Diabetics have been shown to have a higher frequency of periodontal disease and tooth loss. This together with the fact that diabetics also have delayed wound healing means that dental implant placement is more risky in these patients. The aim of this review was to investigate whether there are any effects of diabetes mellitus on implant failure rates, postoperative infections, and marginal bone loss.

Searches were conducted in the PubMed, Web of Science, and the Cochrane Oral Health Group Trials Register, www.clinicaltrials.gov , www.centerwatch.com and www.clinicalconnection.com databases. In addition manual searches of number of dental journals and the reference lists of identified studies was undertaken. Human clinical studies comparing implant failure rates in diabetic and nondiabetic patients were considered. For this review, implant failure represents the complete loss of the implant. Study selection was carried out independently by 3 reviewers, with quality assessment performed by using the Cochrane risk of bias approach. A narrative summary of the studies and meta-analysis are presented.

• 14 studies were included (1 randomised controlled trial, 6 controlled clinical trials, and 7 retrospective analysis) All studies were considered to be at high risk of bias.
• Meta-analysis including all 14 studies found no significant difference between diabetic and non-diabetic patients risk ratio of 1.07 (95% CI = 0.80, 1.44)(p = .65).
• A meta-analysis involving 2 studies found a statistically significant difference (mean difference = 0.20, 95% CI = 0.08, 0.31 p = .001;) between diabetic and non-diabetic patients concerning marginal bone loss, favoring non-diabetic patients.
• Meta-analysis was not possible for postoperative infections.

The authors concluded

The results of the present systematic review should be interpreted with caution because of the presence of uncontrolled confounding factors in the included studies. Within the limits of the existing investigations, the difference between the insertion of dental implants in non-diabetic and diabetic patients did not statistically affect the implant failure rates.

Comment

In their discussion the authors highlight a number of potential issues with the reporting of the available studies eg, lack of information regarding the type of diabetes, level of control and eligibility criteria for inclusion of diabetic patients. Some of the studies also suffered from small numbers and a short duration of follow up. Both of the meta-analysis conducted included both clinical trials and retrospective analysis. The retrospective analysis are more likely to suffer from biases so it may have been useful to restrict the main meta-analysis to only clinical trials although all the available studies were considered to be at high risk of bias.

Links

Chrcanovic BR, Albrektsson T, Wennerberg A. Diabetes and Oral Implant Failure: A Systematic Review. J Dent Res. 2014 Jun 13. pii: 0022034514538820. [Epub ahead of print] Review. PubMed PMID:24928096.