i dont rate biscuits for their teeth either. Ruth, I Don't blame you for being squeamish, mine had them once and never again!! You can also try chunks of meat too, but need to start them small and increase size.
The bone in raw chicken is supposed to be OK for them, but I had to strip the meat off the ones for mine, they couldnt quite get the hang of it (although Molly was 14 at the time!!)