Good point. Employer pays another $20 biweekly for our dental insurance. Our basic dental expenses yearly are $512 for 2 cleanings each with exams and xrays, covered at 100% by the dental insurance-- which costs me $269/year. So, a good deal for us currently, but definitely worth revisiting from time to time.
On a somewhat related note, I'm always amazed when I'm offered a "protection plan" on some electronic gizmo that would be no sweat to replace if it broke. Do I want to "insure" the $100 ipod? Prolly not.