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. RESULTS: Micro CT analysis revealed, SARC with or without adhesive successfully demonstrated the smallest void volume in coronal and apical regions (P <0.05). Furthermore, void distribution patterns in the SARC groups were smaller and more consistent. In POBS, results exhibited no significant differences among the groups (P > 0.05), indicating comparable bond strength across the materials. 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.