Title Increased Post-Operative Complications in Type 2 Diabetes Patients with Higher Hemoglobin A1C (HbA1C) Levels Undergoing Mandibular Overdenture Implant Surgery
Clinical Question In patients with type 2 diabetes undergoing mandibular overdenture implant surgery, is the rate of post-operative complications directly related to higher HbA1C levels?
Clinical Bottom Line Higher HbA1C levels are associated with increased rates of post-operative complications such as peri-implantitis and peri-implant bone loss. However, implants can be successful across a wide range of glycemic control.
Best Evidence  
PubMed ID Author / Year Patient Group Study type
(level of evidence)
17332041Dowell/200750 implants in 35 patients with type 2 diabetes, stratified by HbA1C levelsNon-randomized clinical trial
Key resultsNo significant differences were detected in implant success rates or clinical complications based on glycemic control.
18807573Tawil/200845 patients with T2D; 45 controlsNon-randomized clinical trial
Key resultsHbA1C was the only independent factor affecting complication rate (p=0.04). Significant differences were seen between groups for peri-implantitis (p=0.05) and peri-implant bone loss (p=0.01), but not for soft tissue complications (p=0.85).
25076074Humphers/2014322 patients with diabetes mellitus who underwent foot/ankle surgeryCohort Study
Key resultsHbA1C level was directly related to higher incidence of infection. For every 1% higher the HbA1C level was, risk of infection increased by a factor of 1.59, a significant increase (95% CI, 1.28-1.99). HbA1C level had the highest association with post-operative foot and ankle surgery complications in patients with diabetes compared to other risk factors (OR=1.25; 95% CI, 1.02-1.53). Note: this study looked at foot and ankle surgery post-operative complications and cannot be readily extrapolated to mandibular overdenture implant surgery.
Evidence Search "hemoglobin"[All Fields] AND "implant"[All Fields] AND "complications"[All Fields] "diabetes"[All Fields] AND "implant failure"[All Fields] AND Review[ptyp] "hemoglobin"[All Fields] AND "diabetes"[All Fields] AND "wound healing"[All Fields]
Comments on
The Evidence
The first two articles have high validity. The final article applies to foot wounds as opposed to oral wounds, so it is less directly externally valid for our PICO question. There is a scarcity of research regarding post-operative oral infections in diabetics, so other disciplines, such as podiatry, must be explored for evidence. These were all well designed studies. The controlled trials both included normoglycemic controls and compared them to discrete HbA1C intervals, though the intervals were slightly different between the two studies (i.e. 6-8% vs. 7-9%). HbA1C was evaluated as a continuous variable for the Humphers study. We are limited to only cohort and non-randomized controlled studies because we cannot assign glycemic control to subjects. However, the statistical analyses used in these studies allowed for examination of HbA1C/glycemic control as an independent risk factor for implant success and post-operative complications. After looking closely at a meta-analysis on implant success in diabetics, it was clear that heterogeneity between studies and a frank scarcity of studies relating HbA1C to implant success limited its ability to make conclusions.
Applicability Dental implant surgery can be successful in patients with type 2 diabetes. Improving glycemic control in poorly controlled diabetic patients may result in less post-operative complications such as peri-implantitis and peri-implant bone loss. The evidence indicates that patients with poorer glycemic control may not experience more soft tissue complications than well controlled patients.
Specialty (General Dentistry) (Oral Surgery) (Periodontics)
Keywords Diabetes, HbA1C, glycemic control, dental implants, infection, complications, peri-implantitis, bone loss
ID# 2786
Date of submission 11/26/2014
E-mail sabra@uthscsa.edu
Author Daniel I. Sabra
Co-author(s) e-mail
Faculty mentor Thomas Oates, DMD, PhD
Faculty mentor e-mail oates@uthscsa.edu
Basic Science Rationale
(Mechanisms that may account for and/or explain the clinical question, i.e. is the answer to the clinical question consistent with basic biological, physical and/or behavioral science principles, laws and research?)
None available
Comments and Evidence-Based Updates on the CAT
None available