The effect of different taper preparations on the ability of sonic and passive ultrasonic irrigation to reach the working length in curved canals.
OBJECTIVE
To evaluate the penetration of irrigants up to working length using two different activation systems in curved canals instrumented with 0.04 and 0.08 taper instruments.


METHODS
Sixty-eight mesiobuccal canals from mandibular first molars with curvatures between 30° and 40° were used. The samples were divided into group 1, canals instrumented to size 30, 0.04 taper, and group 2, instrumented to size 30, 0.08 taper. Both groups were irrigated with a contrast solution and divided in 2 subgroups of 15 samples each: Groups 1A and 2A were activated with passive ultrasonic irrigation (PUI), whilst groups 1B and 2B were activated with sonic irrigation (SI). Radiographs were taken to evaluate the penetration of the contrast solution up to working length. This evaluation was performed using Adobe Photoshop CS5. Results were analysed with the chi-square test and a logistic regression model.


RESULTS
Only groups with 0.04 taper demonstrated significant differences where the activation with PUI was superior at reaching working length than SI (P = 0.010). The logistic regression model showed that the only correlation in reaching working length was the activation system used (P = 0.005).


CONCLUSIONS
The results suggest that variation of canal taper does not affect the ability of PUI to reach the working length in curved canals whilst SI obtained inferior results with 0.04 taper canal preparations.
Universidad Europea de Madrid, Spain.
A
A
Merino
R
R
Estevez
C
C
de Gregorio
N
N
Cohenca
D003287:Contrast Media; D003786:Dental Pulp Cavity / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D008422:Materials Testing; D008963:Molar / Q000000981:diagnostic imaging / Q000473:pathology; D009811:Odontometry / Q000379:methods; D011859:Radiography; D012388:Root Canal Irrigants / Q000008:administration & dosage*; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods*; D012973:Sodium Hypochlorite / Q000008:administration & dosage; D013010:Sonication / Q000295:instrumentation / Q000379:methods; D007507:Therapeutic Irrigation / Q000295:instrumentation / Q000379:methods*; D019227:Tooth Apex / Q000000981:diagnostic imaging / Q000473:pathology; D014465:Ultrasonics / Q000295:instrumentation
D003287:Contrast Media; D012388:Root Canal Irrigants; D012973:Sodium Hypochlorite