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1.
Scand J Immunol ; 92(6): e12950, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32738155

RESUMO

Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplasia commonly affecting children with frequent somatic mutations in MAPK pathway genes including BRAFV600E and MAP2K1. Some studies suggest that LCH cells can recruit and modulate inflammatory cells, which could provide reciprocal survival signals. To characterize the immune profile of infiltrating inflammatory cells, and to clarify their participation in LCH pathogenesis, a detailed immunohistochemical analysis was performed. Fifteen (10 children, 5 adults) LCH cases were assessed through macrophage (CD68 and CD163), mature dendritic cell (mDC; CD83 and CD208), regulatory T cell (Treg; CD4, CD25 and FOXP3) and cytotoxic lymphocyte (CL; CD56, CD57, perforin and granzyme B) immunomarkers. Moreover, lymphocytic and LCH markers were also analysed. All cases were S100, CD1a, CD207 and CD4-positive. Bcl-2 and cyclin D1 expression was observed in 13 of 15 cases. In the immune microenvironment, M2-polarized macrophages and Tregs were the predominant cell populations, followed by significantly (P < .005) smaller levels of mDCs and CLs. Additionally, the number of CD3 + cells was significantly higher than that of CD20 + cells. In the CD3 + cell population, there were a significantly higher number of CD4 + cells than CD8 + cells. While there were no differences when comparing the paediatric and adult populations, FOXP3 + cells were significantly higher in patients with multisystem involvement and treated with chemotherapy, than single-site cases and those without chemotherapy. Our results suggest that M2-polarized macrophages and Treg infiltration can promote LCH development and survival, probably through pro-tumoral, immunosuppressive and/or cytokine-mediated mechanisms. This work highlights the need for further exploration of immune-targeted therapy for LCH.


Assuntos
Histiocitose de Células de Langerhans/metabolismo , Células de Langerhans/fisiologia , Macrófagos/metabolismo , Linfócitos T Reguladores/metabolismo , Adulto , Antígenos CD/metabolismo , Diferenciação Celular , Microambiente Celular , Criança , Pré-Escolar , Citocinas/metabolismo , Células Dendríticas/metabolismo , Feminino , Fatores de Transcrição Forkhead/metabolismo , Humanos , Imuno-Histoquímica/métodos , Lactente , Macrófagos/imunologia , Masculino , Linfócitos T Citotóxicos/metabolismo , Linfócitos T Reguladores/imunologia , Células Th2/imunologia
2.
Braz Dent J ; 31(1): 19-24, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32159700

RESUMO

This study evaluated the association between polymorphisms in genes encoding estrogen receptors 1 (ESR1) and 2 (ESR2), vitamin D receptor (VDR) and in microRNA17 (which binds to ESR1 and VDR) with persistent apical periodontitis (PAP) after the endodontic treatment. We included 162 patients who completed endodontic treatment at least one year ago and presented apical periodontitis at the beginning of the root canal therapy. Clinical and radiographic exams were performed to evaluate the presence of PAP or healthy periradicular tissues (healed). Saliva samples were collected as a genomic DNA. The genotyping of ESR1 (rs2234693 and rs9340799), ESR2 (rs1256049 and rs4986938), VDR (rs739837 and rs2228570) and miRNA17 (rs4284505) were performed by real-time PCR. Chi-square test was used to the distribution of genotype and allele frequencies. Haplotype analysis was also performed. Eighty-nine patients were included in the "healed" group and 73 in the "PAP" group. No association was found between the allelic and genotypic polymorphisms studied and PAP (p>0.05). Haplotype analysis also did not demonstrated an association (p>0.05). In conclusion, the genetic polymorphisms in ESR1, ESR2, VDR and miRNA17 are not associated with PAP.


Assuntos
Receptor alfa de Estrogênio/genética , Receptor beta de Estrogênio/genética , MicroRNAs/genética , Polimorfismo Genético , Receptores de Calcitriol/genética , Vitamina D , Estrogênios , Frequência do Gene , Predisposição Genética para Doença , Haplótipos , Humanos , Polimorfismo de Nucleotídeo Único
3.
J Endod ; 45(5): 526-531, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30871729

RESUMO

INTRODUCTION: The outcome of root canal treatment has been reported as intimately related to the host response. Genetic polymorphisms might be associated with apical periodontitis repair. The aim of this study was to evaluate the association between receptor activator of nuclear factor kappa B (RANK), receptor activator of nuclear factor kappa B ligand (RANKL), and osteoprotegerin (OPG) genetic polymorphisms with persistent apical periodontitis (PAP) in Brazilian subjects. METHODS: Subjects with at least 1 year of follow-up after nonsurgical root canal therapy were recalled. Sixty-four subjects with signs/symptoms of PAP and 86 subjects with root canal-treated teeth exhibiting healthy periradicular tissues (healed) were included. Genomic DNA was extracted from saliva and used for RANK (rs3826620), RANKL (rs9594738), and OPG (rs2073618) genotyping by real-time exact tests, and odds ratio were implemented using Epi Info 3.5.2 (Centers for Disease Control and Prevention, Atlanta, GA). A logistic regression analysis was also performed using the time of follow-up as the covariate. All tests were performed with an established alpha of 0.05 (P = .05). RESULTS: An association between allele distribution and the polymorphism in RANK was observed. Subjects who carry the T allele had a lower risk of having PAP (P < .05). In RANKL polymorphism, the genotype distribution was statistically significant different between the PAP and healed groups (P = .05). The time of follow-up was associated with PAP (P < .05). In the logistic regression analysis using time as a covariant, RANK (P < .05) and RANKL (P < .05) were associated with PAP. The polymorphism rs2073618 in OPG was not associated with PAP (P > .05). CONCLUSIONS: These findings suggest that polymorphisms in RANK and RANKL genes are associated with PAP.


Assuntos
Periodontite Periapical , Ligante RANK , Receptor Ativador de Fator Nuclear kappa-B , Brasil , Humanos , Osteoprotegerina , Periodontite Periapical/genética , Polimorfismo Genético , Ligante RANK/genética , Receptor Ativador de Fator Nuclear kappa-B/genética
4.
Caries Res ; 53(4): 441-446, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30759432

RESUMO

The aim of this study was to investigate the association between genetic polymorphisms in MMP8, MMP13, and MMP20 with caries experience and developmental defects of enamel (DDE) in children from the Amazon region of Brazil. Den tal caries and DDE data were collected through clinical examination from 216 children. Genomic DNA was extracted from saliva, and genotyping of selected polymorphisms in MMP8 (rs17099443 and rs3765620), MMP13 (rs478927 and rs2252070), and MMP20 (rs1784418) was performed using TaqMan chemistry and endpoint analysis. χ2 or Fisher's exact tests were used to compare allele and genotype distributions between children with caries experience and caries-free children and between DDE-affected and -unaffected children with an established alpha of 5%. The polymorphism rs478927 in MMP13 was associated with caries experience and DDE (p < 0.05). The analysis performed comparing children with both conditions (caries experience plus DDE) and children with neither of the conditions (caries-free chil dren without DDE) demonstrated that children carrying the MMP13 rs478927 TT genotype were more likely to have concomitant occurrence of these two conditions (OR = 5.8, 95% CI 2.1-15.8; p = 0.0003). In conclusion, the genetic polymorphism rs478927 in MMP13 was associated with caries experience and DDE.


Assuntos
Cárie Dentária/genética , Hipoplasia do Esmalte Dentário/genética , Metaloproteinase 13 da Matriz/genética , Brasil/epidemiologia , Criança , Esmalte Dentário/patologia , Humanos , Polimorfismo Genético
5.
Environ Toxicol Pharmacol ; 66: 104-108, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30639979

RESUMO

Recent studies suggested that genetics contribute to differences in dental fluorosis (DF) susceptibility among individuals having the same environmental exposure. This study evaluated if MMP2, MMP9 and MMP20 are expressed during enamel development and assessed the association between polymorphisms in these genes with DF. Mice susceptible and resistant to DF were used to evaluate if MMPs were candidate genes for DF. The animals received fluoride and their enamels were used for immunohistochemistry. Additionally, 481 subjects from a city with fluoridation of public water supplies were recruited. Genotyping was performed using real time PCR. Allele/genotype frequencies were compared between groups. MMP2, MMP9 and MMP20 immunostaining was detected in both animal groups. DF was observed in 22.4% of the subjects. A borderline association was observed in MMP2 (rs243865), MMP9 (rs17576) and in MMP20 (rs1784418) (p = 0.06, p = 0.08 and p = 0.06 respectively). Briefly, MMPs were expressed during enamel maturation and genetic polymorphisms were not associated with DF.


Assuntos
Fluorose Dentária/genética , Metaloproteinase 20 da Matriz/fisiologia , Metaloproteinase 2 da Matriz/fisiologia , Metaloproteinase 9 da Matriz/fisiologia , Animais , Brasil , Criança , Esmalte Dentário/metabolismo , Feminino , Fluoretos/farmacologia , Genótipo , Humanos , Masculino , Camundongos , Polimorfismo de Nucleotídeo Único
6.
Braz Dent J ; 29(5): 465-468, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30517445

RESUMO

The aim of this study was to evaluate the association between timing of permanent tooth emergence with overweight and obesity in children from Brazilian Amazon region. The studied population consisted of 192 children, 09 to 12 year-old, from public schools at Manaus, Amazonas-Brazil. Clinical examination was performed and the tooth emergence was evaluated according to the number of permanent erupted teeth. Body mass index z-score was calculated. For the statistical analysis 'Overweight/obese' group was compared with 'Normal weight' group in a case to control ratio 1:2. The t-test based on age was used for means comparison between the groups. A linear regression analysis using age and gender as co-variants was used. The established alpha was 5%. One hundred twenty-seven children were classified as normal weight and 65 were classified as overweight/obese (49 were overweight and 16 were obese). Overweight/obesity condition was associated with the gender, in which boys had a higher chance to present higher weight conditions (OR=1.84; CI 95% 1.06-3.37; p=0.04). The mean number of permanent teeth was higher in the overweight/obesity group (p<0.001). Linear regression analysis demonstrated that nutritional status, gender and age were strongly associated with number of permanent erupted teeth (p<0.05). In conclusion, our study demonstrated that timing of permanent tooth emergence is associated with overweigh/obesity in children from Manaus, Brazil.


Assuntos
Dentição Permanente , Sobrepeso/fisiopatologia , Obesidade Pediátrica/fisiopatologia , Erupção Dentária/fisiologia , Índice de Massa Corporal , Brasil , Criança , Feminino , Humanos , Masculino
7.
Braz. dent. j ; 29(5): 465-468, Sept.-Oct. 2018. tab
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-974180

RESUMO

Abstract The aim of this study was to evaluate the association between timing of permanent tooth emergence with overweight and obesity in children from Brazilian Amazon region. The studied population consisted of 192 children, 09 to 12 year-old, from public schools at Manaus, Amazonas-Brazil. Clinical examination was performed and the tooth emergence was evaluated according to the number of permanent erupted teeth. Body mass index z-score was calculated. For the statistical analysis 'Overweight/obese' group was compared with 'Normal weight' group in a case to control ratio 1:2. The t-test based on age was used for means comparison between the groups. A linear regression analysis using age and gender as co-variants was used. The established alpha was 5%. One hundred twenty-seven children were classified as normal weight and 65 were classified as overweight/obese (49 were overweight and 16 were obese). Overweight/obesity condition was associated with the gender, in which boys had a higher chance to present higher weight conditions (OR=1.84; CI 95% 1.06-3.37; p=0.04). The mean number of permanent teeth was higher in the overweight/obesity group (p<0.001). Linear regression analysis demonstrated that nutritional status, gender and age were strongly associated with number of permanent erupted teeth (p<0.05). In conclusion, our study demonstrated that timing of permanent tooth emergence is associated with overweigh/obesity in children from Manaus, Brazil.


Resumo O objetivo deste estudo foi avaliar se a erupção dentária está associada com sobrepeso/obesidade em crianças da região Amazônica brasileira. A população estudada foi composta por 192 crianças, de 9 a 12 anos, de escolas públicas de Manaus, Amazonas-Brasil. O exame clínico foi realizado e a erupção dentária foi avaliada de acordo com o número de dentes permanentes irrompidos. O índice de massa corporal escore-z foi calculado. Para a análise estatística, comparou-se o grupo "sobrepeso / obesidade" com o grupo "peso normal" em uma proporção de controle 1: 2. O teste t baseado na idade foi utilizado para comparação das médias entre os grupos. Uma análise de regressão linear usando idade e sexo como co-variáveis foi utilizada. O alfa estabelecido foi de 5%. Cento e vinte e sete crianças foram classificadas com peso normal e 65 foram classificados com sobrepeso / obesidade (49 com sobrepeso e 16 com obesidade). A condição de sobrepeso / obesidade associou-se ao gênero, no qual os meninos tiveram maior chance de apresentar condições de maior peso (OR = 1,84; IC 95% 1,06-3,37; p = 0,04). O número médio de dentes permanentes irrompidos foi maior no grupo sobrepeso / obesidade (p <0,001). A análise de regressão linear demonstrou que o estado nutricional, sexo e idade foram fortemente associados ao número de dentes permanentes irrompidos (p <0,05). Concluindo, nosso estudo demonstrou que o momento da erupção dos dentes permanentes é associado com sobrepeso / obesidade em crianças de Manaus, Brasil.

8.
Braz Dent J ; 29(2): 179-183, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29898065

RESUMO

Persistent apical periodontitis (AP) is a situation involving an inflammatory and immune response caused mainly by anaerobic polymicrobial infection of the root canal system and the outcome and follow-up of the root canal treatment has been reported as intimately related to host response. The apical periodontitis repair might be associated with genetic polymorphisms. This study aimed to evaluate the association between HIF1A genetic polymorphisms (rs2301113 and rs2057482) with PAP in Brazilian patients. Subjects with at least 1 year of follow-up after root canal therapy (RCT) were recalled. Sixty-four subjects with signs/symptoms of PAP and 84 subjects with root canal-treated teeth exhibiting healthy perirradicular tissues (healed) were included. Genomic DNA was extracted from saliva and used for HIF1A genotyping by real-time PCR. Genotype and allele frequencies were compared by c2 or Fisher's exact tests and odds ratio was implemented, using Epi Info 3.5.2. All tests were performed with an established alpha of 0.05. There was no association between allele and genotype distribution for HIF1As polymorphisms and PAP (p>0.05). The genetic polymorphisms in HIF1A were not associated with persistent apical periodontitis.


Assuntos
Remodelação Óssea/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Neovascularização Patológica/genética , Periodontite Periapical/genética , Polimorfismo Genético , Adulto , Brasil , DNA/genética , Feminino , Frequência do Gene , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Periodontite Periapical/patologia , Reação em Cadeia da Polimerase em Tempo Real , Tratamento do Canal Radicular
9.
Angle Orthod ; 88(5): 590-595, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29761706

RESUMO

OBJECTIVES: To evaluate the genotoxic and cytotoxic effects of Haas appliances through micronuclei test and cytogenetic damage analysis in buccal mucosa epithelial cells of patients undergoing orthodontic treatment. MATERIALS AND METHODS: Twenty-eight patients, 6-12 years of age and of both genders, who required a Haas appliance for the correction of a posterior crossbite were included. Epithelial cells from the mucosa were collected by gently scraping the inside of both the right and left cheeks. The cells were collected before the insertion of the appliance (T0), 1 month after the device was installed (T1), and again 3 months after the appliance was immobilized (T2). The cells were processed to obtain slides. Feulgen/Fast Green was used as the staining method, and the number of normal, karyolytic, pyknotic, nuclear buds, bi/trinucleated, and micronucleus cells were counted under light microscopy. Cellular abnormalities were evaluated with parametric and nonparametric tests for comparison of the means by analysis of variance testing, Tukey posttest, or the Kruskal-Wallis test and then by Dunn's posttest. The significance level was 5%. RESULTS: There were no statistically significant changes in the micronuclei in the evaluated periods ( P > .05). Nuclear buds increased at T1 ( P < .05), returning to baseline levels at T2. Other abnormalities (cariolytic, pyknotic, and bi/trinucleated cells) showed a significant increase at T1 and T2 ( P < .0001). CONCLUSIONS: The Haas appliance did not cause an increase in micronuclei in cells of the buccal mucosa. However, statistically significant increases in cariolytic, pyknotic, and bi/trinucleated cells were observed during treatment, suggesting possible DNA damage.


Assuntos
Mucosa Bucal/efeitos dos fármacos , Aparelhos Ortodônticos Fixos/efeitos adversos , Criança , Dano ao DNA/efeitos dos fármacos , Feminino , Humanos , Masculino , Má Oclusão/terapia , Testes para Micronúcleos , Mucosa Bucal/citologia , Técnica de Expansão Palatina/instrumentação
10.
Arch Oral Biol ; 92: 1-7, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29727722

RESUMO

OBJECTIVE: This replication study aimed to evaluate an association between caries experience and polymorphisms in DEFB1 and miRNA202 in two different Brazilian groups. DESIGN: The population consisted in 312 Brazilian children. Genomic DNA for was extracted from buccal cells isolated from saliva. The genotyping analysis of the polymorphisms in DEFB1 and miRNA202 was performed by real-time polymerase chain reactions. The associations between caries experience, genotype and allele distribution was performed, with an alpha of 0.05. RESULTS: A statistical significant difference was observed between allele distribution and the polymorphism rs12355840 in the miRNA202 for permanent dentition in the Manaus group, in which individuals that carry the allele C had almost three times more chance to have caries (p = .021; OR = 2.7, 95% CI = 1.1-6.7). In the Ribeirão Preto group there was a statistical significant difference for the polymorphism rs11362 in the DEFB1 for both dentition in alleles (p = .043) and genotype (p = .020) distributions. The T allele increased in two times the chance to have caries (OR = 2.03; 95% CI = 1.05-4.07). CONCLUSION: In conclusion, the allelic distribution of the polymorphism rs12355840 in miRNA202 was associated with caries experience in the Manaus group. In the Ribeirão Preto group, the allelic and genotypic distributions in the polymorphism rs11362 in DEFB1 were associated with caries experience.


Assuntos
Cárie Dentária/genética , MicroRNAs/genética , Polimorfismo de Nucleotídeo Único , beta-Defensinas/genética , Alelos , Brasil , Criança , Feminino , Genótipo , Humanos , Masculino , Reação em Cadeia da Polimerase em Tempo Real
11.
Braz. dent. j ; 29(2): 179-183, Mar.-Apr. 2018. tab
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-951532

RESUMO

Abstract Persistent apical periodontitis (AP) is a situation involving an inflammatory and immune response caused mainly by anaerobic polymicrobial infection of the root canal system and the outcome and follow-up of the root canal treatment has been reported as intimately related to host response. The apical periodontitis repair might be associated with genetic polymorphisms. This study aimed to evaluate the association between HIF1A genetic polymorphisms (rs2301113 and rs2057482) with PAP in Brazilian patients. Subjects with at least 1 year of follow-up after root canal therapy (RCT) were recalled. Sixty-four subjects with signs/symptoms of PAP and 84 subjects with root canal-treated teeth exhibiting healthy perirradicular tissues (healed) were included. Genomic DNA was extracted from saliva and used for HIF1A genotyping by real-time PCR. Genotype and allele frequencies were compared by c2 or Fisher's exact tests and odds ratio was implemented, using Epi Info 3.5.2. All tests were performed with an established alpha of 0.05. There was no association between allele and genotype distribution for HIF1As polymorphisms and PAP (p>0.05). The genetic polymorphisms in HIF1A were not associated with persistent apical periodontitis.


Resumo A periodontite apical persistente (PAP) é uma condição que envolve uma resposta inflamatória e imunológica causada principalmente por infecções polimicrobianas de origem anaeróbia no sistema de canais radiculares, tornando o resultado e o acompanhamento do tratamento do canal radicular intimamente relacionados à resposta do hospedeiro. O reparo da periodontite apical pode estar associado a polimorfismos genéticos. Este estudo teve como objetivo avaliar a associação entre os polimorfismos genéticos do HIF1A (rs2301113 e rs2057482) com a PAP em pacientes brasileiros. Indivíduos com pelo menos 1 ano de acompanhamento após o tratamento do canal radicular (TCR) foram agendados para consulta de acompanhamento. Sessenta e quatro indivíduos com sinais/sintomas de PAP e 84 indivíduos com dentes tratados endodonticamente e tecidos perirradiculares saudáveis (cicatrizados) foram incluídos no presente estudo. O DNA genômico foi extraído da saliva e utilizado para a genotipagem do HIF1A por PCR em tempo real. O genótipo e as frequências alélicas foram comparados por teste c2 ou exato de Fisher e odds-ratio foi implementado por meio do software Epi Info 3.5.2. Todos os testes realizados foram estabelecidos com a=0,05. Não houve associação entre alelo e distribuição genotípica para polimorfismos do HIF1A e PAP (p> 0,05). Os polimorfismos genéticos em HIF1A não foram associados à periodontite apical persistente.

12.
Head Neck Pathol ; 12(4): 604-609, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29190002

RESUMO

Hypophosphatemic rickets is a rare genetic disorder involving the regulation of fibroblast growth factor 23 (FGF23), a phosphaturic agent, clinically showing bowing of the legs, short stature and dentoalveolar abscesses. A 7-year-old boy, with previous hypochondroplasia diagnosis, was referred to our pediatric dentistry clinic presenting short stature, bone deformities and sinus tracts at deciduous teeth apex levels not related with trauma, restorations or dental caries. After deciduous teeth extraction, due to root resorption and mobility, light microscopy exhibited typical hypophosphatemic dentin, and micro-computed tomography revealed tubular clefts and porosities throughout the teeth. Laboratory tests confirmed the HR diagnosis, after which the treatment was initiated.


Assuntos
Osso e Ossos/anormalidades , Nanismo/diagnóstico , Deformidades Congênitas dos Membros/diagnóstico , Lordose/diagnóstico , Abscesso Periapical/etiologia , Raquitismo Hipofosfatêmico/diagnóstico , Criança , Erros de Diagnóstico , Humanos , Masculino , Raquitismo Hipofosfatêmico/complicações , Raquitismo Hipofosfatêmico/patologia
13.
Braz Dent J ; 27(2): 196-201, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27058384

RESUMO

This study evaluated physiochemical proprieties of a calcium hydroxide-based paste (Calen®) combined with a zinc oxide cement at different ratios (1:0.5, 1:0.65, 1:0.8 and 1:1). Materials were compared regarding setting time, pH variation, radiopacity, solubility, dimensional changes, flow and release of chemical elements. Data were analyzed statistically by ANOVA and Tukey's test (α=0.05). Longer setting time and higher dimensional changes and solubility values were exhibited by 1:0.65 and 1:0.5 ratios (p<0.05). The 1:0.5 and 1:0.65 ratios exhibited the highest pH values at all time points. All materials exhibited high radiopacity values. Significant differences were found only between 1:0.5 and 1:1 ratios for calcium and zinc release (p<0.05), whereas the amount of zirconium was similar among all groups (p>0.05). Considering the evaluated proprieties, combinations of Calen® paste with ZO at 1:0.5 and 1:0.65 ratios had the best results as root canal filling materials for use in primary teeth.


Assuntos
Materiais Restauradores do Canal Radicular/química , Dente Decíduo , Humanos , Concentração de Íons de Hidrogênio , Teste de Materiais , Solubilidade , Espectrometria por Raios X
14.
Braz. dent. j ; 27(2): 196-201, Mar.-Apr. 2016. tab, graf
Artigo em Inglês | LILACS | ID: lil-778321

RESUMO

Abstract This study evaluated physiochemical proprieties of a calcium hydroxide-based paste (Calen(r)) combined with a zinc oxide cement at different ratios (1:0.5, 1:0.65, 1:0.8 and 1:1). Materials were compared regarding setting time, pH variation, radiopacity, solubility, dimensional changes, flow and release of chemical elements. Data were analyzed statistically by ANOVA and Tukey's test (α=0.05). Longer setting time and higher dimensional changes and solubility values were exhibited by 1:0.65 and 1:0.5 ratios (p<0.05). The 1:0.5 and 1:0.65 ratios exhibited the highest pH values at all time points. All materials exhibited high radiopacity values. Significant differences were found only between 1:0.5 and 1:1 ratios for calcium and zinc release (p<0.05), whereas the amount of zirconium was similar among all groups (p>0.05). Considering the evaluated proprieties, combinations of Calen(r) paste with ZO at 1:0.5 and 1:0.65 ratios had the best results as root canal filling materials for use in primary teeth.


Resumo O objetivo do presente estudo foi avaliar propriedades físico-químicas da pasta à base de hidróxido de cálcio (Calen(r)) combinado com diferentes proporções de óxido de zinco (OZ) (1:0,5 e 1:0,65, 1:0,8 e 1:1) (Calen(r) /OZ). Os materiais foram comparados quanto ao tempo de endurecimento, variação do pH, radiopacidade, solubilidade, alterações dimensionais, escoamento e liberação de elementos químicos. Os dados obtidos foram submetidos à análise de variância (nível de 5% de significância). Maior grau de endurecimento, valores de alterações dimensionais, e solubilidade foram encontrados para Calen(r) /OZ 1:0,65 e 1:0,5. Calen(r) /OZ 1:0,5 e 1:0,65, apresentaram os maiores valores de pH em todos os momentos. Todos os materiais apresentaram valores elevados de radiopacidade com diferenças significativas (p>.05). Foram encontradas diferenças significativas apenas entre Calen(r) /OZ de 1:0,5 e 1:1 na liberação de cálcio e zinco (p< 0,05), enquanto que a quantidade de zircônia foi semelhante entre todos os grupos analisados (p>.05). Em relação às propriedades avaliadas no presente estudo, as combinações de Calen(r) com óxido de zinco nas proporções 1:0,5 e 1:0,65 são mais adequadas como material obturador para os canais radiculares de dentes decíduos.


Assuntos
Humanos , Concentração de Íons de Hidrogênio , Materiais Restauradores do Canal Radicular/química , Dente Decíduo , Teste de Materiais , Solubilidade , Espectrometria por Raios X
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