In this book, leading experts from around the world present the latest knowledge on the risk factors for peri-implant diseases and also examine the prevalence, etiology, and treatment strategy. Reports have suggested that a variety of risk factors, including poor oral hygiene, a history of periodontitis, diabetes, smoking, lack of keratinized mucosa, and implant surface topography, are associated with these diseases. Periodontally compromised patients who do not adhere completely to the supportive periodontal therapy have been found to present a higher implant failure rate, and several studies have shown that periodontal pathogens can translocate from periodontally involved teeth to the peri-implant sulci in partially dentate patients, highlighting the importance of periodontal treatment of the residual dentition prior to placement of dental implants. Recently a new concept was proposed as intraindividual variation exists in core microbiota in peri-implantitis and periodontitis. In elucidating the strength of association of peri-implant diseases with all of the risk factors identified to date, the book will be of interest to practitioners and other professionals in the field.