A method of assessing a gum condition of an individual is provided, which comprising the steps: (a) tooth brushing within an oral cavity of the subject individual; (b) post-brushing rinsing the brushed oral cavity with a post-brushing rinse solution comprising volume from 1ml to 50 ml, for a predetermined post-brushing rinsing time, wherein the predetermined post-rinsing time is from 1second to 1 minute; (c) collecting expectorated post-brushing rinse solution from the subject individual; (d) measuring hemoglobin quantity contained in the collected post-brushing rinse solution; (e) comparing the measured hemoglobin quantity against a known standard of gum conditions corresponding to hemoglobin quantities to assess the gum condition of the subject individual from the compared hemoglobin quantities.