Incidence of implant buccal plate fenestration in the esthetic zone: a cone beam computed tomography study

The aim of this cone beam computed tomography (CBCT) study was to investigate the incidence of fenestration and associated risk factors with virtual placement of an implant in the maxillary incisor region.

Edentulous ridges missing a maxillary central or lateral incisor and amenable for single implant placement were included. Root-form implants (4×12 mm and 3.5×12 mm for the central and lateral incisors, respectively) were placed virtually in the edentulous space following the axis of the ipsilateral crown. Buccolingually, the implants were placed in the ideal prosthetic cingulum position. The angles of the ridge (RA) and implants (IA) in relation to the hard palate and the incidence of fenestration were recorded.

A total of 48 CBCT scans were analyzed. The mean RA and IA were 124.32 degrees and 110.91 degrees, respectively. Nine cases resulted in fenestration, equivalent to 18.75% of the total cases. The discrepancy between the RA and IA was statistically significantly larger in the fenestration sites (19.93 degrees) than in the nonfenestration sites (13.05 degrees). The concavity depth of the alveolar ridge was statistically significantly higher in the fenestration sites (4.79 mm) than in the nonfenestration sites (3.40 mm).

Within the limitations of this study, it can be concluded that the occurrence of fenestration is common (approximately 20%) if an implant is placed in the cingulum position with the axis following that of its restoration.