Survival Outcomes of Crowns with and without Repaired Endodontic Access Cavities: A Retrospective Propensity Score...

This retrospective study aimed to compare the survival outcomes between crowns with repaired endodontic access cavities and intact crowns and to identify factors that influence restoration longevity.

Clinical records of patients who underwent root canal treatment through existing crowns (crowns with repaired access cavities, CRA) or received crowns after root canal treatment (intact crowns, IC) between 2012 and 2023 were analysed. A 1: 1 propensity score matching was applied based on age, sex, tooth type, and crown type. The outcomes of the matched cases were classified as survival or non-survival. Kaplan-Meier analysis and logrank tests were used to compare outcomes between the two groups over time. For CRA, multivariable Cox proportional hazards regression analysis was conducted to identify potential predisposing factors.

Among 608 eligible endodontically treated teeth, 120 CRA and 488 IC met the inclusion criteria. After matching, 120 samples per group were analysed. The survival rate was significantly lower for CRA (85.8%) than for IC (91.7%) (p=0.004). Occlusal parafunctional habits or interferences were the only significant factors affecting CRA survival.

CRA demonstrated lower survival rates than IC, with occlusal parafunctional habits or interferences as key factors influencing their longevity.