Influence of file compression on radiographic diagnosis of periodontal bone loss on smartphones.

Purpose: To evaluate the influence of imaging compression on radiographic diagnosis of periodontal bone loss on smartphones.

Methods: 45 digital periapical radiographs with diverse periodontal bone loss patterns were selected. All radiographs were performed with a CMOS-type sensor and were exported from the acquisition software with two compressions: JPEG with a 10% compression rate and JPEG with a 90% compression rate. Images were shared using the WhatsApp application and three examiners evaluated all radiographs on the smartphone. The examiners' diagnostic agreement was evaluated using the Kappa index. The McNemar and Cochran's Q statistical tests were used to compare the impact of the image compression, examiner, and type of periodontal bone defect on the diagnosis. Statistical analysis was performed using the SPSS software.

Results: Kappa values were greater than 0.7 for all examiners and no statistically significant difference for the periodontal diagnosis, regardless of the image compression, the examiner background, and the type of periodontal bone defect.

Clinical significance: The use of smartphones to analyze and share images has become very common in dentistry. This study shows that images can be shared and analyzed on smartphones without compromising periodontal diagnosis, regardless of their spatial resolution.