Abstract

Background/purpose:Commonly used irrigants for root canal treatment are bactericidal and important for pulp remnants removal but these irrigants may adversely affect the ultrastructural morphology and structural arrangement of the radicular dentin. These changes might dramatically affect the sealing of the root canal system. The aim of this study is to assess the biological effect of the alcoholic andaqueous extracts of moringa on the ultra-structural surface morphology of the radicular dentin.

Materials and methods:A total number of 32 extracted maxillary anterior teeth were decoronated, longitudinally sectioned, and polished. Root sections were randomly and equally divided into 4 groups: group 1 immersed in an alcoholic extract of moringa, group 2 in an aqueous extract of moringa, group 3 in sodium hypochlorite (NaOCl), and group 4 in distilled water (sham control). All groups were immersed for 10 minutes followed by examination of the dentinal surface using scanning electron microscope. Calculation of percentage of dentinal tubules and intertubular dentin was performed. Statistical analysis was performed, and significance was set at 5%.

Results:Both alcoholic and aqueous extracts of moringa widened the dentinal tubule orifices (more patent) and increased the percentage of the intertubular dentin compared to sodium hypochlorite with a statistically significant difference.

Conclusion: Both alcoholic and aqueous extracts of moringa could be used as a better bioactive irrigant in root canal treatment to enhance bonding to radicular dentin by widening (increasing patency) of the dentinal tubules and decreasing the intertubular dentin surface area compared to sodium hypochlorite.

Abstract

Aim:To evaluate the impact of ProTaper Next and Videya N rotary files on root fracture resistance during chemo-mechanical root canal preparation with and without root canal filling.

Methodology:The following files were used to randomly divide a total of 40 newly extracted mandibular premolars into 5 equal groups (n=8); group 1 prepared using ProTaper Next files without filling; group 2 prepared using ProTaper Next files and filled with guttapercha and Totalfil bioceramic sealer; group 3 prepared using Videya N files without filling; group 4 prepared using Videya N files and filled with guttapercha and Totalfil bioceramic sealer; and group 5 without preparation or filling as a control. Using a universal testing machine, all roots were loaded until they fractured, at which point the weight required in Newtons was recorded. The one-way ANOVA test and post hoc analysis were used to quantitatively analyse the data.

Results:The 4 experimental groups without a statistically significant difference between them considerably decreased the fracture resistance of the roots in comparison to the control group.The filled groups showed a non-statistically significant increased fracture resistance compared to the non-filled ones.

Conclusion:Chemo-mechanical root canal preparation decreases the roots’ fracture resistance. Root canal filling using bioceramic sealers might enhance the roots’ fracture resistance.

ABSTRACT

Introduction:The aim of this study was to assess the dynamic cyclic fatigue resistance of an R-Motion file at simulated body temperature and document corresponding phase transformations compared to OneCurve and HyFlex EDM (HFEDM).

Methods:R-Motion (25/.06), OneCurve (25/.06), and HFEDM (25/.06) files were selected and divided into 3 groups (n = 9) according to the file type. Dynamic cyclic fatigue testing was done with a custom-made artificial stainless-steel canal that had a 90° angle of curvature and a 5-mm radius of curvature. Files were operated continuously at body temperature until fracture in the artificial canal. The time to fracture was calculated. Statistical analysis was performed, and significance was set at 5%. Phase transformation temperatures for 2 instruments of each group were analysed by differential scanning calorimetry (DSC) analysis.

Results:The highest mean time to fracture value was measured in the HFEDM group (277.84 ± 2.51), followed by the R-Motion group (115.09 ± 0.01), whilst the lowest value was found in the OneCurve group (44.28 ± 3.63). Post hoc pairwise comparisons were all statistically significant (P < .001). DSC heating curves show austinite start temperatures to be 33.94 °C and 43.32 °C and austinite finish temperatures to be 35.09 °C and 50 °C for R-Motion and HFEDM, respectively. DSC cooling curves show martensite start temperatures to be 27.54 °C and 44.52 °C and martensite finish temperatures to be 29.13 °C and 37.68 °C for R-Motion and HFEDM, respectively. DSC curves of OneCurve failed to demonstrate transformation temperatures within the tested heat range.

Conclusions:Crystalline arrangement of Ni and Ti atoms within the NiTi alloys greatly affects the dynamic cyclic fatigue resistance of the file.