Quantitative comparison of cone beam computed tomography and microradiography in the evaluation of bone density after maxillary sinus augmentation: a preliminary study.

Cone beam computed tomography (CBCT) and microradiographic analyses were comparatively performed in maxillary sinus augmentation to preliminarily verify the diagnostic potential of CBCT on the evaluation of bone regeneration. A two-stage protocol was conducted in 19 consenting patients, all having the crestal bone ≤2 mm, in private dental office. Mineralized human bone allograft particles were used to augment sinus using lateral window approach. A succession of CBCT scans of the maxilla was taken before surgery, after sinus augmentation, and immediately after implant insertion. Using virtual probes, CBCT data were processed by medical imaging software and expressed as gray level (GL). A bone core biopsy was taken at implant placement, 6 months after surgery. Microradiography of transverse sections, taken 6, 8, and 10 mm from the crestal surface, of methacrylate-embedded biopsies was performed to analyze and to evaluate the mineralized material amount (MM%). A total of 21 sinus augmentations were performed. CBCT (mean GL: 646-693) data were not statistically different when comparing 6-, 8-, and 10-mm sites to after grafting/implant-insertion values. Furthermore, microradiographic (mean MM%: 45.3-48.3) data were not statistically different comparing 6-, 8-, and 10-mm sites, due to variation of values among patients. A GL and MM% parallelism was identified considering each patient, instead. A significant correlation (p < .001) between GL and MM% was found after both Wilcoxon test for paired data and simple linear regression analysis. The preliminary result clearly demonstrated the predictability of the CBCT analysis. Due to the limited sample and great variations of the MM% recorded in patients, further clinical and morphometric studies are needed to fulfill diagnostic expectations.