Myriam
I suspect that your teeth will not be useable.
I assume that you are talking about extracted human teeth?
The 2 months in EDTA and the 4 weeks in 5% nitric acid seems to me to be
excessive times for either decalcification agent.
I am assuming that you used a 5-10% disodium EDTA that was buffered? If
so then, with adequate agitation such as a magnetic stirrer, these
should have been decalcified in a month.
For 5% nitric acid, 3-5 days maximum for complete decalcification of a
tooth, again with adequate agitation.
The most important considerations here are:
First adequate fixation, second agitation during decalcification and
lastly but very important- frequent checks on how decalcification is
proceeding. Over decalcification will result in loss of details on
staining and in the case of nitric acid a yellowing of the tissue.
The method to select for decalcification will depend to a large extent
on what information you wish to extract from the sections. 
Please give us some more details of your needs.
Thanks
Barry

-----Original Message-----
From: Myri37@aol.com [mailto:Myri37@aol.com] 
Sent: Tuesday, June 17, 2003 9:12 AM
To: histonet@pathology.swmed.edu
Subject: decalcification in EDTA and acid

Hi histonetters
i need your help 
i put some teeth in EDTA for decalcification for two months, and then to
accelerate decalcification: I put them in acid nitric 5% for four weeks,
i embedded them in paraffine, teeth are too yelow now, and too hard,
what do you think about this, could you give me some advice, or any
protocole please 
thank you very much in advance
Myriam Baali