THE ENDODONTIC FILE IS A DISPOSABLE INSTRUMENT

Most cutting and machining tools wear when properly operated on intend ed substrates, Little is known about endodontic files when machining o n human dentin, It was shown earlier that the efficiency of files was very variable when evaluated on Plexiglas substrates, The present stud y of seven different brands and types of files was undertaken to under stand their wear better when machining human dentin. It was shown that all files evaluated rapidly deteriorated when machining dentin, This decline in efficiency was significant but different within, as well as , among brands, It was suggested that endodontic files be disposable.