This study compared the microleakage of teeth restored with nine frequently used commercial dowel systems in vitro. There were significant differences between the FRC dowels and the stainless steel dowels, and even among the FRC dowel groups. As such, the hypothesis tested, which stated there are no significant differences in microleakage between teeth restored with FRC dowels and those restored with stainless

steel dowels, is rejected. Similarly, Usumez et al reported better relative microleakage results for glass and polyethylene fiber-reinforced dowel groups than for metallic and zirconia dowel groups.[14] The literature reports various leakage measurement methods, such as dye or tracer molecule penetration measurement, evaluation of bacterial Navitoclax supplier penetration, spectrometry of radioisotopes, gas chromatography, and fluid filtration, but there is no consensus Quizartinib on the reliability and precision of these methods. The fluid filtration method was first described by Derkson et al[16] and then modified and used by

Pashley et al[17] to evaluate the leakage of temporary filling materials. With this method, quantitative rather than qualitative results could be obtained, and the method allows the researcher to make repeated measurements at different time intervals owing to the nondestructive design of the method. It is reported that the presence of trapped air and fluids in the microgaps at the bonding interface negatively affects the penetration

and diffusion of dyes, tracer molecules, bacteria, or ions when using the penetration evaluation methods.[18, 19] The selleckchem use of positively pressurized water in the fluid filtration method ensures that these kinds of difficulties are overcome.[20] Several authors reported that fluid filtration method is a more reliable and precise method than penetration measurement methods.[20, 21] As mentioned before, one of the goals of a dowel application is to reseal the prepared root canal by a proper dowel cementation process to avoid microleakage of bacteria and bacterial byproducts.[3] However, none of the dowel systems tested in this study provided an absolute seal. The percentage of the relative microleakage of pressurized water through the root canal ranged from 3.55 × 10−4% to approximately two times higher (7.06 × 10−4%) among the different groups. Test parameters in the current study were designed to standardize the resin cement and root canal surface conditioning procedures; therefore, it must be considered that differences in microleakage among the groups originated from microleakage through the dowel/cement interface.