Durability and Failure Modes of IPS e.max Endocrown in Endodontically Treated Molars: A 10-Year Clinical Report of Two Cases

Restoring endodontically treated teeth (ETT) presents a common challenge in general practice. Whereas the traditional method of using dental posts and full-coverage crowns is well-established, it often runs against the minimally invasive principles of recent adhesive dentistry. A more conservative option is provided by endocrowns, which are monolithic restorations that use the pulp chamber for retention. This study evaluated the long-term clinical performance of two endocrowns (#26, #46) over 10 years. Both restorations were fabricated using the IPS e.max Press system (Ivoclar Vivadent, Schaan, LIE) and cemented with a dual-cure resin cement. Their performance was assessed at baseline, sixth, 12, 18, 60, 84, and 120 months using the modified United States Public Health Service (USPHS) criteria. At the sixth, 12th, 18th, and 50th-month evaluations, both endocrowns demonstrated 100% clinical success. They showed no issues with marginal adaptation, contact points, surface texture, color match, or retention. However, at the 84-month follow-up, endocrown #26 debonded and required replacement, while the restoration #46 survived until the 120-month follow-up, at which point it failed due to a buccal fracture. In conclusion, these findings indicate that while endocrowns can provide excellent short- to medium-term outcomes, their very long-term survival is challenged by the risks of debonding and fracture, underscoring the importance of meticulous case selection and adherence to adhesive protocols.