For those of us fortunate to obtain specimens before the ban was put in place here is a study published earlier this year that looked at a fair number of teeth.  The blog provides a good read for collectors plus other readings in their references..   Blog http://rexmachinablog.com/2019/09/04/thailand-spinosaur-teeth/   Paper https://www.researchgate.net/publication/332698408_Spinosaurid_theropod_teeth_from_the_Red_Beds_of_the_Khok_Kruat_Formation_Early_Cretaceous_in