study evaluated the odontogenic potential of human dental pulp cells (HDPCs) exposed to chitosan scaffolds containing calcium aluminate (CHAlCa) associated or not with low doses of simvastatin (SV). Chitosan scaffolds received a suspension of calcium aluminate (AlCa) and were then immersed into solutions containing SV. The following groups were established: chitosan-calcium-aluminate scaffolds (CHAlCa - Control), chitosan calcium-aluminate with 0.5 µM SV (CHAlCa-SV0.5), and chitosan calcium-aluminate with 1.0 µM SV (CHAlCa-SV1.0). The morphology and composition of the scaffolds were evaluated by SEM and EDS, respectively. After 14 days of HDPCs culture on scaffolds, cell viability, adhesion and spread, mineralized matrix deposition as well as gene expression of odontogenic markers were assessed. Calcium aluminate particles were incorporated into the chitosan matrix, which exhibited regular pores homogeneously distributed throughout its structure. The selected SV dosages were biocompatible with HDPCs. Chitosan-calcium-aluminate scaffolds with 1 µM SV induced the odontoblastic phenotype in the HDPCs, which showed enhanced mineralized matrix deposition and up-regulated ALP, Col1A1, and DMP-1 expression. Therefore, one can conclude that the incorporation of calcium aluminate and simvastatin in chitosan scaffolds had a synergistic effect on HDPCs, favoring odontogenic cell differentiation and mineralized matrix deposition.

Resumo O presente estudo avaliou o potencial odontogênico de células da polpa dental humana (HDPCs) em contato com scaffolds de quitosana contendo aluminato de cálcio (CHAlCa) associado ou não à baixas dosagens de sinvastatina (SV). Scaffolds de quitosana receberam uma suspensão de aluminato de cálcio e foram imersos em soluções contendo a droga. Foram estabelecidos três grupos experimentais: scaffolds de quitosana e aluminato de cálcio (CHAlCa - controle), scaffolds de quitosana-aluminato de cálcio com 0.5 µM SV (CHAlCa-SV0.5), e quitosana-aluminato de cálcio com 1.0 µM SV (CHAlCa-SV1.0). A morfologia e composição foram avaliados por MEV e EDS, respectivamente. Após 14 dias do cultivo das HDPCs sobre os scaffolds, foram avaliados a viabilidade celular, adesão e espalhamento, deposição de matriz mineralizada e expressão gênica de marcadores odontogênicos. Observou-se que as partículas de aluminato de cálcio foram incorporadas à matriz de quitosana, a qual exibiu poros regulares distribuídos por toda sua estrutura. As dosagens selecionadas de sinvastatina foram biocompatíveis com as HDPCs. A concentração de 1 µM de SV induziu intensa expressão de fenótipo odontoblástico pelas HDPCs, demonstrando aumento da deposição de matriz mineralizada e maior expressão de ALP, Col1A1 e DMP-1. Portanto, podemos concluir que a incorporação de aluminato de cálcio e sinvastatina em scaffolds de quitosana apresentou um efeito sinérgico nas HDPCs, favorecendo a diferenciação celular e deposição de matriz mineralizada.

Repair of Bone Defects with Chitosan-Collagen Biomembrane and Scaffold Containing Calcium Aluminate Cement

Abstract Innovative biomaterials can provide a promising new direction for the treatment of bone defects, stimulating a proper repair process, with no damage to adjacent tissues. The purpose of this in vivo study was to evaluate the biocompatibility and the osteoinductive capacity of chitosan-collagen biomembrane and scaffold containing calcium aluminate cement. Eighteen New Zealand white rabbits (Oryctolagus cuniculus) were distributed according to the experimental times of analysis (7, 15 and 30 days). Four bone defects were created in the rabbits calvaria, which were individually filled with the biomembrane, scaffold, blood clot (negative control) and autologous bone (positive control). Histopathological analysis was performed using optical microscope at 32´, 64´, 125´ and 320´ magnifications. Cell response to inflammation and new bone tissue formation was quantified using a score system. The biomembrane group presented greater inflammatory response at 15 days, with significant difference to autologous bone group (p<0.05). There was no statistically significant difference for foreign body type reaction among groups (p>0.05). Concerning new bone formation, linear closure of the defect area was observed more evidently in the group with autologous bone. The scaffold group presented similar results compared with the autologous bone group at 30 days (p>0.05). Both tested biomaterials presented similar biocompatibility compared with the control groups. In addition, the biomembrane and scaffold presented similar osteoinductive capacity, stimulating bone repair process in the course of the experimental time intervals.

Resumo Biomateriais inovadores podem fornecer uma promissora nova direção para o tratamento de defeitos ósseos, estimulando um processo de reparo adequado, sem danos aos tecidos adjacentes. O objetivo deste estudo in vivo foi avaliar a biocompatibilidade e a capacidade osteoindutora de uma biomembrana e um scaffold compostos por colágeno e quitosana, contendo cimento de aluminato de cálcio. Dezoito coelhos (New Zealand White, Oryctolagus cuniculus) foram distribuídos de acordo com os períodos experimentais de análise (7, 15 e 30 dias). Quatro defeitos foram criados na calvaria dos coelhos, que foram individualmente preenchidos com a biomembrana, scaffold, coágulo (controle negativo) e osso autólogo (controle positivo). A avaliação histopatológica foi realizada em microscópio óptico em aumentos de 32´, 64´, 125´ e 320´. A resposta celular à inflamação e à formação de novo tecido ósseo foi quantificada utilizando um sistema de escore. O grupo da biomembrana apresentou maior resposta inflamatória no período de 15 dias, com diferença significativa para o grupo do osso autólogo (p<0,05). Não houve diferença estatística significante para a reação do tipo corpo estranho entre os grupos (p>0,05). Em relação à neoformação óssea, observou-se fechamento linear da área do defeito, que foi mais evidente no grupo em que se utilizou o osso autólogo. O grupo scaffold apresentou resultados semelhantes ao grupo do osso autólogo no período de 30 dias (p>0,05). Ambos os biomateriais testados apresentaram biocompatibilidade similar em comparação com os grupos controle. Além disso, a biomembrana e o scaffold apresentaram capacidade osteoindutora similar, estimulando o reparo ósseo ao longo dos intervalos de tempo experimentais.

Cytotoxicity of New Calcium Aluminate Cement (EndoBinder) Containing Different Radiopacifiers

Abstract This study aimed to evaluate the cytotoxicity of a calcium aluminate cement (EndoBinder) containing different radiopacifiers, Bi2O3, ZnO or ZrO2, compared with Mineral Trioxide Aggregate (MTA). According to ISO 10993-12:2012 (E) recommendations, 0.2 g of each cement were applied in transwell inserts and placed in 24-well culture plates containing 1 mL of culture medium (DMEM). After 24 h of incubation, the extracts (DMEM containing components released from the cements) were applied to immortalized odontoblast-like MDPC-23 cells. Cell viability (MTT test), alkaline phosphatase activity (ALP), total protein production and cell morphology (Scanning Electron Microscopy - SEM) were evaluated. The volume of 50 µL of extract was used to determine the chemical elements released by the cements using Energy Dispersive Spectroscopy (EDS). The following groups were established (n=6): NC - negative control (without treatment); EB - EndoBinder without radiopacifier; EBBO - EndoBinder+Bi2O3; EBZnO - EndoBinder+ZnO; EBZrO - EndoBinder+ZrO2 and WMTA - White MTA. Data were subjected to statistical analysis (Kruskal-Wallis test, level of significance=5%). Cells exposed to the different versions of EndoBinder presented small reduction in viability, total protein production and ALP activity, with values similar to the NC and WMTA groups (p>0.05). Different elements (C, O, Na, Al, P, Si, Cl, Bi, K) released by the cements were detected in the extracts. However, the cells had no significant changes in their morphology. EndoBinder and MTA did not affect negatively the metabolism of the odontoblastic-like cells, showing it to be cytocompatible, irrespective of the used radiopacifier.

Resumo Este estudo avaliou a citotoxicidade de um cimento de aluminato de cálcio (EndoBinder) contendo diferentes radiopacificadores, Bi2O3, ZnO ou ZrO2, comparativamente ao trióxido mineral agregado (MTA). Seguindo a norma ISO 10993-12:2012 (E), 0,2 g de cada cimento foi aplicada em insertos transwell, que foram colocados em placas de cultura de 24 wells contendo 1 mL de meio de cultura (DMEM). Após 24 h de incubação, os extratos (DMEM contendo componentes liberados dos cimentos) foram aplicados sobre células pulpares imortalizadas MDPC-23. Viabilidade celular (teste de MTT), atividade da fosfatase alcalina (ALP), produção de proteína total e a morfologia das células (Microscópio Eletrônico de Varredura - MEV) foram avaliadas. Um volume de 50 µL do extrato foi utilizado para determinar, através de Espectroscopia de Energia Dispersiva (EDS), os elementos químicos liberados pelos cimentos. Os seguintes grupos foram estabelecidos (n=6): NC - controle negativo (sem tratamento); EB - EndoBinder sem radiopacificador; EBBO - EndoBinder+Bi2O3; EBZnO - EndoBinder+ZnO; EBZrO - EndoBinder+ZrO2 e WMTA - MTA branco. Os dados foram submetidos à análise estatística (teste de Kruskal-Wallis, nível de significância=5%). Células expostas às diferentes versões de EndoBinder apresentaram pequena redução na viabilidade, produção de proteína total e atividade da ALP, com valores semelhantes aos grupos NC e WMTA (p>0,05). Diversos elementos (C, O, Na, Al, P, Si, Cl, Bi, K) liberados pelos cimentos foram detectados nos extratos. Entretanto, as células não apresentaram alterações significativas em sua morfologia. EndoBinder e MTA, não afetaram negativamente o metabolismo das células odontoblastóides, mostrando-se citocompatíveis, independente do radiopacificador utilizado.

Effects of a novel calcium aluminate cement on the early events of the progressionof osteogenic cell cultures

The present study evaluated the progression of osteogenic cell cultures exposed to a novel calcium aluminate cement (CAC+) in comparison with the gold standard mineral trioxide aggregate (MTA). Cells were enzimatically isolated from newborn rat calvarial bone, plated on glass coverslips containing either CAC+ or a control MTA samples in the center, and grown under standard osteogenic conditions. Over the 10-day culture period, roundening of sample edges was clearly noticed only for MTA group. Although both cements supported osteogenic cell adhesion, spreading, and proliferation, CAC+-exposed cultures showed significantly higher values in terms of total cell number at days 3 and 7, and total protein content and alkaline phosphatase activity at day 10. The present in vitro results indicate that the exposure to CAC+ supports a higher differentiation of osteogenic cells compared with the ones exposed to MTA. Further experimental studies should consider CAC+ as a potential alternative to MTA when the repair of mineralized tissues is one of the desired outcomes in endodontic therapy.

O objetivo do presente estudo foi avaliar a progressão de cultura de células osteogênicas expostas a um novo cimento de aluminato de cálcio (CAC+) em comparação ao agregado de trióxido mineral (MTA). As células foram obtidas por digestão enzimática de calvária de ratos recém-nascidos, plaqueadas sobre lamínulas de vidro contendo em sua área central discos de CAC+ ou MTA e crescidas em condições osteogênicas por até 10 dias. Durante a cultura primária, observou-se o arredondamento das bordas das amostras de cimento apenas para MTA. Embora ambos os cimentos tenham permitido a adesão, o espraiamento e a proliferação celulares, as culturas crescidas em contato com CAC+ exibiram valores maiores de número total de células em 3 e 7 dias, e de conteúdo de proteína total e atividade de fosfatase alcalina em 10 dias. Os resultados indicam que a exposição ao CAC+ permite o desenvolvimento de uma proporção maior de células em estágios mais avançados da diferenciação osteoblástica, quando comparado ao MTA. Deve-se considerar em futuros estudos experimentais a utilização do CAC+ como um material alternativo ao MTA especialmente quando um dos objetivos do tratamento endodôntico é o de reparação dos tecidos mineralizados da região periapical.

The effects of calcium aluminate cement according to particle sizes on calvarial bone defects in rats / 대한치주과학회지

This present study was carried out to find the effects of calcium aluminate cement(CaO, Al2O3, CAC), which has been developed with bio-compatibility and mechanical properties, in biological environments. Two different particle sizes of CAC - 3.5micrometer vs. 212~250micrometer which is recommended in periodontal bone grafting procedures- were filled in 8mm calvarial defect in Sprague-Dawley rat. The specimens were examined histologically, especially the bone-cement interface and the response of surrounding tissues. The results are as follows; 1. In the control group, inflammatory cells were observed at 2 weeks. At 8 weeks, periosteum and dura mater were continuously joined together in the defect areas. But in the center of defect area were filled up with the loose connective tissues. 2. In the experimental group 1(212micrometer~250micrometer particle), immature bone was formed and outermost layer was surrounded by osteoid layer at 2 weeks. Osteoblasts were arranged between immature bone and osteoid layer. And, osteoid layer was remained until 8 weeks after surgery. 3. In the experimental group 2, periosteum and dura mater lost its continuity at 2 weeks. Scattering of CAC particles and infiltration of inflammatory cells were observed, which this findings deepened at 8 weeks. The result of this study shows that when calvarial defects in white rats are filled with calcium aluminate cement of 212~250micrometer, the materials are to be bio-compatible in growth and healing on surrounding tissues. When further researches are fulfilled, such as direct bone adhesion and bone regeneration ability, it's possible that CAC could be applied to various periodontology fields in the future.

The effect of LiF-maleic acid added calcium aluminate bone cement & CA-PMMA composite bone cement on the healing of calvarial defect6) / 대한치주과학회지

The purpose of this study was to evaluate histologically the effect of LiF-maleic acid added calcium aluminate(LM-CA) bone cement & CA-PMMA composite bone cement on the healing of calvarial defect in Sprague-Dawley rats. The critical size defects were surgically produced in the calvarial bone using the 8mm trephine bur. The rats were divided in three groups : In the control group, nothing was applied into the defect of each rat. LM-CA bone cement was implanted in the experimental group 1 and CA-PMMA composite bone cement was implanted in the experimental group 2. Rats were sacrificed at 2, 8 weeks after surgical procedure. The specimens were examined by histologic analysis, especially about the bone-cement interface and the response of surrounding tissue. The results are as follows; 1. In the control group, inflammatory infiltration was observed at 2 weeks. At 8 weeks, periosteum and dura mater were continuously joined together in the defect area. But the center of defect area was filled up with the loose connective tissue. 2. In the experimental group 1, the bonding between implanted bone cement and the existing bone was seen, which more increased in 8 weeks than 2 weeks. Inflammatory infiltration and the dispersion of implanted bone cement particles were seen in both 2 weeks and 8 weeks. 3. In the experimental group 2, implanted bone itself had a dimensional stability and no bonding between implanted bone cement and the existing bone was seen in both 2 weeks and 8 weeks. Implanted bone cement was encapsulated by fibrous connective tissue. In addition, inflammatory infiltration was seen around implanted bone cement. On the basis of these results, when LM-CA bone cement or CA-PMMA composite bone cement was implanted in rat calvarial defect, LM-CA bone cement can be used as a bioactive bone graft material due to ability of bonding to the existing bone and CA-PMMA can be used as a graft material for augmentation of bone-volume due to dimensional stability.