If you're a dentist, you can hardly escape the barrage of mail, or ads
in all the dental journals.
    In NY, the Brookdale Hospital medical center has for years run a
so-called "maxi-course" on implant placement run by the redoubtable
Norman Cranin.  He may have retired.
    Crown lengthening and surgical extractions are certainly covered in
clinical continuing education courses run by many dental schools.  I
suggest you contact local schools and ask for their bulletin.  Most of
them should be available on-line.

Steve