IADR Abstract Archives
Removal efficacy and cytotoxicity of a calcium hydroxide paste using N-2-methyl-pyrrolidone as a vehicle
Objectives: The purpose of this study was to investigate removal efficacy and cytotoxicity of a newly developed calcium hydroxide [Ca(OH)2] paste (Cleanical™) which contains N-2-methyl-pyrrolidone (NMP) as a vehicle in comparison with Apexcal™ and Calcipex II™, which use different vehicles such as polyethylene glycol (PEG) and propylene glycol (PG), respectively.
Methods: Forty single-rooted maxillary premolars with oval-shaped canals were divided into four groups for the different pastes including pure Ca(OH)2 and aforementioned products. The canals were prepared using nickel-titanium files and filled with each paste. After removal of the paste, micro-computed tomographic (μ-CT) imaging was obtained to assess the volume of residual paste in root canal. Then, the teeth were split longitudinally and the paste-coated surface was assessed by stereomicroscopic observation. The cytotoxicity of the tested materials was assessed by using agar overlay assay. In addition, the effect of the vehicles including NMP, PEG, and PG on cell viability was evaluated. The data were analyzed by using Kruskal Wallis test first, and then, in cases where statistically significant p-values were found, Mann–Whitney’s U post-hoc tests carried out for pairwise comparisons. These analyses were performed with SPSS software at significance level of α = 0.05.
Results: In μ-CT analysis, Cleanical™ showed less residual volume percentage than Apexcal™ and Calcipex II™. In stereomicroscopic analysis, Cleanical™ showed less area percentage of residual paste than Calcipex II™, and similar value compared to Apexcal™. In agar overlay assay, Cleanical™ showed higher cytotoxicity than other pastes. Furthermore, NMP showed lower cell viability compared to other vehicles.
Conclusions: Cleanical™, the NMP-based Ca(OH)2 paste showed better removal efficacy compared to other products. However, as distinct from the advantage, clinicians should be aware of its higher cytotoxicity and consider the possible adverse effect to periradicular tissue when it is extruded beyond apical foramen.
Methods: Forty single-rooted maxillary premolars with oval-shaped canals were divided into four groups for the different pastes including pure Ca(OH)2 and aforementioned products. The canals were prepared using nickel-titanium files and filled with each paste. After removal of the paste, micro-computed tomographic (μ-CT) imaging was obtained to assess the volume of residual paste in root canal. Then, the teeth were split longitudinally and the paste-coated surface was assessed by stereomicroscopic observation. The cytotoxicity of the tested materials was assessed by using agar overlay assay. In addition, the effect of the vehicles including NMP, PEG, and PG on cell viability was evaluated. The data were analyzed by using Kruskal Wallis test first, and then, in cases where statistically significant p-values were found, Mann–Whitney’s U post-hoc tests carried out for pairwise comparisons. These analyses were performed with SPSS software at significance level of α = 0.05.
Results: In μ-CT analysis, Cleanical™ showed less residual volume percentage than Apexcal™ and Calcipex II™. In stereomicroscopic analysis, Cleanical™ showed less area percentage of residual paste than Calcipex II™, and similar value compared to Apexcal™. In agar overlay assay, Cleanical™ showed higher cytotoxicity than other pastes. Furthermore, NMP showed lower cell viability compared to other vehicles.
Conclusions: Cleanical™, the NMP-based Ca(OH)2 paste showed better removal efficacy compared to other products. However, as distinct from the advantage, clinicians should be aware of its higher cytotoxicity and consider the possible adverse effect to periradicular tissue when it is extruded beyond apical foramen.