Caries prevention with SDF in Denture wearers: a preliminary report

Abstract

Objective: to evaluate the effectiveness of semi-annually applied silver diammine fluoride (SDF) solution in preventing dental caries in removable partial denture (RPD) wearers over 36 months. Method: Subjects wearing RPDs and having at least 8 natural teeth were recruited from a dental teaching hospital. The tooth and denture status, as well as demographic data of the subjects were obtained at baseline. Subjects were randomly assigned to receive 38% SDF solution or placebo application to all their exposed tooth surfaces semi-annually, and follow-up clinical examinations were conducted annually by the same calibrated examiner. Data were analysed using Chi-square/t-test. Result: A total of 194 subjects were recruited at baseline. So far 57 subjects (28 in SDF group, 29 in placebo group) with a mean age of 65.5±8.5 years completed the study. Seven (25.0%) and 13 subjects (44.8%) developed new coronal caries in SDF and placebo groups, respectively (p=0.17). The mean numbers of coronal surfaces with new caries were 0.32±0.61 and 0.86±1.38 in SDF and placebo groups, respectively (p=0.12). Among the 1125 coronal surfaces with denture contact, 16 carious lesions (1.4%) developed while 18 carious lesions (0.7%) developed among the 2746 coronal surfaces without denture contact (p=0.012) (relative risk=2.2). Regarding root caries, 8 (25.0%) and 20 (70.0%) subjects developed new root caries in SDF and placebo group respectively (p=0.002). The mean numbers of root surfaces with new caries were 0.64±1.42 and 1.93±1.89 in SDF and placebo groups, respectively (p=0.005). The prevented fraction for root caries was 66.9%. Among the 891 root surfaces with denture contact, 37 carious lesions (4.2%) developed while 37 carious lesions (1.7%) developed among the 2190 root surfaces without denture contact (p<0.001) (relative risk=2.5). Conclusion: The preliminary result suggests that semi-annually applied 38% SDF solution is effective in preventing root caries development in RPD wearers. Support by HKU-SPF.