مختصر صحيح بخاري
Mukhtasar Sahih Bukhari
Book of Wudu (Ablution)
Using the tooth-stick (miswak) is Sunnah
Narrated Hudhaifa (may Allah be pleased with him): When the Prophet (peace and blessings of Allah be upon him) would get up at night, he would rub (clean) his mouth (teeth) with a miswak.