Gerard Byrne BDSc MSD
Successful osseointegration can be achieved in diabetic subjects with good metabolic control.
Although this weak SR suggests that osseointegration occurs in diabetes mellitus subjects with good metabolic control, the limited evidence presented in this SR cannot support any conclusion.
What are the differences in outcomes for implant osseointegration and implant maintenance in diabetic patients with hyperglycemia and glycemic control?
The authors searched one electronic database from 1982 to July 2009. In addition, they checked the reference lists of original and review articles. They included studies in English with both clinical and 'experimental' (animal, and cell culture) studies, and excluded letters to the editor, historical reviews, and unpublished articles. Further inclusion criteria consisted of conventionally placed implants with delayed or immediate loading and with non-disease controls. The authors did not define the outcomes of interest.
The authors identified 18 studies, of which 10 were clinical trials, 7 were studies on rodents and one was a study on blood cultures of rat monocytes. Of the 10 clinical trials, eight were prospective and two retrospective. Clinical studies used various assessment criteria such as: clinical parameters of periodontitis; resonance frequency analysis, electronic mobility testing, and radiographs. Most experimental studies quantified the bone or bone-like tissues adjacent to the implants with histologic and histomorphometric methods. Serum glycemic levels were monitored in many of the studies. No quantitative results were presented; however, the authors state that a total of seven studies showed that diabetes negatively affected osseointegration, and10 human studies reported that successful osseointegration could be attained in diabetic patients with good glycemic (not defined) control. A similar pattern was seen in osseointegration studies on rodents. Peri-implant maintenance indices suggested that the risk of peri-implantitis was not increased in clinical cases with good glycemic control.
The review authors conclude that successful osseointegration can be achieved in diabetic rodents and humans that have good metabolic control (as measured by HbA1c levels); however, due to many limitations, this conclusion is suspect.
Source of Funding:
Funding source not reported
Importance and Context:
Diabetes mellitus as measured by hyperglycemia (HbA1c) has been implicated as a contributing factor in periodontal disease. It is also suggested that diabetes may play a similar negative role in periimplant infection with bone loss, or indeed the osseointegration process for implants. Good glycemic control in diabetic patients, as measured by serum glycemic level and HbA1c level, may be expected to overcome any negative effects on osseointegration.
Strengths and Weaknesses of the Systematic Review:
This SR has many limitations. The authors limited the literature search to only one database in English. The authors did not present sufficient data on the design, size, length, or specific interventions of the included studies. The authors did not specify any outcomes measures, they did not present data, nor did they attempt to synthesize the results of these studies. No information about study demographics, subjects' diabetic treatments, or HbA1c levels was presented. They did not define “good/optimal serum glycemic control.” Study risk of bias was not described. The experimental studies, while fundamental in the research process, cannot be presented as evidence of clinical success. Conclusions that are based on a mix of human and experimental data should not be presented.
Strengths and Weaknesses of the Evidence:
The selected studies are heterogeneous in terms of duration, study subjects (cells, rodents, humans), glycemic control variables and diversity of outcome measures; this limits the discussion and statistical synthesis of results. Inadequate information is presented on individual studies for the reader to determine the validity of the selected studies or their conclusions.
Implications for Dental Practice:
Diabetes mellitus and hyperglycemia are potential barriers to osseointegration of implants and peri-implant bone stability. Good metabolic control of diabetes as measured by serum HbA1c levels should allow for successful osseointegration. The evidence presented by this review is inconclusive regarding the importance of glycemic control for osseointegration. This finding is corroborated by a more recent systematic review (1). However, Oates et al. noted that three studies with interpretable glycemic control information did not show a significant relationship between glycemic control and implant failure. Reference: 1. Oates TW1, Huynh-Ba G, Vargas A, Alexander P, Feine J. A critical review of diabetes, glycemic control, and dental implant therapy. Clin Oral Implants Res. 2013 Feb;24(2):117-27