Don,
PaulB went into detail that I couldnt. I got the info from my RO. She stated that >55Gy was the dosage amount where it becomes a concern, and >70Gy is high risk. She reiterated twice to me that upper jaw was at less of a risk, but didn't state any delta in dosage/risk between the two.

I was my own advocate. I called everyone asking about what I should do. With the arrival of my twins, I was thinking trying to save money and just have it pulled. Due to the fact it was the second to last tooth and not the last molar, it could cause more problems. The best approach agreed to by all was a crown.