Sunshine, according to new dental hygienist, is less intense (8)
I believe the answer is:
daylight
'sunshine' is the definition.
(thesaurus)
'new dental hygienist is less intense' is the wordplay.
'new' indicates anagramming the letters.
'is less' suggests deleting specific letters (less can mean minus).
'dental'+'hygienist'='dentalhygienist'
'dentalhygienist' with 'intense' taken away is 'dalhygit'.
'dalhygit' with letters rearranged gives 'DAYLIGHT'.
'according to' acts as a link.
(Other definitions for daylight that I've seen before include "Clear difference between rivals" , "Is it saved in summer" , "Dawn to dusk" , "Clear space" , "Diurnal illumination" .)