On my 2003 Buick century v-6 has 77000 miles on it. I need details on engine gasket failures. ?

I have a Buick century v-6 and has 77000 miles on it. I umed the Dex Cool was ok for 5 years 100,000 miles. Now I hear there are engine gasket failures due to the Dex Cool. I just serviced it and changed over to the regular antifreeze. Have I waited too long? It is not running hot or leaking. I wish I had changed it sooner, I would hate to have to pay for the repairs. Any info anyone?