Effect of Denture on Oral Microbiome Diversity of Denture-Wearing Older Adult

Background: Dentures remain a treatment option for toothreplacement, however, their role in defining the oralmicrobiome is still elusive.Objective: To evaluate the effect of the insertion of dentureson oral microbiomial profile using metagenomics.Methods: Baseline denture sonicate was obtained from thedenture before insertion, supragingival plaque was collectedbefore and after denture insertion. Metagenomic DNAextraction and next-generation sequencing on the IlluminaMiseq platform were all done using standard protocols.Structural composition analysis was done using QuantitativeInsights into Microbial Ecology (QIIME).Results: A total of 9 respondents, five males (55.6%) and fourelderly females (44.4%) with a mean age of 69.89±3.79participated in this study. The five most common speciesfound in the dental plaque before the insertion of dentureswere Stenotrophomonas (26.06%), Capnocytophaga (9.11%),Streptococcus (3.24%), Unknown (10.58%) and HaemophilusParainfluenza (8.29%). After insertion and use of dentures for6 months, the bacteria identified in the dental plaque wereStenotrophomonas which increased in quantity from 26.06.%to 40.22%. The top five species found on the same dentureafter insertion were Pseudomonas veronii (41.29%) and othersimilar species of Pseudomonas (21%), Stenotrophomonas(30.45%), unknown species ( in the range of 1.93 to 53.53%),Methylobacterium adhaesivum (4.04%) and Pelomonassp.(3.12%). All the species found at baseline on the denturethat was positive with microorganisms before insertion wereabsent on the same denture 6 months after except forStreptococcus species that was also present consistently in 4dentures out of the 9 dentures tested (44.4%). Streptococcusspecies was not one of the top five common species in dentalplaque compared to denture plaque (44.4%).Conclusion: The study observed a relatively diverse microbialcommunity from the dental plaque which increased afterinsertion of a denture. It is suggested that the microbial loadof the denture before insertion might be a risk factor for oralinfection in older people.