An In-vitro Assessment of Effect of Interaction Between Local Anaesthetic Solution with Sodium Hypochlorite on the Sealing Ability of Root Canal Obturation

Abstract

Introduction: Endodontic treatment failures are caused by persistent or secondary infection due to inefficient cleaning or re-infection of the obturated root canal system because of coronal or apical leakage. Intrapulpal Injection (IPI) technique is the most commonly employed supplemental anaesthetic procedure and NaOCl is considered as gold standard irrigating solution. Therefore, this study was designed to explore the action of precipitate form by interaction between LA and Sodium Hypochlorite (NaOCL) on sealing of root canal obturating material. Aim: To evaluate the effect of precipitate formed by interaction of local anaesthetic solution and NaOCl on the sealing ability of root canal obturation, using a push-out bond strength test. Materials and Methods: This was an in-vitro study from October 2019 to January 2020. In this study, forty single rooted premolars were selected and were randomly distributed equally into 4 groups with 10 specimens in each group, based on the test solutions employed. All the teeth were decoronated and the root length was standardised. Group I - irrigated with saline only, Group II- treated with 2% lidocaine hydrochloride with adrenaline 1:100,000 (2% LA) followed by 3% NaOCl, Group III - 2% LA followed by saline and 3% NaOCl, Group IV- 3% NaOCl followed by saline. All root canals were than instrumented using ProTaper Universal rotary system upto F3 and obturation was done using AH plus sealer and GuttaPercha. Sealing ability was evaluated using a micro push-out bond strength, with the help of a universal testing machine and data were analysed statistically. Results: One-way analysis of variance (ANOVA) showed that there is highly significant difference among the various groups (p <0.0001). Within the experimental groups, Group II showed minimum mean push out bond strength (16.39±2.40) as compared to Group III (21.83±1.25) and Group IV (22.50±2.12). Conclusion: Interaction of LA with NaOCl forms precipitate which blocks the dentinal tubules and reduces the mean push out bond strength. It is recommended to irrigate thoroughly with saline after intrapulpal injection (2%LA) before irrigating with NaOCl.

Keywords

• intrapulpal injection
• precipitation
• push out bond strength
• sealer