AN EVALUATION OF NITINOL AND STAINLESS-STEEL FILES USED BY DENTAL STUDENTS DURING A LABORATORY PROFICIENCY EXAM

Eighty-one dental students instrumented two curved canals in acrylic blocks with the use of stainless steel files in one block and nitinol files in the other. Overlay tracings were made of photographs taken before and after instrumentation of the acrylic blocks and differences between the tracings were measured along the canal walls. The canals instrumented with nitinol files were shaped better than those instrumented with stainless steel files; working length was maintained more often without ledging the canal walls and with less zipping of the apical foramen.