Study to Evaluate Implant Survival Rate of Astra Tech Fixture ST in the Posterior Maxilla With One-stage Surgery and Early Loading

Study Overview
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Brief Summary
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The purpose of this study is primarily to evaluate implant survival rate of Astra Tech Fixture ST placed in the posterior maxilla. A one-stage surgical protocol will be used and the implants will be loaded four weeks after implant installation (early loading). Marginal bone levels, plaque and status of the periimplant mucosa will also be evaluated. The subjects will be followed for three years.

Official Title
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An Open Prospective Study to Evaluate the Survival Rate and Marginal Bone Response of Astra Tech Dental Implants, Fixture ST, in Patients With Tooth Loss in the Posterior Maxilla.

Conditions
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Jaw, Edentulous, Partially

Intervention / Treatment
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* Device: Astra Tech Fixture ST


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age 18 - 75 Unilateral or bilateral edentulism in the posterior maxilla, last tooth should be the canine or the first bicuspid Willing to give informed consent Exclusion Criteria: Bone height < 5 mm, in the planned implant area Bone width < 5 mm, in the planned implant area Previous bone augmentation procedure in the planned implant area Previous failures of endosseous implants Untreated caries and/or periodontal disease of residual dentition History or presence of any systemic or local disease or condition that would compromise post-operative healing and/or osseointegration Systemic corticosteroids or any other medication that would compromise post-operative healing and/or osseointegration Current alcohol or drug abuse Unable or unwilling to return for follow-up visits for 3 years

Ages Eligible for Study
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Minimum Age: 18 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
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Astra Tech Fixture ST<br> | Device: Astra Tech Fixture ST<br>* Astra Tech Fixture ST Ø 3.5 and 4.5 cm in lengths of 9, 11, 13, 15, 17 and 19 mm.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Implant Survival Rate | An implant that has failed to osseointegrate, lost its osseointegration or fractured will be considered a failure effective from the date of removal. Implant Survival Rate will be calculated using the Kaplan-Meier method based on the number of placed implants. Patients who discontinued the study after the last implant failure do not affect the cumulative survival rate. | At follow-up visit: 6 months after implants have been loaded | 
| Implant Survival Rate | An implant that has failed to osseointegrate, lost its osseointegration or fractured will be considered a failure effective from the date of removal. Implant Survival Rate will be calculated using the Kaplan-Meyer method based on the number of placed implants. Patients who discontinued the study after the last implant failure do not affect the cumulative survival rate. | At follow-up visit: 1 year after implants have been loaded | 
| Implant Survival Rate | An implant that has failed to osseointegrate, lost its osseointegration or fractured will be considered a failure effective from the date of removal. Implant Survival Rate will be calculated using the Kaplan-Meyer method based on the number of placed implants. Patients who discontinued the study after the last implant failure do not affect the cumulative survival rate. | At follow-up visit: 2 years after implants have been loaded | 
| Implant Survival Rate | An implant that has failed to osseointegrate, lost its osseointegration or fractured will be considered a failure effective from the date of removal. Implant Survival Rate will be calculated using the Kaplan-Meyer method based on the number of placed implants. Patients who discontinued the study after the last implant failure do not affect the cumulative survival rate. | At follow-up visit: 3 years after implants have been loaded | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Implant Failure | Total number of implants reported as failure. | 3 years after implant placement |