There is growing evidence that periodontitis may affect general health. This study by university researchers from the Netherlands was assigned to explore the robustness of observations that periodontal therapy leads to the improvement of glycemic control in diabetic patients….
A literature search (until March 2009) was carried out using two databases (MEDLINE and the Cochrane Library) with language restriction to English. Selection of publications was based on original investigations and controlled periodontal intervention studies where the diabetic control group received no periodontal treatment, and study duration of ≥3 months.
Screening of the initial 639 identified studies and reference checking resulted in five suitable articles. A total of 371 patients were included in this analysis with periodontitis as predictor and the actual absolute change in A1c (ΔA1c) as the outcome. The duration of follow-up was 3–9 months. All studies described a research population of Type 2 diabetic patients in whom glycemic control improved after periodontal therapy compared with the control group (range ΔA1c: Δ−1.17 up to Δ−0.05%). The studies in a meta-analysis demonstrated a weighted mean difference of ΔA1c before and after therapy of −0.40% (95% CI −0.77 to −0.04%, P = 0.03) favoring periodontal intervention in Type 2 diabetic patients. Nevertheless, this improvement in %A1c must be interpreted with care due to limited robustness as evidenced by heterogeneity among studies (59.5%, P = 0.04)
The current review provides the most accurate reflection of available literature to date to answer the question of whether periodontal treatment affects the general health of Type 2 diabetic patients by improving glycemic control compared to no periodontal treatment after at least 3-month follow-up. Although previous systematic reviews on this topic were conducted, researchers believe that the current inclusion criteria of available studies result in a better understanding of the effect of periodontal treatment on diabetic patients for the following reasons: 1) Only studies with at least 3-month follow-up were included. A1c is a reflection of the mean blood glucose concentration over the preceding 1–3 months and a difference over a shorter period may be clinically less relevant. 2) Only controlled studies in the analysis in which the control group with Type 2 diabetes received no periodontal treatment to overcome the problem of a possible Hawthorne effect were used. 3) The calculation of WMD is the most suitable parameter for a proper meta-analysis since back-transformation of a standardized mean difference will lead to an overestimation of the total effect of periodontal therapy.
Thus, the researchers concluded, periodontal therapy for Type 2 diabetic patients with periodontitis is favorable and can reduce A1c levels on average by 0.40% more than in nonintervention control subjects.
Diabetes CareFebruary 2010vol. 33 no. 2 421-427