title: Interaction between lidocaine hydrochloride (with and without adrenaline) and various irrigants: A nuclear magnetic resonance analysis.
abstract: BACKGROUND
  Interaction between local anesthetic solution, lidocaine hydrochloride (with and without adrenaline), and root canal irrigants such as sodium hypochlorite (NaOCl), ethylene diamine tetra-acetic acid (EDTA), and chlorhexidine (CHX) has not been studied earlier. Hence, the purpose of this in vitro study was to evaluate the chemical interaction between 2% lidocaine hydrochloride (with and without adrenaline) and commonly used root canal irrigants, NaOCl, EDTA, and CHX.
  
  
  METHODS
  SAMPLES WERE DIVIDED INTO EIGHT EXPERIMENTAL GROUPS: Group I-Lidocaine hydrochloride (with adrenaline)/3% NaOCl, Group II-Lidocaine hydrochloride (with adrenaline)/17% EDTA, Group III- Lidocaine hydrochloride (with adrenaline)/2% CHX, Group IV-Lidocaine hydrochloride (without adrenaline)/3% NaOCl, Group V-Lidocaine hydrochloride (without adrenaline)/17% EDTA, Group VI-Lidocaine hydrochloride (without adrenaline)/2% CHX, and two control groups: Group VII-Lidocaine hydrochloride (with adrenaline)/deionized water and Group VIII-Lidocaine hydrochloride (without adrenaline)/deionized water. The respective solutions of various groups were mixed in equal proportions (1 ml each) and observed for precipitate formation. Chemical composition of the formed precipitate was then analysed by nuclear magnetic resonance spectroscopy (NMR) and confirmed with diazotation test.
  
  
  RESULTS
  In groups I and IV, a white precipitate was observed in all the samples on mixing the respective solutions, which showed a color change to reddish brown after 15 minutes. This precipitate was then analysed by NMR spectroscopy and was observed to be 2,6-xylidine, a reported toxic compound. The experimental groups II, III, V, and VI and control groups VII and VIII showed no precipitate formation in any of the respective samples, until 2 hours.
  
  
  CONCLUSIONS
  Interaction between lidocaine hydrochloride (with and without adrenaline) and NaOCl showed precipitate formation containing 2,6-xylidine, a toxic compound.
authors.affiliation: Department of Conservative Dentistry and Endodontics, Meenakshi Ammal Dental College and Hospital, Meenakshi University, Chennai, Tamil Nadu, India.
authors.forename: Nirmal
authors.initials: N
authors.lastname: Vidhya
authors.affiliation: Department of Conservative Dentistry and Endodontics, Meenakshi Ammal Dental College and Hospital, Meenakshi University, Chennai, Tamil Nadu, India.
authors.forename: Balasubramanian Saravana
authors.initials: BS
authors.lastname: Karthikeyan
authors.affiliation: Department of Conservative Dentistry and Endodontics, Meenakshi Ammal Dental College and Hospital, Meenakshi University, Chennai, Tamil Nadu, India.
authors.forename: Natanasabapathy
authors.initials: N
authors.lastname: Velmurugan
authors.affiliation: Department of Conservative Dentistry and Endodontics, Meenakshi Ammal Dental College and Hospital, Meenakshi University, Chennai, Tamil Nadu, India.
authors.forename: Mohan
authors.initials: M
authors.lastname: Abarajithan
authors.affiliation: Department of Chemistry, College of Engineering, Anna University, Guindy, Chennai, Tamil Nadu, India.
authors.forename: Sivasankaran
authors.initials: S
authors.lastname: Nithyanandan
keywords: 2; 6-xylidine; Lidocaine hydrochloride; precipitate; sodium hypochlorite
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