Ana Flávia Sanches Borges

Dye staining gap test: An alternative method for assessing marginal gap formation in composite restorations

Objective. The aim of this study was to evaluate and compare marginal adaptation of composite restorations assessed by a dye staining method and by scanning electron microscopy (SEM) analysis. Material and methods. Twenty bovine incisors were selected and ground flat to expose dentin. Two cylindrical cavities were prepared on the central area of flattened surfaces. Single bond adhesive system was applied in accordance with the manufacturers instructions and the cavities were filled with Filtek Z250 or Filtek Flow. The specimens were polished and replicas were obtained in epoxy resin. The replicas were observed by SEM for marginal quality/quantity evaluation. Caries detector was then applied on each specimen for 5 s to verify marginal adaptation through dye staining of the formed gaps on the outer margins. Images of the stained gaps were transferred to a computer measurement program to determine gap length. The length of the gap was expressed as the percentage of total length of the margins observed. Data were submitted to two-way ANOVA and Pearson correlation. Results. Filtek flow showed 36% and 34% and Filtek Z250 27% and 29% of gap in the margins when evaluated by SEM analysis and by the dye staining test, respectively. There was no difference between the composites, regardless of the evaluation technique. There was a strong positive correlation (r=0.83) between the results obtained with the tested methods to assess marginal gap. Conclusion. Dye staining the gaps can be used with good reliability to evaluate the gap formation in composite restorations.Objective. The aim of this study was to evaluate and compare marginal adaptation of composite restorations assessed by a dye staining method and by scanning electron microscopy (SEM) analysis. Material and methods. Twenty bovine incisors were selected and ground flat to expose dentin. Two cylindrical cavities were prepared on the central area of flattened surfaces. Single bond adhesive system was applied in accordance with the manufacturers instructions and the cavities were filled with Filtek Z250 or Filtek Flow. The specimens were polished and replicas were obtained in epoxy resin. The replicas were observed by SEM for marginal quality/quantity evaluation. Caries detector was then applied on each specimen for 5 s to verify marginal adaptation through dye staining of the formed gaps on the outer margins. Images of the stained gaps were transferred to a computer measurement program to determine gap length. The length of the gap was expressed as the percentage of total length of the margins observed. Data...

Inhibition of mineral loss at the enamel/sealant interface of fissures sealed with fluoride- and non-fluoride containing dental materials in vitro

Objective. In this in vitro study we evaluated the enamel mineral loss effect of fluoride-containing and non-fluoride-containing materials at different distances from the sealant margin, and verified the fluoride-releasing capability of these materials. Material and methods. Extracted molars were randomly assigned into nine groups (n=12): Concise (C), FluroShield (F), Helioseal Clear Chroma (H), Vitremer (V), Fuji II-LC (FII), Ketac Molar (KM), Fuji IX (FIX), Single Bond (SB), and Clearfil Protect Bond (CF). All groups were subjected to thermo and pH cycling. Enamel mineral loss was evaluated by cross-section micro-hardness analysis at distances: −100 µm, 0 µm, 100 µm, 200 µm. The mineral loss data were analyzed using a multi-factor ANOVA with split-plot design, and fluoride-released data were submitted to ANOVA and Tukey tests. Results. FIX demonstrated a lower mineral loss than C, F, and H, but did not differ from the SB, CF, V, FII, and KM groups, which also demonstrated no difference among them. C, F, H, and V presented the highest mineral loss, with no difference among them. V did not differ from the other groups (p>0.05). Regarding the different distances from the sealant margin, −100 µm presented the lowest mineral loss. FIX showed the highest fluoride release on the 7th and 14th days of evaluation, while CF showed high fluoride release only on the 7th day. Conclusion. Resin sealant did not prevent enamel mineral loss, contrary to glass-ionomer cement, which showed the highest capacity for fluoride release. It is not exclusively the presence of fluoride in a materials composition that indicates its capability to interfere with the development of enamel caries-like lesions.OBJECTIVE In this in vitro study we evaluated the enamel mineral loss effect of fluoride-containing and non-fluoride-containing materials at different distances from the sealant margin, and verified the fluoride-releasing capability of these materials. MATERIAL AND METHODS Extracted molars were randomly assigned into nine groups (n = 12): Concise (C), FluroShield (F), Helioseal Clear Chroma (H), Vitremer (V), Fuji II-LC (FII), Ketac Molar (KM), Fuji IX (FIX), Single Bond (SB), and Clearfil Protect Bond (CF). All groups were subjected to thermo and pH cycling. Enamel mineral loss was evaluated by cross-section micro-hardness analysis at distances: -100 microm, 0 microm, 100 microm, 200 microm. The mineral loss data were analyzed using a multi-factor ANOVA with split-plot design, and fluoride-released data were submitted to ANOVA and Tukey tests. RESULTS FIX demonstrated a lower mineral loss than C, F, and H, but did not differ from the SB, CF, V, FII, and KM groups, which also demonstrated no difference among them. C, F, H, and V presented the highest mineral loss, with no difference among them. V did not differ from the other groups (p > 0.05). Regarding the different distances from the sealant margin, -100 microm presented the lowest mineral loss. FIX showed the highest fluoride release on the 7th and 14th days of evaluation, while CF showed high fluoride release only on the 7th day. CONCLUSION Resin sealant did not prevent enamel mineral loss, contrary to glass-ionomer cement, which showed the highest capacity for fluoride release. It is not exclusively the presence of fluoride in a materials composition that indicates its capability to interfere with the development of enamel caries-like lesions.

Novel Nanotechnology of TiO2 Improves Physical-Chemical and Biological Properties of Glass Ionomer Cement

The aim of this study was to assess the performance of glass ionomer cement (GIC) added with TiO2 nanotubes. TiO2 nanotubes [3%, 5%, and 7% (w/w)] were incorporated into GICs (Ketac Molar EasyMix™) powder component, whereas unblended powder was used as control. Physical-chemical-biological analysis included energy dispersive spectroscopy (EDS), surface roughness (SR), Knoop hardness (SH), fluoride-releasing analysis, cytotoxicity, cell morphology, and extracellular matrix (ECM) composition. Parametric or nonparametric ANOVA were used for statistical comparisons (α ≤ 0.05). Data analysis revealed that EDS only detected Ti at the 5% and 7% groups and that GICs physical-chemical properties were significantly improved by the addition of 5% TiO2 as compared to 3% and GIC alone. Furthermore, regardless of TiO2 concentration, no significant effect was found on SR, whereas GIC-containing 7% TiO2 presented decreased SH values. Fluoride release lasted longer for the 5% and 7% TiO2 groups, and cell morphology/spreading and ECM composition were found to be positively affected by TiO2 at 5%. In conclusion, in the current study, nanotechnology incorporated in GIC affected ECM composition and was important for the superior microhardness and fluoride release, suggesting its potential for higher stress-bearing site restorations.

Diagnóstico e conduta clínica perante dentes supranumerários localizados em pré-maxila: relato de um caso

Dentre os defeitos do desenvolvimento craniofacial, a Hiperdontia representa uma alteracao de numero do desenvolvimento dentario relevante, devido a sua alta prevalencia e ao seu potencial para comprometer funcional e esteticamente os pacientes acometidos. O presente trabalho descreve o caso de um paciente de 5 anos de idade, acometido pelo desenvolvimento de dois elementos dentarios supranumerarios em regiao anterior de maxila. O caso foi diagnosticado a partir de avaliacao radiografica associada a erupcao ectopica de um dos elementos supranumerarios por face palatina dos incisivos superiores deciduos, os quais se apresentavam com mobilidade fisiologica devido ao desenvolvimento de seus sucessores. O tratamento eleito para o caso foi a extracao dos elementos deciduos com mobilidade e do elemento supranumerario erupcionado, optando-se pela remocao do elemento supranumerario incluso em momento posterior, uma vez que este nao se encontrava associado a nenhum comprometimento funcional ou estetico e tambem pelo fato de que a remocao do mesmo geraria alta morbidade ao paciente pediatrico. O caso descrito salienta a importância do cirurgiao no acompanhamento do desenvolvimento craniofacial humano, uma vez que este pode ser acompanhado de disturbios significativos. Alem disso, o presente caso alerta a comunidade odontologica para a importância do bom planejamento e conduta terapeutica adequados para cada caso.