Nuclear imaging to visualize periodontal inflammation: Findings of a randomized controlled trial.

Objective: To investigate non-surgical periodontal therapy by 18F-fluorodeoxyglucose (2-[¹⁸F]FDG) uptake using positron emission tomography (PET) integrated with computed tomography (CT).

Subjects: Eighty-five patients with peripheral artery disease and severe periodontitis-randomized into three groups receiving therapy with (PT1; n = 29) or without (PT2; n = 28) systemic antibiotics or no treatment (controls: n = 28)-underwent nuclear imaging at baseline and at 3 months.

Results: Clinical inflammation (periodontal inflamed surface area; PISA) did not significantly differ across the groups at baseline (p = 0.395) but was significantly reduced at 3 months (p < 0.001), and significantly more so in the PT1/PT2 groups than in the control group (p < 0.001/=0.025) and in the PT1 than in the P2 group (p = 0.001). Radiotracer uptake was measured in both jaws using maximum and mean 'standardized uptake values' (SUV_max, SUV_mean) and 'target-to-background ratios' (TBR_max, TBR_mean). At 3 months, reductions were relatively small in absolute numbers and fell short of revealing correlations with PISA or significant differences across the groups. Still, they were very consistent in both treatment groups, whereas reductions were not consistently seen in the control group.

Conclusions: 2-[¹⁸F]FDG PET/CT scans did reflect the clinical effects of periodontal treatment very consistently but, for reasons yet to be clarified, less closely than expected.