Angulated Screw-retained Crowns Following Immediate Implant Placement

Study Overview
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Brief Summary
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There are two choices of restorations and implant abutments connection now: cemented and screw-retained.The excess cement, which would be difficult to completely remove, might lead to series of biological complications. The angulated screw channel (ASC) abutments, which recently introduced by Nobel Biocare , largely address the problem with visible screw access that may compromise esthetics. However, all of the present studies were clinical reports, thus the clinical efficacy of ASC abutments still needs the verification of evidence-based medicine with larger sample. Therefore, we designed a randomized controlled clinical trial study, aiming to verify the clinical efficacy of the ASC abutments by comparing screw-retained (with ASC abutments) single implant crowns with cemented ones in esthetic region.

Official Title
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Clinical Evaluation of Cemented and Angulated Screw-retained Crowns Following Immediate Implant Placement: a Randomized Controlled Clinical Trials

Conditions
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Tooth Diseases

Intervention / Treatment
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* Procedure: Immediate implant placement
* Procedure: Angulated screw-retained crowns placement
* Procedure: Cemented crowns placement


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ≥18 years old and in good health; Single tooth implant (type 1) in the esthetic region; Patients with natural teeth adjacent to single implant crowns; Patients with periodontal treatment before implant surgery; The implants are from Nobel Biocare system with tapered link and the permanent restoration is a single crown and all-ceramic; Soft tissue in the implanting-and-adjacent areas is healthy and free of infection Exclusion Criteria: Multiple implants in the esthetic region, or the restoration is a bridge Patients with bone augmentation procedures; Heavy smokers (>10 cigarettes/day); Medically compromised patients (American Society of Anesthesiologists (ASA) classification III-IV); Implants in an incorrect three-dimensional position (definition according to ITI VOL1); Uncontrolled diabetes mellitus; Unwilling to participate in the present study.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Angulated screw-retained crown<br>Restorations are connected to the implants by angulated screw channel system | Procedure: Immediate implant placement<br>* Implants are placed in fresh socket<br>Procedure: Angulated screw-retained crowns placement<br>* To insert the restorations by angulated screw systems<br>|
| Placebo Comparator: Cemented crown<br>Restorations are cemented onto the implant abutment | Procedure: Immediate implant placement<br>* Implants are placed in fresh socket<br>Procedure: Cemented crowns placement<br>* To cement the restorations onto the implant abutment<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| BOP% | Percentage of bleeding on probing positive | from baseline to 1-year follow-up | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| PPD | Pocket probing depth | from baseline to 1-year follow-up | 
| MBL | Marginal bone loss | from baseline to 1-year follow-up | 
| PES | pink esthetic score | from baseline to 1-year follow-up |