Influence of Platform-switching on Bone Level Alterations: a 3 Year Randomized Clinical Trial (RCT).

Study Overview
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Brief Summary
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The concept of platform-switching has been introduced to implant dentistry based on clinical observations of reduced periimplant crestal bone loss. However, published available data are controversial and most studies are limited to 12 months. The aim of the present RCT was to test the hypothesis that platform-switching has a positive impact on crestal bone level changes after 3 years.

Detailed Description
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Two implants with a diameter of 4 mm were inserted crestally in the posterior mandible of 25 subjects. After three months of submerged healing, single-tooth crowns were randomly placed, either with (3.3mm platform, test) or without platform-switching (4mm platform, control). Patients were followed up at short intervals for monitoring of healing an oral hygiene. Statistical analysis for the influence of time and platform-type on bone levels employed the Brunner-Langer Model.

Official Title
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Influence of Platform-switching on Bone Level Alterations: a 3 Year RCT.

Conditions
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Periimplant Crestal Bone Level Changes

Intervention / Treatment
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* Device: platform-shifted implant


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: good general health edentulous gap in the posterior mandible for placement of 2 implants sufficient bone height above the alveolar nerve for placement of implants with a height of 9.5mm bone width for placement of implants with diameter of 4mm at least 4mm keratinized mucosa medium or a thick soft tissue biotype Exclusion Criteria: infectious disease diabetes or osteopathy active periodontitis medication influencing bone metabolism lactating or pregnant women

Ages Eligible for Study
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Minimum Age: 30 Years
Maximum Age: 75 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: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: platform-switched implant<br>platform-switched implant | Device: platform-shifted implant<br> <br> |
| Active Comparator: platform-matched implant<br>platform-matched implant | Device: platform-shifted implant<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of vertical implant bone level |  | Implant insertion (baseline), 3 months (reopening), 4 months (crown mounting), 12, 25 and 38 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| probing depths |  | 4, 8, 12, 25, 38 months | 
| Bleeding |  | baseline, 4, 8, 12, 25, 38 months | 
| Plaque |  | baseline, 4, 8, 12, 25, 38 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Bacteria, bone level, bone loss, dental implants, implant design, platform-shifting, platform-matching