Posterior partial crowns out of lithium disilicate with or without posts: A randomized controlled study at 9 years follow up.

Objective: These randomized controlled clinical aims to evaluate the long-term clinical performance of posterior lithium disilicate partial crowns used to restore endodontically treated teeth (ETT), with or without fiber post placement, over a 9-year period in patients who did not report any bruxism activities at baseline.

Materials and methods: Participants were recruited at the University of Siena, Siena, Italy. Patient were≥18 years, in need for one partial crown on posterior teeth (molars and premolars) following endodontic treatment and with at least 50 % of the coronal structure remaining. Patients were randomly assigned to two groups: Group 1 received fiber posts for abutment build-up, and Group 2 did not. Lithium disilicate partial crowns were fabricated and adhesively cemented for both groups. Clinical and radiographic evaluations were conducted at baseline, 1, 2, 3, and 9 years. Failures were defined as post debonding/fracture, root fracture, crown dislodgement/fracture, or the presence of periapical lesion. Cox regression analysis was used to assess the influence of post placement and tooth type.

Results: A total of 120 patients were enrolled. At the 9-year follow-up, survival of ETT ranged between 88.8 % in molars without post and to 85.7 % in premolars with no post. No statistically significant difference was observed regarding post placement or tooth type on failure rates (p > .05).

Conclusion: The findings of the present clinical trial support the idea in patients with no report of bruxism, the insertion of a fiber post for the reconstruction of endodontically treated teeth with partial crown lithium disilicate in posterior teeth is not a necessary procedure.

Clinical significance: When at least 50 % of coronal structure is maintained, fiber post placement does not significantly influence survival rates. Lithium disilicate partial crowns provide excellent long-term outcomes in restoring endodontically treated posterior teeth.