Available chlorine consumption from NaOCl solutions passively placed in instrumented human root canals. (28th July 2014)

• Record Type: Journal Article
• Authors: Ragnarsson, K. T.; Rechenberg, D. K.; Attin, T.; Zehnder, M.
• Is Part Of: International endontic journal. Volume 48:Number 5(2015:May)
• Page Start: 435
• Page End: 440
• Publication Date: 2014-07-28
• Subjects: Endodontics -- Periodicals; 617.6342
• DOI: 10.1111/iej.12332
• Languages: English
• ISSNs: 0143-2885

Abstract

<abstract abstract-type="main" id="iej12332-abs-0001"> <title>Abstract</title> <sec id="iej12332-sec-0001" sec-type="section"> <title>Aim</title> <p>To monitor chlorine consumption from nonagitated aqueous sodium hypochlorite (NaOCl) solutions in human root canals using a recently developed assay, which can determine the order of magnitude of available chlorine in small volumes of liquid.</p> </sec> <sec id="iej12332-sec-0002" sec-type="section"> <title>Methodology</title> <p>The root canals of 80 extracted single‐rooted human teeth were instrumented to ProTaper Universal F4 and irrigated using 1% NaOCl. Subsequently, canals were irrigated with copious amounts of deionized water to rinse out the residual chlorine. Subsequently, the teeth were sealed externally and placed in a water bath of 37 °C. Root canals were filled with NaOCl of 1%, 2.75%, 5.5%, or distilled water for 1, 10, 100 or 1000 min (<italic>n </italic>= 5 teeth per solution and time). Consumption of chlorine was measured using paper points pre‐impregnated with 15% potassium iodide. Colour change of the paper points was determined photo‐electronically, assessing their red value after absorbing solutions from root canals. Measurements were compared to a standard series of NaOCl down to 0.001% (<italic>n </italic>= 5 paper points per concentration).</p> </sec> <sec id="iej12332-sec-0003" sec-type="section"> <title>Results</title> <p>Red values of the paper points inserted into the root canal were affected by initial NaOCl concentration and time (two‐way <sc>anova</sc>, <italic> P </italic><<italic> </italic>0.05). If NaOCl concentrations above 0.1% are considered to be clinically relevant, then 5.5% NaOCl retained its activity in the root canal for more than 100 min, whereas 1% NaOCl lost its activity between 10 and 100 min.</p> </sec> <sec id="iej12332-sec-0004" sec-type="section"> <title>Conclusions</title> <p>Nonagitated NaOCl solutions can remain biologically active in human root canals for extended time periods.</p> </sec> </abstract>