Purpose: to develop a clinically relevant model where the effect of the presence or absence of smear layer on bacterial colonization of root canal can be determined
N= 26 extracted maxillary or mandibular canines with single straight canals.
- The experimental group was subdivided into two groups based on the type of high volume final flush
- G1 smear layer not removed – received a final flush of 20 ml of sterile water
- G2 smear layer removed – received a final flush of 10 ml of 17% REDTA followed by 10 ml of 2.5% NaOCI
- Streptococcus anginosus was the organism used in this investigation
- SEM examination for presence/absence of smear layer in canal surfaces
Most highlighted Results:
- Teeth with smear layer showed lower bacterial counts than where smear layer was removed
- Over 10—fold higher count of bacteria were recovered from teeth without a smear layer compared to teeth with a smear layer
- Sonicating the teeth for 5 min effectively removed the smear layer
Removal of smear layer increased bacterial count. a smear layer of debris could be created after final flush and drying of the canal.
Weakness: investigating a single type of microorganisms