dental implant, implant treatment, patient compliance, peri-implantitis
| INTRODUC TI ONIt is well-established that the maintenance of healthy tissues around implants is one of the key factors in the long-term success of implants. Plaque accumulation induces an inflammatory process that may lead to a progressive destruction of soft and hard tissues and, ultimately, to implant failure. 1-3 The inflammatory process, mucositis, is a marginal inflammation without attachment or bone loss, 4 similar to gingivitis around natural teeth. The inflammatory process associated with the loss of marginal supporting bone around an implant is defined as peri-implantitis. 5,6 One problem with the diagnosis of peri-implant disease is that substantial variation in prevalence has been reported in the same patient population depending on which diagnostic criteria are used. 7The current guidelines for the definition and diagnosis of peri-implant diseases were established in the sixth, seventh, and eighth European Workshops on Periodontology. 6,8,9 The prevalence of peri-implantitis seems to be of the order of 10% at implant level and 20% at patient level during 5-10 years of function. 10 A meta-analysis reported a weighted mean prevalence of peri-implant mucositis of 43% (1196 patients and 4209 implants) and a weighted mean prevalence of peri-implantitis of 22% (2131 patients and 8893 implants).However, the authors stated that the heterogeneity in definition criteria of peri-implantitis could be a confounder.Peri-implantitis has been primarily described as a simple infectious pathologic condition of peri-implant tissues. 1,11 Many local factors, such as implant surface, topology, and bacterial contamination at the implant/abutment junction, and patient factors, such as smoking habit, poor oral hygiene, history or presence of periodontitis, genetics, and excessive alcohol consumption, have also been associated with an increased risk of developing peri-implant diseases. [12][13][14][15][16] The etiology of alveolar bone loss around implants plays a crucial role in the classification of the disease. The most common theories to explain alveolar bone loss are the infection theory and the overload theory. 17 The infection theory states that implants are susceptible to similar types of disease as teeth, the major difference being that the term periodontitis is reserved for teeth and peri-implantitis is reserved for implants. The overload theory has not been clearly determined. Some studies have suggested that Occlusal overload may play a role when associated with plaque accumulation or pre-existing inflammation. 18 A third theory has also been developed, where alveolar bone loss is explained by the synergy of combined factors, such as surgical procedures, prosthodontics, and patient disorders. 17 The difference between primary and secondary peri-implantitis has also been presented. In primary peri-implantitis, bacterial infection is the primary cause of alveolar bone loss, whereas secondary peri-implantitis may originate from other factors. 1...