Root Canal InfectionNCT07206108
Clinical Trial of Modified Endocrown and Personalized Post-core and Crown for Large-area Tooth Defects After Root Canal Treatment
A study testing modified endocrown in people with Root Canal Infection and Tooth Defect, run by Nanfang Hospital, Southern Medical University at 1 site in China.
Trial summary
This study intends to adopt a multicenter, randomized controlled, single-blind, non-inferiority clinical trial design. 246 premolars that meet the inclusion criteria after complete root canal treatment will be selected from the clinical practice and randomly divided into two groups. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Root Canal Infection, Tooth Defect, Post and Core Technique
- What is being tested?
- modified endocrown
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 246 participants
- Where
- 1 siteChina
- Study dates
- 4 Aug 2025to 31 Dec 2029
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- 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.
Who cannot join
- 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.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
China1 site, 1 recruiting
- Recruiting
Nanfang Hospital of Southern Medical University
China
Wenjuan Yan, 15802018770, ywj918@smu.edu.cn
About this study
Official title: 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
This study intends to adopt a multicenter, randomized controlled, single-blind, non-inferiority clinical trial design. 246 premolars that meet the inclusion criteria after complete root canal treatment will be selected from the clinical practice and randomly divided into two groups. One group will be restored with the modified endocrown, and the other group will be restored with personalized post and core combined with full crown. Follow-up visits were conducted at 6 months, 1 year and 2 years after the operation respectively. Through clinical and imaging examinations, the survival rates of the two different restorations were evaluated and used as the main evaluation indicators to fill the gap in efficacy data of the modified endocrown in clinical applications, providing a strong evidence-based medical basis for subsequent restoration improvement and standardized application.
- Conditions
- Root Canal Infection, Tooth Defect, Post and Core Technique
- Being tested
- modified endocrown
- Keywords
- Modified endocrown, endocrown, personalized post and core combined with full crown, CAD/CAM, Teeth defect, Restoration of large-area defective teeth after root canal treatment
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
modified endocrownProcedure or surgery
Combining the advantages of post-core crown and endocrown, an modified endocrown was designed
| Study group | Role | What they receive |
|---|---|---|
| modified endocrown | Experimental | 1. preparation of residual crown: A. occlusal surface reduction of about 1.5-2mm, hole edge angle rounded;B. root canal orifice extension: remove all decay, remove root canal filling material 2mm below the root canal orifice;C. pulp cavity wall formation: form 2-5° extension of the wall, if there is a concave with mobile resin restoration.
2. model design: use CEREC digital intraoral scanner
3. Cutting: using CEREC MCX CAD/CAM system, cutting lithium disilicate glass ceramic block (IPSe. max CAD), fitting modified pulp cavity retention crown on teeth, adjusting occlusion, post-treatment of restoration, bonding with all-acid etching resin cement. Receives: Procedure: modified endocrown |
| Personalized pile core combined with full crown | No intervention | 1. Coronal preparation: Remove all existing restorations and carious tissue, eliminate unsupported enamel, flatten the root surface, establish the definitive margin, and ensure the dentin ferrule is ≥1 mm thick and ≥1.5 mm high. 2. Post-space preparation: Set post depth at ⅔-¾ of root length (≥ clinical crown length) using the working-length and periapical radiograph; remove obturation material to this depth with a pilot drill, leaving ≥4 mm apical seal. 3. Core restoration: Take a polyether impression of the post space, have a Co-Cr post-and-core fabricated, lute it with self-adhesive resin cement (RelyX U100/U200; 3M-ESPE), then prepare the core for a full crown. 4. Full-crown fabrication: Record a polyether impression/optical scan, have a lithium-disilicate ceramic crown (IPS e.max CAD) milled, try-in and adjust, then cement definitively with the same self-adhesive resin cement following manufacturer instructions. |
What is being measured
The primary outcome is the main question the study is designed to answer.
survival rate
To evaluate secondary caries, proximal anatomy, gingival health, tooth integrity, marginal adaptability, fracture and retention, and radiographic results of the restoration, and to calculate FDI scores for the above indicators according to the World Dental Federation evaluation criteria (FDI), calculate the survival rate of the restoration
Measured: 6 month、1 year、2 years
Secondary outcomes (3)
Tooth reserve volume
After root canal treatment and before tooth preparation, each tooth was scanned by CEREC extraoral scanner before tooth preparation. Each tooth was scanned by CEREC extraoral scanner to obtain an original STL file A before tooth preparation. After tooth preparation, the original STL file A1 after tooth preparation was obtained. The files A and A1 were imported into reverse engineering software (GeomagicControlX2020; Geomagic Inc.), calculated and recorded the amount of tooth preparation tissue of each tooth, and finally statistically analyzed the amount of tooth preparation tissue of the two groups.
Measured: immediately
patient satisfaction
visual analogue scale，VAS
Measured: 2 years
Adjust the amount of grinding tissue and the time of occlusal adjustment
After the prostheses are made, the prostheses are scanned by CEREC extraoral scanner, and each prosthesis will obtain an original STL file B, which will be bonded and fixed, adjusted, and scanned again by the same scanner to obtain the final STL file B1 of the prosthesis. The files B and B1 will be imported into reverse engineering software (Geomagic Control X2020; Geomagic Inc., calculated the adjustment tissue volume of the restoration, recorded the adjustment time during the operation, and finally analyzed the adjustment tissue volume and adjustment time of the two groups of restoration statistically.
Measured: immediately
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Oct 2025
- Study start4 Aug 2025
- Primary completion31 Dec 2029 (estimated)
- Study completion31 Dec 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Root Canal InfectionStudies of the same condition, open and under way.
- More trials run by Nanfang Hospital, Southern Medical UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 246 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Nanfang Hospital, Southern Medical University
- Sponsor type
- University, hospital or other
- Collaborators
- Stomatological Hospital of Southern Medical University, Guanghua Stomatological Hospital, Sun Yat-sen University
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07206108
- Sponsor's protocol ID
- NFEC-2025-270
- Status last verified
- Sep 2025
- First submitted
- 25 Sep 2025
- Last updated
- 3 Oct 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 3 Oct 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- 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
- ClinicalTrials.gov ID
- NCT07206108
- Acronym / sponsor ID
- NFEC-2025-270
- Conditions
- Root Canal Infection, Tooth Defect, Post and Core Technique
- Keywords
- Modified endocrown, endocrown, personalized post and core combined with full crown, CAD/CAM, Teeth defect, Restoration of large-area defective teeth after root canal treatment
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 246 participants (estimated)
- Lead sponsor
- Nanfang Hospital, Southern Medical UniversityUniversity, hospital or other
- Collaborators
- Stomatological Hospital of Southern Medical University, Guanghua Stomatological Hospital, Sun Yat-sen University
- Study start
- 4 Aug 2025 (actual)
- Primary completion
- 31 Dec 2029 (estimated)
- Study completion
- 31 Dec 2029 (estimated)
- First posted
- 3 Oct 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study intends to adopt a multicenter, randomized controlled, single-blind, non-inferiority clinical trial design. 246 premolars that meet the inclusion criteria after complete root canal treatment will be selected from the clinical practice and randomly divided into two groups. One group will be restored with the modified endocrown, and the other group will be restored with personalized post and core combined with full crown. Follow-up visits were conducted at 6 months, 1 year and 2 years after the operation respectively. Through clinical and imaging examinations, the survival rates of the two different restorations were evaluated and used as the main evaluation indicators to fill the gap in efficacy data of the modified endocrown in clinical applications, providing a strong evidence-based medical basis for subsequent restoration improvement and standardized application.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| modified endocrown | Experimental | Procedure: modified endocrown1. preparation of residual crown: A. occlusal surface reduction of about 1.5-2mm, hole edge angle rounded;B. root canal orifice extension: remove all decay, remove root canal filling material 2mm below the root canal orifice;C. pulp cavity wall formation: form 2-5° extension of the wall, if there is a concave with mobile resin restoration. 2. model design: use CEREC digital intraoral scanner 3. Cutting: using CEREC MCX CAD/CAM system, cutting lithium disilicate glass ceramic block (IPSe. max CAD), fitting modified pulp cavity retention crown on teeth, adjusting occlusion, post-treatment of restoration, bonding with all-acid etching resin cement. |
| Personalized pile core combined with full crown | No intervention | –1. Coronal preparation: Remove all existing restorations and carious tissue, eliminate unsupported enamel, flatten the root surface, establish the definitive margin, and ensure the dentin ferrule is ≥1 mm thick and ≥1.5 mm high. 2. Post-space preparation: Set post depth at ⅔-¾ of root length (≥ clinical crown length) using the working-length and periapical radiograph; remove obturation material to this depth with a pilot drill, leaving ≥4 mm apical seal. 3. Core restoration: Take a polyether impression of the post space, have a Co-Cr post-and-core fabricated, lute it with self-adhesive resin cement (RelyX U100/U200; 3M-ESPE), then prepare the core for a full crown. 4. Full-crown fabrication: Record a polyether impression/optical scan, have a lithium-disilicate ceramic crown (IPS e.max CAD) milled, try-in and adjust, then cement definitively with the same self-adhesive resin cement following manufacturer instructions. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- 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.
Key exclusion criteria (8 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| modified endocrownCombining the advantages of post-core crown and endocrown, an modified endocrown was designed | Procedure or surgery | modified endocrown |
Primary outcome
survival rate
Time frame: 6 month、1 year、2 years
To evaluate secondary caries, proximal anatomy, gingival health, tooth integrity, marginal adaptability, fracture and retention, and radiographic results of the restoration, and to calculate FDI scores for the above indicators according to the World Dental Federation evaluation criteria (FDI), calculate the survival rate of the restoration
3 secondary outcomes
Tooth reserve volume
Time frame: immediately
patient satisfaction
Time frame: 2 years
Adjust the amount of grinding tissue and the time of occlusal adjustment
Time frame: immediately
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Oct 2025.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing modified endocrown in people with Root Canal Infection and Tooth Defect, run by Nanfang Hospital, Southern Medical University at 1 site in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 3 Oct 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Each site lists its own contact: choose the nearest one under Trial locations. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
survival rate (time frame: 6 month、1 year、2 years). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Oct 2025.