Bond strength and void formation of self-adhesive resin cement with polyethylene fiber posts in the root canal systems

Background/purpose: Compromised structure in endodontically treated teeth requires reliable luting agents to ensure durable post-restoration. This study investigated the bonding strength and void formation of self-adhesive resin cement (SARC) used with polyethylene fiber posts in endodontically treated teeth, an essential aspect of post-endodontic restorations, especially when the remaining tooth structure is compromised. Materials and methods: Thirty-five extracted single-rooted human mandibular premolars were divided into five groups (n = 7 per group) based on different cementation protocols: Group 1 and 2 received SARC with adhesive pretreatment, Group 3 and 4 received SARC without adhesive pretreatment, and Group 5 received conventional adhesive resin cement (CAR). Micro-computed tomography (Micro-CT) was used to evaluate void formation and distribution, while push-out bond strength (POBS) testing and scanning electron microscopy (SEM) were performed to assess bond strength and analyze failure modes. SEM analysis revealed that cohesive failure within the polyethylene posts was predominant across all groups. Conclusion: These findings indicate the clinical viability of SARC, especially without adhesive pretreatment as an effective and simplified post-cementation method, particularly in cases with restricted visibility. This approach offers reduced void formation, contributing to improved long-term durability of the restoration.