Cytotoxicity and cytokine production by calcium silicate-based materials on periodontal ligament stem cells

Abstract This study investigated the effect of three commercial calcium silicate-based materials (CSBM) on cytotoxicity and pro-and anti-inflammatory cytokines production in cultured human periodontal ligament stem cells (hPDLSCs). Culture of hPDLSCs was established and characterized. Extracts of Bio-C Sealer (Angelus, Londrina, PR, Brazil), MTA Fillapex (Angelus, Londrina, PR, Brazil) and PBS Cimmo HP (Cimmo Soluções em Saúde, Pouso Alegre, MG, Brazil) were prepared by placing cement specimens (5 x 3 mm) in culture medium. Then, the extracts were serially two-fold diluted (1, 1:2, 1:4, 1:8, 1:16) and inserted into the cell-seeded wells for 24, 48 and 72 h for MTT assays. TNF-α and IL-10 cytokines were quantified by ELISA at 24h-cell supernatants. Data were analyzed by ANOVA and Tukey's test (α = 0.05). All CSBM exhibited some cytotoxicity that varied according to extract concentration and time of evaluation. MTA Fillapex presented the highest cytotoxic effects with significant reduction of metabolic activity/cell viability when compared to Bio-C Sealer and Cimmo HP®. TNF-α was significantly upregulated by the three tested cements (p < 0.05) while only MTA Fillapex significantly upregulated IL-10 in comparison to control. Taken collectively, the results showed that PBS Cimmo HP®, Bio-C Sealer and MTA Fillapex present mild and transient cytotoxicity and slightly induced TNF-α production. MTA Fillapex upregulated IL-10 release by hPDLSCs.

Resumo Este estudo investigou o efeito de três materiais comerciais à base de silicato de cálcio (CSBM) na citotoxicidade e na produção de citocinas pró e antiinflamatórias em células-tronco do ligamento periodontal humano (hPDLSCs). Cultura de hPDLSCs foi estabelecida e caracterizada. Extratos de Bio-C Sealer (Angelus, Londrina, PR, Brasil), MTA Fillapex (Angelus, Londrina, PR, Brasil) e PBS Cimmo HP® (Cimmo Soluções em Saúde, Pouso Alegre, MG, Brasil) foram preparados com a colocação de espécimes dos cimentos (5 x 3 mm) em meio de cultura. Em seguida, os extratos foram diluídos (1, 1: 2, 1: 4, 1: 8, 1:16) e inseridos nos poços semeados de células para ensaio de citotoxicidade por meio de MTT por 24, 48 e 72 h. As citocinas TNF-α e IL-10 foram quantificadas por ELISA em sobrenadantes de células de 24 h. Os dados foram analisados por ANOVA e teste de Tukey (α = 0,05). Todos os CSBM exibiram alguma citotoxicidade que variou de acordo com a concentração do extrato e o tempo de avaliação. O MTA Fillapex apresentou os maiores efeitos citotóxicos com redução significativa da atividade metabólica / viabilidade celular quando comparado ao Bio-C Sealer e Cimmo HP®. O TNF-α foi regulado positivamente pelos três cimentos testados (p <0,05), enquanto apenas o MTA Fillapex regulou positivamente a liberação de IL-10 em comparação com o controle. Tomados em conjunto, os resultados mostraram que PBS Cimmo HP®, Bio-C Sealer e MTA Fillapex apresentam citotoxicidade leve e transitória e induziram a produção de TNF-α. O MTA Fillapex regulou positivamente a liberação de IL-10 por hPDLSCs.

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.

Tooth discoloration using calcium silicate-based cements for simulated revascularization in vitro

Abstract The endodontic revascularization may be an alternative treatment for necrotic immature teeth, however, several treatment steps may cause tooth discoloration. This study evaluated the use of three calcium silicate-based cements with different radiopacifying agents on the color alteration (∆E) of extracted premolars after simulation of revascularization. Forty single rooted extracted premolars were shaped with #1-6 gates Glidden drills, rinsed with sodium hypochlorite, and filled with fresh human blood. Three calcium silicate-based cements with different radiopacifying agents (bismuth oxide - CSBi, calcium tungstate - CSW, and zirconium oxide - CSZr) were applied over the blood clot (n=10). The control group received the application of a temporary zinc oxide-based cement (TFZn) (n=10). ∆E was measured with a spectrophotometer, using the L*a*b* color system of the International Commission on Illumination (CIELab), in different times: prior to the preparation of the access cavity (t0); right after treatment (t1); and after one (t2), two (t3), three (t4) and four (t5) months. The tooth site for color evaluation was standardized by silicon matrix, the color reading was performed 3 times per tooth, and the teeth were stored in 37º water between evaluations. ∆E, whiteness (WID index) and yellowness (b*) were evaluated. Data were subjected to one-way ANOVA and repeated measures ANOVA, followed by Tukey's post hoc test (α=0.05). All groups were similar in ∆E1 (t0-t1). The ∆E was the lowest and constant in the control group. In all evaluation times, CSBi presented the highest ∆E (p<0.01). CSW and CSZr were similar in all evaluated times and presented intermediate ∆E values. WID index from CSBi and CSW presented more distancing from 'white' reference. CSBi presented the greatest decrease in yellowness (b* value). The cement containing bismuth oxide presented the highest color alteration values. All tested calcium silicate-based cements presented clinically perceptible discoloration. Calcium tungstate and zirconium oxide may be used as alternative radiopacifiers to decrease tooth discoloration after endodontic tooth revascularization.

Resumo A revascularização endodôntica pode ser um tratamento alternativo para dentes imaturos necrosados, porém, várias etapas do tratamento podem causar alteração de cor dental. Este estudo avaliou o uso de três cimentos a base de silicato de cálcio com diferentes agentes radiopacificadores na alteração de cor (∆E) de pré-molares extraídos após a simulação de revascularização. Quarenta pré-molares unirradiculares extraídos foram conformados com brocas gates glidden #1-6, irrigados com hipoclorito de sódio, e preenchidos com sangue humano fresco. Três cimentos a base de silicato de cálcio com diferentes agentes radiopacificadores (óxido de bismuto - CSBi, tungstato de cálcio - CSW, e óxido de zircônio - CSZr) foram aplicados sobre o coágulo sanguíneo (n=10). O grupo controle recebeu a aplicação de um cimento temporário a base de óxido de zinco (TFZn) (n=10). ∆E foi medida com um espectrofotômetro, utilizando o sistema de cor L*a*b* da International Commission on Illumination (CIELab), em tempos diferentes: previamente ao preparo da cavidade de acesso (t0); logo após o tratamento (t1); e após um (t2), dois (t3), três (t4) e quatro (t5) meses. O local do dente para a avaliação de cor foi padronizado por uma matriz de silicone, a leitura da cor foi realizada 3 vezes por dente, e os dentes foram armazenados em água a 37ºC entre as avaliações. ∆E, 'clareamento' (índice WID) e tom amarelado (b*) foram avaliados. Os dados foram submetidos ao teste de ANOVA um fator e teste ANOVA de medidas repetidas, seguidos pelo teste post hoc de Tukey (α=0,05). Todos os grupos foram semelhantes em ∆E1 (t0-t1). A ∆E foi menor e constante no grupo controle. Em todos os tempos de avaliação, CSBi apresentou os maiores valores de ∆E (p<0.01). CSW e CSZr foram semelhantes em todos os tempos avaliados e apresentaram valores intermediários de ∆E. O índice WID de CSBi e CSW se distanciaram mais da referência 'branco'. CSBi apresentou maior diminuição no tom amarelado (valor de b*) os outros grupos. O cimento contendo óxido de bismuto apresentou os maiores valores de alteração de cor. Todos os cimentos testados apresentaram alteração de cor clinicamente perceptível. O tungstato de cálcio e óxido de zircônio podem ser usados como radiopacificares alternativos para a diminuição da alteração de cor dental após o processo de revascularização endodontica.

Effect of different dimensions of test samples on the volumetric change assessment of endodontic materials

Abstract New methodologies using micro-CT to evaluate solubility besides dimensional and morphological changes of endodontic materials are proposed. However, there is no standardization in the methods. The aim of this study was to assess the effect of different dimensions of test samples on volumetric change evaluation of different endodontic materials. AH Plus, FillCanal and Sealapex root canal sealers, Biodentine, IRM and MTA root-end filling cements were used in the tests. Samples of each material with a thickness of 1.5 mm and different diameters were manufactured: 6.3, 7.75, and 9.0 mm. The samples were scanned in micro-computed tomography (micro-CT) after setting and after 7 days of immersion in distilled water. The volumetric change was evaluated by means of the difference in the total volume of the specimens before and after immersion. Data were submitted to ANOVA and Tukey tests (p<0.05). The size of the samples did not affect the percentage of volumetric change of the materials (p>0.05). All sample sizes had greater volume loss for Sealapex among the sealers and Biodentine for the cements (p<0.05). In conclusion, Biodentine and Sealapex had the highest volume loss after immersion. Samples with 1.5 mm thickness, and diameters ranging between 6.3 and 9.0 mm can be used to assess the stability of endodontic materials using micro-CT without affecting the percentage of volumetric change.

Resumo Novas metodologias utilizando micro-CT são propostas para avaliar a solubilidade além de alterações dimensionais e morfológicas em materiais endodônticos. No entanto, não há padronização nos métodos. O objetivo deste estudo foi avaliar o efeito de diferentes dimensões de corpos de prova na avaliação da alteração volumétrica de diferentes materiais endodônticos. Os cimentos obturadores AH Plus, FillCanal e Sealapex e os cimentos retrobturadores Biodentine, IRM e MTA foram utilizados nos testes. Foram confeccionadas amostras de cada material com espessura de 1.5 mm e diâmetros diferentes: 6.3, 7.75 e 9.0 mm. As amostras foram escaneadas em microtomografia computadorizada (micro-CT) após a presa e após 7 dias de imersão em água destilada. A alteração volumétrica foi avaliada por meio da diferença no volume total dos corpos de prova antes e após a imersão. Os dados foram submetidos aos testes ANOVA e Tukey (p<0,05). A dimensão das amostras não afetou o percentual de alteração volumétrica dos materiais (p>0,05). Todos os diâmetros de amostra mostraram maior perda de volume para Sealapex entre os cimentos obturadores e Biodentine entre os cimentos retrobturadores (p<0,05). Como conclusão, Biodentine e Sealapex mostraram a maior perda volumétrica após a imersão. Amostras com 1.5 mm de espessura e diâmetros variando entre 6.3 e 9.0 mm podem ser usadas para avaliação da estabilidade de materiais endodônticos utilizando micro-CT, sem influenciar no percentual de alteração volumétrica.

Cytotoxicity, and antimicrobial and physicochemical properties of sealers incorporated with Uncaria tomentosa

Abstract This study evaluated the cytotoxicity, the antimicrobial and physicochemical properties of root canal sealers incorporated with phytotherapic Uncaria tomentosa (UT). Unmodified AH Plus (Dentsply, DeTrey, Germany) and MTA Fillapex (Angelus, Londrina, Brazil) were used as controls. UT was incorporated into AH Plus and MTA Fillapex, at concentrations of 2% and 5% of the total weight of these sealers (w/w). Flowability, setting time, and solubility were evaluated following ISO requirements. The pH values were measured at periods of 12, 24, 48 hours, and 7 days. The antimicrobial activity of the sealers against Enterococcus faecalis was analyzed by both direct contact tests in freshly prepared sealers, and after 7 days. The cytotoxicity of the samples was evaluated by the MTT assay, to check Balb/c 3T3 cell viability. The statistical analysis was performed by one-way ANOVA and Tukey's test (p < 0.05). The incorporation of UT was associated with a decrease in flow, for both sealers, an increase in AH Plus setting time, increase in MTA Fillapex pH values, and solubility (after 14 days), for both sealers (p < 0.05). Regarding the antibacterial evaluation, bacterial reduction was reported after incorporation of UT into both AH Plus and MTA Fillapex, up to 7 days after handling of the material (P<0.05). UT incorporation decreased the cytotoxic effects of both AH Plus and MTA Fillapex sealers in a way directly proportional to their respective concentrations (p < 0.05). In conclusion, UT can be added to both sealers to reduce their cytotoxicity, and improve their antibacterial effects, without compromising their original physicochemical properties.

Investigation of a modified hydraulic calcium silicate-based material - Bio-C Pulpo

Abstract This study evaluated the physicochemical, biological, and antimicrobial properties of a new hydraulic calcium silicate-based modified material, and compared it with MTA Repair HP and MTA Angelus. The materials were assessed regarding color luminosity (L), color change, radiopacity, setting time, and ISO 6876:2012 linear flow. Volumetric filling and volume change were evaluated using microcomputed-tomography (µCT). Chemical characterization after 28 days in Hank's Balanced Salt Solution (HBSS) and pH analysis were also assessed. Biological characterization of cytotoxicity and microbiological assessment were also undertaken. Shapiro-Wilk, ANOVA, Levene and post hoc analyses with Bonferroni correction were performed, adopting a 5% significance level (p <0.05). Bio-C Pulpo exhibited the highest L values after 90 days. All tested materials demonstrated color change during the analyses, and had radiopacity above 5 mm Al. MTA Repair HP set faster than Bio-C Pulpo, whereas the latter had the highest linear flow. MTA Repair HP had the highest volumetric filling in µCT analysis. Bio-C Pulpo showed the highest alkalinity during all tested periods, and the highest volumetric loss (above 9%), in comparison with MTA Repair HP and MTA Angelus. Bio-C Pulpo did not form calcium hydroxide after hydration. MTA Repair HP demonstrated the highest cytocompatibility, and Bio-C Pulpo, the highest cytotoxicity. No inhibition halos were observed for any material, and similar higher turbidity values were seen after direct contact. Composition additives used in Bio-C Pulpo modified its properties, and both the absence of calcium hydroxide deposition after hydration, and the related cytotoxicity of this material are of particular concern.

12-year follow-up of regenerative endodontic treatment of immature permanent upper incisors with acute abscess

Abstract This case report discusses the endodontic treatment of a 7-year-old girl who suffered trauma (intrusion) to the immature upper central incisors secondary to a fall from a bicycle. Thirty days after the accident the patient was brought by her mother for clinical and radiographic assessment with a chief complaint of swelling and tenderness to percussion and palpation. Acute apical abscess associated with immature teeth were diagnosed. A decision was made to perform regenerative endodontic treatment. Access cavities were made and the root canals were disinfected by irrigation with 2.5% sodium hypochlorite. Final irrigation was performed with 17% EDTA. Due to pain and presence of secretions, 2% chlorhexidine gel was applied as an intracanal medicament. Seven days later, at the second visit, the root canals were once again disinfected and the canals of the right and left permanent upper central incisors were filled with double antibiotic paste (metronidazole/ciprofloxacin) and calcium hydroxide paste, respectively. Zinc oxide was mixed in both pastes. At the third visit, after 21 more days, the pastes were removed and the periapical areas were stimulated with a #80 K-file to encourage clot formation within the pulp cavities. A mineral trioxide aggregate (MTA) paste cervical plug was placed and the teeth were restored with glass ionomer cement. Radiographs and CBCT scans demonstrated complete root formations. The patient has been followed for 12 years, with evidence of clinical success throughout.

Resumo Este relato de caso discute o tratamento endodôntico de uma menina de 7 anos que sofreu trauma nos incisivos centrais superiores imaturos, após queda de bicicleta. Trinta dias após o acidente, a paciente foi levada pela mãe para avaliação clínica e radiográfica com queixa principal de inchaço e sensibilidade à percussão e palpação. Foram diagnosticados abscessos apicais agudos em ambos os dentes. Foi decidido por realizar o tratamento endodôntico regenerativo. Após acessos coronários, os canais radiculares foram submetidos à protocolos de antissepsia com auxílio de irrigação com hipoclorito de sódio a 2,5% e EDTA 17%. Devido à dor e presença de secreções, foi utilizada medicação intracanal com clorexidina gel 2% por 7 dias. Na segunda sessão, os canais radiculares foram novamente submetidos aos procedimentos de antissepsia e os canais dos incisivos centrais superiores permanentes direito e esquerdo foram preenchidos com pasta antibiótica dupla (Metronidazol / Ciprofloxacina) e pasta de hidróxido de cálcio, respectivamente. Em ambas as pastas foi adicionado o óxido de zinco. Na terceira sessão, após mais 21 dias, as pastas foram removidas e as regiões periapicais foram estimuladas com lima K nº 80 para incentivar a formação de coágulos sanguíneos no interior das cavidades pulpares. Tampões cervicais de MTA foram adaptados e os dentes restaurados com cimento de ionômero de vidro resinoso. Radiografias e tomografias computadorizadas demonstraram formações radiculares completas. A paciente é acompanhada há 12 anos, com evidências clínicas e radiográficas de sucesso.

Biocompatibility, biomineralization, and maturation of collagen by rtr®, bioglass and dm bone® materials

Abstract This study evaluated the biocompatibility, biomineralization, and collagen fiber maturation induced by Resorbable Tissue Replacement (RTR®; β-tricalcium phosphate [TCP]), Bioglass (BIOG; bioactive glass), and DM Bone® (DMB; hydroxyapatite and β-TCP) in vivo. Sixty-four polyethylene tubes with or without (control group; CG) materials (n=8/group/period) were randomly implanted in the subcutaneous tissue of 16 male Wistar rats (four per rat), weighting 250 to 280 g. The rats were killed after 7 and 30 days (n=8), and the specimens were removed for analysis of inflammation using hematoxylin-eosin; biomineralization assay using von Kossa (VK) staining and polarized light (PL); and collagen fiber maturation using picrosirius red (PSR). Nonparametric data were statistically analyzed by Kruskal-Wallis and Dunn tests, and parametric data by one-way ANOVA test (p<0.05). At 7 days, all groups induced moderate inflammation (p>0.05). At 30 days, there was mild inflammation in the BIOG and CG, and moderate inflammation in the RTR and DMB groups, with a significant difference between the CG and RTR (p<0.05). The fibrous capsule was thick at 7 days and predominantly thin at 30 days in all groups. All materials exhibited structures that stained positively for VK and PL. Immature collagen fibers were predominant at 7 and 30 days in all groups (p>0.05), although DMB exhibited more mature fibers than BIOG at 30 days (p<0.05). RTR, BIOG, and DMB were biocompatible, inducing inflammation that reduced over time and biomineralization in the subcutaneous tissue of rats. DMB exhibited more mature collagen fibers than BIOG over a longer period.

Resumo Este estudo avaliou a biocompatibilidade, biomineralização e maturação das fibras de colágeno induzidas por Resorbable Tissue Replacement (RTR®; fosfato β-tricálcico [TCP]), Bioglass (BIOG; vidro bioativo) e DM Bone® (DMB; hidroxiapatita e β-TCP) in vivo. Sessenta e quatro tubos de polietileno com ou sem (grupo controle; GC) os materiais (n=8/grupo/período) foram implantados aleatoriamente em tecido subcutâneo de 16 ratos machos Wistar (quatro por rato), pesando entre 250 a 280g. Os ratos foram mortos após 7 e 30 dias (n=8), e as amostras foram removidas para análise da inflamação utilizando hematoxilina-eosina; avaliação da biomineralização utilizando coloração de von Kossa (VK) e luz polarizada (LP); e maturação das fibras colágenas, utilizando picrosirius red (PSR). Os dados não-paramétricos foram analisados pelos testes de Kruskal-Wallis e Dunn, e os paramétricos pelo teste de one-way ANOVA (p<0.05). Aos 7 dias, todos os grupos induziram inflamação moderada (p>0,05). Aos 30 dias, houve inflamação leve nos grupos BIOG e GC, e inflamação moderada nos grupos RTR e DMB, com diferença significativa entre os GC e RTR (p<0,05). A cápsula fibrosa foi espessa aos 7 dias, e predominantemente fina aos 30 dias em todos os grupos. Todos os materiais exibiram estruturas positivas para VK e LP. Fibras colágenas imaturas foram predominantes aos 7 e 30 dias em todos os grupos (p>0,05), embora o DMB exibiu fibras mais maduras do que o BIOG aos 30 dias (p<0,05). RTR, BIOG e DMB foram biocompatíveis, induzindo inflamação que reduziu com o tempo, e biomineralização no tecido subcutâneo de ratos. O DMB exibiu mais fibras colágenas maduras do que o BIOG em período mais longo.

Physicochemical properties of a bioceramic repair material - biomta

Abstract This study aimed to assess the physicochemical properties of a repair material in the Brazilian market, BioMTA, in comparison to other two materials currently in use (Biodentine and MTA Angelus). The initial setting time was evaluated using Gillmore needle. The pH was measured with a pH-meter after 24 h, 3, 7, 14 and 21 days. The radiopacity was determined using the equivalence in millimeters of aluminum (mm Al) from digitized occlusal radiographs. Solubility was determined after immersion in water for 7 days. The data were analyzed by one-way ANOVA and Tukey tests (a=0.05). The BioMTA initial setting time (5.2 min) was lower than the other materials (p<0.05). All materials showed an alkaline pH at 21 days. At 24 h, BioMTA was the most alkaline material (p<0.05); and at 3, 7, 14 and 21 days there was no difference between BioMTA and Biodentine (p>0.05), both being more alkaline than MTA Angelus (p<0.05). The radiopacity of BioMTA (4.2 mm Al) was significantly higher compared to Biodentine (p<0.05) and lower than MTA Angelus (p<0.05). The solubility of the materials was -4.2%, -1.6% and 4.1% for BioMTA, MTA Angelus and Biodentine, respectively, with a significant difference between them (p<0.05). Therefore, it can be concluded that BioMTA displayed a shorter setting time, an alkaline pH, a higher radiopacity, and a gain in mass.

Resumo Este estudo teve como objetivo avaliar as propriedades físico-químicas de um material reparador disponível no mercado brasileiro, BioMTA, em comparação com outros dois materiais atualmente em uso (Biodentine e MTA Angelus). O tempo de presa inicial foi avaliado usando a agulha de Gillmore. O pH foi medido com um pH-metro após 24 h, 3, 7, 14 e 21 dias. A radiopacidade foi determinada aplicando a equivalência em milímetros de alumínio (mm Al) de radiografias oclusais digitalizadas. A solubilidade foi determinada após imersão em água por 7 dias. Os dados foram analisados ​​por meio dos testes ANOVA de uma via e Tukey (a=0,05). O tempo de presa inicial do BioMTA (5,2 min) foi menor do que os outros materiais (p<0,05). Todos os materiais apresentaram pH alcalino aos 21 dias. Às 24 h, o BioMTA foi o material mais alcalino (p<0,05); e aos 3, 7, 14 e 21 dias não houve diferença entre BioMTA e Biodentine (p>0,05), sendo ambos mais alcalinos que MTA Angelus (p<0,05). A radiopacidade do BioMTA (4,2 mm Al) foi significativamente maior em comparação ao Biodentine (p<0,05) e menor que o MTA Angelus (p<0,05). A solubilidade dos materiais foi de -4,2%, -1,6% e 4,1% para BioMTA, MTA Angelus e Biodentine, respectivamente, havendo diferença significativa entre eles (p<0,05). Portanto, pode-se concluir que o BioMTA apresentou um menor tempo de presa, pH alcalino, uma alta radiopacidade e um ganho em massa.

Physical-mechanical properties of a resin-modified calcium silicate material for pulp capping

Abstract The purpose of this study was to investigate and to compare the physical-mechanical properties of a resin-modified calcium silicate material (TheraCal LC), used for pulp-capping, to MTA (Angelus) and a calcium hydroxide cement (Dycal). Specimens of each material (n=12) were prepared in Teflon molds (3.58 mm x 3 mm) and measured before and after immersion in distilled water for 24 h and 30 days to evaluate the dimensional change. The same specimens were submitted to compressive strength test on a Universal Testing Machine (Instron) (1 mm/min). Root canals were filled with the cements (n=8), and after 24 h, the bond strength (push-out test) to dentin was also assessed on a Universal Testing Machine (1 mm/min). Eight additional specimens of TheraCal LC were prepared to evaluate the bond strength immediately after light curing. Data were analyzed using One-Way ANOVA, and Tukey or Bonferroni post hoc tests (p<0.05). Percentage expansion of TheraCal LC was above the Specification No. 57 of ANSI/ADA, in both periods. The dimensional change for TheraCal LC was higher than MTA in 24 h and 30 days; and Dycal in 30 days (p<0.05). TheraCal LC had higher compressive and bond strength to dentin in comparison with MTA and Dycal (p<0.05). Although TheraCal LC expanded more than the ANSI/ADA recommendation, its compressive and push-out bond strength to dentin were satisfactory and superior to MTA and Dycal.

Resumo O objetivo deste estudo foi investigar e comparar as propriedades físico-mecânicas de um material à base de silicato de cálcio modificado por resina (TheraCal LC) ao MTA (Angelus) e um cimento de hidróxido de cálcio (Dycal). Espécimes de cada material (n=12) foram fabricados em moldes de Teflon (3,58 mm x 3 mm) e medidos antes e após imersão em água destilada por 24 h e 30 dias para avaliar a alteração dimensional. Os mesmos espécimes foram submetidos ao teste de resistência à compressão em uma Máquina Universal de Testes (Instron) (1 mm/min). Canais radiculares foram preenchidos com os cimentos (n=8), e após 24 h, a resistência de união (teste de push-out) também foi avaliada em uma Máquina Universal de Testes (1 mm/min). Oito amostras adicionais de TheraCal LC foram preparadas para avaliar a resistência de união imediatamente após a fotoativação. Os dados foram analisados utilizando os testes ANOVA de 1-fator e Tukey; ou Bonferroni (p<0,05). A expansão percentual do TheraCal LC ficou acima da Especificação No. 57 do ANSI/ADA, em ambos os períodos. Os valores de alteração dimensional para TheraCal LC foram maiores que MTA em 24 h e 30 dias; e Dycal em 30 dias (p<0,05). TheraCal LC apresentou maior resistência à compressão e união à dentina em comparação ao MTA e Dycal (p<0,05). Embora TheraCal LC tenha expandido mais que a recomendação da ANSI/ADA, sua resistência à compressão e de união à dentina foram satisfatórias e superiores ao MTA e Dycal.

Clinical and radiographic evaluation of a new stain-free tricalcium silicate cement in pulpotomies

Abstract The aim of this study was to evaluate and compare the clinical and radiographic success rates of pulpotomies in primary molars using a new stain-free tricalcium silicate cement (Bio-C Pulpo) versus a conventional white MTA (MTA Angelus) as a pulpotomy medicament for primary teeth. Seventy primary teeth in 33 patients were randomly divided into two groups, MTA Angelus (n = 34) and Bio-C Pulpo (n = 36). Clinical and radiographic follow-up examinations were conducted at seven days (except radiographic follow-up), and at one, three, six and 12 months. At 12 months, the clinical success rate of the MTA Angelus group was 100 percent (28 out of 28), and the radiographic success rate was 100 percent (28 out of 28). In comparison, the clinical success rate for the Bio-C Pulpo group was 100 percent (29 out of 29), and the radiographic success rate was 100 percent (29 out of 29). No significant differences were found between the groups at any follow-up evaluation. According to Fisher´s exact test, a significant difference was observed between the pulpotomy agent and tooth discoloration (p < 0.001). The success rates were 100% for the Bio-C Pulpo group, with no case of discoloration, and 10.31% for the MTA Angelus group. Both MTA Angelus and Bio-C Pulp pulpotomy medicaments are appropriate options for pulpotomies in primary teeth, and enable high clinical and radiographic success rates. However, more long-term studies are required to test the new Bio-C Pulpo medicament.

Dental discoloration caused by Grey-MTAFlow cement: analysis of its physicochemical, biological and antimicrobial properties

Abstract Tricalcium silicate-based cement are materials used in reparative and regenerative procedures in endodontics. A recently proposed formulation aimed to enhance handling during clinical use with a versatile material applicable by syringe. Although, the use of bismuth oxide as radiopacifier and grey raw powder are drawbacks considering aesthetics. Objectives Evaluate physicochemical, biological, and antimicrobial properties of Grey-MTAFlow (Ultradent) and assess whether the addition of zinc oxide (ZnO) prevents dentinal discoloration caused by bismuth oxide. Methodology Grey-MTAFlow was manipulated in 'thin' consistency for all tests. Luminosity, color change, ion migration to dentine, radiopacity, setting time, ISO 6876:2012 linear flow, volumetric lateral flow and central filling of simulated grooves scanned using micro-computed tomography (μCT), pH, calcium release, volumetric change using μCT, chemical characterisation, cytotoxicity, and antimicrobial activity were assessed. Addition of 5% ZnO to Grey-MTAFlow and a bismuth-containing experimental composition were comparatively tested. Statistical analyses used Shapiro-Wilk, T-test, ANOVA, and Kolmogorov-Smirnov (p<0.05). Results The addition of ZnO to Grey-MTAFlow prevented dentine darkening after 90 days due to bismuth migration reduction, although no statistical difference was found (p=0.863). ZnO addition significantly enhanced Grey-MTAFlow radiopacity without differences in initial setting time. Grey-MTAFlow presented an ISO linear flow of 10.9 mm and a balanced volumetric lateral flow with central filling in μCT evaluation. All compositions presented an alkaline pH after immersion. Grey-MTAFlow had a significantly higher calcium ion release after 28 days in comparison to 24 hours (p=0.011) and volumetric expansion of 0.4±1.8% after immersion. ZnO addition altered the hydrated cement matrix once calcium hydroxide (portlandite) could not be detected in characterisation. Neither of the materials produced inhibition halos nor reduced bacterial turbidity, but all presented cytocompatibility above 100%. Conclusion Grey-MTAFlow expanded after immersion and exhibited higher luminosity values after the evaluation period when ZnO was added, but chemical modifications after this addition occurred.

Cytotoxicity, inflammation, biomineralization, and immunoexpression of IL-1β and TNF-α promoted by a new bioceramic cement

Abstract Aim To evaluate the cytotoxicity, biocompatibility and mineralization capacity of BIO-C PULPO, and MTA. Methodology L929 fibroblasts were cultured and MTT assay was used to determine the material cytotoxicity on 6, 24, and 48 h. A total of 30 male rats (Wistar) aged between 4 and 6 months, weighing between 250 and 300 g were used. Polyethylene tubes containing BIO-C PULPO, MTA, and empty tubes were implanted into dorsal connective tissue. After the experimental periods (7, 15, 30, 60, and 90 days) the tubes were histologically analyzed using hematoxylin-eosin (H&E), immunolabeling of IL-1β and TNF-α, and von Kossa staining, or without staining for polarized light analysis. The average number of inflammatory cells was quantified; the mineralization assessment was determined by the area marked in μm2 and semiquantitative immunolabeling analyses of IL-1β and TNF-α were performed. Then, data underwent statistical analysis with a 5% significance level. Results It was observed that BIO-C PULPO and MTA presented cytocompatibility at 6, 24, and 48 similar or higher than control for all evaluated period. On periods 7 and 15 days, BIO-C PULPO was the material with the highest number of inflammatory cells (p<0.05). On periods 30, 60, and 90 days, BIO-C PULPO and MTA presented similar inflammatory reactions (p>0.05). No statistical differences were found between Control, BIO-C PULPO, and MTA for immunolabeling of IL-1β and TNF-α in the different periods of analysis (p<0.05). Positive von Kossa staining and birefringent structures under polarized light were observed in all analyzed periods in contact with both materials, but larger mineralization area was found with BIO-C PULPO on day 90 (p<0.05). Conclusion BIO-C PULPO was biocompatible and induced mineralization similar to MTA.

Tratamento com MTA Repair HP de extensa perfuração radicular após iatrogenia: relato de caso / Treatment with MTA Repair HP of extensive root perforation after iatrogeny: case report

Objetivo: relatar um caso clínico de perfuração radicular causada por iatrogenia, em terço cervical e médio de um incisivo central superior, dente 21, com presença de lesão óssea periapical. Relato de caso: clinicamente, pôde-se constatar ausência de edema e fístula. Na avaliação da condição pulpar e dos tecidos perirradiculares, o dente apresentou dor na palpação, ausência de mobilidade e de dor em percussão vertical e horizontal. Após os exames de imagem obtidos por meio de tomografia computadorizada de feixe cônico (TCFC; Prexion 3D), constatou-se lesão perirradicular extensa, canal radicular obliterado e perfuração radicular em face vestibular após tentativa de acesso cirúrgico. Como escolha de tratamento, optou-se por recuperar o trajeto original do canal de maneira a obter acesso intracanal, realização do preparo químico-mecânico e obturação pela técnica do cone único, para posteriormente promover o selamento adequado da perfuração com MTA Repair HP (Angelus, Londrina, PR, Brasil). Após seis meses, o dente apresentava-se assintomático e, radiograficamente, observou-se o reparo da lesão periapical. Considerações finais: o correto planejamento, o conhecimento dos materiais utilizados e a abordagem terapêutica foram de suma importância para o manejo adequado do caso. (AU)

Objective: to report a clinical case of root perforation, caused by iatrogeny in the cervical and middle third of an upper central incisor, tooth 21, with presence of periapical bone lesion. Case report: clinically, there was no edema and fistula. Facing the evaluation of the pulp condition and the periradicular tissues, the tooth presented pain on palpation, absence of mobility and pain on vertical and horizontal percussion. After the imaging exams, obtained by cone-beam computed tomography (CBCT; Prexion 3D), extensive periradicular lesion, obliterated root canal and root perforation were observed in the buccal face after attempted surgical access. As a choice of treatment, we chose to recover the original path of the canal in order to obtain intracanal access, chemicomechanical preparation and obturation by the single-cone technique to later promote proper sealing of the perforation with MTA Repair HP (Angelus, Londrina, PR, Brazil). After six months, the tooth was asymptomatic and, radiographically, the repair of the periapical lesion was observed. Final considerations: the correct planning, knowledge of the materials used and therapeutic approach were of paramount importance for the proper management of the case. (AU)

A randomized clinical trial of cavity liners after selective caries removal: one-year follow-up

Abstract Alternatives for the treatment of caries disease, such as minimally invasive approaches, have been developed in recent years. Objective: To carry out clinical and radiographic evaluations of three cavity liners after selective caries removal. Methodology: Thirty-six primary molars with deep occlusal caries lesions without pulp involvement (from children of both genders, aged between 5 and 8 years) were randomly divided into the following groups: calcium hydroxide cement (CHC) group; mineral trioxide aggregate (MTA) group and Portland cement with added zirconium oxide (PCZ) group. The following-up period was 6- and 12-month. The clinical and radiographic success rates were evaluated through chi-square test. The radiographic measurements were compared by ANOVA followed by Tukey's test (p<0.05). Results: Thirty-six patients were included, but thirty-four returned for 12-month follow-up. The overall success rate of the therapy for the three groups was 94.11% and no statistically significant differences occurred in the comparison among groups (p>0.05). Nineteen radiographs were selected to measure the dentin barrier thickness. The intragroup comparison presented a statistically significant increase of the dentin barrier for all groups, at 12-month follow-up. However, the MTA group showed increase of the dentin barrier, over time, 6- to 12-month follow-up. The intergroup comparison revealed no statistically significant differences (p>0.05). Conclusion: The clinical and radiographic data showed that all cavity liners provided effective treatment of primary teeth after selective caries removal.

Initial inflammatory response after the pulpotomy of rat molars with MTA or ferric sulfate

Abstract Purpose To compare, both qualitatively and quantitatively, the inflammatory cells, vascular density and IL-6 immunolabeled cells present in the pulp after pulpotomy with white MTA versus 15.5% ferric sulfate (FS). Methodology Forty-eight mandibular first molars from 24 Wistar rats were divided into MTA or FS groups and subdivided according to the period after pulpotomy procedure (24, 48 and 72 hours). Four teeth (sound and untreated) were used as controls. Histological sections were obtained and assessed through the descriptive analysis of morphological aspects of pulp tissue and the quantification of inflammatory cells, vascular density and interleukin-6 (IL-6) expression. Data were statistically analyzed (p<0.05). Results The number of inflammatory cells was similar in both groups, being predominantly localized at the cervical radicular third. In the MTA group, increased inflammation was observed at 48 hours. Vascular density was similar in both groups and over time, being predominant in the medium radicular third. No correlation was found between the number of inflammatory cells and the vascular density. Pulp tissue was more organized in MTA-treated teeth. In both groups, a weak to moderate IL-6 expression was detected in odontoblasts and inflammatory cells. Comparing both groups, there was a greater IL-6 expression in the cervical radicular third of teeth treated with MTA at 24 hours and in the medium and apical thirds at 72 hours, while in the FS group a greater IL-6 expression was found in the apical third at 24 hours. Conclusion The MTA group presented better histological features and greater IL-6 expression than the FS group. However, no difference was observed between the groups regarding the inflammatory status and vascularization, suggesting the usefulness of FS as a low-cost alternative to MTA.

Comparison between calcium hydroxide mixtures and mineral trioxide aggregate in primary teeth pulpotomy: a randomized controlled trial

Abstract Objectives: To evaluate the effect of calcium hydroxide (CH) associated with two different vehicles as a capping material for pulp tissue in primary molars, compared with mineral trioxide aggregate (MTA). Methodology: Forty-five primary mandibular molars with dental caries were treated by conventional pulpotomy using one of the following materials: MTA only (MTA group), CH with saline (CH+saline group) and CH with polyethylene glycol (CH+PEG group) (15 teeth/group). Clinical and periapical radiographic examinations of the pulpotomized teeth were performed 3, 6, and 12 months after treatment. Data were tested by chi-squared analysis and a multiple comparison post-test. Results: The MTA group showed both clinical and radiographic treatment success in 14/14 teeth (100%), at all follow-up appointments. By clinical evaluation, no teeth in the CH+saline and CH+PEG groups had signs of mobility, fistula, swelling or inflammation of the surrounding gingival tissue. However, in the CH+saline group, radiographic analysis detected internal resorption in up to 9/15 teeth (67%), and inter-radicular bone resorption and furcation radiolucency in up to 5/15 teeth (36%), from 3 to 12 months of follow-up. In the CH+PEG group, 2/11 teeth (18%) had internal resorption and 1/11 teeth (9%) presented bone resorption and furcation radiolucency at all follow-up appointments. Conclusion: CH with PEG performed better than CH with saline as capping material for pulpotomy of primary teeth. However, both combinations yielded clinical and radiographic results inferior to those of MTA alone.

Effect of sonic and ultrasonic activation on physicochemical properties of root canal sealers

Abstract Objective: To evaluate the effect of ultrasonic and sonic activation on physicochemical properties of AH Plus, MTA Fillapex, ADSeal, GuttaFlow Bioseal, and GuttaFlow 2 sealers. Methodology: Three experimental groups were formed: no activation (NA), ultrasonic activation (UA), and sonic activation (SA). The sealers were manipulated according to the manufacturers' instructions. A 3-mL syringe was adapted to receive 1 mL of sealer. Activation was performed with a 20/.01 ultrasonic insert (20 s/1W) in the UA group. A size 35.04 sonic tip was used (20 s/10,000 cycles/min-1) in the SA group. The molds for physicochemical analysis were filled and evaluated according to ANSI/ADA specification no. 57: setting time (ST), flow (FL), dimensional change (DC), solubility (SB), and radiopacity (RD). Statistical analysis was performed by Kruskal-Wallis, one-way ANOVA, and Tukey's tests (P<0.05). Results: Regarding ST, only AH Plus and GuttaFlow 2 in the NA group met the ANSI/ADA standards. All FL values were greater than 20 mm in diameter, as determined by ANSI/ADA. The tested sealers and protocols did not comply with the ANSI/ADA standards for DC. As for SB, only MTA Fillapex, regardless of the activation protocol, did not follow the ANSI/ADA standards. All of the investigated sealers, regardless of the activation protocol, presented radiographic density higher than 3 mm Al, as proposed by ANSI/ADA. Conclusions: UA and SA promoted changes in the physicochemical properties of the evaluated root canal sealers, mainly in ST and F. Thus, it is important to evaluate the physicochemical properties of endodontic sealers associated with activation techniques prior to clinical application in order to determine whether the properties follow the parameters set by ANSI/ADA, ensuring safety and quality of root canal filling.

Effects of MTA and Brazilian propolis on the biological properties of dental pulp cells

Abstract: The aim of this study was to evaluate the effect of mineral trioxide aggregate (MTA) and Brazilian propolis on the cell viability, mineralization, anti-inflammatory ability, and migration of human dental pulp cells (hDPCs). The cell viability was evaluated with CCK-8 kit after 1, 5, 7, and 9 days. The deposition of calcified matrix and the expression of osteogenesis-related genes were evaluated by Alizarin Red staining and real-time PCR after incubation in osteogenic medium for 21 days. The expression of inflammation-related genes in cells was determined after exposure to 1 μg/mL LPS for 3 h. Finally, the numbers of cells that migrated through the permeable membranes were compared during 15 h. Propolis and MTA significantly increased the viability of hDPCscompared to the control group on days 7 and 9. In the propolis group, significant enhancement of osteogenic potential and suppressed expression of IL-1β and IL-6 was observed after LPS exposure compared to the MTA and control groups. The number of migration cells in the propolis group was similar to that of the control group, while MTA significantly promoted cell migration. Propolis showed comparable cell viability to that of MTA and exhibited significantly higher anti-inflammatory and mineralization promotion effects on hDPCs.

A comparison of the sealing abilities between Biodentine and MTA as root-end filling materials and their effects on bone healing in dogs after periradicular surgery

ABSTRACT Objectives: To compare the sealing ability and biocompatibility of Biodentine with mineral trioxide aggregate (MTA) when used as root-end filling materials. Methodology: The Cell Counting Kit-8 (CCK-8) assay was used to compare the cytotoxicity of MTA and Biodentine. Twenty-one extracted teeth with a single canal were immersed in an acidic silver nitrate solution after root-end filling. Then, the volume and depth of silver nitrate that infiltrated the apical portion of the teeth were analyzed using micro-computed tomography (micro-CT). Seventy-two roots from 3 female beagle dogs were randomly distributed into 3 groups and apical surgery was performed. After six months, the volume of the bone defect surrounding these roots was analyzed using micro-CT. Results: Based on the results of the CCK-8 assay, MTA and Biodentine did not show statistically significant differences in cytotoxicity (P>0.05). The volume and the depth of the infiltrated nitrate solution were greater in the MTA group than in the Biodentine group (P<0.05). The volume of the bone defect was larger in the MTA group than in the Biodentine group. However, the difference was not significant (P>0.05). The volumes of the bone defects in the MTA and Biodentine groups were smaller than the group without any filling materials (P<0.05). Conclusions: MTA and Biodentine exhibited comparable cellular biocompatibility. Biodentine showed a superior sealing ability to MTA in root-end filling. Both Biodentine and MTA promoted periradicular bone healing in beagle dog periradicular surgery models.