Composition effect of the dental liquid mixture on droplet evaporation and deposition

The dilution effect of dental irrigants and the composition model of the liquid mixture have been typically overlooked in the transmission investigation of dental surgery. As the mass concentration of non-volatile components in droplets can determine the equilibrium size of dehydrated droplet nuclei and even the viral activity, the present study aims to numerically assess the evaporation characteristics of dental droplets in different compositions. The influence of organics in human saliva and adjuncts in dental irrigants can be revealed by the droplet spatial–temporal distribution, evaporation and deposition statistics. The results showed that the use of salt as an adjunct in dental irrigants could help enlarge the equilibrium size of droplet nuclei over 10 μm and increase the fraction of deposited droplets by 3%. The size range of suspended particles exhibited an even 300% difference amongst the irrigant types. Droplets in the three-composition models have shorter evaporation times and larger deposition rates than the two-composition models. Therefore, the composition difference in the dental liquid mixtures should be further considered when conducting cross-infection assessments. The results can promote the development of dental guidelines by modifying the adjunct in dental irrigants to reduce the possibility of cross-infection.