How accurate is DNA test using a toothbrush?

DNA tests using a toothbrush can be quite accurate, as they can collect cells from saliva and oral tissues left on the brush. However, the accuracy depends on the amount of DNA present and the quality of the sample. Environmental factors and contamination risks can also affect results. Overall, while such tests can provide useful information, they may not be as reliable as tests performed with more controlled samples, like blood or cheek swabs.