Randomized clinical trial on arresting dental root caries through silver diammine fluoride applications in community-dwelling elders

Abstract

Objectives: To investigate the effectiveness of silver diammine fluoride (SDF) solution application in arresting dental root caries and to assess the color of arrested caries lesions. Methods: This study was conducted in elderly centers in Hong Kong. A total of 83 elders with 157 root surfaces with active caries lesion were randomly allocated into 3 groups: Gp1 (placebo control)—annual application of soda water; Gp2–annual application of SDF solution; Gp3–annual application of SDF solution immediately followed by potassium iodide (KI) solution. Color of the arrested root caries lesion was assessed with reference to PANTONE color plates and classified into one of the followings: yellow (7401U); light brown (1245U); dark brown (4635U); and black (Black U). Status of root surfaces was assessed every 6 months by the same independent examiner. Results: After 30 months, 100 (64%) of the included root caries lesions were reviewed. The arrest rates of root caries were 45%, 90%, and 93% in Gp1 (control), Gp2 (SDF) and Gp3 (SDF/KI), respectively (χ2 test, p < 0.001). Pairwise comparisons showed elders in the control group had a lower proportion of the active root caries changed to arrested (p < 0.001) and the proportions of root caries being arrested in the SDF and SDF/KI groups were not significantly different (p > 0.05). The distributions of arrested caries lesions by color were not significantly different between the SDF and SDF/KI groups (χ2 test, p > 0.05). Conclusions: Application of SDF solution, with or without application of KI afterwards, is effective in arresting root caries among elders in a water fluoridated area. In the long term, blackening of arrested root caries is not reduced by immediate application of KI after the application of SDF. Clinical significance: In a water fluoridated area, annual application of SDF solution or SDF/KI solution can arrest dental root caries in elders. In the long term, application of KI does not reduce the blackening of arrested caries lesions caused by SDF.