It's a tricky business for a number of reasons: Firstly, judging by the number of laterals I've identified already, I.affinis make up a fraction of a percent of all finds at Beltinge (1 in 500?); secondly, having done a web search for example images of anteriors, it looks like I really need to find complete teeth in order to reliably ID ones in my collection; and, lastly, from what I've read elsewhere, it appears even the experts struggle to tell the difference between various Mackerel shark anterior teeth (like C.hopei & I.affinis), since they're remarkably similar.
The search was a bust.
Basically, I was looking for complete anterior teeth with a slender, upright main cusp, that had smooth, unstriated enamel, and a cutting edge extending to the base of the side cusps. It would likely have a single, small, pointed cusplet on either side of the main cusp.
Sounds just like C.hopei so far. Where they differ seems to be that the root lobes look fatter than C.hopei (See here), hence their alternative name of Isurolamna inflata. It also seems that the edge of the enamel that meets the root in between the cusplets on the labial side forms a shallow 'W' (see right hand image at the top of this page), as opposed to a straight-ish line or a shallow, upside-down 'V'. Note: the 'W' thing is suggested here.