If you used a toothbrush in a dream, then it suggests you to be more indulgent with what other people saying to you. There is no need to take every opinion as very important to your being. On the other hand, you are the one who says more then he should, therefore you brush the teeth, because you are trying to wash away that guilt.
Dream dictionary: Toothbrush dream meanings
…(Boy | Broom | Employee) A toothbrush in a dream is a sign of hygienic conditions, prosperity, purity, cleanliness, repentance, or asking someone for forgiveness. Brushing and cleaning one’s teeth in a dream is also a sign of being religious, a family person, a concerned relative and a generous kin. If one sees himself brushing his teeth, and if his gums bleed in the dream, it means that he will become free from his sins and curtail his evildoing, or it could mean the opposite, that is to proceed with abhorrent actions, cause harm to one’s own family, steal their money, or defame them. Brushing one’s teeth in a dream also could mean reservation and prudence with one’s words, purifying oneself from sin, faith after disbelief, paying one’s debts, doing what pleases God Almighty, fulfilling one’s promises, a pregnancy, or a marriage. (Also see Broom)…
(arb. See Toothbrush)