The present results showed significant variations in the adhesion capacity of the Lactobacillus strains studied. Adhesion to oral surfaces is of primary importance for bacterial colonization in the mouth. Only one of the L. delbrueckii subsp. bulgaricus dairy starter culture strains investigated had a high adhesion percentage. This strain might then be considered for further investigations in the oral environment.
The purpose of this study was to investigate the amount of residual monomer in a composite resin after light-curing with different sources, light intensities and spectra of radiation. The resin specimens (4 mm in diameter; 2 mm thick) (n=5) were inserted in Plexglass matrixes and light-cured with a halogen lamp, LED and PAC units for 40, 40 and 5 s, respectively. The polymerized specimens were ground and 25 mg of each specimen were immersed in 8 mL 96% ethanol for 24 h to extract the residual monomer. The amount of residual monomer was determined by the standard straight line method. The light spectrum of the different LCUs was shot and processed through researches of the absorbation of the standard solutions at a level of lambda=275 nm and their extracts. Data were analyzed statistically by variational dispersion analysis and Tukey-Kramer test at 5% significance level. It was observed that, the halogen lamp produced the smallest amount of monomer under sufficient light intensity. The spectrum of light radiation of PAC was within the limits of 450- 490 nm and was of extremely high intensity. This imposes the use of short-limited light impulses, but also might lead to deterioration quality of polymerization. The LED unit had the best spectral radiation. An increase of light intensity was proved necessary.
Background: The reduced fracture resistance in endodontically treated teeth requires the use of radicular posts, with their advantages and disadvantages.
Aim: To evaluate the clinical performance of teeth restored with or without radicular posts at 6 and 12 months.
Materials and methods: The study included 22 patients who received endodontic therapy on premolars with a loss of one or two proximal walls. The premolars were divided into groups according to the restoration method: metal post group (MP), fiber post group (FP), and no post group (NP). For the NP group, a dentinal core of fiber-reinforced composite was used. The McNemar test, marginal homogeneity test and Kruskal-Wallis test were used in the statistical analysis. At the 6 and 12 month recall, both the direct composite restorations and the integrity of the post systems were assessed.
Results: At 6-month recall assessment, there was no statistically significant difference in the categories of ‘appropriate colour’, ‘secondary caries’ and ‘obturation integrity’. That was not the case with ‘marginal discoloration’, ‘marginal adaptation’, ‘proximal contact’ and ‘surface smoothness’. The recall at 12 months showed a continuation of this tendency, with significant decrease in the category of ‘adequate colour’. Assessment of post longevity at the two recalls did not show any significant changes. The teeth restored without a post showed survival rates comparable to that of teeth restored with a post for the 12-month period of observation.
Conclusions: There were no failures of the different posts used. The observed changes were attributed to the progressive deterioration of the composite restorations.
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