Thank you for your opinion Sharon Day O'Conner. However, I stand by my original statement that all patents have expired before twenty nine years.
So called patent extensions are not really extensoins because the owners of certain patents such as drugs are not able to profit from their inventions until they receive FDA approval even though a patent has been granted.Patents are anticompetitive.They are monopolies that don't violate the Sherman antitrust act. This.provision is irrelevant re amalgam patents. Even where it applies ,it has to be for less than five years and the owner of the patent has to show due diligence.