Evaluation of microplastic release due to the use of different types of toothbrushes: An experimental study

Objective: The aim of this study was to demonstrate the presence of microplastics in saliva samples collected after the use of different brands of children's toothbrushes and to evaluate the potential contribution of toothbrush bristles to oral microplastic exposure. Materials and Methods: Children aged 7–14 years were included in the study, and five different brands of toothbrushes (Oral-B, TePe, Splat, Curaprox, Rocs) were distributed to the participants. In the preliminarygroup, saliva samples were collected after one month of toothbrush use, while in the control group, saliva collected before toothbrush use was prepared in various combinations (pure saliva, saliva + RIPA, saliva + microplastic + RIPA) and analyzed. For the detection of microplastics, Nile Red staining, one of the labeling methods, was applied. Imaging was performed using fluorescence microscopy (Texas Red, Phase Contrast, and Bright Field filters), and digital microscopy analyses were also conducted. Results: While no significant fluorescence emission was observed in the control group saliva samples, microplastic particles with similar morphology and density were consistently detected in all preliminary group samples collected after toothbrush use. Micrometer-scale particles of varying sizes were identified in the images. Under digital microscopy, no staining was observed in the control group, whereas red-stained areas derived from Nile Red indicated the presence of microplastics in the experimental group. Conclusion: Microplastics have become a major component of environmental pollution, posing potential risks to both ecosystems and human health. This study demonstrated that children's toothbrushes may release microplastics during use, which can subsequently be transferred into the oral cavity through saliva. In the future, without disregarding the oral health benefits of plastic toothbrushes, the development of biodegradable or natural-material alternatives may represent an important step toward reducing oral microplastic exposure. Keywords: Plastic