Comparison of preconditions for tooth sample collection and compositional change over time

Abstract: Background The mouth can be colonized by many bacterial species that are associated with both health and disease. Bacteria analyses are an important part of diagnosing and treating dental diseases, but there is no consensus regarding which sampling method to use for these analyses. Aim The aim of this study was to find out whether there are differences in bacterial composition in one, two and three days old dental plaque and if there are regional differences between anterior, posterior, right and left surfaces in the mouth over time. Method Plaque sample collection was performed at specific tooth sites on six healthy young adults. Sampling was made three times after dental plaque had been accumulated for one, two and three days respectively. During the accumulation periods the participants had to abstain from all forms of oral hygiene. Bacteria DNA extraction was performed followed by 16S sequencing. All gene sequences were matched against the Human Oral microbiome database. The results were analyzed in SPSS and SIMCA.  Result When comparing the bacteria composition between day one, two and three a statistically significant difference was found. The analyzes also showed a difference in composition between the posterior and anterior regions of the mouth over time, but no significant difference between the right and the left side of the mouth over time.  Conclusion  The result suggests that the sampling method should be chosen carefully and determined by the specific aim of the dental plaque analysis.