Peri-implant diseases are the main biological complication of implant treatment and greatly influence treatment success [1]. Risk indicators for peri-implantitis include a history of periodontitis, poor oral hygiene, and smoking [2,3,4]. Peri-implantitis is often encountered clinically, occurring in 12 to 43% of implants and 28 to 47% of implant patients [5,6,7,8]. Similarities between the pathology and pathogenic factors of peri-implantitis and those of periodontal disease (such as periodontitis) have been described [9,10,11]; however, many points remain unclear [12]. For this reason, discussion is ongoing about the clinical criteria and selection of treatment options for peri-implantitis [13, 14].

The diagnostic criteria and treatments for peri-implant diseases such as peri-implantitis are not currently standardized. In contrast, periodontitis is diagnosed by periodontal tissue probing, attachment level, the status of oral hygiene, tooth mobility, occlusion, and furcation and dental X-ray imaging.

Ideally, peri-implant mucositis is discovered in its early stages to allow longer maintenance therapy, preventing complications and maintaining a high success rate [15]. No previous study describing clinical examination, such as probing the tissue surrounding implants, has been reported in Japanese patients. In this study, we statistically evaluated various clinical examination parameters during implant maintenance to determine correlations between them.