Citotoxicity evaluation of three dental adhesives on vero cells in vitro

To evaluate, in vitro, the potential cytotoxicity of three different dental adhesives systems (Adper Single Bond 2 -SB, Silorane System Adhesive Bond -SSAB and Single Bond Universal -SBU) on cultivated Vero cells after different contact times. The cells were cultured in a concentration of 2 x 105 cells/mL for 24h and grown to sub-confluent monolayers. VERO cells were exposed to 25µl of conditioned extracts obtained from 24h, 48h and 72h immersion of adhesive samples in culture medium (DMEM), immediately after polymerization. Fresh DMEM was used as negative control. Cell metabolism was evaluated by the MTT assay (3-(4,5-dimethylthiazol-2-yl)-2, 5diphenyl-tetrazolium bromide). The data were analyzed statistically by ANOVA, considering a significance of 5%. The values of cell viability ranged from 94.2% at 72h (SBU) to 109.6% at 48h (SB). The mean percentage of viability after exposure to the extracts of SB, SSAB and SBU were 103.2%, 100.63% and 97.43%, respectively. There was no statistically significant difference (p= 0.342) between the experimental and negative control groups. At all exposure times, all adhesives tested in this study presented no cytotoxicity to Vero cells in vitro

Efeito da colonização de streptococcus Mutans nas propriedades físicas de Diferentes cimentos odontológicos

Dental materials must withstand the exposure to the several substances in the oral cavity, which is an important requirement for their clinical performance. This study evaluated, in vitro, the effect of Streptococcus mutans bacterial colonization, for thirty days, on physical properties of dental cements. Cylindrical specimens (4 mmx 2 mm) were prepared from five different cements: glass ionomer cement (Ketac Cem – 3M/ ESPE), zinc phosphate (Cimento de Zinco – SS White), resinous with dual cure polymerization (RelyX ARC – 3M/ESPE), resinous with light cure (RelyX Veneer – 3M/ESPE) and self-adhesive resinous with dual cure (RelyX U200 – 3M/ESPE). Samples were divided into experimental groups according to experimental design: G1 – Control (n=10): 100% of relative humidity for 24h; G2 – BHI (n=10): immersion in BHI + 1% sucrose for 30 days; G3 – BHI + S. mutans (n=30): immersion in BHI + 1% sucrose, for 30 days, after S. mutans biofilm adherence on the surfaces of the disks. Samples were analyzed using surface roughness, Vickers microhardness, diametral tensile strength and optical microscopy. Data collected were analyzed using ANOVA and Tukey-Krammer tests (α = 0.05). Glass ionomer cement presented a significant increase in surface roughness values after storage in BHI and BHI + S. mutans. Resin cements showed no significant difference. Regarding microhardness, it was observed statistically significant difference between samples of BHI + S. mutans group and the other groups of all tested materials. It was not possible to determine roughness and microhardness of zinc phosphate cement specimens of BHI and BHI + S. mutans. With respect to the diametral tensile test, glass ionomer and zinc phosphate cements showed a significant change in the results of groups BHI and BHI + S. mutans, while the same was not observed for the other materials. Optical microscopy images showed alterations in the surface of the non-resinous materials, while resinous materials did not show any change. Based on the results, it can be concluded that none of the materials tested remained unaffected by Streptococcus mutans biofilm, and that the effects were material-dependent.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESOs materiais odontológicos devem suportar a exposição às várias substâncias presentes na cavidade bucal, sendo este um importante requisito para seu desempenho clínico. Este estudo avaliou, in vitro, o efeito da colonização bacteriana por Streptococcus mutans, durante trinta dias, sobre propriedades físicas de diferentes cimentos odontológicos. Foram confeccionadas amostras cilíndricas (4 mm x 2 mm) a partir de cinco diferentes cimentos: ionômero de vidro (Ketac Cem – 3M/ ESPE), fosfato de zinco (Cimento de Zinco – SS White), resinoso com polimerização dual (RelyX ARC – 3M/ESPE), resino fotopolimerizável (RelyX Veneer – 3M/ESPE) e resinoso auto-adesivo com polimerização dual (RelyX U200 – 3M/ESPE). As amostras foram divididas em grupos experimentais segundo o tratamento experimental ao qual foram submetidos: G1 – Controle (n=10): 100% de umidade relativa durante 24h; G2 – BHI (n=10): imersão em BHI + 1% sacarose durante 30 dias; G3 – BHI + S. mutans (n=30): imersão em BHI + 1% sacarose, por 30 dias, após formação de biofilme de S. mutans na superfície. As amostras foram avaliadas através de análises de rugosidade superficial, microdureza Vickers, tração diametral e microscopia óptica. Os dados obtidos foram analisados utilizando-se os testes de ANOVA e Tukey-Krammer (α=0,05). O cimento de ionômero de vidro apresentou aumento significativo dos valores de rugosidade superficial após armazenamento em BHI e BHI + S. mutans. Os cimentos resinosos não apresentaram alteração significativa. Quanto à microdureza superficial, observou-se diferença estatística significante entre as amostras do grupo BHI + S. mutans e os demais grupos para todos os materiais testados. Não foi possível determinar a rugosidade e a microdureza superficial dos espécimes do cimento de fosfato de zinco pertencentes aos grupos BHI e BHI + S. mutans. Com relação ao teste de tração diametral, os cimentos de ionômero de vidro e fosfato de zinco apresentaram alteração significativa nos resultados dos grupos BHI e BHI + S. mutans, não sendo observado o mesmo para os demais materiais. As imagens de microscopia óptica permitiram a observação de alterações na superfície dos materiais não resinosos nos diferentes meios de armazenamento, enquanto que os materiais resinosos não apresentaram qualquer alteração. Com base nos resultados obtidos é possível concluir que nenhum dos materiais testados foi capaz de se manter inalterado na presença do biofilme de Streptococcus mutans, e que os efeitos provocados pelo biofilme foram material-dependente

Variações anatômicas que interferem no tratamento endodôntico - revisão da literatura

Introdução: o tratamento endodôntico visa manter o dente na cavidade bucal mesmo com a perda de sua vitalidade pulpar. No entanto, a ocorrência de variações na anatomia dental pode dificultar e/ou comprometer a eficácia do tratamento. Objetivo: realizar uma revisão da literatura acerca das variações anatômicas que podem interferir no tratamento endodôntico. Revisão: relatos de diferentes tipos de variações anatômicas acometendo todos os elementos dentais foram encontrados na literatura, além de diferentes métodos diagnósticos auxiliares. Conclusão: para um tratamento endodôntico de sucesso, é essencial ter amplo conhecimento da anatomia dental, pois qualquer elemento dentário pode ser acometido por variações na sua anatomia. Cabe ao cirurgião dentista, na prática clínica, sempre desconfiar da existência dessas variações e fazer uma investigação criteriosa para que seja possível estabelecer corretamente o diagnóstico e definir a abordagem terapêutica mais apropriada

Protective effect of calcium nanophosphate and CPP-ACP agents on enamel erosion

The aim of this study was to assess the effect of different remineralizing agents on enamel microhardness (KHN) and surface topography after an erosive challenge. Forty-eight human enamel specimens (4 × 4 mm) were randomly assigned to 4 groups: control (no treatment), fluoride varnish, calcium nanophosphate paste and casein phosphopeptide-amorphous calcium phosphate paste (CPP-ACP). Both pastes were applied for 5 minutes, and fluoride varnish, for 24 h. Four daily erosive cycles of 5 minutes of immersion in a cola drink and 2 h in artificial saliva were conducted for 5 days. KHN readings were performed at baseline and after 5 days. The percentage of enamel hardness change (%KHN) was obtained after erosion. The surface topography was evaluated by atomic force microscopy (AFM). The data were tested using ANOVA, Tukey's and paired-T tests (p < 0.05). After an erosive challenge, there was no statistically significant difference between the control (96.8 ± 11.4 KHN / 72.4 ± 3.0 %KHN) and the varnish (91.7 ± 14.1 KHN / 73.4 ± 5.5 %KHN) groups. The nanophosphate group showed lower enamel hardness loss (187.2 ± 27.9 / 49.0 ± 7.9 %KHN), compared with the CPP-ACP group (141.8 ± 16.5 / 60.6 ± 4.0 %KHN), and both were statistically different from the varnish and the control groups. AFM images showed a rough surface for the control and the varnish groups, a non-homogeneous layer with globular irregularities for CPP-ACP, and a thick homogeneous layer for the nanophosphate group. None of the agents provided protection against the development of erosion; however, nanophosphate paste was able to reduce enamel surface softening after the erosive challeng

Importance of GLUT1 in differential diagnosis of vascular anomalies

Vascular anomalies (VAs) include a group of distinct lesions, such as vascular system congenital malformations, as well as benign and malignant vascular tumors. These lesions may present similar clinical and histopathological features, leading to mistaken diagnoses and incorrect treatment choices. It is important that professionals responsible for monitoring the development of VAs conduct precise investigations and use the appropriate terminology. The human glucose transporter protein isoform 1 (GLUT1) has been proposed as a tool to aid in differential diagnosis between different VAs, given that it is a sensitive and specific marker for identification of infantile hemangiomas (HIs) in any organ. This article presents a review of the literature on this protein as an effective tool for identification and possible differential diagnosis between several VAs