Clinical Evaluation of Two Post Systems for Single Crown Restoration of Anterior Teeth: A Randomized Controlled Clinical Trial

Endodontically treated maxillary anterior teeth frequently present with significant loss of coronal tooth structure, compromising their resistance to fracture and complicating restoration. prefabricated fiber posts are widely used to retain a composite core prior to crown placement, but the degree to which a post adapts to the internal canal wall - leaving minimal or no gap between the post and the remaining gutta-percha - may influence long-term clinical performance and resistance to microleakage.

This study is a randomized controlled trial comparing a custom-adapted ultra-high-molecular-weight polyethylene (UHMWPE) fibers post (Ribbond-type), individually formed to the canal anatomy, against a prefabricated fiber post. Eligible teeth are endodontically treated maxillary anterior teeth with 1-2 missing coronal axial walls (mesial, distal, labial, and/or palatal), assessed at the cementoenamel junction, where any remaining sound walls meet a minimum height of 1.5-2 mm and a circumferential thickness of approximately 1 mm, in line with established ferrule criteria.

Participants will be randomly allocated to receive either the Ribbond post or the prefabricated fiber post, followed by a standardized composite core build-up and definitive crown restoration. Post space preparation, dentin conditioning, and cementation will follow a standardized step-by-step clinical protocol for each group.

The primary outcome is the post-gutta-percha gap distance, measured radiographically and expressed continuously in millimeters, with cases additionally classified as showing no gap versus any measurable gap. This dichotomization and its expected baseline distribution are informed by prior clinical data reporting outcomes in maxillary anterior teeth. The secondary outcome is post and restoration retention, evaluated clinically at follow-up using USPHS criteria.