Bone classification: an objective scale of bone density using the computerized tomography scan.

Dental implants are subject to masticatory loads of varying magnitude. Implant performance is closely related to load transmission at the bone-to-implant interface where bone quality will be highly variable. The type and architecture of bone is known to influence its load bearing capacity and it has been demonstrated that poorer quality bone is associated with higher failure rates. To date, bone classifications have only provided rough subjective methods for pre-operative assessment, which can prove unreliable. The results of an extensive analysis of computerized tomography scans using Simplant software (Columbia Scientific Inc., Columbia, MD, USA) demonstrate that an objective scale of bone density based on the Houndsfield scale, can be established and that there is a strong correlation between bone density value and subjective quality score (P = 0.002) as well as between the bone density score and the region of the mouth (P < 0.001).