ABSTRACT
Objectives@#This study aimed to investigate the presence of microplastic chips at the tips of toothbrush bristles using optical microscopy. @*Methods@#Toothbrushes available in South Korea were tested. We randomly selected 12 toothbrushes, including four domestically produced and eight imported toothbrushes. Toothbrushes with tapered bristle ends were excluded. Toothbrushes with conventional bristle shapes based on visual inspection were included. Three identical toothbrushes were prepared. The outer bristles of each toothbrush were sampled using ScotchTM tape and prepared using a scalpel for optical microscopy.The inspector visually assessed both the bristle diameter and the presence of microplastic chips that remained attached to the ends of the toothbrush bristles under light microscopy (40× magnification). @*Results@#All toothbrush bristles met the criteria for soft bristles (diameters ranging from 0.2 to 0.25 mm). The incidence of microplastic chips varied among toothbrush bristles, ranging from a minimum of 3.6% to a maximum of 86.2%. Notably, toothbrushes with smaller diameter bristles exhibited higher levels of microplastic chips. @*Conclusions@#This study confirmed that the trimming conditions of toothbrush bristles and the occurrence of microplastic chips vary among different toothbrushes. Our findings suggest that toothbrush manufacturers need to improve their manufacturing processes to prevent the generation of microplastic chips during bristle trimming.
ABSTRACT
Objectives@#This study compares the labeling information on the sizes of interdental brushes marketed in Korea to their actual sizes. Moreover, it analyzes the relationship between the size of the passage hole diameter (PHD), brush diameter, stem diameter, and stem length. @*Methods@#Among the commercially available interdental brushes in Korea, 171 interdental brushes, 3 in each size, were collected from 9 companies. The labels of the collected interdental brushes were researched, and the PHD was measured and compared. The correlation between the passage hole diameter, brush diameter, stem diameter, and stem length was analyzed. Multiple regression analysis was performed to verify the effect of brush diameter, stem diameter, and stem length on the determination of the PHD. @*Results@#The sizes of the interdental brushes were expressed using the ISO labeling or the Small, Medium, Large (S, M, L) labeling and indicated in units of 0.1. The concordance rate of the measured PHD and named PHD was 39.7%. The measured brush diameter, stem diameter, and stem length increased as the interdental brush size increased. There was a significant correlation (P<0.01) between PHD, brush diameter, stem diameter, and stem length. The order of variables with the most to least significant influence on PHD was stem diameter (β=0.528), brush diameter (β=0.404), and stem length (β=0.074). @*Conclusions@#This study shows that the label and actual size of interdental brushes did not match, and the concordance rate between the measured and labeled PHDs was low. Therefore, the interdental brush size labels among manufacturers should be standardized. Moreover, these manufacturers must provide the correct size information for the interdental brushes.