Is the use of the siwak a Sunnah in and of itself, or is the Sunnah cleanliness, and toothpaste can replace it?

The early scholars differed on whether using soap and similar substances could substitute for using a miswak stick. As for using toothpaste and a brush in the modern era, it is closer to using a miswak stick in achieving the desired result. However, using the miswak stick is preferred, following the example of the Prophet (peace and blessings be upon him) and due to its health benefits. For those unable to do so, there is no harm, and what is important is achieving cleanliness and freshening the mouth.