Dental implants are generally elective surgical procedures and should be undertaken on patients who are systemically healthy enough to undergo elective, outpatient procedures. Some common systemic diseases may also directly affect the rates of implant survival. It has been shown that implant failure rates were similar for patients with well-controlled diabetes (HbA1C < 8%) and patients without diabetes; with failure rates in patients with Type 2 diabetes overall demonstrating a marginally significant increase in failures.54 Patients with uncontrolled diabetes may be poor implant and surgical candidates and demonstrate higher levels of early and late implant failures.55 In humans, hyperglycemia is known to impair wound healing, impair host defense against pathogens, prolong the inflammatory response to injury, and impair new bone formation and bone repair.55 The recommended osseointegration periods may be extended in diabetics due to this delay in wound healing caused by hyperglycemia.56 Future studies are needed to identify distinct cut-off points and quantify the risks, if any, associated with diabetes and development of peri-implantitis.
Osteoporosis may also potentially affect implant survival. Osteoporosis and osteopenia are diseases characterized by low bone mass and micro-architectural deterioration with a consequent increase in bone fragility and susceptibility to fracture.57,58 Osteoporosis is diagnosed when bone mineral density (BMD) is 2.5 standard deviations or more below mean for age and gender-matched individuals and osteopenia is characterized as BMD between 1 and 2.5 standard deviations.57,58 While osteoporosis/osteopenia have common risk factors with periodontal and peri-implant diseases, including cigarette smoking, dietary factors, and medications, periodontal disease has been independently associated with osteoporotic status.59 Peri-implantitis, periodontal disease and osteoporosis are mediated by similar dysfunction in the bone remodeling process and the interaction between these diseases may be expected. Patients with osteoporosis demonstrated decreased alveolar and axial bone density and mass and thinner cortical bone than healthy counterparts.60 To date, studies have not shown a definitive association of peri-implantitis with osteoporosis or osteopenia, although implant placement and use of bisphosphonate medications have been shown to potentially mitigate alveolar bone loss in osteoporotic patients.3,61-63