An evaluation of luting agent application technique effect on fibre post retention

OBJECTIVE: Aim of the study was to assess the bond strengths of three adhesive/resin cement/fibre post systems by using different application methods of the luting agent. METHODS: Three types of fibre post systems were selected for this study. ENA Post (Micerium), Anatomical Post (Dentalica), and Endo Light-Post (RTD) were luted in prepared root canals, using proprietary adhesive system and resin cement. Each group was divided into three subgroups (n=10). For each subgroup, a different technique was used to place the luting agent into post space: using a lentulo spiral; applying the cement onto the post surface; injecting the material with a specific syringe. A push-out test was performed on sections from apical, middle and coronal parts of each specimen. All fractured specimens were observed using a scanning electron microscope to identify the types of failure. RESULTS: Bond strengths were not statistically influenced by root region (p>0.05) but were significantly affected both by post/adhesive/cement system and by the application technique of the luting agent (p<0.05). The microscopic analysis of the specimens revealed a prevalence of post/cement and mixed failures. CONCLUSIONS: The best results with the push-out test were obtained when the luting agent was brought into the post space with lentulo spirals or specific syringes. Only ENA Post system showed similar bond strength values independently from the application method of the luting agent.