Ash-Shaykh Abdul Muhsin Al-Abaad was asked the following question
Question: Does the tooth brush take the place of the siwaak specifically in the lands which there is no siwaak except a a little, like in Europe?
Answer: “Yes, this is possible it takes its place because the intent is to clean and purification. However, a person using a miswak and being concerned to use it, even though it may not be found in his land, no doubt it is more deserving. However, no doubt [the tooth brush] takes it’s place because the intent is cleanliness. Yes”.
[Sharh Ibn Majah no. 33]
Faisal Ibn Abdul Qaadir Ibn Hassan