Purpose:
To evaluate the influence of apical size on cleaning of apical 1/3 of curved canals prepared with rotary instrumentation.
Materials/Methods:
- n=44 freshly extracted mx M1 teeth
- inclusion: mature, curvature 20-40 degrees, radius curvature <10mm
- MB canals instrumented to different apical sizes (30.02, 35.02, 40.02, 45.02) using crown down (Hero 642 rotary system)
- after instrumenting, apical 1/3 subject to histo analysis at 40x with morphometric analysis
Results:
- % of uninstrumented root canal dentin was higher when apical enlargement performed with instruments 30.02 and 35.02 vs. with 40.02 and 45.02 (P< .05)
- more debris observed when apical enlargement performed with 30.02, 35.02 (P< .05).
- significant correlation exists between amount of remaining debris and perimeter of unistrumented root canal dentin (P<.001)
Clinical Significance:
No apical enlargement size allowed root canal walls to be prepared completely. Apical 1/3 cleanliness can be predicted by increasing instrument diameter.