Evaluation of Using Different Screwed Abutment Height

Study Overview
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Brief Summary
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A prospective randomized controlled clinical trial will be conducted. Study groups will be assigned as described above. The patients will be randomly divided into two groups in order to study the influence of prosthetic screw abutment in marginal bone loss (MBL) around Bone Level Tapered implants (BLT® Roxolid® SLActive® guided implants, Straumann Dental Implant System, Institut Straumann AG, Basel, Switzerland).

Detailed Description
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48 patients will be selected with partial edentulism in the maxilla or mandible, requiring two dental implants in the posterior areas (molars and premolars). Each patient will be randomly allocated in one of the two groups: test group (n=36) or control group (n=12) and all the implants will be placed by residents of the International Master in Oral Surgery and Master in Periodontics of the same University. Study groups Group 1: Two stage approach (cover screw in first surgery and healing abutment in second surgery) (12 patients) Group 2: One stage approach (healing cap over trans-epithelial abutments) (36 patients).Two subgroups according to different trans-epithelial height abutment: Subgroup 2.1: Screw-retained abutment of 1 mm height (18 patients) Subgroup 2.2: Screw-retained abutment of 2.5 mm height (18 patients) Clinical Parameters and Outcomes Three-dimensional volumetric changes in hard and soft tissues (Cone-beam computed tomography superposed with digital cast models). Marginal bone level (MBL) change: Standardized intraoral periapical x-rays will be taken on the day of surgery, 4, 6, 12, 24 and 36 months following surgery. Probing depth, bleeding on probing and keratinized mucosa width will be measured in the follow-up visits in 3 different points in buccal (Mesial, center and distal). VAS Scale: The visual analog scale or visual analog scale (VAS).

Official Title
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Evaluation of Straumann Bone Level Tapered® Implants Using Screwed Abutment Height in Partially Edentulous Patients: a Randomized Controlled Clinical Trial

Conditions
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Bone Loss

Intervention / Treatment
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* Device: Dental implant placement with COVER SCREW (two surgeries in control group) or DEFINITIVE TRANSEPITHELIAL ABUTMENT (one surgery in test group)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Signed informed consent Overall, healthy subjects Females and males of at least eighteen-years Requiring a minimum of two implants (molar and/or premolar teeth) Adequate oral hygiene (less than 15% FMPS) Able to follow instructions and attend a regular compliance Enough bone to place a standard implant of 4.1 mm diameter. Exclusion Criteria: Acute local infection Occlusal overload with parafunctional activity (assessed clinically) Large occlusal discrepancies Untreated periodontal disease assessed by Socransky et al. parameters (≥2mm clinical attachment loss in two consecutive visits within 1 year) Smokers (more than 10 cigarettes/day) Drug and/or alcoholic dependencies Medical conditions contraindicating implant surgery History of head and/or neck radiation Bisphosphonate therapy

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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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: Each patient will be randomly allocated in one of the two groups: test group (n=36) or control group (n=12)
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Control group<br>Group 1: 2 stage approach (cover screw) (12 patients): cover screw is placed over the dental implants in the first surgery and a second surgery will be performed to expose the implants and placing a healing abutment after 2-4 months, DEVICES: COVER SCREW (first surgery) and HEALING ABUTMENT (second surgery) | Device: Dental implant placement with COVER SCREW (two surgeries in control group) or DEFINITIVE TRANSEPITHELIAL ABUTMENT (one surgery in test group)<br>* Dental implant placement using cover screws (first surgery) and a healing abutment (second surgery) or definitive transepithelial abutments the same day of the implant placement (one unit surgery)<br>|
| Experimental: Test group<br>Group 2: Protective plastic cap over different definitive trans-epithelial abutments are placed in the unic surgery performed (36 patients): Definitive transepithelial abutments will be placed the same day of the implant placement surgery. DEVICE: DEFINITIVE TRANSEPITHELIAL ABUTMENT | Device: Dental implant placement with COVER SCREW (two surgeries in control group) or DEFINITIVE TRANSEPITHELIAL ABUTMENT (one surgery in test group)<br>* Dental implant placement using cover screws (first surgery) and a healing abutment (second surgery) or definitive transepithelial abutments the same day of the implant placement (one unit surgery)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Marginal bone loss | Periimplant bone level by measuring from the implant platform to the first bone to implant contact. Messuret in 2 points: MESIAL AND DISTAL with intra-oral XR. (measured in millimeters) | After implant loading (baseline)and once every year to 36 months follow-up | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Probing depth | Measuring this outcomes at 4 different points .(Mesial Buccal, Center Buccal, Distal Buccal and central lingual) (measured in millimeters). | After implant loading (baseline)and once every year to 36 months follow-up | 
| Bleeding on probing | Measuring this outcomes at 4 different points .(Mesial Buccal, Center Buccal, Distal Buccal and central lingual) (measured in millimeters). | After implant loading (baseline)and once every year to 36 months follow-up | 
| Keratinized mucosa width | Measuring this outcomes at 4 different points .(Mesial Buccal, Center Buccal, Distal Buccal and central lingual) (measured in millimeters). | After implant loading (baseline)and once every year to 36 months follow-up | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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bone loss, dental implant, bone implant interface, Peri implant Endosseous Healing, Dental implant abutment