Dened Myller Barros Lima

In vitro antimicrobial activity of root canal sealers and calcium hydroxide paste

Aim: To evaluate the in vitro antimicrobial activity of different root canal sealers and calcium hydroxide (CH) paste. Materials and Methods: The sample was composed of two sealers (Fill Canal® and Sealer 26®), one CH cement (Hydro C®), and a CH paste. The agar diffusion test was performed in Petri dishes inoculated with the following microorganisms: Streptococcus salivarius, Streptococcus oralis, Streptococcus mitis, Lactobacillus casei, Streptococcus mutans, Candida albicans, Candida krusei, and Candida tropicalis. The diameters of the zones of microbial growth inhibition were measured after 24 h. The tests were performed in triplicate. Data were analyzed statistically by ANOVA and Tukeys test at 5% significance level. Results: Fill Canal® exhibited the largest mean zone of microbial growth inhibition against the Candida species and differed significantly from the other groups (P < 0.001). When inhibition was observed against S. mitis and S. oralis, the CH paste presented a larger mean zone of microbial growth inhibition than those of the other materials (P < 0.05). Regarding the inhibition of S. mutans, a statistically significant difference was observed only between the CH paste and Hydro C® (P < 0.05); the paste produced the largest mean zone of microbial growth inhibition against this microorganism. Regarding the inhibition of S. salivarius, Fill Canal® presented smaller mean zone of microbial growth inhibition than Sealer 26® and CH paste (P < 0.05). Conclusion: All the materials presented zones of microbial growth inhibition against all the test bacteria. Fill Canal® presented the largest mean zone of inhibition against the Candida species. For the Streptococcus cultures, none of the sealers presented inhibition superior to that of the CH paste.

Avaliação Topográfica do Forame Infraorbital em Crânios Secos Humanos

Resumen pt: Objetivo: mensurar a localizacao do forame infraorbital (FIO) em pecas anatomicas maceradas, considerando-se o dimorfismo sexual. Metodo: utilizou-se uma...

Evaluation of Fluoride Release, pH and Microhardness of Glass Ionomer Cements

Objective: To evaluate fluoride release, pH and microhardness of glass ionomer cements (GIC). Material and Methods: Four different cements: Vidrion ® R (G1), Vitro Fil ® (G2), Maxxion ® (G3) and Magic Glass ® (G4) and a composite resin (G5 - control group) comprised the sample. Thirty specimens were manufactured (10 mm x 3 mm) and stored in deionized water. Analyses were performed after 24 hours, 7 days and 28 days. The following devices were used for measurements: fluorometer, pH meter and microhardness tester. Data were analyzed by Kruskal-Wallis, Mann-Whitney, Friedman and Wilcoxon tests (α = 0.05) using the SPSS ® software (Statistical Package for Social Sciences) version 17. Results: GICs were able to release fluoride; however, the amount released decreased with increasing immersion time (p <0.002). The pH of all products increased over time, the lowest value was identified for Magic Glass (5.93) and the highest for Maxxion (6.94) at time of 24 h. Materials showed significant decrease in surface microhardness, especially G4 for presenting the lowest recorded values (p <0.05). Conclusion: GICs are fluoride-releasing restorative materials with pH favorable to oral homeostasis and good mechanical behavior.

ADERÊNCIA IN VITRO DE STREPTOCOCCUS MUTANS À SUPERFÍCIE DE BRAQUETES ORTODÔNTICOS METÁLICOS E DE POLICARBONATO

Objective: to verify Streptococcus mutans (ATCC 25175) adherence to the surface of two types of orthodontic brackets. Material and Methods: Three metal and three polycarbonate brackets were used and testes according to the following groups: G1 (2 mL of BHI broth plus 140 µL of inoculum), G2 (2 mL of BHI broth containing sucrose plus 140 µL of inoculum) and G3 (2 mL of BHI broth - sterility control). A bracket of each type was immersed in each solution (G1, G2 or G3). All solutions were incubated at 37°C/24h, microaerophilic. Then, each bracket was transferred to a test-tube containing 2 mL of sterile saline solution, which underwent serial dilutions. Aliquots of 0.02 mL from each dilution were inoculated in triplicate on Petri-plates containing MSB culture medium through drop technique. Plates were incubated at 37oC, microaerophilics. After 48h, it was performed the CFU/mL counting. Results: CFU/mL means for the brackets immersed in G1 were 6.3x102 (metal) and 1x102 (polycarbonate). For G2, the means were 5.6x105 (metal) and 2.4x105 (polycarbonate). Difference was found for the number of CFU/mL adhered to the surfaces of brackets incubated in G1. Nevertheless, no difference was verified for the group incubated in G2. Conclusion: It is estimated that there are differences between metal and polycarbonate brackets’ surfaces. Presence of sucrose enhanced adherence of microorganisms to the surfaces evaluated. DESCRIPTORS: Bacterial Adhesion. Biofilms. Orthodontic Brackets.