Clinical Trial of Modified Endocrown and Personalized Pos... | NCT07206108

Status Module

Name	Class
Stomatological Hospital of Southern Medical University	UNKNOWN
Guanghua Stomatological Hospital, Sun Yat-sen University	UNKNOWN

Description Module

Arms/Interventions Module

Arm Groups

Label	Type	Description	Intervention Names
modified endocrown	Experimental	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. model design: use CEREC digital intraoral scanner 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.	Procedure: modified endocrown
Personalized pile core combined with full crown	No Intervention	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. 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. 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. 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.

Name	Type	Description	Arm Group Labels	Other Names
modified endocrown	Procedure	Combining the advantages of post-core crown and endocrown, an modified endocrown was designed	modified endocrown

Outcomes Module

Primary Outcomes

Measure	Description	Time Frame
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	6 month、1 year、2 years

Secondary Outcomes

Measure	Description	Time Frame
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.

Eligibility Module

Eligibility 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.