METHODS	Extracted noncarious human teeth were randomly divided into 4 groups of 15 each and restored according to manufacturer 's instructions : group 1 , SureFil and Prime & Bond NT ; group 2 , SureFil and PQ1 ; group 3 , SureFil , PermaFlow , and PQ1 ; group 4 , Heliomolar and Syntac Single-Component ( control ) .\