Is an appropriate distance achieved between dental implants?

In the anterior, aesthetic zone, patients consider the aesthetic outcome of implants as an essential factor often priming over the functional factor. Implant positioning in relation to the mesio-distal dimensions of the alveolar ridge is a factor influencing the degree of bone remodelling following implant placement. This may in turn negatively influence the soft-tissue topography and the aesthetic outcome of the implant therapy, and compromise the implant longevity at later stages. Ideally, the distance between a tooth and an implant should be 1.5mm, and between two implants, 3mm.

Our aim was to evaluate the actual distance achieved between dental implants and adjacent teeth/implants in different areas of the mouth.

Methods:

Data of dental implants conducted by experienced periodontists was retrieved. Utilizing computer-based software, the patient’s OPG radiographs were used to measure the distances of implants in relation to adjacent teeth and to adjacent implants when present, and compared between different implant positions.

Results:

Data was collected from 219 implants in 50 patients.These implants were evenly distributed between arches (114 maxillary, 105 mandibular) and were mainly positioned posteriorly (110 molars, 68 premolars, 41 incisors). The mean distance between implants and teeth was 2.79±1.7 mm while distance between implants was 4.18±1.7 mm (P<0.001).  In the maxilla, the distances were closer to optimal than the mandible: maxillary distance between implants and teeth 2.22±1.2 mm and between implants 3.99±2.4 mm (P<0.001), while In the mandible, the distance from teeth was 3.28±1.9 mm and between implants 4.41±2.1 mm (P=0.003).

In the anterior area, implants were positioned closer to teeth (1.98±0.9 mm) than in the pre-molar (3.05±1.6 mm) and molar (4.97±1.7 mm) regions (P<0.001).

Conclusion:

While implants inserted in the anterior area tend to be in ideal position to maintain aesthetic and longevity, posterior implants are placed more distant, which might affect implant long term survival.