Efficacy of continuous apical negative ultrasonic irrigation (CANUI) in penetration of simulated lateral canals in extracted teeth

Abstract

The aim of this study was to evaluate the efficacy of continuous apical negative ultrasonic irrigation into simulated lateral canals and the apical third in straight and curved root canals. Two simulated lateral canals were created 2, 4 and 6 mm from the working length in 120 single-rooted teeth (6 canals/tooth, n = 360 straight, n = 360 curved). The teeth were randomly divided into 3 experimental groups: positive pressure irrigation (PPI) (n = 20); passive ultrasonic irrigation (PUI) (n = 20); continuous apical negative ultrasonic irrigation (CANUI) (n = 20). 20% Chinese ink was added to a 5% sodium hypochlorite solution and delivered into the root canals. The results showed a significantly higher (P < 0.05) penetration of irrigant into the lateral canals and up to working length in the CANUI group for straight and curved roots. CANUI improves penetration into the lateral canals and up to the working length of the cleared teeth in straight and curved roots.

Effectiveness of various irrigant activation techniques on the penetration of sodium hypochlorite into lateral canals of mature permanent teeth: A systematic review and meta-analysis

“…Following a title and abstract screening, 23 studies were found to be eligible for full-text evaluation. A total of 12 studies were selected to include in the systematic review ( Castelo-Baz et al, 2021 , Castelo-Baz et al, 2016 , Castelo-Baz et al, 2012 , de Gregorio et al, 2012 , de Gregorio et al, 2010 , de Gregorio et al, 2009 , Kanumuru et al, 2015 , Khare and Suprabha, 2017 , Pawar et al, 2013 , Souza et al, 2019 , Spoorthy et al, 2013 , Yaghi and Kaloustian, 2016 ), with the omission of 11 studies. The reasons for the exclusion are outlined in Appendix C. A total of 10 studies were qualified for inclusion in the meta -analysis ( Castelo-Baz et al, 2021 , Castelo-Baz et al, 2016 , Castelo-Baz et al, 2012 , de Gregorio et al, 2012 , de Gregorio et al, 2010 , Khare and Suprabha, 2017 , Pawar et al, 2013 , Souza et al, 2019 , Spoorthy et al, 2013 , Yaghi and Kaloustian, 2016 ) ( Fig.…”

“… Study IATs No. of teeth Number of lateral canals n (%) 2 mm 4 mm 4.5 mm 6 mm Overall Straight canals Castelo-Baz et al, 2021 CNI 20 0 (0) 0 (0) – 0 (0) 0 (0) PUI 20 15 (37.5) 10 (25) – 15 (37.5) 40 (33.3) Souza et al, 2019 CNI 20 2 (5) – 4 (10) 13 (32.5) 19 (15.8) PUI 20 26 (65) – 29 (72.5) 34 (85) 89 (74.2) Kanumuru et al, 2015 CNI 15 0 (0) 8 (26.6) – 16 (53.3) 24(26.7) PUI 15 30 (1 0 0) 30 (1 0 0) – 30 (1 0 0) 90 (1 0 0) SI 15 14 (46.7) 18 (60) – 30 (1 0 0) 62 (68.9) Pawar et al, 2013 CNI 20 0 (0) – 0 (0) 0 (0) 0 (0) PUI 20 28 (70) – 40 (1 0 0) 40 (1 0 0) 108 (90) SI 20 0 (0) – 4 (10) 6 (15) 10 (8.3) …”

“…A change in the needle-insertion depth ( Boutsioukis et al, 2010 ), degree of root canal curvature ( Ahmad et al, 1988 , Boutsioukis et al, 2013 , Castelo-Baz et al, 2021 , Castelo-Baz et al, 2016 ), activation of NaOCl and its continual replenishment ( Pashley et al, 1985 , Stojicic et al, 2010 , Zehnder, 2006 ), and anatomic variations of the lateral canals ( Ricucci et al, 2013 ). Other factors such as power intensity ( Jiang et al, 2011 ), renewal rate, concentration, volume ( Ricucci et al, 2013 ), flow rate ( Pereira et al, 2021 ), and activation time ( Retsas et al, 2022 ) of the irrigant in the lateral canals also have a great implication on the degree of irrigant penetration.…”

Preclinical Testing of Boron-Doped Diamond Electrodes for Root Canal Disinfection—A Series of Preliminary Studies

“…Similarly to previous alternative approaches to root canal disinfection such as continuous apical negative ultrasonic irrigation [18,19], high-frequency electrical pulses [20], electric current and silver electrodes [21] as well as Er:YAG laser irradiation [22], BDD electrodes led to a decrease in bacterial count but could not predictably prevent bacterial regrowth [23] under clinical conditions.…”

“…However, it has recently been shown for ultrasonic activation systems to cause smear layers in the apical parts of the canal system [16], counteracting the desire of removing bacterial biofilms, which are more resistant than their planktonic counterparts [17]. In addition, a wide variety of advanced treatment modalities have been introduced including continuous apical negative ultrasonic irrigation [18,19], highfrequency electrical pulses [20], electric current and silver electrodes [21] as well as Er:YAG laser irradiation [22]. Most of these techniques result in a decrease in bacterial numbers but cannot predictably prevent bacterial regrowth [23].…”