Aim: The objective of this systematic review was to evaluate the diagnostic value of CBCT compared with 2D imaging and clinical gold standard techniques in peri-implant bone defect detection and measurement. Materials and methods: Literature search was performed using MEDLINE, Embase and Web of Science databases up to July 2017. Clinical, ex vivo, in vitro and animal studies that assessed and measured peri-implant bone defects using different imaging modalities were included in this review. Two reviewers performed data extraction and qualitative analysis. The methodological quality of each study was reviewed using the QUADAS-2 tool. Results: The initial search revealed 2849 unique papers. Full-text analysis was performed on 60 articles. For the present review, nine studies were considered eligible to be included for qualitative analysis. CBCT performed similar to intraoral radiography in mesiodistal defect detection and measurements. Additional buccolingual visualisation and volumetric and morphological assessment of peri-implant bone defects are major advantages of 3D visualisation with CBCT. Nevertheless, one must be aware of metal artefacts masking osseointegration, shallow bony defects and other peri-implant radiolucencies, thus impeding early diagnosis of intrabony lesions. Conclusions: The present review did not provide evidence to support the use of CBCT as standard postoperative procedure to evaluate peri-implant bone. Up to date, we are clinically forced to remain with intraoral radiography, notwithstanding the inherent limitations related to restricted field of view and two-dimensional overlap. A 3D imaging approach for postoperative implant evaluation is crucial, making further development of an optimised and artefact-free CBCT protocol indispensable. Keywords: bone defects, CBCT, imaging, implant dentistry, peri-implantitis