Polymethylmethacrylate (PMMA) Hosts Microbiome Associated with Oral Malodor

Previous study suggested that fixed dental prostheses (crowns) increase oral malodor production. There might be a role to temporary acrylic crowns contributing to oral malodor. In the current study, we analyzed the microbiome associated with malodorous temporary dental crowns. The study population comprised nineteen patients (mean age 45.8 +/- 10.9, 8 females) who visited the Tel Aviv University dental clinic. Temporary crowns were scored by an odor judge using a 6-point malodor organoleptic scale (0-5) and temporary crowns that were scored 2 and above were assigned as malodor positive. Microbial DNA was extracted from the temporary dental crowns and analyzed using next generation 16S rDNA sequencing. Taxa identified could be classified into 11 phyla, 50 genera and 119 core species. Malodor positive samples demonstrated higher abundance of the phyla Proteobacteria and Actinobacteria and the genera Tannerella, Alloprevotella, Treponema, Olsenella and Bifidobacterium. Malodorous samples showed higher bacterial diversity and significant differences in microbial population. Taken together these results suggest a difference between the microbial populations of malodorous and non-malodorous temporary dental crowns both in composition and diversity.