Q. Periapical radiography - criteria for endosteal implants?

Periapical radiographs are images of a limited region of the mandibular or maxillary alveolus.  Periapical radiographs are produced by placing the film intraorally parallel to the body of the alveolus with the central ray of the X-ray device perpendicular to the alveolus at the region of interest, producing a lateral view of the alveolus. Periapical radiographs provide a lateral view of the jaws and no cross sectional information.

In terms of the objectives of pre-prosthetic imaging, periapical radiography is

1. A useful high yield modality for ruling out local bone or dental disease.

2. Of  limited value in determining quantity because the image is magnified, may be distorted, and does not depict the third dimension of bone width.

3. Of limited value in determining bone density or mineralization (the lateral cortical plates prevent accurate interpretation and cannot differentiate subtle trabecular bone changes.

4. Of value in identifying critical structures, but of little use in depicting the spatial relationship between the structures and the implant site.

5. The implant bone interface is depicted only at the mesial, or distal, inferior, and crestal aspects or, where the central ray the X-ray source is tangent to the implant surface. Other regions of the implant interface are simply not depicted well by this modality.