What is the ruling on using the miswak? Does brushing the teeth replace using the miswak?

It is Sunnah to clean the mouth and teeth with a miswak or a similar item while performing ablution. (Mevsılî, el-İhtiyâr, 1/8) This cleanliness is considered part of natural disposition (fitrah). (Muslim, Taharah, 56 [261]) The Messenger of Allah (peace be upon him) said in a hadith, “If I had not found it difficult for my ummah, I would have ordered them to use the miswak at every prayer time.” (Ibn Majah, Taharah, 7 [287]; see also Bukhari, Tamanni, 9 [7240]; Muslim, Taharah, 42 [252] 7)

In the practice of the Prophet (peace be upon him), cleaning the mouth and teeth was the main objective, and the miswak was used for this purpose at that time. Today, a toothbrush is used instead of the miswak. Using any product or method suitable for oral and dental health fulfills this Sunnah.

Source: T.C. Diyanet İşleri Başkanlığı, Din İşleri Yüksek Kurulu