Effect of Geometric Modifications of Implant Scan Bodies

Study Overview
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Brief Summary
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The aim of this clinical study will be the effect of geometric modifications of implant scan bodies compared to conventional transfer techniques on passivity of all on four mandibular restorations

Detailed Description
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The aim of this study will be the effect of geometric modifications of implant scan bodies compared to conventional transfer techniques on passivity of all on four mandibular restorations. Evaluation method: The trueness of the final impression and the passivity of the final prosthesis will be evaluated by two methods: Invitro evaluation For each patient in every group, the standard tessellation language (STL) files of scanned impressions will be superimposed on the reference file to determine the 3D surface, linear, and angular position analysis. The STL files for both frameworks will be superimposed on the reference file to determine the passivity. In vivo (Clinical) evaluation Radiographic evaluation using long cone parallel technique will be done for the framework after 6 month (T6) after one year (T12), and after 18 month (T18) from insertion.

Official Title
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Effect of Geometric Modifications of Implant Scan Bodies Compared to Conventional Transfer Techniques on Passivity of Mandibular All on Four Restorations

Conditions
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Prosthesis Durability

Intervention / Treatment
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* Device: Implant supported hybrid prosthesis


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 1. All selected patients will have four implants placed in the mandibular interforaminal region according to all -on -four concept. 2. All selected patients have a healthy mucosa and with no clinical complications. 3. All patients are cooperative and approve the proposed treatment protocol. Exclusion Criteria: 1. Patients who reject to participate in the study. 2. Patients who need implant placement as a result of previous implant failure.

Ages Eligible for Study
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Minimum Age: 45 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

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
Interventional Model Description: For group (I): For each patient, two final impressions will be made a) Final impression will be done by conventional one-step impression technique.For the same patient, another final impression using unmodified scan bodies will be done by direct intraoral scan technique. For group (II): For each patient, two final impressions will be made a) Final impression will be done by conventional one-step impression technique.For the same patient another final impression using subtractive modified scan bodies will be done by direct intraoral scan technique. Conventional impression for both groups will be poured into stone cast with multiunit abutments analogues, then scanned to be as a reference file for each patient.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: • Group I (control group)<br>Final impression will be done by conventional one-step impression technique. For the same patient, another final impression using unmodified scan bodies will be done by direct intraoral scan technique. | Device: Implant supported hybrid prosthesis<br>* For each patient, implant supported mandibular hybrid prosthesis will be fabricated digitally. Frameworks will be tried in patient's mouth, scanned intraorally by intraoral scanner (IOS).<br>|
| Active Comparator: • Group II (Test Group)<br>Final impression will be done by conventional one-step impression technique. For the same patient another final impression using subtractive modified scan bodies will be done by direct intraoral scan technique | Device: Implant supported hybrid prosthesis<br>* For each patient, implant supported mandibular hybrid prosthesis will be fabricated digitally. Frameworks will be tried in patient's mouth, scanned intraorally by intraoral scanner (IOS).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| passivity of the prosthesis | Radiographic evaluation using long cone parallel technique will be done for the framework | one year | 
| trueness of final impressions | For each patient in every group, the standard tessellation language (STL) files of scanned impressions will be superimposed on the reference file to determine the 3D surface, linear, and angular position analysis | one year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| patient satisfaction | patient satisfaction will be evaluated using Visual analogue scale questionnaire | one year |