[Leica] O/T Any Dentists 'round here? Cracked tooth - Options?

[rdandcb at home.netspeed.com.au (Rick Dykstra)]

Apparently we're all Dentists here on the LUG. :-)  Some advice please.

I had a cracked molar sealed back in June.  Lower right jaw, the  
third molar from the back (starting from a wisdom tooth).  My teeth  
are great in general but this one has had some history.  It had  
fillings when I was a teenager, then more substantial fillings in my  
late twenties and now the crack seal job with the rear outside  
quarter taken back and filled, at 44 years.  Back in June my dentist  
said that a root canal would not be an option for this tooth, due to  
the crack, and that if it didn't settle extraction would be the only  
option.  Eeek!  Over the last week its been giving me serious  
trouble, just as it was in June.

A friend at work says that her dentist offered to do a root canal on  
her cracked molar, though she had it extracted at the time (it was a  
wizzy).  So the question is, is doing a root canal on a cracked molar  
like mine generally an option, or not?  Perhaps my dentist is a  
little conservative. ??

Thanks for any clues.  I'm in there this afternoon so your early  
thoughts would be valued.

Regards, Rick Dykstra.  Australia.