Effect of QMix® Irrigating Solution on Bacterial Reduction after Using Different Irrigation Protocols: an in Vitro Study

Abstract

The present study aimed to evaluate the efficacy of QMix 2in1 as an antibacterial irrigating solution on the Entrococcus faecalis within the root canal of extracted anterior teeth using different agitation techniques and different times by the aid of direct count of colony forming units (CFUs). Sixty four extracted teeth with single canal were selected for the study. The teeth were decoronated using a high speed diamond stone with water coolant and the root length was standardized at length of 15mm. Protaper rotary system were used for instrumentation and enlarging the canals in a crown down manner up to file size F5 (50/5). After each file, the canal was irrigated with 2ml of 5.25% NaOCl, and the smear layer was removed by using 5ml 5.25% of NaOCl followed by 5ml of EDTA and 5ml of saline. Then the roots were coated with nail polish. Then, the teeth were sterilized in autoclave for 20 minutes at 121oC and the apices were sealed with wax and then the canals were sampled with sterile paper points to confirm that they are totally sterilized. The E. faecalis was inoculated at 37oC for 24 hours and resuspended in saline to reach a final concentration of 3X108 cells/ml, and adjusted to No.1 macFarland turbidity standard. The samples were contaminated with a 3ml of bacterial suspension and fresh bacterial suspension was prepared and replaced every 72-hours for a period of three weeks, then a random specimen from each subgroup were cultured using size #40 sterile paper point to confirm the contamination with the bacteria. The samples were divided into 2 groups of 32 teeth according to the irrigating solution, and each group has 2 subgroups according to the activation method (n=16) and each one subdivided into 2 subgroups according to the irrigation time (n=8). • Group IA1: The specimens were irrigated with 5ml 2.5% NaOCl solution for 30 seconds (2.5ml / 15 sec) followed by 5ml 17% EDTA solution for 30 seconds (2.5ml / 15 sec). Both solutions were activated using a matching F5 Gutta Percha cone. • Group IA2: The specimens were irrigated with 5ml 2.5% NaOCl solution for 60 seconds (2.5ml / 30 sec) followed by 5ml 17% EDTA solution for 60 seconds (2.5ml / 30 sec). Both solutions were activated using a matching F5 Gutta Percha cone. • Group IB1: The specimens were irrigated with 5ml 2.5% NaOCl solution for 30 seconds (2.5ml / 15 sec) followed by 5ml 17% EDTA solution for 30 seconds (2.5ml / 15 sec). Both solutions were activated using an ultrasonic Irrisafe tip size 25. • Group IB2: The specimens were irrigated with 5ml 2.5% NaOCl solution for 60 seconds (2.5ml / 30 sec) followed by 5ml 17% EDTA solution for 60 seconds (2.5ml / 30 sec). Both solutions were activated using an ultrasonic Irrisafe tip size 25. • Group IIA1: The specimens were irrigated with 5ml QMix solution for 60 seconds (1ml / 12 sec). The solution was activated using a matching F5 Gutta Percha cone. • Group IIA2: The specimens were irrigated with 5ml QMix solution for 120 seconds (1ml / 24 sec). The solution was activated using a matching F5 Gutta Percha cone. • Group IIB1: The specimens were irrigated with 5ml QMix solution for 60 seconds (1ml / 12 sec). The solution was activated using an ultrasonic IrriSafe tip size 25. • Group IIB2: The specimens were irrigated with 5ml QMix solution for 120 seconds (1ml / 24 sec). The solution was activated using an ultrasonic IrriSafe tip size 25. At the end of the procedure, the samples were flushed with 2ml saline. The samples were taken by 3 sterile paper points size #35 and transferred to a test tube containing 1ml saline. Each sample was homogenized by vortexing for 30 seconds. Serial 10-fold dilution (1:10, 1:100 and 1:1000) was made in saline. Then 0.1 mm from each dilution was smeared to be inoculated on surface of the plate media (BHI agar plates), incubated at 37°C for 48 hours, and colony-forming units (CFU) per 1 ml were enumerated. The results showed that both irrigants decreased the bacterial count, and there were no statistically significant difference between them (P ≥ 0.05). The results showed also that there were statistically significant bacterial reduction when activation was employed and when the activation time was increased (P ≤ 0.05).