The description mentioned by you is not sufficient to arrive at a rational diagnosis.
A proper clinical examination would be the best step for that, or at least a look at the clinical photograph would be helpful if you can post it. Yellowishness of the teeth can be due to many reasons.
The extrinsic factors can be eliminated by procedure called as scaling and for intrinsic factors procedures like bleaching and other camouflage procedures can be done.
Regards.
Answered2017-09-21 15:11:51
Let others know if this answer was helpful