Intra-surgical vs. radiographic bone level assessments in measuring peri-implant bone loss

Objective: To evaluate the accuracy between the intra-surgical and the peri-apical radiographic measurements of bone loss at implant with peri-implantitis. Materials and methods: A total of 46 Branemark implants in 24 patients with diagnosis of peri-implantitis were included in the study. The amount of peri-implant bone loss occurred at those implants was measured during peri-implant surgery and compared to the radiographic bone loss measured by three independent examiners. Results: The mean bone loss measured on radiographs underestimated the intra-surgical bone loss at the correspondent sites (0.7 mm at the mesial and 0.6mm at the distal sites); this underestimation was found to be a consistent finding in all the three examiners. Only 21% of the radiographic measurements corresponded to the clinical bone loss assessments, while an over- and underestimation within a range of 1-2 mm was recorded in 57% of the cases. There was a moderate positive linear correlation between the radiographic measurements and the clinical bone loss for mesial and distal sites (r = range 0.58-0.65). The variability between the three examiners in the radiographic measurements was frequently on the range of +/- 1-2 mm. Conclusion: The radiographic measurements of bone loss at implant affected by peri-implantitis often underestimated the clinical bone loss occurred at the implants. A difference of about +/- 1-2 mm in the estimation of radiographic bone loss could be merely assigned as inter-examiner different assessments.