Modified endocrown versus personalized post-and-core plus full crown for large premolar defects after root canal
A Multicenter, Randomized Controlled, Single-blind, Non-inferiority Clinical Trial of Modified Endocrown and Personalized Post Core Combined With Full Crown for Large-area Tooth Defects After Root Canal Treatment
We will test whether a modified endocrown works as well as a personalized post-and-core with a full crown for adults who have large premolar tooth defects after root canal treatment.
Quick facts
| Phase | Not applicable |
|---|---|
| Study type | Interventional |
| Enrollment | 246 (estimated) |
| Ages | 18 Years to 65 Years |
| Sex | All |
| Sponsor | Nanfang Hospital, Southern Medical University Academic / other |
| Drugs / interventions | chemotherapy |
| Locations | 1 site (China) |
| Trial ID | NCT07206108 on ClinicalTrials.gov |
What this trial studies
This is a multicenter, randomized, single-blind non-inferiority trial enrolling 246 premolars that have completed root canal treatment. Eligible teeth will be randomized to receive either a modified endocrown restoration or a personalized post-and-core combined with a full crown, using clinical and imaging guidance and CAD/CAM workflows where applicable. Participants will be followed at 6 months, 1 year, and 2 years to record clinical and radiographic outcomes, with the primary outcome being restoration survival rate. The trial aims to provide comparative efficacy and safety data to guide restorative choices for large-area premolar defects after endodontic therapy.
Who should consider this trial
Good fit: Ideal candidates are adults with premolars that completed root canal treatment at least two weeks earlier, have good oral hygiene, retain at least 50% of the crown or two crown walls, have adequate root length and occlusion, and are not planned as abutments for fixed or removable prostheses.
Not a fit: Patients with subgingival defects that cannot be managed by crown lengthening, poor periodontal health or probing depths >4 mm, insufficient remaining crown or root length, heavy smoking or other severe oral habits, or teeth intended as FPD/RPD abutments are unlikely to benefit from the interventions tested.
Why it matters
Potential benefit: If successful, the modified endocrown could offer an equally durable but less invasive and more tooth‑conserving restoration option for affected premolars.
How similar studies have performed: Previous laboratory and small clinical series of endocrowns have shown promising short-term results, but large randomized long-term comparisons against personalized post-and-core restorations are limited.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * 1: The affected tooth was a premolar that had undergone complete root canal treatment for two weeks. Both imaging and clinical examinations indicated no abnormal periapical reactions. 2: The oral hygiene condition is good. There is no periodontitis or combined periodontal and endodontic lesions with a probing depth greater than 4mm. There are no severe oral bad habits (such as smoking more than 20 cigarettes per day, chewing betel nuts, etc.) 3: At least 50% of the crown structure should be retained, or at least two crown walls should be retained, and the tooth defect should not be located under the gums or can be aligned with the gums or located above the gums through crown lengthening surgery. 4: The affected tooth has sufficient root length to ensure a pedicle-crown ratio of at least 1:1 and a root tip closure of at least 3 mm. 5: The occlusal function is normal. 6: Treated premolars will not be used as abutments for FPD or RPD restoration. Exclusion Criteria: * 1: Root canal retreatment of the affected tooth. 2: Loosening \> I °, alveolar bone resorption exceeds 1/3 of the root length. 3: Loss of adjacent teeth and occlusal teeth. 4: The patient is in the preconception period and the pregnancy period. 5: Patients with night bruxism, deep overbite, tight occlusion or severe limited mouth opening, and temporomandibular joint diseases. 6: Patients who have a history of chemotherapy or radiotherapy in the head and neck region within 5 years, suffer from severe systemic and organic diseases, have physical disabilities or mental illnesses that affect oral hygiene care, or have received drug treatment that may affect or promote bone metabolism within the past 3 months. 7: The affected tooth has imaging manifestations of absorption inside and outside the root, or the anatomical morphology of the root and root canal is poor, such as short and small roots, curved root canals, small roots or residual roots that cannot meet the cord-to-root ratio standard for pile-core crown restoration. 8: The researchers consider other situations that are not suitable for participation.
Where this trial is running
China
- Nanfang Hospital of Southern Medical University — China, China (Recruiting)
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.