**13. Conclusions**

Periapical radiographic examination should be part of each patient's periodontal evaluation and should be coupled with a detailed recording of pocket depths, gingival margin location, and bleeding on probing. Radiographic evaluation should be updated every 2 years. Periapical radiographs often underestimate the amount of periodontal bone loss, and early changes are usually not detected. Significant interdental bone loss can occur and may not be detectable on periapical radiographs because the density of the intact buccal and lingual or palatal bone plates obscure changes that occur as the result of periodontitis. Comparison of periapical radiographs of the same area taken at different times will only be reliable in documenting dramatic changes in bone levels since variations in angulation of the beam, placement of the film, and development of the image make accurate measurements taken over time very difficult and unreliable.

Recent use of three-dimensional radiographic techniques with CBCT gives a much more accurate picture of periodontal bone loss than do two-dimensional radiographs and will be more widely used as this technology becomes available in more clinics.
