- Purpose: to determine if canal length is altered significantly after SLA and CF between two groups of teeth: straight versus severely curved. Also, whether the amount of canal length alteration was influenced by tooth type: molars versus premolars.
- N= 86 intact Max and mand extracted premolars and molars, 49 curved and 37 straight (determind by Schneider ).
- Access was made, Reference cusp was flattened to facilitate reproducible, accurate measurements.
- #10 K-file was placed ,excess file protruding from the root-end was viewed and measured before treatemnt with a stereomicroscope.
- Access was modified with tapered fissure bur, gates glidden (#2,3,4), #10 K-file protrusion was remeasured .
- The change in canal length was determined by subtracting the length of protrusion of the file (pre – post-TX).
Most highlighted Results:
1.The study showed a measurable statistically significant decrease in WL after SLA and CF with a mean of 0.17mm.
2.Curved canals showed a significant decrease in length compared to straight canals. However, the difference was very small.
3.There was no significant influence between length change and tooth type.
Especially in curved canals, preflaring would reduce the risk of over-instrumenting the canals.
(*SLA: Straight Line Access, CF: Coronal Flaring)