3.1 Study population
Of the initial 162 participants who responded to the questionnaire 15 were excluded because they stated belonging to a profession other than dentist, hygienists and assistants, or the responses were incomplete.
Questions 1, 2-4, 5: A sample of 147 people from Italy and the USA, subjected to a quantitative online questionnaire was considered for final analysis. Among it, the ratio of males to females was 1:1.3, with an average age of 42.9+/-12.0. Demographic information was summarized in Table 2.
Question 3: According to the questionnaire’s responses 25 were smokers and 9 former smokers. Smokers showed a significantly lower baseline SPO2 level (97.9+1.0% vs. 98.3+1.2%) and a lower SPO2 decrease (0.5+1.0% vs. 1.4+3.0%) while SPO2 levels after 4 hours showed no significant differences (97.4+1. vs. 96.9+3.1)
Question 6: Regarding the occupation, 101 were dentists/orthodontists, 6 hygienists and 40 dental assistants.
Table 2. Demographic information of the participants included in the study (N=147)
Variables
|
n
|
Gender
|
Males
|
62
|
Females
|
85
|
Age (years) (mean ± SD) 42.9+12.0
|
Males
|
45.5+13.2
|
Females
|
40.9+10.8
|
Body mass index - BMI (mean ± SD) 22.7+3.4
|
Males
|
24.5+3.0
|
Females
|
21.3+3.1
|
Question 7: Regarding the most frequent activities listed in the questionnaire while donning a FFP2, 99 subjects (69%) reported performing conservative (dental) procedures, 58(40%) endodontic procedures, 64(45%) oral surgery procedures, 43(30%) periodontal procedures, 59(41%) orthodontic procedures, and 47(33%) pedodontics procedure not involving orthodontic appliances.
Questions 8 and 10: For the entire sample population the baseline saturation was 98.6+1.2 and after four hours of mask wearing there was a significant decrease in oxygen saturation to 97.0+2.9 (p<0.01), while there was no significant difference in SPO2 decrease between people younger than 50 and those older (1.3+2.0% vs. 1.1+3.2%), or between dentists, assistants or hygienist, and no significant differences were found between degrees of stressful procedures and oxygen desaturation. Facial screens, repellent aprons and air conditioning showed no impact in %SpO2 decrease.
Questions 9 and 11: Baseline heart rates showed a significant difference between professional groups (Anova P<0.05) in particular, the post hoc analysis pointed out a difference between dentists and assistants in which assistants showed an average of 84.0+15.5 bpm vs. 76.05+12.6 bpm in dentists. However, this information needs to be placed in the context of significant gender and age differences that make this aspect per se not significant. Moreover, no significant differences were found in the other parameters and heart rate at 4 hours. We assessed potential markers for heart rate differences and it could be due to a higher prevalence of female hygienists than in the other categories of the population sample (Spearman’s Rho p< 0.01) while age was not significantly different among categories. There were no significant differences between heart rate and SPO2 at baseline and after 4 hours and between those who removed the mask often, seldom or never. The combination of masks and other personal protection equipments (PPE), in particular protective screen and scrubs, showed to have no statistically significant influence neither when worn together nor just either one, in both heart rate and SpO2 saturation.
Questions 12 and 13: Regarding additional personal protective equipment, 115 (78%) responders reported using face shields, 21 (14%) goggles, 141 (96%) protective gloves, 68 (46%) prescription glasses, 104 (71%) protective scrub, 117 (80%) surgical cap, and 26 (25%) shoe cover. The presence of air conditioning while working was mentioned by 99 (60%) subjects. (Table 3)
Table 3. Use of additional personal protective equipment
PPE
use
|
Face shields
|
Goggles
|
Protective gloves
|
Prescription glasses
|
Protective scrub
|
Surgical cap
|
Shoe cover
|
Use of AC
|
% of use
|
78%
|
14%
|
96%
|
46%
|
71%
|
80%
|
25%
|
99%
|
PPE: Personal protective equipment, AC : air conditioning
Question 14: Regarding symptoms after 4 hours, the participants reported a median of 2 symptoms, while only 22 (15%) participants reporting no symptoms. The most frequent reported complaints were: 94 (64%) fatigue, 53 (36%) headache, 46 (31%) external ear pain, 25 (17%) dark circles under the eyes (venous pooling), 15 (10%) nasal discharge, and 16 (10%) sore throats. (Table 4)
Table 4. Symptomatology after 4 hours of wearing FFP2 protection masks
Symptoms after 4hs
|
Fatigue
|
Headache
|
External ear pain
|
Dark circles under eyes
|
Nasal discharge
|
Sore throat
|
No symptoms
|
%
|
64%
|
36%
|
31%
|
17%
|
10%
|
10%
|
15%
|
Question 15: 105 (64%) of the subjects reported that using the mask influenced their communication with their patients.
Questions 16 and 17: On a non-parametric scale of 1-10 (1 unable to communicate, 10 the mask is not a problem at all) the median for communication score was respectively 7 for removing the mask often, 6 for seldom removing, and 5 for never removing the mask during the 4 hours. Participants who remove their masks more often also reported lower communication scores (P<0.001). This aspect alone suggests the necessity of the professional to use augmentative communication devices to facilitate communication among staff and between professionals and patients. In order to assess potential confounding factors, we performed multinomial logistic regression for mask removal frequency using the two significant factors: communication difficulties (question 15) and reporting of headache (question 14). This regression showed a significant effect only for communication difficulties and thus revealing only a minimal impact of headache on mask removal. There were no significant correlations between protection devices used and need for mask removal, which was more frequent in those who also reported headaches (p<0.01). There was no statistical difference in total symptoms reported between those who remove masks more often and those who did not. Seventy-five subjects (51%) reported that they had to remove their mask while being with a patient because either it was too uncomfortable or the patient was not able to understand them. When compared with those who had to remove the mask to be understood by patients and the non-parametric scale on question 16, 72 participants stated they never needed to remove the mask (49%), 56 reported seldom (38%) and 19 often (13%), thus there were no significant correlations between protective device used.