Clinical Trial Combining PVP-I and NaF in Preventing Root Caries

Abstract

Objectives: To investigate the effectiveness of 4-monthly application of 10% povidone iodine (PVP-I) followed by 5% sodium fluoride (NaF) vanish in preventing root caries. Methods: This randomized clinical trial was registered (clinicaltrials.gov # NCT 03654820) and conducted in long-term care facilities (residential home or day care centre) in Hong Kong. Participant inclusion criteria were: 1) aged above 60 years, 2) had at least 6 natural teeth, and 3) had basic self-care and communication ability. Participants were randomly allocated into 2 groups and received the corresponding interventions: Group 1 (test): 4-monthly application of 10% PVP-I followed by 5% NaF varnish (PVP-I & NaF); Group 2 (positive control): annual application of 38% silver diamine fluoride (SDF) solution. Each root surface was assessed using the criteria recommended by the International Caries Detection and Assessment System. New root caries was recorded when a sound or filled surface at baseline was found to have a caries lesion at follow-up assessment. The participants were examined by the same two calibrated examiners at baseline and follow-up. Results: At baseline, 353 elders (68 men and 285 women) were examined and their mean age was 74.8 (SD=8.5) years. After 12 months, 295 (83.6%) participants were examined. The mean numbers of root surface with new caries were 0.7 in Group 1 (PVP-I & NaF) and 0.9 in Group 2 (SDF). The difference between the two groups was not statistically significant (t-test, p>0.05). Presence of visible plaque on the root surface was positively correlated with new caries (OR=6.83, CI: 4.304, 10.849). Conclusions: After one year, the effectiveness of 4-monthly application of 10% PVP-I and 5% NaF varnish in preventing root caries was not significantly different from that of annual application of 38% SDF solution. This may be an alternative strategy to SDF application for root caries prevention.