## 3 Results
### Microbial Adhesion onto OE, Growth and Biofilm Formation
mitis/oralis_ CFU counted in saliva A/Tp-SUP-treated samples were 2 logs lower than those in saliva A/saline-treated samples; such decrease was of about 1 log when comparing saliva P/Tp-SUP vs. saliva P/saline. The second most representative species in saliva A/saline was _S. thermophilus_, followed by _S. salivarius_ and traces of _N. flava/subflava_ and _R. aeria_, while, in all the other groups, these species were consistently below the detection limit of the assay. Subsequently, in parallel groups, the saliva-contaminated OE were incubated for 23 h at 37 \({}^{\circ}\)C + 5% CO\({}_{2}\) and then exposed to saline or Tp-SUP for additional 1 h, in the presence of CFDA. Then, the OE were washed with warm saline, transferred to new wells, and the fluorescence emission was measured. As shown in Figure 2, a consistent difference was detected when comparing the RFU onto saliva A/saline vs. saliva P/saline OE although without reaching significance (_p_ = 0.0621). Moreover, Tp-SUP treatment drastically reduced the amounts of biofilm, independently of the groups considered. In particular, when comparing saliva A/saline vs. saliva A/Tp-SUP or saliva P/saline vs. saliva P/Tp-SUP, significant decreases were consistently observed upon Tp-SUP treatment in both cases. \begin{table}
\begin{tabular}{l c c c c c c c} \hline \hline
**Species Identified at** & \multicolumn{3}{c}{**Saliva A/Saline**} & \multicolumn{3}{c}{**Saliva P/Saline**} & \multicolumn{3}{c}{**Saliva A/Tp-SUP**} & \multicolumn{3}{c}{**Saliva P/Tp-SUP**} \\ \hline  & **CFU** & **(\%)** & **CFU** & **(\%)** & **CFU** & **(\%)** & **CFU** & **(\%)** \\ \hline _Neisseria flava/subflava_ & \textless{}0.1 & 0.028 & \textless{}0.1 & 0.2 & \textless{}0.1 & 2.27 & \textless{}0.1 & 2.94 \\ _Streptococcus thermophilus_ & 7 & 1.98 & \textless{}0.1 & 0.2 & \textless{}0.1 & 2.27 & \textless{}0.1 & 2.94 \\ _Streptococcus mitis/oralis_ & 342 & 97.1 & 48 & 99.1 & 4 & 90.9 & 3 & 88.2 \\ _Streptococcus salivarius_ & 3 & 0.85 & \textless{}0.1 & 0.2 & \textless{}0.1 & 2.27 & \textless{}0.1 & 2.94 \\ _Rothia aeria_ & \textless{}0.1 & 0.028 & \textless{}0.1 & 0.2 & \textless{}0.1 & 2.27 & \textless{}0.1 & 2.94 \\ _Candidia_ spp. & \textless{}0.1 & - & \textless{}0.1 & - & \textless{}0.1 & - & \textless{}0.1 & - \\ _Lactobacillus_ spp. & \textless{}0.1 & - & \textless{}0.1 & - & \textless{}0.1 & - & \textless{}0.1 & - \\ \hline Total CFU/100 \(\mu\)L \(\times\) 10\({}^{4}\) & 352.4 & 100 & 48.6 & 100 & 4.6 & 100 & 3.6 & 100 \\ \hline \hline \end{tabular}  
* The two sets of OE, contaminated with saliva A and P and incubated for 23 h, were split in two sub-groups and exposed to saline or Tp-SUP for additional 1 h. Each sub-group was then analyzed to assess the total microbial load at time 24 h, by CFU assay. The colonies isolated after incubation in selective media were counted, clustered and identified by MALDI TOF MS or API gallery system. The results are given as microbial load (mean of CFU/100 \(\mu\)L \(\times\) 10\({}^{4}\)) and as percent of bacterial species.  
\end{table} 
Table 2: Microbial load onto saliva-contaminated OE subsequently exposed or not to Tp-SUP.