Background: This ambispective study evaluated the prognostic factors for long-term survival and success of endodontically treated teeth (ETT) in patients treated at an educational hospital. Methods: Patients who received root canal treatment (RCT) at Princess Nourah bint Abdulrahman University (2018–2023) were included if the following criteria were met: follow-up time of a minimum of 12 months was available, and clear pre- and post-treatment periapical radiographs. Two calibrated examiners assessed RCT quality along with pre-treatment and follow-up periapical index (PAI) scores. Coronal restorations were evaluated for quality, type, and timing. Data on oral hygiene, smoking, systemic health, periodontal status, and occlusal factors were collected. Tooth survival was defined as a functional, asymptomatic tooth, while success required a clinically asymptomatic tooth with a PAI score ≤ 2. Multivariate regression analysis was performed to assess the influence of the collected variables on tooth survival and success. Statistical significance was set at p < 0.05. Results: A total of 461 ETT from 242 patients were analyzed. The survival rate was 89%, while 81% met the treatment success criteria. Most patients were female (65%), and only 8.9% had a healthy periodontium. Multivariate analysis identified preoperative PAI score, obturation density, and coronal restoration quality as significant predictors of survival and success (Nagelkerke R² = 0.338). Conclusions: ETT demonstrated high survival and success rates. Preoperative PAI score, obturation density, and coronal restoration quality were key predictors of long-term treatment outcomes, highlighting the importance of comprehensive pre-treatment assessment and high-quality endodontic and restorative procedures.

Background/Objectives: Root canal treatment (RCT) is a crucial procedure for preserving dental health. While its clinical success rates are well documented, patient-reported outcomes regarding quality of life remain less explored. This study aimed to assess the long-term impact of RCT performed in an educational hospital on patients’ oral-health-related quality of life (OHRQoL) using the Oral Health Impact Profile-14 (OHIP-14). Methods: A total of 1500 patients who underwent non-surgical RCT between April 2018 and February 2023 were called and invited for a follow-up visit. During the visit, all teeth that had undergone RCT were assessed clinically and radiographically by two calibrated examiners to evaluate RCT quality and pre- and post-treatment periapical index (PAI) scores. Demographic information and OHIP-14 responses were collected, and the data were recorded. Results: Patients reported high levels of satisfaction (95%) and no negative impact on their OHRQoL. Statistical analysis revealed that post-operative periapical index (PAI) scores (p < 0.001), patient gender (p = 0.003) and nationality (p = 0.029) significantly influenced OHRQoL perceptions; Conclusion: These findings emphasize the effectiveness of RCT in enhancing patients’ quality of life and highlight the impact of demographic factors—such as gender and whether the patient is a resident or a national of the country, along with post-treatment severity of the disease—on patient-reported outcomes.