Dental implants offer a viable long-term treatment option for patients with missing teeth. The use of metallic dental implants has relatively high reliability and long-term success rates; however, it is not without complications and the need for ongoing maintenance persists. Particles are generated during the life span of an implant, and this can have significant physiological implications such as disrupted osseointegration and bone resorption (osteolysis) that may in turn lead to implant loss. Particles can be released during implant bed preparation, from implant surface due to shear forces during fixture insertion, from implant-abutment interface due to wear and during functional loading. Exposure to the oral environment such as saliva, bacteria and chemicals such as fluoride can further facilitate the corrosion and degradation of titanium. A wide range of 10 to 20 μm in sizes of the released particles were reported in several locations such as at implant surface and peri-implant bone as well as distant sites such as the lungs, liver and kidney.

One common issue that can have detrimental impact on the long-term outcome of implant restorations and cause implant failure is peri-implantitis. Peri-implantitis is a plaque-associated pathological condition occurring in tissues around dental implants. It is characterised by inflammation in the peri-implant mucosa and subsequent progressive loss of surrounding supporting bone in which the implant is anchored. The risk of peri-implantitis is dependent on several of factors, and the frequency of peri-implantitis diagnosis has been reported to be 1–47% with selected implant systems. The large variation is due to the criteria used in diagnosis of peri-implantitis, e.g. some diagnose peri-implantitis with 0.5 mm crestal bone loss while at the other extreme 4 mm bone loss is needed for the diagnosis. Moderate to severe peri-implantitis (signs include bleeding on probing/suppuration and bone loss greater than 2 mm) was reported in 14.5% of patients. Recently, the 2017 World Workshop Consensus report stated that in the absence of previous examination that records a diagnosis of peri-implantitis can be made with probing depths of greater than 6 mm and crestal bone loss greater than 3 mm in the presence of bleeding and/or suppuration on gentle probing.