| Objectives Post and core restoration technology is currently the most common residualcrown and root repair techniques used in recent years, with the rapid development ofmaterials science, various materials gradually applied post-core restoration techniques.Among the material, the properties of the fiber post and core are the most prominent, andtherefore these composite materials are most widely used. Fiber-reinforced post bondthrough the dentin through resin by forming two layers of interface, fiber post-resininterface and resin-dentin interface, its bond strength depends on the interface of micro-mechanical retention tightness, the data showed that approximately60%of repair failureare resulting from failure of the connection between fiber post and resin. How to improvefiber post-resin effective connection strength to reduce the rate of repair failure becomesthe focus of current research. In this study, used of ultrasonic cleaning machine of differentlengths of time combined with H2O2treatment of fibers posts to establish the adhesivebonding models, and then compared with those specimens of untreated posts.Methods In this study, the specimens were made by following method: PP plastic pipeswere used as an external frame, filling with resin and inserting of FiberWhite specimenstreated by different kinds of treatment protocal. Then the specimens were divided into thefollowing groups: Fiber posts direct silane treatment were assigned as Control group. Fiberposts soaked in30%H2O2solution for15min followed by silane treatment were assignedas H2O2group. Fiber posts soaked in30%H2O2solution with ultrasonic washing for2minfollowed by silane treatment were assigned as H2O2+US2group. Fiber posts soaked in30%H2O2solution with ultrasonic washing for5min followed by silane treatment wereassigned as H2O2+US5group. Fiber posts soaked in30%H2O2solution with ultrasonicwashing for15min followed by silane treatment were assigned as H2O2+US15group. Thesurfaces of specimens were observed using a scanning electron microscope, and then werecut into pieces using a diamond grinding machine for a thickness of1.5mm of a sheet,three test pieces of each specimen were introduced to push-out test and then observed thefailure mode under the dissecting microscope.Results SEM: surface of fiber posts without any treatment coats a layer of resin materialuniformly, and the surface were smoother than other groups with rarely observed brokenglass fibers. Fiber posts soaked in30%H2O2solution for15min have a rougher surfacewith many shallow fibers were exposed to the surface and broken fibers left of a bunch ofgrooves with smooth surface. Fiber posts soaked in30%H2O2solution with ultrasonicwashing for2min shows more rough surface compare to untreated posts but smoother thanfiber posts soaked in30%H2O2solution for15min. The surface of iber posts soaked in 30%H2O2solution with ultrasonic washing for5min were only smoother than fiber postssoaked in30%H2O2solution with ultrasonic washing for15min, with a lot of rough deepgroove left of broken fibers. The surface of fiber posts soaked in30%H2O2solution withultrasonic washing for15min shows the most rough surface with a lot of grooves fromdifferent layers demonstrates vary of roughness. Push-out test: The bond strength ofH2O2+US2group were stronger than those from Control group and H2O2+US15group.The bond strength of H2O2+US5group were stronger than H2O2+US15group. Nostatistically significance between other groups. Failure mode: Pearson Chi-square test wereperformed, the Chi-square value of between groups are10.52, test level is P<0.05,indicates specimens from each experimental group fails in different ways. After furtherinspection carried by Chi-square between the two groups, which the group test levelP’<0.005, H2O2+US2group vs Control group, Pearson Chi-square value is7.72, P<0.005.H2O2+US5group vs Control group Pearson Chi-square value is7.72, P<0.005. ThereforerefuseH0to acceptH1, proofed that H2O2+US2group and H2O2+US5group were bothdifferent to Control group on failure mode. No significance were observed between othergroups.Conclusions This study use H2O2alone or accompanied by ultrasound cleaning duringdifferent periods to treat the surface of glass fiber to observe the bond strength betweendifferent treatment protocols. These results suggest that the concentration of30%H2O2inultrasound-assisted for2min processing of fiber posts can significantly improve bondstrength of fiber post-resin interface. The results may have reference value for the clinicalapplication of fiber post implant. However, due to issues such as our focus on the subjectand limitation of technical conditions, there are some differences between the model andactual situation in the clinical use of the subject. A model need to be introduced for furtherstudy, which more in line with the actual environment of the oral fiber post-resin usage. |
