Value addition property of a cationic surfactant on endodontic irrigant: A confocal laser scanning microscope study

Abstract

Introduction: Chlorhexidine (CHX) is a commonly used root canal irrigant with high surface tension which prevents its penetration into the isthmus and fins of the root canal. Surfactants have known to reduce the surface tension of the liquid. Cetylpyridinium chloride (CPC) is a cationic surfactant. The aim of this study is to assess the contact angle formed and depth of penetration of the endodontic irrigant with and without the addition of surfactant. Methods: Contact angle analysis – Ninety-nine freshly extracted and cleaned single-rooted mandibular premolars were obtained. Thirty-three teeth were sectioned longitudinally and then transversely. The sections were mounted on an acrylic block, polished to obtain a flat dentin surface. Five microliter of Group 1: 2% CHX as control, Group 2: 2% CHX + 0.1% CPC, and Group 3: 2% CHX + 0.2% CPC were placed on the dentin surface and subjected to contact angle analysis. Depth of penetration – Access cavity was prepared in sixty-six teeth and instrumented to working length till Protaper Gold F2. The samples were assigned to Groups 1, 2, and 3 and irrigated accordingly, and subjected to a confocal laser scanning Microscopy. Data were analyzed using one-way ANOVA and Tukey multiple comparison test. Karl Pearson's correlation test was performed to analyze the correlation between the two. Results: Group 3 had the lowest contact angle (12.82°) and the highest depth of penetration (222.74 μm) when compared to Group 1 and Group 2. Karl Pearson's correlation showed no correlation between the contact angle and the depth of penetration. Conclusion: Higher the concentration of CPC, lower is the contact angle formed with the dentin and higher is the depth of penetration into the dentinal tubule.

Effect of Addition of Cetylpyridinium Chloride Cationic Surfactant on the Antimicrobial Activity of Chlorhexidine Endodontic Irrigant

“…The combination of 2% CHX + 0.2% CPC was used as an endodontic irrigant for the first time by Thirunarayanan and Hegde [ 13 ] to overcome one of the CHX irrigant drawbacks, which is the high surface tension. The antimicrobial activity of this combination was assessed as mouthwash and in different concentrations.…”

“…Contrary to the earlier-stated result, the findings of this study was not consistent with Davis et al [ 15 ] and Mattigatti et al [ 34 ] who stated that MTAD showed more zones of inhibition and antimicrobial activity on E. faecalis than those of 2% CHX; this may be related to the differences in the methodology used for assessing the antimicrobial activities of the irrigants used in their studies for the agar diffusion test that is affected by the irrigant diffusibility, which is in turn affected by the irrigant surface tension [ 15 , 34 ]. MTAD has less surface tension than 2% CHX because of the presence of surfactant in its composition; therefore, it had more inhibition zones [ 13 ]. The present study was consistent with that of Agrawal et al [ 17 ], who stated that MTAD is more effective than 2% CHX, which may be related to the differences in the contact time between the microorganism and the irrigants.…”

“…One of the drawbacks of CHX is the high surface tension that affects its penetration to complex root anatomy, reducing its antimicrobial effect. Studies revealed that this drawback could be overcome by incorporating surface-active agents, such as surfactants in the irrigant composition [ 12 , 13 ].…”

“…Thirunarayanan and Hegde [ 13 ] were the first to report the use of CPC as a surfactant in combination with CHX for the cleaning of root canals. They found that adding CPC improved the depth of CHX penetration by lowering the irrigant's surface tension.…”