Effect of silver diammine fluoride on micro-ecology of plaque from extensive caries of deciduous teeth - in vitro study

Abstract

Background: The mechanism of action of silver diammine fluoride (SDF) on plaque micro-ecology is seldom studied. This study investigated micro-ecological changes in dental plaque on extensive caries of deciduous teeth after topical SDF treatment. Methods: Deciduous teeth with extensive caries freshly removed from school children were collected in clinic. Unstimulated saliva collection and initial plaque sampling were done before tooth extraction, then each caries was topically treated with 38% SDF in vitro. After intervention, each tooth was stored respectively in artificial saliva at 37°C. Repeated plaque collections were done at 24 h and 1 week post-intervention. Post-intervention microecological changes including microbial diversity, microbial metabolism function as well as species correlations were analyzed and compared after pyrosequencing of the DNA from the plaque sample using Illumina MiSeq platform. Results: After SDF application, microbial diversity decreased (P > 0.05), although not statistically significant. Microbial community composition post-intervention was noticeably different from that of supragingival and pre-intervention plaque as well as saliva. At 1 week post-intervention, the relative content of Pseudomonas, Fusobacterium and Pseudoramibacter were higher than before, while most of the other bacteria were reduced, although the changes were not statistically significant (P > 0.05). The inter-microbial associations became more complex, much more positive associations among survived bacteria were observed than negative ones. COG function classification diagram showed carbohydrate transportation and metabolic functions in the plaque were significantly reduced at 24 h and 1 week post-intervention. Conclusions: SDF has extensive antimicrobial effect on dental plaque, which may reduce carbohydrate metabolism in dental plaque and help promote new balance of the plaque flora.

The impact of Er:YAG laser combined with fluoride treatment on the supragingival plaque microbiome in children with multiple caries: a dynamic study

“…Although oral hygiene in children has been improved, the oral environment promotes the predominance of cariogenic bacteria in the long term, and it is difficult to achieve significant changes with short-term treatment. As reported, fluoride affects biofilm formation and reduces acid production in S. mutans biofilms, but this antibiofilm activity decreases over time [ 30 ]. The period assessed in the present study was 1 month after treatment, and less antibacterial activity due to fluoride was observed at this time.…”

Antibacterial Activity of Silver and Its Application in Dentistry, Cardiology and Dermatology

“…SDF has an intense antimicrobial effect on dental plaque. It reduces the metabolism of carbohydrates in dental plaque and stimulates a different balance of plaque flora [ 41 , 42 ].…”