The resin cement was mixed with an auto-mixing tip and loaded directly onto the dowels. The dowels were inserted into the prepared canals with a slightly rotating action and finger pressure. Excess cement was removed, and the remainder was sealed with glycerin gel (Liquid Strip, Ivoclar Vivadent) to inhibit oxygen contact. After cementation, the gutta-percha was removed. Microleakage measurements were made 24 hours after cementation.

A modified fluid filtration method was used for the measurements.[14] The sealing ability of the cemented dowels was determined by following the movement of an air bubble progressing www.selleckchem.com/products/poziotinib-hm781-36b.html within a micropipette 25 μl in volume and 65 mm in length. All tubes, the pipette, and the microsyringe of the test system were filled with distilled water at room temperature, this website under a pressure of 211 cm H2O (20,692 Pa). The test system was attached to the specimens using an 18-gauge needle and a plastic

cone as an adapter. Measurements of fluid movement were made four times, at 2-minute intervals for 8 minutes, and then averaged. The average movement results were used to calculate the volume of the leaking fluid (average movement × fluid volume per mm [25 μl/65 mm]). Then values were expressed as “μl/min.cm H2O” (hydraulic conductance = Lp).[14] The fluid flow rate through the 18-gauge needle and unfilled tooth canals, which were prepared for dowel placement, was measured for each dowel system individually by weighing the amount of water that could pass through the root canal in 1 minute. These values served both as a positive control and as 100% leakage, to which measurements of cemented groups could be compared (as a percentage).[14] Initially, a Kolmogorov-Smirnov normality test was performed to analyze the homogeneity of the variances over the data, and it was seen that the data were normally distributed (p > 0.05).[15] Later, a one-way ANOVA test was performed, and Tukey HSD, as a post hoc test, was used to identify the significant differences among the groups. The data were selleck chemicals llc finally post hoc analyzed with PASS (power analysis

and sample size) test (NCSS/PASS 2007, NCSS LLC.; Kaysville, UT) at a confidence level of 95%. The SSP group had the highest relative microleakage average (7.06 × 10−4%), and the CSG group had the lowest relative microleakage average (3.55 × 10−4%). One-way ANOVA test showed significant differences among the results of the groups (p < 0.05). Further post hoc Tukey HSD analysis showed no significant differences among the CSG, TAG, LEQ, USZ, HEG, and SOG groups (p > 0.05); however, the relative microleakage results of CSG and TAG groups were significantly lower than the results of STG and TZG groups (p < 0.05). The relative microleakage of the SSP group was significantly higher than all the FRC dowel groups, with the exception of the STG and TZG groups (p < 0.05) (Table 2).