In Vitro Evaluation of Microleakage and Microhardness of Ethanolic Extracts of Propolis in Different Proportions Added to Glass Ionomer Cement.

OBJECTIVE: To evaluate the effect of ethanolic extracts of propolis (EEP) addition in different proportions to glass ionomer cement (GIC) on microleakage and microhardness of GIC. STUDY DESIGN: The cement was divided into four groups: one using the original composition and three with 10%, 25%, and 50% EEP added to the liquid and then manipulated. For microleakage assessment, sixty primary molars were randomly divided into four groups (n=15). Standard Class II cavities were prepared and then filled with EEP in different proportions added to GICs. Microleakage test was performed using a dye penetration method. The data were analyzed using one-way ANOVA and Mann-Whitney U tests (α = 0.05). Disc shaped specimens were prepared from the tested GIC to determine Vickers hardness (VHN). The data were analyzed using one-way ANOVA and post hoc Tukey test (α = 0.05). RESULTS: There were no statistically significant differences between the groups in terms of microleakage (p > 0.05). There were statistically significant differences between the VHN values of groups (p < 0.05). Increasing addition of EEP to GIC statistically significantly increased VHN value of GIC (p < 0.05). CONCLUSIONS: The addition of EEP to GIC increased the microhardness of the GIC and did not adversely affect the microleakage. Thus, it might be used during routine dental practice due to its antibacterial properties.

Biofilm formation by Staphylococcus epidermidis on nitrogen ion implanted CoCrMo alloy material.

Staphylococcus epidermidis is the primary cause of medical device-related infections due to its adhesion and biofilm forming abilities on biomaterial surfaces. For this reason development of new materials and surfaces to prevent bacterial adhesion is inevitable. In this study, the adhesion of biofilm forming S. epidermidis strain YT-169a on nitrogen (N) ion implanted as well as on as-polished CoCrMo alloy materials were investigated. A medical grade CoCrMo alloy was ion implanted with 60 keV N ions to a high dose of 1.9 x 10(18) ions/cm(2) at substrate temperatures of 200 and 400 degrees C. The near-surface implanted layer crystal structures, implanted layer thicknesses, and roughnesses were characterized by XRD, SEM and AFM. The number of adherent bacteria on the surfaces of N implanted specimens was found to be 191 x 10(6) CFU/cm(2) for the 200 degrees C and 70 x 10(6) CFU/cm(2) for the 400 degrees C specimens compared to the as-polished specimen (3 x 10(6) CFU/cm(2)). The adhesion test results showed that S. epidermidis strain YT-169a adhere much more efficiently to the N implanted surfaces than to the as-polished CoCrMo alloy surface. This was attributed mainly to the rougher surfaces associated with the N implanted specimens in comparison with the relatively smooth surface of the as-polished specimen.