I would like to know the ruling regarding manicures or pedicures?
It is necessary to make sure water reaches the skin for wudhu. If the area of a fingernail remains dry in any one of the four washable parts of wudhu, the wudhu will be considered incomplete. (Qadi Thanaullah Panipatti in Mala Budda Minhu p.33)
Regarding your question, artificial nails involves the use of UV gel or artificial glue. UV gel has a permanent effect which will prevent the water from reaching, hence, ones Wudhu and Salah would not be accepted.
Only Allah Knows Best
Mohammed Tosir Miah
Darul Ifta Birmingham