Ozlek E, et al. Restor Dent Endod. 2019 Nov;45:e24. https://doi.org/10.5395/rde.2020.45.e24

The aim of this in vitro study was to evaluate the adhesion strength of two new fiber post systems (FiberSite™ Post and Cytec™ Blanco Post) cemented with two different adhesive resin cements (Panavia™ SA and Maxcem™ Elite). Root canals of sixty extracted human mandibular premolars were prepared using ProTaper Universal™ rotary files (Dentsply Sirona Endodontics, York, PA, USA). The root canals were irrigated with 5.25% sodium hypochlorite (NaOCl) during instrumentation. After root canal preparation, the canals were irrigated with 2 mL of 17% EDTA (1 min), followed by 2 mL of 5.25% (5 min) NaOCI, and 2 mL saline. The root canals were dried with paper points and divided randomly into two study groups (n = 30) according to the type of post system: Group 1, FiberSite™ Post (MegaDental, Partanna, Italy); and group 2, Cytec™ Blanco Post (Hahnenkratt, Königsbach-Stein, Germany), with one of the two adhesive resin cements: Subgroup A, Panavia™ SA Cement Plus Automix (Kuraray, Osaka, Japan); subgroup B, Maxcem™ Elite (Kerr, Orange, CA, USA). Following thermocycling, the adhesion strength was evaluated using the push-out adhesion (bond) strength test. Fractographic analysis was performed using stereomicroscope. The data were analyzed using two-way analysis of variance (p = 0.05). The adhesion strength values of both the posts were significantly higher when cemented with subgroup B (Maxcem™ Elite). The highest adhesion strength value was demonstrated by group 1B (FiberSite™ post cemented with Maxcem™ Elite cement). The type of post did not have a significant impact on the bond strength values for either cement material.

Background. This study aimed to examine the retreatment efficiency of four NiTi rotary file systems with micro-computed tomography (micro-CT). Methods. Forty premolar teeth were shaped up to F2 using the ProTaper Universal rotary file system and obturated with MTA Fillapex. The root canals were scanned with micro-CT to evaluate the volume of root canal filling before retreatment. The samples were randomly divided into four groups according to the file system used to remove root canal filling material (n=10): ProTaper Universal Retreatment, ProTaper NEXT, EdgeFile XR, and EdgeFile® X3 NiTi system. All the samples were scanned with a micro-CT device for the second time to evaluate the amount of residual filling material in the root canals. The percentages of filling material removed from root canals were calculated. Additionally, the time spent on the removal of the root canal filling material was recorded. The data were analyzed using the Shapiro-Wilk and Kruskal-Wallis tests. Results. There were no significant differences between the groups in the percentage of root canal filling material removal. However, a statistically significant difference was found between the groups in the time required to reach the apex and remove the entire filling material. The time required to remove the root canal filling material was higher in the EdgeFile® X3 group. Conclusion. NiTi files manufactured for root canal preparation can be used effectively and safely to remove root canal filling materials. EdgeFile XR produced for retreatment can be used as an alternative to ProTaper Universal Retreatment files.

The aim of this study is to evaluate the effect of using gel and solution forms of NaOCI during the chemomechanical preparation of the root canals on postoperative pain at different time intervals. 114 patients with mandibular molar teeth and symptomatic irreversible pulpitis were included in the study. All patients were divided into two groups based on the irrigant used during root canal preparation (n=57): Group 1, 5.25% NaOCI, Group 2, 5.25% NaOCI gel. All groups were filled with gutta-percha and AH Plus root canal sealer using single-cone technique. VAS scale (1-10) was used for postoperative pain assessment. After endodontic treatment, all patients were asked to record their postoperative pain levels at the 6th, 24th, 48th, 72nd hours, and 1 week later. The data were analyzed using Chi-Squared, Independent Samples T, Cochran Q and Friedman tests. Statistically significant difference was not found between the distributions of pain levels at different times according to the groups (p>0.050). A statistically significant difference was observed between the distributions of pain levels measured at different times in the solution group (p<0.001). A statistically significant difference was found between the distributions of pain levels measured at different times in the gel group (p<0.001). In both groups, highest postoperative pain levels occurred in the first 6 hours. Pain levels of the gel group as 38,5% mild, 17.3% moderate, 5.8% severe and pain levels of the solution group were obtained as 46.2% mild, 26.9% moderate, 9.6% severe at the 6th hour. The use of the gel form of NaOCI during the chemomechanical preparation of the root canals showed similar postoperative pain when compared to the solution form.

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® Bioseal, Coltène/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