Study to Evaluate Bone and Gum Dimension Changes Around Dental Implants Placed in Different Positions in Bone.

Study Overview
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Brief Summary
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The purpose of this study is to test two standard of care techniques of placing dental implants, and to compare how people's bones and gums respond to two different depths at which implants are placed.

Detailed Description
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The purpose of this study is to test epicrestal and subcrestal placement of dental implants, and to compare how people's bones and gums respond to two different depths at which implants are placed.

Official Title
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Evaluation of Changes of Hard and Soft Tissues After Epi-crestal and Sub-crestal Placement of Ankylos Dental Implants.

Conditions
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Mouth, Edentulous

Intervention / Treatment
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* Device: Ankylos dental endosseous implants-Sub-crestal
* Device: Ankylos dental endosseous implants-Epi-crestal


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subjects must have read, understood and signed an informed consent form; Subjects must be 18 to 70 years of age; Subjects must be able and willing to follow study procedures and instructions; Subjects must have indication to receive two implants in a bilateral maxillary or mandibular edentulous areas (for at least 4 months post extraction) in areas of pre-molars (first or second) and molars (first or second); Sufficient width and height of bone to place at least 8mm length and any compatible in diameter Ankylos implant; Sufficient vertical clearance to place a single tooth crown replacement; No apical disorder/inflammation at the area of the implant site. Exclusion Criteria: Subjects participating in other clinical studies within 1 month prior to screening and/or involving therapeutic intervention (either medical or dental) that could affect bone or soft tissue healing; Female subjects who are pregnant or lactating, or who intend to become pregnant during the study period following entrance into the study; Subjects with parafunctional habits; Subjects who have failed to maintain good plaque control; Subjects with any systemic condition like uncontrolled diabetes mellitus, cancer, HIV, disorders that compromise wound healing, chronic high dose steroid therapy, bone metabolic diseases, radiation or other immuno-suppressive therapy which would preclude periodontal surgery; Absence of occlusal stability in centric occlusion; Subjects with the presence of acute infectious lesions in the areas intended for surgery; History within the last 3 months of weekly or more frequent use of smokeless chewing tobacco, pipe or cigar smoking and cigarette smoking (greater than 10 cigarettes per day) Present alcohol or drug abuse; Angulation requirements of the restoration exceeding approximately 15 degrees; Systemic corticosteroids or any other medication that would compromise post-operative healing and/or osseointegration (e.g. calcium channel blocker, dilantin).

Ages Eligible for Study
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Minimum Age: 18 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: This was a split mouth study design in which the same patient was used for both arms.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Implants placed at sub-crestal position.<br>Ankylos dental endosseous implants-Sub-crestal | Device: Ankylos dental endosseous implants-Sub-crestal<br>* Implants placed subcrestally<br>|
| Active Comparator: Epi-crestal implants.<br>Ankylos dental endosseous implants-Epi-crestal | Device: Ankylos dental endosseous implants-Epi-crestal<br>* Implants placed Epi-crestally<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Marginal Bone Level (MBL) | Changes in MBLs at 18 months and 30 months after implant placement were chosen as primary outcome parameters. Results are described as mean values and standard deviations. Note: Mean changes in MBL for epicrestal and subcrestal placements at lingual and buccal sites is also referred to as mid-facial bone levels. To determine MBL changes between T0 and each follow-up visit, MBLs at T0 were subtracted from the complementary values for that implant at T18 and T30. | Implant placement, and 18 months and 30 months after implant placement | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Mid-Buccal Soft Tissue Height | Soft tissue levels were measured clinically from a fixed reference point to the mid buccal soft tissue margin using a stent. Measurements were made from fixed reference points, by using a stent to perform clinical measurements in a reproducible position. | From final restoration (6 months after implant placement), and 12 months, 18 months, 30 months, 42 months, 54 months, and 66 months after implant placement | 
| Change of Interproximal Levels After Final Restoration | Analysis of interproximal bone height change measured by periapical radiographs. The height of the papilla will be assessed at the mesial and distal sites of the implants, by means of the published papilla Jemt index. Measurements will be assessed by reviewing the clinical photographs. Reference: Jemt, T. (1997) Regeneration of gingival papillae after single-implant treatment. International Journal of Periodontics and Restorative Dentistry 17: 326-333. | From final restoration (6 months after implant placement), and 18 months, 30 months, 42 months, 54 months, and 66 months after implant placement | 
| Change in Marginal Bone Level (MBL) | Changes in MBLs at 66 months after implant placement were chosen as a secondary outcome parameter. Results are described as mean values and standard deviations. Note: Mean changes in MBL for epicrestal and subcrestal placements at lingual and buccal sites is also referred to as mid-facial bone levels. To determine MBL changes between T0 and each follow-up visit, MBLs at T0 were subtracted from the complementary values for that implant at T18, T30 and T66. | Implant placement, and 66 months after implant placement |