Horizontal and Vertical Dimensional Changes of Peri-implant Facial Bone Following Immediate Placement and Provisionalization of Maxillary Anterior Single Implants: A 1-Year Cone Beam Computed Tomography Study

Purpose: This cone beam computed tomography study (CBCT) evaluated horizontal and vertical dimensional changes to the facial bone following maxillary anterior single immediate implant placement and provisionalization. Materials and Methods: CBCT scans taken immediately after (T1) and 1 year after surgery (T2) were evaluated. The midsagittal cut of each implant was identified, and measurements were made at predetermined levels. Horizontal facial bone thickness (HFBT) was measured at 0, 1, 2, 4, 6, 9, and 12 mm apical to the implant platform. Vertical facial bone level (VFBL) was the perpendicular distance from the implant platform (0) to the most coronal point of the facial bone. Measurements were recorded and changes between T1 and T2 were calculated. The data were analyzed statistically at a significance level of α = 0.05. Results: CBCT scans of 21 patients were analyzed. At T2, the mean HFBT changes ranged from -1.23 to -0.08 mm at the seven different levels evaluated. The mean VFBL change was -0.82 mm. The HFBT changes at the 1- to 9-mm levels were not significantly different from one another, but they were significantly smaller than the change at the 0-mm level and significantly greater than the change at the 12-mm level. Significant positive correlations were observed only between horizontal and vertical changes and between horizontal change and initial VFBL at the implant platform. While the VFBL of eight implants (38%) was apical to the implant platform at T2, none was noted at T1. Conclusions: Dimensional changes to the peri-implant facial bone following maxillary anterior single immediate implant placement and provisionalization should be expected. The greatest HFBT change was noted at the implant platform level, in part because HFBT change is correlated to the initial VFBL and the change in VFBL at that level. Keywords: cone beam computed tomography, facial bone, immediate implant placement and provisionalization, immediate tooth replacement, maxillary anterior implants, measurement