Objective: To compare spiral with conventional CT for multiplanar reco
nstruction (MPR) prior to dental implant placement. Methods: Ten patie
nts underwent conventional and then Spiral CT at 1 mm slice thickness.
In six patients (Group A) the pitch was 1:1, the other four (Group B)
it was 2:1. Image quality and clinical features were evaluated separa
tely on axial and reconstructed images by two experienced radiologists
who scored each parameter from 1 (poor, non-diagnostic) to 3 (good, d
iagnostic). Results: Loss of spatial resolution with spiral CT was not
significant and the diagnostic yield poorer only for trabecular bone
structure. The MPRs were better and depiction of the mandibular canal
more reliable. Conclusions: We recommend the use of spiral CT instead
of conventional CT for dental MPR because examination time is shorter
and patient comfort is improved. Use of a pitch of 2:1 permits a marke
d reduction in X-ray dose with no loss of image quality.