Browsing by Author "Neelakantan, Prasanna"

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A Chitosan-Based Irrigant Improves the Dislocation Resistance of a Mineral Trioxide Aggregate-Resin Hybrid Root Canal Sealer
(Springer Heidelberg, 2020) Ozlek, Esin; Rath, Priti Pragati; Kishen, Anil; Neelakantan, Prasanna
Objectives To investigate the effectiveness of root canal irrigation with chitosan on the dislocation resistance of a root canal sealer (MTA Fillapex) in vitro, measured by the push-out bond strength test. Materials and methods Root canals of mandibular premolars (n = 57) were prepared using rotary files with 5.25% sodium hypochlorite as the irrigant during instrumentation. Following this, the specimens were randomly divided into three groups (n = 19) based on the final irrigant: group 1, 0.2% chitosan solution; group 2, 17% EDTA solution; group 3, saline. Three specimens from each group were analyzed using scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS). The remaining specimens of each group were divided into two subgroups (n = 8) based on the method of agitation of the final irrigants (chitosan/EDTA/saline): subgroup A, sonic (Endoactivator, Dentsply Maillefer); subgroup B, no activation (control). After irrigation, all specimens obturated with a commercial mineral trioxide aggregate-resin hybrid sealer (MTA Fillapex, Angelus, Londrina, Brazil). Dislocation resistance was measured using the push-out bond strength test after 3 weeks. The data were analyzed using Kruskal-Wallis test (P = 0.05). Results Immaterial of the irrigant agitation, groups irrigated with chitosan showed significantly higher bond strength values than those irrigated with EDTA (P < 0.05). Groups irrigated with saline showed the least bond strength values (P < 0.05). When EDTA was used, sonic agitation significantly improved the bond strength of the sealer, compared to the control (P < 0.05). There was no significant difference between sonic agitation and the control when chitosan solution was used as the final irrigant (P > 0.05). The nitrogen/carbon ratio was significantly higher in chitosan groups compared to the control group (P < 0.05). Conclusion This study provides the first evidence that chitosan irrigation improves the dislocation resistance of MTA-resin hybrid root canal sealer, compared to EDTA and saline irrigation.
Dentinal Tubule Penetration and Dislocation Resistance of a New Bioactive Root Canal Sealer Following Root Canal Medicament Removal Using Sonic Agitation or Laser-Activated Irrigation
(Aves Press Ltd, 2020) Ozlek, Esin; Neelakantan, Prasanna; Akkol, Elif; Gunduz, Huseyin; Ucar, Yagmur Arzu; Belli, Sema
Objective: To investigate the influence of sonic agitation or laser-activated irrigation techniques on the removal chlorhexidine (CHX) and modified triple antibiotic paste (mTAP) on the sealer penetration depth and dislocation resistance of Guttaflow Bioseal. Methods: Single-rooted mandibular premolars (n=96) were prepared with rotary nickel titanium instruments and randomly divided into two groups (n=48) based on the intracanal medicaments used: Group 1, mTAP; Group 2, CHX gel. After 7 days, the specimens in each group were divided into three subgroups (n=16) based on the supplementary irrigation technique used to remove the medicaments: laser activated irrigation (Er, Cr: YSGG laser, Waterlase MD, Biolase Technology Inc., San Clemente, CA, USA), sonic agitation (EndoActivator, Dentslpy Sirona Endodontics, PA, USA) and syringe-and-needle irrigation (control) techniques. Canals were filled with single matched-taper gutta-percha cone and a calcium silicate-based sealer (GuttaFlow (R) Bioseal, Coltene/Whaledent, Langenau, Germany). At the end of three weeks, sealer penetration was investigated using confocal microscopy (n=6), and dislocation resistance was calculated by measuring the push-out bond strength (n=10). Statistical analysis was performed using three-way analysis of variance (ANOVA) and Tukey post-hoc test (P=0.05). Results: Laser activated irrigation resulted in significantly higher depth of sealer penetration compared to sonic agitation and syringe irrigation (P<0.01). The average sealer penetration depths were recorded as 846.6 mu m, 786.5 mu m and 505 mu m in the Er,Cr:YSGG laser, EndoActivator and control groups, respectively. The mean bond strength obtained in group 3 (syringe-and-needle irrigation) was significantly less than the other groups (P<0.05). The mean values were 9.08 in the Er,Cr:YSGG laser group, 8.44 in the EndoActivator group and 5.08 in the needle group. Conclusion: Er,Cr;YSGG laser irrigation to remove the medicaments was advantageous to other irrigation techniques in sealer penetration and dislocation resistance of the sealer.