I have a quick question. If you have Roza and you have a very painful toothache so you use clove oil on cotton wool and place it on the tooth, does it break your fast? Sometimes you can taste the bitter taste of the clove oil. I read one fatwa by a Hanafi jurist that it doesn't break the fast.
بِسْمِ اللهِ الرَّحْمنِ الرَّحِيْم
In the name of Allah, the Most Gracious, the Most Merciful
In such an incident, as long as the medicine or the taste of the clove oil does not reach the throat (i.e. one doesn't swallow it) the fast will remain, even if the bitterness remains in the mouth.
However, one should try to avoid such medicine unless totally necessary as it is very hard to maintain the fast in such a way because if he swallows the medicine the fast will break.
Only Allah knows best
Written by Maulana Belaal Ahmed
Checked and approved by Mufti Mohammed Tosir Miah
Darul Ifta Birmingham
 Fataawa Mahmoodiya vol 10 pg 155