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

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.

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).