To determine the change of labial bone mass 1 year after immediate implant placement and delayed implant placement by cone beam computed tomography(CBCT), and to evaluate the diagnostic value of CBCT for post-implant labial bone mass during esthetic zone.

A total of 22 implants from 22 patients in maxillary anterior region were followed up with 11 immediate implant placements and 11 delayed implant placements. CBCT images were obtained at three different time point: one week before surgery, immediately after surgery, and one year after implant placement. Labial bone thickness and height were recorded with four sites identification designed by ourselves in this study. The software of SPSS 13.0 was used for statistical analysis.

Significant vertical reduction of labial bone was found in immediate implant placements after 1-year(t=3.316, P=0.009), while no significant difference in delayed implant placement(t=2.073, P=0.068). The 1-year horizontal bone alteration was significantly different at 1 mm apical to the implant/abutment interface(t=2.369, P=0.042)and midimplant(t=3.474, P=0.007); while no significant difference was found at 1 mm coronal to implant bottom both in immediate implant and delayed implant(t=1.596, P=0.145).

CBCT can be used to evaluate the post-implant labial bone mass in esthetic zone. Labial bone and alteration one year after implant placement can be qualitatively assessed by CBCT.