Abstract:

Objective
 To compare the clinical efficiency of Path File rotary nickel-titanium files and stainless steel K-files in mechanical glide path and preflaring,and to evaluate the clinical efficiency of Path File.Methods 252 root canals in 80 patients needing root canal treatment were randomly divided into  experienced physicians  using Path File(DP) group,experienced physicians  using stainless steel K-files(DK) group,interns using path File(SP) group,and interns using stainless steel K-files (SK) group,and  there were 20 patients in each group.In mechanical glide path and preflaring，the Path File rotary nickel-titanium files were used in  DP and SP groups，while the stainless steel K-files were applied in the DK and SK groups.In both DP and DK groups，the building of mechanical glide path and root canal preflaring were operated by experienced physicians.In both SP and SK groups，the building of mechanical glide path and root canal preflaring were operated by interns.The time for mechanical glide path and root canal preflaring was compared between four groups.The visual analog pain score(VAS) value ruler was used to evaluate the occurrence of postoperative pain after root canal filling.The operating time,postoperative pain,and  root canal cleaning efficiency were compared between  four groups.Results The occurrence of postoperative pain in Path File groups (15%-20%) and in stainless steel K-files groups (25%－35%) was not statistically significant after preflaring(P>0.05).The operation time in  Path File groups was significantly shorter than that in  stainless steel K-files groups (7.44 min±3.58 min vs 2.21 min±2.31 min) by experienced physicians and (9.75 min±5.29 min) vs (4.07 min±6.41 min) by interns  (P<0.05).The cleaning  efficiency in Path File groups was higher than that in stainless steel K-files groups (85%－95% vs 30%－55%) (P<0.05).There were no significant differences of the  operating time,occurrence of postoperative pain,and root canal cleaning efficiency operated by physians or interns in Path File groups (P>0.05).Conclusion Compared with stainless steel K-files, Path File can make  mechanical glide path and preflaring in a very short period of time,so unexperienced  physians could reach an operator results as similar as the experienced  physians.

Key words: nickel-titanium rotary instruments；Path File nickel-titanium files；K-files, preflaring, Postoperative pain