## 3 Results  
The survey and its results are reported in Table 1 (Demographic data); Table 2 (Prior to COVID-19); Table 3 (After COVID-19); Table 4 (The Mask Fitter); Table 5 (Fogging). Numbers refer to the relative question of the survey. Responses were received from all the participants (20). \begin{table}
\begin{tabular}{c c c c c} \hline  & \multicolumn{4}{c}{**Demographic Data**} \\ \hline \multirow{2}{*}{1. Age} & 20–29 & 30–39 & 40–49 & 50+ \\ \cline{2-5}  & 0 (0\%) & 6 (30\%) & 5 (25\%) & 9 (45\%) \\ \hline \multirow{2}{*}{2. Gender} & Male & Female & Non-binary & Prefer not to say \\ \cline{2-5}  & 5 (25\%) & 15 (75\%) & 0 (0\%) & 0 (0\%) \\ \hline \multirow{2}{*}{3. Qualification} & Dentist & Dental Nurse & Dental Hygienist & Other \\ \cline{2-5}  & 7 (35\%) & 11 (55\%) & 2 (10\%) & 0 (0\%) \\ \hline \end{tabular}
\end{table} 
Table 1: **Section 1**: Demographic data. Figure 6: The Mask Fitter positioning. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multicolumn{5}{c}{**Prior to COVID-19**} \\ \hline \multicolumn{5}{c}{4. Prior to COVID-19 did you routinely wear a face mask?} \\ \hline Yes & No & & \\ \hline
19 (95\%) & 1 (5\%) & & \\ \hline \multicolumn{5}{c}{5. If you wore a mask was it:} \\ \hline All the time & Only for contact & Only for treating & Only for aerosol & \\  & with patients & patients & generating & procedures \\ \hline
5 (25\%) & 4 (20\%) & 7 (35\%) & 4 (20\%) & \\ \hline \multicolumn{5}{c}{6. What type of mask was it? (more than one choice allowed)} \\ \hline Simple face mask & Surgical face & & & \\ (e.g., acrylic screen) & mask & FFP2 & FFP3 & other \\ \hline
9 (45\%) & 20 (100\%) & 0 (0\%) & 0 (0\%) & 1 (5\%) \\ \hline \multicolumn{5}{c}{7. For how many years have you been wearing a mask of any type?} \\ \hline
0–5 & 6–10 & 11–20 & 20+ & \\ \hline
3 (15\%) & 2 (10\%) & 7 (35\%) & 8 (40\%) & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: **Section 2: Prior to COVID-19. ** \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multicolumn{5}{c}{**After COVID-19**} \\ \hline \multicolumn{5}{c}{8. What type of face mask do you currently use? (more than one choice allowed)} \\ \hline Simple Face & Surgical Face & & & \\ Mask & & & & \\ \hline
17 (85\%) & 10 (50\%) & 20 (100\%) & 1 (5\%) & 2 (10\%) \\ \hline \multicolumn{5}{c}{9. How easy is it to achieve a comfortable fit of your mask on your face?} \\ \hline Very easy & Easy & Medium & Difficult & Very difficult \\ \hline
0 (0\%) & 0 (0\%) & 4 (20\%) & 5 (25\%) & 11 (55\%) \\ \hline \multicolumn{5}{c}{10. Over short-term use (up to one hour) how comfortable is your mask?} \\ \hline Very low & Low & Medium & High & Very high \\ \hline
0 (0\%) & 0 (0\%) & 9 (45\%) & 6 (30\%) & 0 (0\%) \\ \hline \multicolumn{5}{c}{11. Over mid-term use (up to four hours) how comfortable is your mask?} \\ \hline Very low & Low & Medium & High & Very high \\ \hline
0 (0\%) & 3 (15\%) & 11 (55\%) & 6 (30\%) & 5 (25\%) \\ \hline \multicolumn{5}{c}{12. Over long-term use (full working day) how comfortable is your mask?} \\ \hline Very low & Low & Medium & High & Very high \\ \hline
3 (15\%) & 9 (45\%) & 6 (30\%) & 2 (10\%) & 0 (0\%) \\ \hline \multicolumn{5}{c}{13. How confident are you that you have achieved an effective seal?} \\ \hline Very low & Low & Medium & High & Very high \\ \hline
0 (0\%) & 3 (15\%) & 8 (40\%) & 7 (35\%) & 2 (10\%) \\ \hline \multicolumn{5}{c}{14. Do you think that a customized face mask adapted to you face anatomy would be beneficial?} \\ \hline Yes & No & Do not know & \\ \hline
15 (75\%) & 1 (5\%) & 4 (20\%) & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: **Section 3: After COVID-19. *** 22. Can you please give the reason (for your answer to question 21)? 18 responses received. The comments broadly followed the response to question 21, \"for both selected patients and procedures\" and \"positive comments\".