Indiana University-Purdue University Indianapolis (IUPUI) / This in-vitro, prospective, randomized study microscopically compared the debridement efficacy of passive ultrasonic irrigation (PUI) using the Ultrasonic Bypass System and different irrigating protocols. Eighty extracted maxillary anterior teeth were randomly assigned to four groups. Teeth were instrumented using EndoSequence rotary instrument system and treated with passive ultrasonic irrigation with different irrigating regimens for one minute. Group one (control) was treated with hand/rotary instrumentation. Group two was treated with hand/rotary instrumentation followed by a one-minute PUI using the Ultrasonic Bypass System with 6.0-percent NaOCl. Group three was treated with hand/rotary instrumentation followed by a one-minute PUI using the Ultrasonic Bypass System with 17-percent EDTA. Group four was treated with hand/rotary instrumentation followed by a one-minute PUI using the Ultrasonic Bypass System with 30 seconds of 6.0-percent NaOCl and 30 seconds of 17-percent EDTA. Teeth were sectioned longitudinally and each half was divided into three equal parts from the anatomic apex. The half with the most visible part of the apex was used for SEM evaluation. A scoring system for debris and smear layer removal was used. Statistical analysis was performed using a Kruskal-Wallis test, which determines if there are any differences among the four groups. Following this test, a Wilcoxon Rank Sum test was used to compare each pair of groups. The addition of a one-minute PUI with the Ultrasonic Bypass System significantly enhanced the removal of smear layer when compared with the hand/rotary instrumentation with conventional irrigating solutions. The Ultrasonic Bypass System when used with the combination of 6.0-percent NaOCl and 17-percent EDTA after hand/rotary instrumentation significantly removed smear layer at the coronal, middle, and apical areas of a tooth when compared with all other groups. A one-minute PUI with the Ultrasonic Bypass System combined with NaOCl and EDTA is significantly better in smear removal and ultimately will result cleaner canal wall.

Indiana University School of Dentistry located on the campus of Indiana University-Purdue University Indianapolis (IUPUI) / This in-vitro, prospective, randomized study microscopically compared the debridement efficacy of negative pressure irrigation with the EndoVac (Discus Dental, Culver City, CA) versus the Canal CleanMax (Maximum Dental, Inc., Secaucus, NJ). Sixty extracted human canines were instrumented using a combination of hand-instrumentation with Lexicon K-type files and rotary instrumentation with ProTaper files. All canals were irrigated with 6.0-percent sodium hypochlorite and 17- percent ethylenediaminetetraacetic acid (EDTA). However, the irrigation/aspiration techniques differed among three groups of 20 randomly selected teeth. Group one (control) was irrigated with only a 12-ml Monoject syringe via 30-gauge side-vented, closed-end needle. Group two was irrigated with the EndoVac system. Group three was irrigated similar to group one, but with the adjunct of the Canal CleanMax system. All teeth were sectioned longitudinally, and the more intact sections were divided into coronal, middle, and apical thirds. Each portion of the canal was photographed with a scanning electron microscope (SEM). The photographs were scored by two independent examiners according to relative amount of debris and/or smear layer present, as well as relative number of patent dentinal tubules. These scores were statistically analyzed using a Krustal-Wallis test and Wilcoxon Rank Sum tests to determine differences between groups. The coronal aspect of root canal walls irrigated with the EndoVac system exhibited significantly less debris and/or smear layer present when compared to the coronal aspect of root canals irrigated with only a standard 12-ml Monoject syringe equipped with 30-gauge ProRinse side-vented, closed-end needle (control). There were no other significant differences in scores between any groups at any location. For all locations combined, the EndoVac system produced significantly cleaner root canal walls as compared to the control. No significant differences were seen between the Canal CleanMax and Control or Canal CleanMax and EndoVac. This study suggested negative pressure irrigation delivery with the EndoVac system during and after hand-rotary instrumentation is more effective in removal of debris and smear layer from the coronal third and combined thirds of root canal walls compared to irrigation with a standard 12-ml Monoject syringe equipped with 30-gauge ProRinse side-vented, closed-end needle.