Dentin Debris Research Articles

Effectiveness of a Novel Sea Buckthorn Medicament in Enterococcus faecalis Infected Root Canals: An In vitro Microbial Study

Introduction: This study aimed to formulate the sea buckthorn (SBT) extract-based herbal intracanal medication and evaluate its antibacterial effectiveness against Enterococcus faecalis. Materials and Methods: Ninety freshly extracted single-rooted mandibular premolars were collected, decoronated to a uniform root length of 15 mm, and standardly enlarged up to ProTaper Gold size F3. The final irrigation protocol was done, and root canals were contaminated with E. faecalis. Samples were subjected to five medicaments, respectively: Group 1: Normal saline, Group 2: SBT, Group 3: Calcium hydroxide (CH) paste, Group 4: 2% chlorhexidine (CHX) gel, and Group 5: SBT + CH. After incubating for 1, 3, and 7 days, dentin debris was collected at intervals using a Peeso reamer and cultured on agar plates. Colony-forming units (CFUs) were counted after incubation, and values were statistically analyzed. One-way ANOVA and Tukey’s honestly significant difference test for intergroup comparison and repeated measures ANOVA for comparison within groups were done. Statistical significance was set at P < 0.05. Results: The CFU values of SBT were the lowest of all the groups, followed by SBT + CH, CHX, and CH groups. The intergroup comparison showed a highly significant difference in all three observation periods (1, 3, and 7 days). Conclusions: SBT outperformed the benchmark medicament, CHX gel, with regard to its disinfection potential against E. faecalis. Moreover, its combination with CH proved to have a synergistic antibacterial action.

Comparative Evaluation of Penetration Depth and Antimicrobial Efficacy of Calcium Hydroxide, MAS Paste, Nitrofurantoin, and Levonadifloxacin against Enterococcus faecalis: A Confocal Laser Scanning Microscopic Study

Abstract Aim: The most prevalent species in persistent and secondary infections linked to endodontic failure is Enterococcus faecalis. The objective of this in vitro investigation was to assess the antibacterial efficacy and penetration depth of calcium hydroxide, nitrofurantoin, levonadifloxacin, and a mixture of antibiotic and steroid paste (MAS paste) against E. faecalis. Materials and Methods: A total of 40 single-rooted tooth samples were decoronated apically and coronally to yield 10 mm root sections. All tooth samples were biomechanically prepared and were inoculated with E. faecalis bacteria for 21 days. The study involved four groups, each containing 10 teeth as follows: group 1—calcium hydroxide, group 2—MAS paste consisting of ciprofloxacin, metronidazole as antibiotics, and dexamethasone as corticosteroid, group 3—nitrofurantoin, and group 4—levonadifloxacin. For 7 days, the corresponding intracanal medications were injected into the canals. On the seventh day, dentinal debris was extracted from the blocked lumen to quantitatively evaluate the antibacterial activity of the experimental medications. The depth of penetration (DOP) of medicaments under study was assessed by viewing 1 mm thick horizontal sections under a confocal laser scanning microscope, one from each of the four subgroups. The sections were stained with florescent stain before being under the microscope. Results: Results showed that on day 7, the mean colony-forming units were lowest for levonadifloxacin, indicating the highest antimicrobial efficacy (P < 0.05). This was followed by nitrofurantoin, MAS paste, and calcium hydroxide. Additionally, levonadifloxacin achieved the greatest DOP, followed by nitrofurantoin, MAS paste, and calcium hydroxide. These results suggest a correlation between DOP and antimicrobial efficacy. Conclusion: Within the confines of this study, it can be concluded that levonadifloxacin exhibited the highest antimicrobial efficacy, even at a low concentration of 8 µg/mL. Therefore, it can serve as a viable intracanal medicament in endodontic therapy.

Enhancing Root Canal Therapy with NIR-II Semiconducting Polymer AIEgen and Low-Concentration Sodium Hypochlorite Synergy.

Despite significant efforts to eliminate bacterial biofilm within root canals, achieving effective disinfection remains challenging due to the complex anatomy and limitations of disinfectants. In this study, a second near-infrared (NIR-II) semiconducting polymer with aggregation-induced emission (AIE) properties, named PIDT-TBT, is deliberately designed and synthesized. This proposes an AIE luminogen-based sterilization strategy in synergy with a low concentration of sodium hypochlorite (NaClO). Water-dispersible PIDT-TBT nanoparticles (NPs) are prepared, demonstrating good biocompatibility, as well as photothermal and photodynamic properties. Subsequent antibacterial tests show that PIDT-TBT NPs exhibit excellent bactericidal effects against three bacterial strains: Staphylococcus aureus, Streptococcus mutans, and Enterococcus faecalis, upon 808nm laser irradiation. In synergy with a low concentration of NaClO (0.5%) solution, PIDT-TBT NPs significantly improves the outcome of root canal treatment under 808nm laser irradiation in a human extracted tooth root canal infection model. Additionally, it is found that PIDT-TBT NPs combine with a low concentration of NaClO solution could safely dissolve dentin debris and further increase the efficiency of root canal preparation by altering the elemental composition of the inner root canal wall.

Diode laser to enhance irrigation of the root canal system: systematic literature review

The use of lasers in endodontics has revolutionized the dental field by offering a precise and less invasive option to treat pulp and periapical problems. This is why the importance of the diode laser in endodontics is recognized in order to potentiate the irrigation of the root canal system. The aim of this study was to interpret, by means of a systematic literature review, the use of the diode laser to enhance root canal irrigation in endodontics. Through a systematic review, 18 original articles related to the aforementioned topic were analyzed, which were obtained from the electronic search of the following databases: Springer, BioMed Central, Multidisciplinary Digital Publishing Institute, PubMed, Wiley Online Library. In addition. It was obtained as results that it is possible to reach areas such as lateral or accessory canals that may be inaccessible for traditional irrigation techniques, eliminating dentin debris, smear layer and other residues; however, despite its advantages it should be considered that the application of the diode laser should not replace conventional treatment, but should be considered as a possible complementary treatment. It is concluded that the application of the diode laser in endodontic therapy improves the efficiency of root canal system disinfection

Relevance of irrigation in cleaning the ROOT canal isthmusES

The root canal irrigation going along with instrumentation is a mandatory attitude in current endodontic practice. To increase the evacuation efficacy of dental pulp remnants, dentin debris and bacterial biofilms from root canals and lateral irregularities including canal isthmuses, various procedures of irrigants activation were conceived. If not yet quite satisfactory, among various techniques of irrigant activation currently used the passive ultrasonic activation proved to be more efficient to achieving cleaning and disinfection of root canal isthmuses.

Efficacy of the GentleWave System in the removal of biofilm from the mesial roots of mandibular molars before and after minimal instrumentation: An exvivo study.

To compare the efficacy of Enterococcus faecalis biofilm removal using the GentleWave System (GWS) (Sonendo Inc, CA) on non-instrumented versus minimally instrumented root canal systems. Thirty-four mandibular molars were autoclaved and allocated to four groups: Negative control (n = 5); positive control (n = 5); Group 1: non-instrumentation + GWS (NI + GWS) (n = 12); and Group 2: minimal instrumentation + GWS (MI + GWS) (n = 12). Of 34 samples, 24 samples with Vertucci type 2 configuration within the mesial root of each sample were allocated to Groups 1 and 2 and then matched based on the working length and root canal configuration. After inoculation of samples with E. faecalis for 3 weeks, the GWS was used on Group 1 without any instrumentation and Group 2 after instrumentation of mesial canals until size 20/06v. CFU and SEM analysis were used. Log10 (CFU/mL) from the positive control, and Group 1 and 2 were 7.41 ± 0.53, 3.41 ± 1.54, and 3.21 ± 1.54, respectively. Both groups showed a statistically significant difference in the reduction of viable E. faecalis cells compared to the positive control (Group 1 [p = .0001] and Group 2 [p < .0001]), whilst showing no significant difference between the two tested groups (p < .05). The use of GWS on the non-instrumented root canal system could be an effective disinfection protocol in removing the biofilm without dentin debris formation.

Photodynamic Suppression of Enterococcus Faecalis in Infected Root Canals with Indocyanine Green, TroloxTM and Near-Infrared Light.

Recently, our group showed that additional supplementation of Trolox™ (vitamin E analogue) can significantly enhance the antimicrobial photodynamic effect of the photosensitizer Indocyanine green (ICG). Up to now, the combined effect has not yet been investigated on Enterococcus faecalis in dental root canals. In the present in vitro study, eighty human root canals were inoculated with E. faecalis and subsequently subjected to antimicrobial Photodynamic Therapy (aPDT) using ICG (250, 500, 1000 µg/mL) and near-infrared laser light (NIR, 808 nm, 100 Jcm-2). Trolox™ at concentrations of 6 mM was additionally applied. As a positive control, irrigation with 3% NaOCl was used. After aPDT, root canals were manually enlarged and the collected dentin debris was subjected to microbial culture analysis. Bacterial invasion into the dentinal tubules was verified for a distance of 300 µm. aPDT caused significant suppression of E. faecalis up to a maximum of 2.9 log counts (ICG 250 µg/mL). Additional application of TroloxTM resulted in increased antibacterial activity for aPDT with ICG 500 µg/mL. The efficiency of aPDT was comparable to NaOCl-irrigation inside the dentinal tubules. In conclusion, ICG significantly suppressed E. faecalis. Additional application of TroloxTM showed only minor enhancement. Future studies should also address the effects of TroloxTM on other photodynamic systems.

Assessment of Penetrability for Different Endodontic Irrigation Activating Techniques Using Cone-Beam Computed Tomography and Periapical Digital Radiography—An In Vitro Study

The elimination of necrotic and inflamed pulp tissue, dentin debris, and microorganisms is essential for the success of endodontic treatment. However, the root canal’s complexity has led to incomplete cleaning and disinfection. This study aims to compare the efficacy of the penetrability of three different irrigation activating techniques to the apical third of the root canal. Sixty sound single-rooted human mandibular premolars are prepared with rotary instrumentation under continuous sodium hypochlorite irrigation. Three irrigation activation techniques are utilized: group 1 (n = 20), conventional needle irrigation (CN); group 2 (n = 20), side-vented endodontic needle irrigation (EN); and group 3 (n = 20), manual activation irrigation with gutta-percha cone (MA). The penetrability is assessed with the aid of a radiopaque irrigation solution using digital radiography in conjunction with cone-beam computed tomographic (CBCT) measurements. Data are analyzed using a statistical package for social sciences (SPSS), using multiple comparisons to compare the baseline and test values. One-way analysis of variance with post hoc analysis (Tukey honestly significant difference) is performed to detect the statistically significant differences between groups. Manual activation (MA) shows effective delivery of the irrigant into full WL, followed by endodontic needle (EN) and conventional (CN) methods of activation (p &lt; 0.001). The results of the present study show that maximum penetrability of the irrigant is observed with manual activation (MA) using a gutta cone in comparison with the conventional needle (CN).

Efficacy of different irrigant activation devices in removing dentin debris from an artificial isthmus connecting curved canals.

The aim of this study was to evaluate the debridement efficacy of sonic irrigation (EDDY; VDW, Munich, Germany and EndoActivator; Dentsply-Sirona, Ballaigues, Switzerland) and ultrasonically activated irrigation (Irrısafe; Satelec Acteon, Merignac, France) in a simulated canal isthmus connecting curved canals. Transparent resin blocks were produced containing two curved canals connected with an isthmus. The isthmus was then filled with dentin debris. Three irrigant activation cycles were performed and the amount of remaining debris was compared analysing pictures taken after each activation cycle. Data were statistically analysed using one-way ANOVA and post hoc Tukey tests at a significance level of p < 0.05. EDDY showed greater efficiency in removing dentin debris from the simulated isthmus than the other techniques tested. An increase in the activation time enhanced the efficiency of both EDDY and ultrasonically activated irrigation in debris removal.

Efficacy of Laser-Activated Irrigation Versus Ultrasonic-Activated Irrigation: A Systematic Review.

This study aimed to conduct a systematic review and critical analysis of the evidence pertaining to the efficacy of laser-activated irrigation (LAI) versus ultrasonic-activated irrigation (UAI) in mature permanent teeth. A comprehensive literature search was performed using PubMed and Google Scholar. Additionally, a hand search was performed to identify relevant studies related to UAI and LAI. The search covered all articles published from January 1997 to December 2021. The identified studies were screened for eligibility using the inclusion and exclusion criteria. The included articles were then subjected to data extraction and analysis. The search yielded 1,637 results. Of these, 23 articles were included in this systematic review. All included articles were assessed for the outcomes of antimicrobial efficacy, smear layer, and dentin debris removal. The majority of the articles reported the superiority of LAI over UAI. Within the confines of this systematic review, the current evidence mandates that LAI has superior efficacy over UAI in the elimination of microorganisms, dentin debris, and smear layer from the root canal system.

Assessment of Irrigant Agitation Devices in Simulated Closed and Open Root Canal Systems

The invitro efficacy of irrigant activation devices has not been contrasted to their safety. This was attempted in this study using apically closed versus patent simulated root canal systems in epoxy resin models, with the latter featuring a simulated periapical lesion. All 72 models had 2 joining canals connected by an isthmus, which was filled with dentin debris. The simulated periapical lesion was filled with colored gelatin in the 36 respective models. Canals were irrigated with 1.3% sodium hypochlorite. Samples were divided into 4 subgroups per system (n=9): conventional irrigation, sonic low (EndoActivator; Dentsply Sirona, Charlotte, NC) and high frequency (EDDY; VDW, Munich, Germany), and ultrasonic agitation of the irrigant (always applying 3 cycles of 20seconds). The total cleared surface areas (mm2) in the simulated isthmus and periapical lesion were compared between systems and devices using parametric tests (P<.05). The cleaning of the isthmus was more effective in the apically open compared with the closed systems and was also significantly influenced by the agitation method (P<.001). In the closed systems, EDDY and ultrasonic agitation achieved the significantly (P<.05) best cleaning of the isthmus. In the open systems, ultrasonic agitation showed the single best result (P<.05). EDDY caused by far the highest and ultrasonic agitation the lowest dissolution of the gelatin in the simulated periapical lesion. Under the conditions of this study, ultrasonic agitation of a previously administered sodium hypochlorite irrigant was more laterally targeted and thus safer and more effective than sonic agitation methods.

Effect of EDDY and manual dynamic activation techniques on postoperative pain in non-surgical retreatment: a randomized controlled trial

BackgroundDuring non-surgical retreatment process, the products such as dentin debris, root canal fillings, irrigation solutions, microorganisms and remaining pulp tissues can extrude to the apical area and can cause the postoperative pain and flare-up. Thus, the aim of this study was to evaluatethe effect of EDDY and manual dynamic activation (MDA) techniques on postoperative pain (PP) associated with retreatment.MethodsNinety patients scheduled for retreatment were treated at a single visit. Non-vital mandibular premolar teeth diagnosed with asymptomatic apical periodontitis were included in this study. The patients were divided into two groups (n = 45) on the basis of the need for additional irrigation activation procedures (EDDY and MDA). The patients’ post-treatment pain levels were asked to rate the intensity of their pain on a 10-point numerical rating scale (NRS) at the 12th, 24th, 48th, and 72nd h and 7 days.The data were analyzed using the chi-square and Wilcoxon signed-rank test was used for within-group comparisons and Mann Whitney U test was used to compare the groups by time period.ResultsThe difference in postoperative pain intensity between two groups was statistically significant at 12, 24, 48, and 72 h (p < 0.05). There was no significant difference at 7 days. Moreover, no statistically significant difference was found between the two groups in terms of gender and analgesic medication intake (p > 0.05). Pain intensity after the treatment was lesser in the MDA groupthanin the EDDY group at 12, 24, 48, and 72 h.ConclusionThis study could lead us to conclude that the two activation systems can be used during endodontic retreatment with no difference at PP 7 days later. However, a comparison of the groups indicated that the EDDY resulted in significantly more PP at 12, 24, 48, and 72 h.Trial registration ClinicalTrials.gov Identifier: NCT04726670.

Efficacy of removing calcium hydroxide deposits from endodontic instruments prior to sterilization using different cleaning methods

Introduction. Endodontic instruments during root canal treatment come into contact with dentinal debris, irrigation solutions and medication agents, which reminants should be eliminated before sterilization. The aim of the study was to verify the effectiveness of different cleaning methods for removing calcium hydroxide paste residues from the surfaces of the working parts of hand instruments, as well as to propose an effective protocol for cleaning endodontic instruments before sterilization. Material and methods. Forty-two new hand endodontic instruments were used to remove calcium hydroxide paste from the filled canals of extracted teeth. After contamination with medication, they were divided into the four groups and subjected to individual decontamination methods - mechanical, chemical and ultrasonic, as well as a combined protocol. The instruments were then observed under a light microscope. The effectiveness of the methods was evaluated based on the amount of residual matter on the surface of the working parts of the instruments. Results. The combined protocol showed a statistically significant difference in the achieved level of cleanliness compared to mechanical (?2 = 12.00 p &lt; 0.05) and chemical methods (?2 = 12.00 p &lt; 0.05), but there was no statistically significant difference compared to ultrasonic cleaning in disinfectant solution (?2 = 2.4 p &gt; 0.05). By applying combined protocol, instruments with completely clean surfaces were found, as well as the lowest values of contamination at the level of the entire group of instruments (8.33%). Conclusion. The protocol that consisted of mechanical cleaning with a sponge soaked in chlorhexidine gluconate, chemical soaking in sodium hypochlorite, and ultrasonic cleaning in a disinfectant showed the best efficiency in removing calcium hydroxide residues.

Stereomicroscope Analysis of the Cleaning Capacity of an Abrasive-Expansive System in Oval Canals: A Laboratory Study

Background: The aim of this study was to evaluate, by means of a stereomicroscope, the influence on the removal of smear layer obtained by the XP-endo Finisher and Tornado Disinfection Kit systems during the final agitation of the irrigating solution, in conservative preparations. Materials and methods: Ten extracted human lower premolars were chemically-mechanically prepared with the ProDesign Logic 2 NiTi rotary system (25/.05) and 2.5% NaOCl. The same specimens were submitted to three different protocols of agitation of the irrigating solution: Conventional irrigation, XP-endo Finisher and Tornado Disinfection Kit. For this, a closed system was made, the roots were cleaved and three holes were made in each third of the root canal and filled with dentinal debris to take initial photos under a stereomicroscope. The amount of debris was rated using a 4-point scoring system. The data obtained were submitted to the Wilcoxon, Kruskal-Wallis and Dunn tests (p&lt;0.05). Results: In the analysis of the effectiveness of each protocol, it was possible to observe a statistically significant difference in the removal of debris in all thirds for all protocols (p&lt;0.05). Regarding the difference in score found before and after application of the protocol, a significant difference was observed between the apical and the middle third in the Tornado Disinfection Kit group (p&lt;0.05) and there was no difference between the same third for different groups (p&gt;0.05). Conclusion: Based on the methodology and the results presented, it was concluded that both evaluated protocols improved the cleaning of root canal recesses in all thirds, with no difference between them.

Isthmus morphology influences debridement efficacy of activated irrigation: A laboratory study involving biofilm mimicking hydrogel removal and high-speed imaging.

Little is known about the influence of isthmus morphology on the debridement efficacy of activated irrigation. The aim of this study was to investigate the influence of isthmus morphology on the debridement efficacy of laser-activated irrigation (LAI), EDDY and needle irrigation (NI), and to explain the methods of isthmus cleaning by LAI and EDDY. Four root canal models (apical diameter: 0.30 mm, taper: 0.06, curvature: 23°, length: 20 mm) were produced by CAD-CAM with different isthmus morphologies: long-wide (4 mm; 0.4 mm), long-narrow (4 mm; 0.15 mm), short-wide (2 mm; 0.4 mm) and short-narrow (2 mm; 0.15 mm). The isthmuses were filled with a hydrogel containing dentine debris. The canals were filled with irrigant and models were assigned to the following irrigation protocols (n=240): needle irrigation (NI) with a 30G needle, Eddy, and LAI (2940 nm Er:YAG-laser, 15 Hz, 40 mJ, SWEEPS, tip at the canal entrance). Standardized images of the isthmuses were taken before and after irrigation, and the amount of removed hydrogel was determined using image analysis software and compared across groups using Kruskal-Wallis test followed by Dunn's multiple comparison. Visualization of the isthmus during activation was achieved using a high-speed camera. The pattern and speed of the flow in the isthmus as well as transient and stable cavitation were analysed using imaging software. Laser-activated irrigation, EDDY and NI removed more hydrogel in short-wide isthmuses than in narrow isthmuses (p < .001). LAI and EDDY removed more hydrogel than NI in every isthmus configuration (p < .001). EDDY showed eddies and stable cavitation, and LAI showed transient cavitation at each pulse, and pulsed horizontal flow with the highest particle speed in closed short isthmuses. Isthmus morphology influences debridement in all irrigation groups. Short-wide isthmuses were the easiest to clean while narrow isthmuses were the most challenging to clean. Width seems to be a more critical anatomical parameter than length. LAI and EDDY resulted in the greatest biofilm removal and performed better than NI. EDDY produced eddies and stable cavitation in the isthmus, and LAI showed transient cavitation and pulsed horizontal flow.

The Effectiveness of Laser Assisted Irrigation in Endocanalary Disinfection and Hard Tissue Debris Removal: A Systematic Review

Introduction: The control of the bacterial load during an endodontic treatment is challenging; the usual chemomechanical procedures such as conventional needle irrigation (CNI) has not always shown satisfying outcomes. Hence, the necessity of finding complementary methods such as passive ultra-sonic irrigation (PUI), sonic activated irrigation (SAI) and laser assisted irrigation (LAI) in order to achieve the most complete disinfection of the endodontic system. The aim of our study is to systematically review and critically analyze the current evidence of the effectiveness of laser assisted irrigation when compared to CNI, PUI, SAI. Materials and methods: Electronic search on four data-bases: PubMed, Scopus, ScienceDirect and Cochrane Library was done looking for Systematic reviews, in-vitro and clinical controlled trials assessing the effectiveness of LAI in removing bacteria and dentine debris. Articles were selected, deduplicated than assessed. The studies that met all the inclusion criteria were included and were further screened in order to extract their data and evaluate their methodological quality. Results: The electronic search yielded a total of 895 potentially eligible record. After the final stage of selection, 25 studies, that are all in-vitro were included; the risk of bias and quality assessment was done through the Preferred Reporting Items for Systematic Reviews and Meta-Analysis and the Joanna Briggs Institute critical appraisal Checklist. All in all, LAI showed better results when compared to CNI in both removal of bacteria and smear layer, yet when compared to PUI and SAI, the studies could not testify significantly for the superiority of an activation method over another. Conclusion: The use of LAI increased the potential of the irrigant within the endodontic system, especially when compared to CNI. Yet the current data could not give a conclusive judgment of the effectiveness of LAI when compared to PUI and to SAI; eventually further studies need to be performed.

Multispecies biofilm removal by a multisonic irrigation system in mandibular molars.

The aim of the study was to assess biofilm removal efficacy of GentleWave System and passive ultrasonic irrigation (PUI). Twenty-two human mandibular molars with Vertucci's type II configuration in the mesial root were selected. Teeth were autoclaved, inoculated with dental plaque and incubated in a CDC biofilm reactor for two weeks. The mesial roots were instrumented up to 20.06 file (V-Taper) for the GentleWave group and up to 35.04 file (Vortex Blue) for PUI group. Irrigation was performed using GentleWave and PUI irrigation protocols (n=11). Dentine debris on paper points samples were obtained for quantitative real-time polymerase chain reaction (qPCR) and 16S ribosomal RNA gene sequencing (next-generation aequencing-NGS). For qPCR, a non-parametric test (α=0.05) was used. Next-generation sequencing data were analysed using mothur, with alpha diversity calculated as the Shannon and Chao1 indices and Bray-Curtis dissimilarities were used for beta diversity. Differences in alpha diversity and abundances of genera were evaluated using Kruskal-Wallis test. Differences in community composition were evaluated using analysis of similarity with Bonferroni correction for multiple comparisons. Quantitative real-time polymerase chain reaction results showed that the reduction estimated in percentages for both groups was equivalent (p > .05). NGS analysis showed that both techniques promoted a significant reduction in reads and OTUs number (p < .05). Shannon alpha diversity and Chao1 index showed no differences between pre- or post-treatment samples for both groups (p > .05). Additionally, pre-treatment communities differed from post-treatment samples in both groups regarding bacterial taxa reduction (ANOSIM R=0.50 and 0.55, p< .001). Bacterial reduction in mesial roots of mandibular molars prepared to 35.04 with PUI was similar to those prepared to 20.06 with a multisonic irrigant activation system.

A Multimethod Assessment of a New Customized Heat-Treated Nickel-Titanium Rotary File System.

This study aimed to compare three endodontic rotary systems. The new Genius Proflex (25/0.04), Vortex Blue (25/0.04), and TruNatomy (26/0.04v) instruments (n = 41 per group) were analyzed regarding design, metallurgy, and mechanical performance, while shaping ability (untouched canal walls, volume of removed dentin and hard tissue debris) was tested in 36 anatomically matched root canals of mandibular molars. The results were compared using one-way ANOVA, post hoc Tukey, and Kruskal–Wallis tests, with a significance level set at 5%. All instruments showed symmetrical cross-sections, with asymmetrical blades, no radial lands, no major defects, and almost equiatomic nickel–titanium ratios. Differences were noted in the number of blades, helical angles, cross-sectional design, and tip geometry. The Genius Proflex and the TruNatomy instruments had the highest and lowest R-phase start and finish temperatures, as well as the highest and lowest time and cycles to fracture (p < 0.05), respectively. The TruNatomy had the highest flexibility (p < 0.05), while no differences were observed between the Genius Proflex and the Vortex Blue (p > 0.05). No differences among tested systems were observed regarding the maximum torque, angle of rotation prior to fracture, and shaping ability (p > 0.05). The instruments showed similarities and differences in their design, metallurgy, and mechanical properties. However, their shaping ability was similar, without any clinically significant errors. Understanding these characteristics may help clinicians to make decisions regarding which instrument to choose for a particular clinical situation.

Comparison of Dentin Debris Extrusion After the Use of WaveOne Gold and Procodile Q NiTi File

The goal of root canal treatment is to prevent and treat apical periodontitis, by eliminating inflamed pulp tissue as well as microorganism and necrotic pulp tissue by chemomechanical debridement and providing a good quality root canal filling. According to Sjögren, et al. [1] the success rate of root canal treatment goes as high as 96% in teeth without periapical lesions. Salehrabi, Rotstein [2] metanalyses, found a 97% retention rate of root canal treated teeth while Hannahan, Eleazer [3] showed no statistical difference in the success rate between single implants and teeth with non-surgical root canal treatments. The root canal instrumentation is perform using different type of hand files or mechanical driven rotary or reciprocation instruments. However, during root canal instrumentation dentin debris, pulp tissue, and bacteria are likely to get extruded through the apical foramen. This extrusion might be responsible for the presence of severe postoperative pain and/or swelling [4].

Comparison of Er:YAG laser and ultrasonic in root canal disinfection under minimally invasive access cavity.

The disinfection of root canal through minimally invasive access cavity remains questionable. This in vitro study compared the effectiveness of three disinfection measures including conventional irrigation, ultrasonic assisted irrigation, and erbium:yttrium-aluminum-garnet (Er:YAG) laser assisted irrigation through conventionally or minimally invasive access. Sixty-six extracted maxillary first molars were randomly divided into group 1 conventionally invasive access group (CIA) and group 2 computer-guided minimally invasive access group (MIA). Each group was further randomly divided into three subgroups, (A) conventional irrigation (CI), (B) passive ultrasonic agitation (PUI), and (C) Er:YAG laser activated irrigation (LAI). Enterococcus faecalis (E. faecalis) infection model was established inside all root canals after instrumentation was performed up to ProTaper Universal F2. After various disinfection methods, microbial samples were collected from root canals by paper tip method and cultured, and colony forming units (CFU) values of each sample were calculated. Then the root canals were enlarged to the size of F3, after which dentin debris was collected from the F3 file. After dilution and culturing, the CFU value was calculated for each group. Two-way analysis of variance (ANOVA) was performed to test the interaction. The results revealed a significant antagonism (F = 3.394, P = 0.043). The bacterial CFU counts of group B and group C were significantly less than that of group A (P < 0.05), and there was no significant difference between group B and C (P > 0.05). Additionally, group 2A was better than group 1A (P < 0.05); there was no significant difference between group 1B and group 2B, group 1C and group 2C (P > 0.05). Comparison of the bacterial CFU counts in dentin debris after disinfection, the results revealed a significant antagonism (F = 7.224, P = 0.002), and group C had the least. The disinfection effect of Er:YAG laser or ultrasonic assisted computer-guided minimally invasive access is similar to conventionally invasive access, and Er:YAG laser is better than ultrasonic in removing bacteria from dentinal tubules and is easy to operate, which is more suitable for minimally invasive root canal treatment.