Intricate Evaluation of Time-Bound Effectiveness of Different Canal Irrigants in Smear Layer Eradication: An Original Research Study

Abstract

Aim: This study aims to evaluate the time-bound effectiveness of different canal irrigants in smear layer eradication.

Materials and Methods: This study examines a sample of 80 mandibular right lateral incisors; all extracted over three months for non-traumatic dental research. The teeth were selected based on optimal conditions, with no signs of carious decay etc. Roots were embedded in acrylic resin for stability, and occlusal surfaces were standardised by flattening with diamond rotary instruments, creating uniform access cavities for accurate experimental replication. Working length was determined using a No. 15 K-file set 1 mm short of the apex, and ProTaper Gold rotary files were utilised for canal instrumentation to minimise aberrations. Group 1, comprising 40 teeth, underwent saline irrigation followed by a final rinse with 7% Maleic Acid. Group 2, also with 40 teeth, had saline irrigation followed by varying rinsing times with 3 ml of MTAD,30 seconds, 1 minute, and 1.5 minutes, assessing its effectiveness at different intervals.

Statistical Analysis and Results: Statistical analysis and results showed highly significant outcomes. Efficacy was assessed through Scanning Electron Microscopy (SEM). For Group 1, after 30 seconds of Maleic Acid application, scores were recorded as follows: coronal 1.15±0.44, middle 1.09±0.51, and apical 0.95±0.43 (Pearson Chi-Square test). After one minute, the scores were 1.11±0.52 (coronal), 1.05±0.45 (middle), and 0.85±0.67 (apical). After 1.5 minutes, scores were 1.13±0.23 (coronal), 1.07±0.48 (middle), and 0.92±0.55, indicating varying efficacy by exposure time. For Group 2, after 30 seconds of MTAD irrigation, scores were significantly higher: coronal 2.11±0.51, middle 1.45±0.43, and apical 1.07±0.41. After one minute, scores were 1.72±0.52 (coronal), 1.22±0.67 (middle), and 0.97±0.75 (apical). After 1.5 minutes, findings were 2.01±0.71 (coronal), 1.35±0.46 (middle), and 1.98±0.57 (apical).

Conclusion: This study concluded that 7% Maleic Acid is generally more effective than MTAD, especially in the apical third of the canal. While MTAD is known for its antimicrobial properties and lower cytotoxicity, Maleic Acid excels at opening dentinal tubules in challenging areas.