Evidence unclear on whether Type I or II diabetes increases the risk of implant failure.

DATA SOURCES

PubMed, Web of Science and the Cochrane Oral Health Group Trials Register, www.clinicaltrials.gov, www.centerwatch.com and www.clinicalconnection.com databases. Manual searches of a number of dental journals and the reference lists of identified studies were undertaken.

STUDY SELECTION

Human clinical studies comparing implant failure rates in diabetic and non-diabetic patients were considered. Three reviewers independently selected studies.

DATA EXTRACTION AND SYNTHESIS

The definition of implant failure used was complete loss of the implant. Study quality was assessed using the Cochrane risk of bias approach. A narrative summary of the studies and meta-analysis are presented.

RESULTS

Fourteen studies were included (one randomised controlled trial, six controlled clinical trials and seven retrospective analysis); all 14 were considered to be at high risk of bias. Meta-analysis (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 of two 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, favouring non-diabetic patients. Meta-analysis was not possible for postoperative infections.

CONCLUSIONS

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.