Inaccuracy of buccal bone thickness estimation on cone-beam CT due to implant blooming: An ex-vivo study

The aim of this article was to evaluate the accuracy of buccal bone thickness measurements around implants on CBCT.

Forty-four Osseospeed EV implants (3.6 in Ø) were placed guided and flapless in five fresh frozen human cadaver heads. The buccal peri-implant bone was measured clinically via guided bone sounding. Post-op CBCTs were taken with two different CBCT scanners (NewTom^® and Accuitomo^® ) on which the buccal bone was measured. Consequently, after implant removal, a new CBCT was made without implant artefacts (image reference standard) on which the real buccal bone thickness was scored.

Due to an average blooming (artificial increase of implant diameter) percentage of 12%-15%, the buccal peri-implant bone thickness was underestimated by 0.3 mm on both CBCT devices. Immediately adjacent to the implant blooming area, a doubtful zone of about 0.45 mm was observed in which the buccal bone was not always visible. Buccal bone that was thick enough to fall outside this doubtful zone could always be visualized.

The findings in this study may help the clinician in the decision-making process whether or not to intervene surgically in areas with ambiguous CBCT results.