Dental implants are small metal posts that look like miniature screws. They are surgically implanted into the jawbone where they serve as substitute tooth roots. Implants are used in dentistry to reestablish function and aesthetics to areas of the mouth were natural teeth are missing.

Classical dental implants are made in two pieces. One part anchors in the jawbone and one part serves as a connecting post (an abutment) that attaches to a crown restoration or to attachment clasps that hold a denture in place.

Occasionally the materials used to fasten the two implant components together work their way loose and over time the abutment may begin to disconnect. If this happens a small gap appears between the implant and abutment. There are many reasons why this loosening occurs. One reason may be the design of the implant itself and another may be the way the two components are fastened together.

This study will assess the performance of an implant with a new design. The investigators hypothesize that using this implant design will reduce the risk of an implant-abutment disconnect and improve long-term success of implant therapy.

While the external hex dental implant design has had very good clinical success, it is limited by retention screw loosening at the junction of the implant fixture and abutment; a situation that leads to micro-movement between components.

A number of clinical complications may arise when implant components separate. Micro-movement between the implant abutment and seating platform is thought to contribute to the formation of a "biological gap", the most notable consequence being gradual resorption of crestal alveolar bone over time.

We hypothesize that the "ACE CONNECT" two-piece implant design with an internal connection will limit screw loosening by providing a stable junction between the body of the implant and the abutment; a more stable junction will limit micro-movement and prevent the formation of a gap between components. Limiting the gap will lead to less inflammation of peri-implant soft tissues and reduced resorption of bone adjacent to the implant.

Inclusion Criteria:

• Need for replacement of non-adjacent missing teeth with dental implants
• Edentulous in the area for more than 2 months
• Minimum native bone height and width to receive a 10mm X 4mm implant

Exclusion Criteria:

• Untreated decay or periodontal disease in residual dentition
• Need for bone or soft-tissue augmentation in the proposed implant site
• Pregnancy
• Consistent use of medications likely to compromise bone healing
• Chronic disease condition likely to compromise bone healing
• Consistent smoking over 10 cigarettes during the immediate past 6 months

Dental school periodontology clinic