Conclusions The results of this systematic review suggested that NiTi rotary instruments were associated with lower canal transportation and apical extrusion when compared to SST h and files , whereas both groups had similar outcomes in terms of success of therapy , amount of residual bacteria , and cleansing ability after treatment .
Introduction This systematic review evaluated the effectiveness of  nickel‐titanium ( NiTi ) rotary files compared to stainless‐steel ( SST ) h and files .
Effect of three nickel-titanium rotary file techniques on infected root dentin reduction.
OBJECTIVE This study compared the bacterial reduction of in vitro infected root canals after instrumentation by 3 nickel-titanium ( NiTi ) rotary files with different taper and diameter versus manual stainless steel files . STUDY DESIGN Sixty-four single-rooted human teeth were infected with a suspension of Streptococcus sanguis measured by optical density . Teeth were divided r and omly into 4 groups of 16 and prepared with Flexofiles , GT rotary files , HERO 642 , and ProFile . Bacterial samplings were performed before ( S1 ) , during ( S2-S3 ) , and after ( S4 ) instrumentation . RESULTS All techniques significantly reduced the number of bacterial cells in the root canals ( P < .05 ) . There was no significant difference between NiTi and manual instrumentation at S2 , S3 , or S4 . Concerning bacterial reduction , the results suggest that a manual stainless steel file preparation is as efficient as a NiTi rotary instrumentation . CONCLUSION Regardless of the root canal preparation technique , its taper , and diameter , the root dentin remained infected and was not bacteria-free at the end of the experiment
Conclusions The results of this systematic review suggested that NiTi rotary instruments were associated with lower canal transportation and apical extrusion when compared to SST h and files , whereas both groups had similar outcomes in terms of success of therapy , amount of residual bacteria , and cleansing ability after treatment .
Introduction This systematic review evaluated the effectiveness of  nickel‐titanium ( NiTi ) rotary files compared to stainless‐steel ( SST ) h and files .