Type I diabetes is caused by a progressive autoimmune reaction which destroys the cells in the pancreas that produce insulin. It is unknown what first starts this cascade of immune events, but evidence suggests that both a genetic predisposition and environmental factors, such as a viral infection, are involved.
Type 2 diabetes is often linked to obesity and is the predominate form, that adults seeking dental implant therapy have. The two key problems associated with dental implant surgery for diabetic patients include impaired wound healing and an increased risk of infection. In addition dry mouth, caries and periodontal disease are more commonly found with these patients.
A summary of 8 studies as of 2009, by Bornstein et al, reporting on 1088 dental implants placed in diabetic patients showed 87 implant failures for a 92.1% implant survival rate. Two trends were noted in these 8 studies: 1) more failures occurred in diabetic patients early after implant placement and 2) the percentage of implant failures appeared to lie within the normal range. Studies by Alsaadi et al, of 720 implants reported in 2007 and 2008 showed 96% early success with dental implants placed in diabetic patients and 98.1% in non-diabetic patients. Anner et al (2010), reported on 162 implants placed in diabetic patients with a 95% survival rate at 2 years after dental implant placement. Zupnik et al studied 341 dental implants and found a slightly lowered implant success rate with those placed in diabetic patients, yet the success rate of 96% at 4 years was not statistically significant between diabetics and non-diabetics. Authors have generally reported failure rates that vary from 2 x a normal failure rate and some studies report no difference in implant survival rate such as Accursi’s report in 2000 of 387 diabetic patients.
Statistical significance means that although the results between 2 groups vary, the data may or may not be due to chance. Consequently researchers use statistical significance to show how 2 treatment comparisons significantly vary (beyond chance) or don’t vary significantly.
Why is there such a big difference between research studies in dental implant survival rates for diabetic patients? Often, diabetic patients have varying levels of blood sugar control and/or other medical problems that affect wound or bone healing, smoking, varying levels of alcohol intake and varied levels of overall physical fitness. Professionally I have found all these factors to affect implant survival rates and find that taking the time with patients to help them understand how they can influence their results is effective. I am impressed with how often patients are motivated to manage the factors they can control and improve their implant treatment outcomes.