Monitoring the effectiveness of root canal procedures on endotoxin levels found in teeth with chronic apical periodontitis

Abstract

Objective:The aim of this study was to monitor the effectiveness of root canal procedures by using different irrigants and intracanal medication on endotoxin levels found in root canals of teeth with chronic apical periodontitis.Material and Methods:Thirty root canals of teeth with pulpal necrosis associated with periapical lesions were selected and randomly divided into groups according to the irrigants used: GI - 2.5% NaOCl, GII - 2% chlorhexidine (CHX) gel, and GIII - saline solution (SS) (all, n=10). Samples were collected with sterile/apyrogenic paper points before (S1) and after root canal instrumentation (S2), after use of 17% ethylenediaminetetraacetic acid (EDTA) (S3), and after 30 days of intracanal medication (Ca(OH)2+SS) (S4). A turbidimetric kinetic Limulus Amebocyte Lysate assay was used for endotoxin measurement.Results:Endotoxins were detected in 100% of the root canals investigated (30/30), with a median value of 18.70 EU/mL. After S2, significant median percentage reduction was observed in all groups, irrespective of the irrigant tested: 2.5% NaOCl (99.65%) (GI), 2% CHX (94.27%) (GII), and SS (96.79%) (GIII) (all p<0.05). Root canal rinse with 17% EDTA (S3) for a 3-minute period failed to decrease endotoxin levels in GI and a slight decrease was observed in GII (59%) and GIII (61.1%) (all p>0.05). Intracanal medication for 30 days was able to significantly reduce residual endotoxins: 2.5% NaOCl (90%) (GI), 2% CHX (88.8%) (GII), and SS (85.7%) (GIII, p<0.05). No differences were found in the endotoxin reduction when comparing s2 and s4 treatment groups.Conclusion:Our findings demonstrated the effectiveness of the mechanical action of the instruments along with the flow and backflow of irrigant enduring root canal instrumentation for the endotoxin removal from root canals of teeth with chronic apical periodontitis. Moreover, the use of intracanal medication for 30 days contributed for an improvement of endotoxin reduction.

Clinical efficacy of EDTA ultrasonic activation in the reduction of endotoxins and cultivable bacteria

“…Even with nickel‐titanium (NiTi) rotary and reciprocating instruments, it is still not possible to overcome this problem (Marinho et al . , ).…”

LPS levels in root canals after the use of ozone gas and high frequency electrical pulses

“…2 Thus, considering the results observed when using the ozone gas system 14,19 and high frequency electrical pulses 13,15 on microbial strains, analysis of these systems on bacterial LPS was also thought to be pertinent.…”

“…12,20 LAL assay was used to quantify LPS levels as it is extremely sensitive to measurement. 2,10 The turbidimetric LAL assay indicated that the endotoxins were present in all previously contaminated samples. The concentrations ranged from 0.1 to 12.8 EU/mL in the positive control group, and this was in accordance with Jacinto et al 21 who reported endotoxin concentrations ranging between 2.3 and 22.1 EU/mL.…”

“…2,11 The samples collected from the canals were mixed with the LAL reagent and automatically monitored over time with the help of a photometer until turbidity developed. The increase in optical density was measured by the reaction time, which is inversely proportional to the amount of LPS present in the sample.…”

“…1,2,3 LPS is released during multiplication or death of gram-negative bacteria, and is associated with many biological effects, such as release of pro-inflammatory mediators 4 and induction of periapical bone resorption. 5 The endotoxins can adhere to mineralized tissues 6 and disseminate through the dentinal tubules, 7 making root canal sterilization difficult if only chemo-mechanical preparation is used.…”