Reduction by air purifier of particulate concentration during orthodontic procedures: a pilot study.

BACKGROUND: The SARS-CoV-2 pandemic has raised awareness of the importance of air quality. This pilot study arose from the need to reduce the concentration of particulate matter in the dental office during orthodontic procedures. To evaluate the efficacy of using an air purifier during orthodontic care in the dental office to reduce the concentration of ambient particulate matter. RESULTS: Significant reductions in particle numbers were obtained for all particle sizes except the largest particles counted (10 µm) through use of the air filter. A marked association between higher humidity levels and higher particle counts was also observed. CONCLUSIONS: Using an air purifier during dental care achieves a significant reduction in the concentration of ambient particles in the dental office. There is a correlation between higher relative humidity and higher particle concentration. The probability of obtaining a maximum particulate concentration level of 0.3 and 0.5 µm is 1000 times lower when using an air purifier.

Determinants of masticatory performance assessed by mixing ability tests.

STATEMENT OF PROBLEM: Studies determining the main predictors of masticatory performance by using mixing ability tests are sparse. PURPOSE: The purpose of this clinical study was to identify potential determinants of masticatory performance assessed by analyzing a patient's masticatory ability using bicolored chewing gum and visual, quantitative, and interactive methods. MATERIAL AND METHODS: Nondental participants attending healthcare centers were consecutively recruited in Granada, Spain. The inclusion criteria were older than18 years and resident in the coverage area of the reference healthcare centers for at least the previous 6 months. The participants were excluded if they had received dental treatment in the previous 6 months or they were unable to communicate. The masticatory performance was determined by using 2-colored chewing gum (Kiss 3 white and blue; Smint) that was masticated for a total of 20 strokes. The masticated gum was crushed between 2 transparent glass slides, creating a 1-mm-thick specimen that was subsequently scanned. The mixed-color area was calculated as a percentage by using Photoshop as described by Schimmel et al and designated as the standard method. In addition, all images made were analyzed by using the Web application the Chewing Performance Calculator. In addition, the masticated bolus was inspected visually, and mastication performance was classified as being poor, moderate, or good. Sociodemographic data, as well as data on behaviors, medical and nutritional status, health-related quality of life, saliva, and general oral health, were collected for all participants to identify the main determinants of masticatory performance. RESULTS: One hundred thirty-seven participants were enrolled. The masticatory performance values obtained using both methods (standard method and Chewing Performance Calculator) were significantly greater for well masticated gum (P<.001), which had been visually classified as being poorly masticated (69.1% for standard method and 43.5% for Chewing Performance Calculator), moderately masticated (89.7% for standard method and 67.3% for Chewing Performance Calculator), and well masticated (97.3% for standard method and 80.3% for Chewing Performance Calculator). The bivariate analyses revealed that masticatory performance was significantly higher in younger people (<65 years) (P=.008), who also had a higher basal salivary flow rate (P<.001), were nondenture users (P=.002), and had more standing teeth and occlusal units (P<.001). However, the multiple regression analyses showed that the number of occlusal units was the only significant predictor of masticatory performance. In addition, the mean masticatory performance (95% confidence interval: 47.7% to 56.8%) was found to be greatly improved (by 1.2% to 2.2%), with each occlusal unit, in accordance with the Chewing Performance Calculator and between 0.8% and 1.8% according to the standard method; the basal masticatory performance was calculated as 72.1% to 81.2% (95% confidence interval). CONCLUSIONS: The number of occlusal units is one of the main predictors of masticatory performance when a 2-color bolus is used to test mixing ability.

Air particulate concentration during orthodontic procedures: a pilot study.

BACKGROUND: This study evaluates the particle dispersion involved in dental procedures carried out during orthodontic treatments. Variants such as temperature and relative humidity in the dental cabinet were considered. METHODS: Using a particle counter, a pilot study was conducted, in which 98 consecutive recordings were made during appointments of patients undergoing orthodontic treatments. Temperature, relative humidity and particles present at the beginning (AR) and during the appointment (BR) were recorded. A control record (CR) of temperature, relative humidity and particles present was made before the start of the clinical activity. In addition to conventional statistics, differential descriptive procedures were used to analyse results, and the influence of relative humidity on particle concentration was analysed by statistical modelling with regression equations. RESULTS: The number of particles present, regardless of their size, was much higher in AR than in CR (p < .001). The same was true for relative humidity and ambient temperature. The relationship between relative humidity and particle number was determined to be exponential. LIMITATIONS OF THE STUDY: The limitations are associated with sample size, environmental conditions of the room and lack of discrimination among the procedures performed. CONCLUSIONS: This pilot study shows that from the moment a patient enters a dental office, a large number of additional particles are generated. During treatment, the number of particles of 0.3 microns-which have a high capacity to penetrate the respiratory tract-increases. Moreover, a relationship between relative humidity and particle formation is observed. Further studies are needed.

Chewing Performance Calculator: An interactive clinical method for quantifying masticatory performance.

STATEMENT OF PROBLEM: There is a need to quantitatively differentiate between impaired and normal mastication by using straightforward and reliable methods because currently available methods are expensive, complex, and time-consuming. PURPOSE: The purpose of this clinical study was to assess the reliability, validity, and clinical utility of a new Web-based software program designed to calculate masticatory performance, the Chewing Performance Calculator (CPC) measuring masticatory performance (MP), by analyzing the area of mixed bicolored chewing gum. MATERIAL AND METHODS: One hundred and ten participants were consecutively recruited from the School of Dentistry of the University of Salamanca. MP was determined by using 2-colored chewing gum that was masticated for a total of 20 strokes. The masticated gum was then flattened between 2 transparent glass tiles, generating a 1-mm-thick specimen that was scanned to calculate the percentage of area where the 2 colors were mixed. The area was calculated by using a photo-editing software program as described by Schimmel et al (standard method). In addition, all the images were analyzed by using the CPC Web application, which took as input the image of the masticated bolus enclosed in a custom plastic platen that allowed 3 parts of the image to be selected interactively: the platen, the bolus background, and the mixed color fraction of the bolus. The application then computed MP as a percentage. Additionally, an oral examination was carried out to record the number of occlusal units. These data were used to assess the validity of CPC by using the Pearson correlation coefficient. Construct validity was assessed by using ANOVA by comparing the MP scores obtained for masticated gums, classified upon inspection as being poorly, moderately, or highly mixed. The time spent evaluating the specimens with GSM and CPC methods was also recorded and used to indicate the usefulness of the procedure. RESULTS: The MP was found to range between 5.2% and 100% (95% CI: 80.8-88.8) with the GSM and between 9.2% and 96.4% (95% CI: 60.0-67.6) with the CPC. The time needed to calculate MP by using the GSM was significantly higher (235.2 versus 260.5 seconds) than that with the CPC (42.3 to 48.6 seconds). Both methods were significantly intercorrelated (r=0.65; P<.001) and correlated with the number of occlusal units (r=0.54 for CPC and r=0.40 for GSM). The correlation coefficient of MP calculated by using CPC (r=0.54; P<.001) was greater than that calculated by using GSM (r=0.40; P<.001). Moreover, both methods showed adequate construct validity because the values calculated for MP significantly increased as the mixing of the masticated gums also increased, subjectively classified as poor, moderate, and high. CONCLUSIONS: The CPC software program allowed MP to be determined in a valid and easy-to-use manner by using 2-colored chewing gum.