Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

The influence of irrigant activation, concentration and contact time on sodium hypochlorite penetration into root dentine: an ex vivo experiment

Virdee, S. S., Farnell, D., Silva, M. A., Camilleri, J., Cooper, P. R. and Tomson, P. L. 2020. The influence of irrigant activation, concentration and contact time on sodium hypochlorite penetration into root dentine: an ex vivo experiment. International Endodontic Journal 53 (7) , pp. 986-997. 10.1111/iej.13290

PDF - Published Version
Available under License Creative Commons Attribution Non-commercial No Derivatives.

Download (9MB) | Preview


Aim To establish if irrigant activation techniques, namely manual‐dynamic‐activation (MDA), passive‐ultrasonic‐irrigation (PUI) and sonic‐irrigation (SI), improve the tubular penetration of sodium hypochlorite (NaOCl) into root dentine when compared with conventional‐needle‐irrigation (CNI). Secondly, investigate if increasing NaOCl concentration and/or contact‐time improves the performance of these techniques. Methodology A total of 83 extracted human maxillary permanent canines were decoronated to 15 mm and root canals prepared to a size 40,.10 taper. Root dentine was stained with crystal violet for 72 h and embedded in silicone. Eighty specimens were randomly distributed into 16 groups (n = 5) according to the irrigant activation technique, NaOCl concentration (2%; 5.25%) and irrigant contact‐time (10 min; 20 min). All activation techniques were used for 60 s in the last minute of irrigation. Additionally, 3 teeth were not exposed to NaOCl to confirm adequate dentine staining had occurred (i.e. negative control). All specimens were subsequently dissected, observed under a light microscope and NaOCl penetration depth (µm) determined by measuring the average width of bleached dentine using ImageJ software. Statistical comparisons were made with paired and unpaired t‐tests, ANOVAs followed by post‐hoc Tukey and Dunnett’s tests, and a general linear model (α < 0.05). Results Overall, NaOCl penetration ranged from 38.8 µm – 411.0 µm with MDA, PUI and SI consistently resulting in significantly greater tubular infiltration than CNI (P < 0.05). The deepest measurements in the coronal, middle and apical segments were all recorded in the MDA; 5.25%; 20 min group and the least in the CNI; 2%; 10 min group. Increasing either irrigant concentration or contact‐time resulted in significantly greater NaOCl penetration depths for all techniques and segments of the canal (P < 0.05). However, when irrigant concentration and contact‐time were increased together, a significant interaction effect between these two independent variables was observed on overall NaOCl penetration (P < 0.05). Conclusions Agitating irrigants with MDA, PUI or SI, as well as using greater irrigant concentrations or contact‐times, potentiated NaOCl penetration into root dentine. However, longer durations of NaOCl exposure at lower concentrations resulted in similar depths of tubular penetration as those achieved at higher concentrations.

Item Type: Article
Date Type: Publication
Status: Published
Schools: Dentistry
Publisher: Wiley
ISSN: 0143-2885
Date of First Compliant Deposit: 30 March 2020
Date of Acceptance: 12 March 2020
Last Modified: 02 Jul 2020 12:22

Actions (repository staff only)

Edit Item Edit Item


Downloads per month over past year

View more statistics