crown

Hi,
1 month ago i visited a dentist just to take a look on my tooth. After X-ray she told me i need crown for my tooth which were root-chanal. she worked on my 2 teeth no.9 and 11 and put crown. my tooth were not damage or decayed or not any craks. When i complain her she told me becuse my tooth were root-chanal and the stage after root-channal is crown.
My question
Is that really neccessary to put crown for teeth that isn't painful, damaged or cracked and just is root-chanal?
Now i am in a really bad feeling . i think that i lost 2 of my tooth by the dentist because of her fault.
Please answer my question and tell me what i can do.
Thanksfull
Mina

[Jerome Tsang, DDS]

It depends on the extent of tooth structure available and the reason as to why there was a need to have the root canal performed in the first place.  If there is plenty of tooth structure, then it isn't necessary to do a crown on a root canal treated tooth.  If it was a back molar which takes more of a "beating" due to the chewing motion, it is almost always recommended to do a crown on that tooth.

[simpleman1]

Teeth become brittle when they are root treated and are likely to fracture...if covered with a full crown..strengthens the tooth and fractures can very well be avoided. If your dentist did crowns that would only increase the longevity of those teeth.