Assessment of the Effect of Different Irrigation Protocols on the Penetration of Irrigation Solution into Simulated Lateral Canals (In Vitro Study).

OBJECTIVE: To compare the effectiveness of lateral canal irrigation penetration by conventional needle, passive ultrasonic, sonic endo activator, and Erbium laser (2780nm). METHODS: A total of 40 palatal roots of human maxillary first molars were collected and instrumented at a working length of 12 mm by an X1-X4 rotary Protaper Next system (Dentsply, Maillefer, Ballaigues, Switzerland) using the crown-down technique. Artificial lateral canals were made at 2, 4, and 6 mm from the apex on mesial and distal sides using an ISO rotary reamer (Dentsply, Maillefer, Ballaigues, Switzerland; #10 for mesial, #08 for distal). The samples were then cleared using methyl salicylate. A solution of black ink and normal saline was used as an irrigant for the root canal. The percentages of the penetration of the ink into the lateral canals were measured using a stereomicroscope (Q-Scope, Arnhem, The Netherlands) with the aid of program Image J. The Tukey test is used to assess the significant difference between intragroup and intergroup comparisons of different thirds, and the T-test is used to assess the significant difference between every two groups and for the mesial and distal sides of each group. The level of significance was set at 0.05. RESULTS: Results showed that none of the activation techniques used resulted in complete lateral canal penetrations; however, on both sides at all thirds, the Erbium laser (2780 nm) achieved the highest results with a highly significant statistical difference (p=0.05) with all other groups, and the least penetration was in the conventional needle group. CONCLUSION: The size of the lateral canal is a restricting factor for all activation methods; the best results can be achieved by laser. Conventional needles cannot be used alone to disinfect complex canal anatomy; however, passive ultrasonic and sonic endo activator activations can produce comparable results.

Evaluation of Antimicrobial Activity and Cytotoxicity of an Epoxy Resin-Based Endodontic Sealer Containing Nanoparticles Amorphous Calcium Phosphate.

Background: The main cause of posttreatment disease in endodontics is the remaining of microorganisms within the root canal walls after endodontic therapy. Therefore, it is essential to use root canal sealers with potent antibacterial properties. These sealers play a vital role in eradicating any remaining microorganisms and preventing recontamination, especially in situations where there might be microleakage. Aim: The objective of this research was to examine the antimicrobial properties of epoxy root canal sealers containing nanoparticle amorphous calcium phosphate (NACP) against planktonic Enterococcus faecalis in a controlled laboratory environment. Furthermore, the study aimed to assess the potential cytotoxic effects of these sealers. Method: In order to determine the antimicrobial activity, the epoxy resin sealer (AH Plus, Dentsply, Germany) was supplemented with NACP from Sigma-Aldrich, at a concentration of 3wt.%, as per the previous flowability tests. The agar well diffusion assay method was employed to evaluate the antibacterial efficacy. For this, cultured plates (n = 8) were prepared, with each plate containing three wells: one with AH Plus, one with AH Plus + NACP, and one with NACP alone. Subsequently, the plates were sited at 37°C in an incubator and allowed to incubate overnight. The width of the inhibition zones was then analyzed and recorded by the SPSS statistical software package (Version 20.0 for Windows, SPSS, Chicago, IL, USA). The cytotoxicity of the NACP incorporated AH Plus and AH Plus sealers were tested indirectly by MTT assay and directly by the multiparametric high content screening toxicology assay using fibroblast-like cells as cell lines. Results: AH Plus + NACP showed a higher antimicrobial activity than AH Plus with significant difference (P < 0.0001). Both materials showed nonsignificant difference compared to negative control, which indicated lower cytotoxicities. For AH Plus, P=0.3599, 0.5959, and 0.4071, with time intervals 24, 72, and 168 hr, respectively. For AH Plus + NACP, P=0.4386, 0.6182, and 0.2080, with 24, 72, and 168 hr, respectively. Conclusions: NACP incorporation with epoxy resin sealer AH PLUS had a higher antimicrobial activity with lower cytotoxic effect indicating their potential therapeutic values.

Cleaning Efficiency of Root Canal after Irrigation with New Irrigation Technique: A Scanning Electron Microscopic Study.

INTRODUCTION: The aim of this study was to evaluate the ability of pressurized water irrigation technique (AquaPick Device) as an intra-canal irrigation technique and compare it with sonic irrigation device (Endoactivator) for their ability to remove smear layer from canals. METHODS AND MATERIALS: Total number of 80 single rooted teeth (premolars) were prepared, divided into eight main groups, Group 1: Aquapick with apically vented needle/18 mm depth, Group 2: Aquapick with apically vented needle/15 mm depth, Group 3: Endoactivator device/18 mm depth, Group 4: Endoactivator device/15 mm depth, Group5: Aquapick with 2 side vented needle/18 mm depth, Group 6: Aquapick with 2 side vented needle/15 mm depth and two control groups. Then all samples were tested by SEM in 3, 6 and 9-mm distances from the apical foramen. The data were statistically analyzed using Kruskal Wallis and Mann-Whitney U tests. RESULTS: There was a high significant difference among the tested groups with the best removal of smear layer by the use of pressurized water irrigation device with apical vented needle especially at the 3 mm area. CONCLUSION: Pressurized water irrigation technique could be used as intra-canal irrigation technique with good results.

Evaluation of Canal Transportation after Using Different Types Rotary Glide Path Files.

Introduction: Canal transportation is a common problem caused by rotary instruments. The purpose of the present study was to evaluate root canal transportation after using WaveOne Gold Glider, ProGlider, Path File and K-file. Methods and materials: Forty resin blocks with L-shaped canals were divided into four groups (n=10). Group 1; canals were prepared with WaveOne Gold Glider, group 2; ProGlider, group 3; Path Files and group 4; #10, #15, and #20 stainless steel manual K-Files. Pre- and post-instrumentation photographic images were superimposed and resin removed from the inner and outer surfaces of the root canal was calculated through 3 points at 3, 6 and 9 mm from the end of canal which represented canal transportation. All data were analyzed by one way ANOVA test. The level of significance was set at 0.05. Results: Statistical analysis by one-way ANOVA test revealed that there was no significant differences (P>0.05) between the tested files in canal transportation in apical, middle and coronal third. The last amount of canal transportation happened at the apical third in WaveOne Gold Glider group. Conclusions: This in vitro study showed that using WaveOne Gold Glider files lead to less canal transportation especially in the apical third area with less significant differences with ProGlider, PathFiles and K-File.