Conventional Needle Research Articles

Antibacterial Efficacy of Sonic Versus Ultrasonic Irrigation of the Root Canal System: A Systematic Review

Introduction: Irrigant mechanical agitation has been claimed to enhance the antibacterial efficacy during the root canal treatment. The aim of this study was to systematically review the antibacterial efficacy of ultrasonic compared to sonic agitation of sodium hypochlorite (NaOCl). Materials and methods: Four databases (Cochrane Library, Medline, ScienceDirect and Scopus) were searched to identify systematic reviews, clinical and in vitro trials evaluating biofilm removal following the use of sonic irrigation (SI), passive ultrasonic irrigation (PUI) or both and the conventional syringe and needle irrigation (SNI) on mature permanent teeth or models simulating the root canal. Articles were selected according to the inclusion criteria, data were extracted and the methodological quality was assessed independently by two reviewers. Results: The electronic and hand search retrieved 1028 studies. Two clinical controlled trials, thirteen in vitro controlled trials and one systematic review were included. The risk of bias and quality of the selected studies were qualified as moderate and high according to the JBI (Joanna Briggs Institute) and the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) checklists. Overall, both sonic and ultrasonic irrigation improved the bacterial reduction over the conventional irrigation method. However, most of the available evidence could not state significant differences between the antibacterial efficacy of the two methods. Conclusion: It may be concluded that sonic and ultrasonic activation of the irrigants are beneficial in bacterial reduction when compared to conventional needle irrigation, yet, the current data could not find significant differences between the two techniques.

Effect of Different Instrumentation and Irrigation Methods on Apical Microbial Extrusion: An Ex Vivo Study

Background: Periapical extrusion of debris, irrigating solution and microorganism are the major contributing factors for flare-ups during root canal therapy. The aim of this ex vivo study was to evaluate the effect of different types of instrumentation in combination with different irrigation methods on apical bacterial expulsion. Material and Methods: Three hundred and ten extracted human permanent teeth were infected with Enterococcus faecalis. After incubation at 37°C for 24 h, three hundred teeth were instrumented with three different instrumentations using two irrigation methods. The remaining ten teeth were used as negative and positive control groups, in which no inoculation was done and no instrumentation was carried out respectively. Three hundred teeth were equally divided in three groups (n = 100), in which instrumentation was performed using a protaper universal rotary file (group 1), WaveOne reciprocating file (group 2) and a flexiCON rotary file (group 3). In each group, 50 samples were irrigated with conventional needle irrigation, and 50 samples were irrigated with the endoVac irrigation method. During instrumentation, apically extruded bacteria were collected in an Eppendorf tube. Microbiological samples were taken from the Eppendorf tube and incubated for 24h, and colony-forming units were counted. The data collected were statistically analysed. Results: The group 2 showed highest bacterial extrusion using conventional irrigation while group 3 showed lowest using endovac irrigation system. Conclusion: FlexiCON rotary instrumentation with the endoVac irrigation system produced significantly less bacterial extrusion than the other techniques.

Calcium Hydroxide Removal Using Four Different Irrigation Systems: A Quantitative Evaluation by Scanning Electron Microscopy

This study compares conventional endodontic needle irrigation, passive ultrasonic irrigation, apical negative pressure irrigation, and mechanical activation to remove calcium hydroxide from single straight root canals. Eighty-four mandibular premolars were prepared in a crown-down manner up to size #40. Two teeth represented a negative control, and another two served as a positive control. Calcium hydroxide paste was placed inside root canals. The remaining eighty samples were analyzed based on the activation techniques, and the cleanliness of the canals was quantified using Fiji’s software on 500× magnified SEM backscattered electron micrographs. Considering the whole canal, all instruments showed better performance than conventional endodontic needle irrigation in removing calcium hydroxide (p < 0.05). Irrisafe and XP-endo Finisher could remove a significantly higher amount of calcium hydroxide than Endovac (p < 0.05). Irrisafe and XP-endo Finisher have been able to remove more calcium hydroxide than EndoVac.

Real-world practice of acute leukemia intrathecal chemotherapy administration: A Mexican nationwide survey

IntroductionIntrathecal chemotherapy is a mainstay component of acute lymphoblastic leukemia treatment. In Mexico, there is a considerable practice variability in aspects, such as the manner of preparation and the administration technique. ObjectiveOur objective was to describe the different techniques used for the application of ITC and review the existing recommendations in the literature. MethodA cross-sectional, nationwide survey study was conducted by an electronic questionnaire sent to hematologists and oncologists in Mexico. We collected demographic data, personal experience, intrathecal chemotherapy techniques, drug preparation and postprocedural conduct. ResultsWe received 173 responses. Twenty percent had an anesthesiologist administering sedation and pain management. The platelet count considered safe was 50 × 109/L in 48% of the participants. In 77% (n = 133) of the cases, the conventional needle with stylet used was, 49% did not receive any added diluent in the intrathecal chemotherapy and only 42% were recommended to rest in a horizontal position for more than 30 min. ConclusionWe identified a considerable variation in the administration of intrathecal chemotherapy across the hematologists in Mexico. We discuss the implications and opportunities in reducing the variation in our setting, highlighting the unmet need to establish guidelines that should be evaluated by the Mexican professional society to produce a position paper regarding practice standardization.

Safety and Efficiency of an Articulating Needle Driver in Advanced Laparoscopic Abdominal Surgery.

Objective: Robotic platforms offer articulating needle drivers but are associated with high costs and lack tactile feedback. The recently developed mechanical Laparoscopic Articulating Needle Driver (LAND) (Flexdex®) for conventional laparoscopy offers enhanced dexterity without these limitations. The goal of this study was to assess safety and efficiency during the implementation of the LAND, and describe its learning curve, in an expert center for laparoscopic surgery. Methods: All LAND-assisted procedures after clinical implementation for a period of 16 months were included into this study. Primary outcome domains were safety (intra- and postoperative complications within 30 days) and efficiency (operative time, suturing, and knot tying time of staple defects of enteroenterostomy). CUmulative SUM (CUSUM) analysis was utilized to describe the enteroenterostomy suturing time learning curve across consecutive cases by plotting the deviation from the series mean. Results: Forty-five procedures (34 Roux-en-Y gastric bypass [of which 7 including diaphragmatic hernia repair], 2 diaphragmatic hernia repair with Nissen fundoplication, and 2 right-sided hemicolectomy) were included into this study. Median (range) operative time and enteroenterostomy suturing time were 68 (46-177) minutes and 161 (112-241) seconds, respectively, comparable with conventional needle driver standards. One procedure was converted to the conventional needle driver due to device malfunctioning and one patients' postoperative course was complicated by a Clavien-Dindo grade 3a complication (intraluminal bleeding requiring gastroscopy). CUSUM chart displays a progression toward the mean from case 22 onward, indicating a limited learning curve. Conclusion: The LAND can be implemented safely and efficiently at a center of excellence for laparoscopic surgery and is associated with a limited learning curve.

Precision Medicine in Aortic Anastomosis: A Numerical and Experimental Study of a Novel Double-Sided Needle.

Background: Hand-sewn anastomosis is a crucial part of aortic reconstruction surgery and significantly affects its outcome. The present study presents a novel, bidirectional surgical needle aimed to improve aortic anastomosis in terms of speed and ease of use. Our objective was to assess the efficacy of the new design in comparison with the conventional needle. Methods: A series of simulations were conducted with COMSOL software in order to perform a fatigue comparative analysis between the new and the conventional needle design. Ease of penetration into a piece of polydimethylsiloxane was evaluated. Lastly, the prototype was tested under in-vitro conditions in comparison with the conventional needle. Results: Based on fatigue analysis, the new needle design improves durability, provided the two tips are equally used. The polytetrafluoroethylene coating improves penetration into the tissue by 7% to 17%, while electropolishing improves penetration up to 19%. When using the novel needle design, the average anastomotic task completion time was significantly reduced by 22% and the overall distance of hand movements was significantly reduced by 20%. Conclusions: The proposed design exhibited a shorter anastomotic time and seems promising in relation to ease of use and simplicity of the anastomotic technique it introduces.

SEM Evaluation of Various Intracanal Irrigation Devices on Smear Layer Removal: A Comparative Study

The present study aimed at assessing the effectiveness of different intracanal irrigation devices on the removal of the smear layer. The recently extracted 80 lower premolars having single canal were chosen for this in vitro study. A round diamond bur was used to gain endodontic access and the root canal was entered with a #15 K-file until the tip was just seen at the apical foramen. Manual instrumentation of root canals of all teeth was done using the step-back method. The samples were later divided randomly into four groups. Later, each sample was exposed to final irrigation by using four different irrigation systems, group 1: conventional needle irrigation, group 2: irrigation with ultrasonic activation, group 3: irrigation with EndoVac system activation, group 4: irrigation with EndoActivator. The samples were next mounted and visualized under scanning electron microscope (SEM) for the absence or presence of the smear layer. Irrigation with EndoVac system activation showed the presence of least smear layer (2.40 ± 0.32), followed next by EndoActivator (3.24 ± 0.46) and ultrasonic activation (4.96 ± 0.54) and conventional needle irrigation (5.20 ± 0.10). No statistically significant difference was found in the apical and coronal thirds of the root canal in removal of the smear layer on an intragroup comparison. However, a statistically significant (p < 0.001) difference was seen between the groups at the apical and coronal thirds on an intergroup comparison. This study demonstrated the EndoVac system group to be efficient in removal of the smear layer when compared to the EndoActivator system, ultrasonic activation, and conventional needle irrigation group. The definitive objective of endodontic therapy is to transform the affected teeth to a healthy and functional state. The irrigants can reach the working length when delivered by an effective irrigation delivery system. This type of delivery system should deliver adequate volume of irrigants all the way up to the working length and have sufficient flow and be efficient at debridement of complete canal system.

Axially rigid steerable needle with compliant active tip control

Steerable instruments allow for precise access to deeply-seated targets while sparing sensitive tissues and avoiding anatomical structures. In this study we present a novel omnidirectional steerable instrument for prostate high-dose-rate (HDR) brachytherapy (BT). The instrument utilizes a needle with internal compliant mechanism, which enables distal tip steering through proximal instrument bending while retaining high axial and flexural rigidity. Finite element analysis evaluated the design and the prototype was validated in experiments involving tissue simulants and ex-vivo bovine tissue. Ultrasound (US) images were used to provide visualization and shape-reconstruction of the instrument during the insertions. In the experiments lateral tip steering up to 20 mm was found. Manually controlled active needle tip steering in inhomogeneous tissue simulants and ex-vivo tissue resulted in mean targeting errors of 1.4 mm and 2 mm in 3D position, respectively. The experiments show that steering response of the instrument is history-independent. The results indicate that the endpoint accuracy of the steerable instrument is similar to that of the conventional rigid HDR BT needle while adding the ability to steer along curved paths. Due to the design of the steerable needle sufficient axial and flexural rigidity is preserved to enable puncturing and path control within various heterogeneous tissues. The developed instrument has the potential to overcome problems currently unavoidable with conventional instruments, such as pubic arch interference in HDR BT, without major changes to the clinical workflow.

Evaluation of the effect of calcium hydroxide paste on sealer penetration into dentinal tubules by confocal laser scanning microscopy.

The study evaluated sealer penetration after calcium hydroxide (Ca(OH)2 ) removal from the root canals. Sixty single-rooted mandibular premolars were divided into six groups. Ca(OH)2 paste placed into the root canals except for the control group (CG) was removed using the following irrigation techniques: conventional needle irrigation (CNI), EndoActivator (EA), EndoVac (EV), passive ultrasonic irrigation (PUI) and photon-induced photoacoustic streaming (PIPS) technique. After canal filling, the penetration depth, penetration area and penetration percentage of the sealer were determined using confocal microscopy. The CG and EA had a greater penetration depth than CNI in the middle section. The CG exhibited a higher dentinal tubule penetration area than CNI, EV and PUI in the middle section. EA was significantly more effective than PUI in the coronal section for the percentage of sealer penetration. EA and PIPS removed Ca(OH)2 from root canals effectively because they presented similar penetration to the CG in all sections.

The antibacterial efficacy of photon-initiated photoacoustic streaming in root canals with different diameters or tapers

BackgroundIn recent years, the concept of minimally invasive endodontics has been proposed, which could be described as preventing or treating diseases by preserving more dental tissue and creating minimal damage. In the process of root canal preparation, it was recommended to use instruments with a smaller taper to preserve more tooth tissue and improve the preservation rate of the affected teeth. Photon-induced photoacoustic streaming (PIPS) was a new type of laser-activated irrigation technology, which was now widely used in endodontic treatment. The purpose of this article was to evaluate the bactericidal effect of PIPS with NaOCl in root canals with different widths or tapers.MethodsTwenty-three maxillary first molars with three independent root canals were included in this study. The mesiobuccal (MB), distobuccal (DB), and palatal (P) root canals were prepared at sizes of #10/.02, #25/.02, and #25/.06, respectively. After being incubated with a bacterial suspension for 4 weeks, the specimen were irrigated with 2% NaOCl activated by conventional needle irrigation (CNI) (n = 10) or PIPS (n = 10). Three specimen were not treated (control group). Before and after irrigation, the presence of bacteria was assessed with an adenosine 5'-triphosphate (ATP) assay kit and biofilms were assessed using confocal laser scanning microscopy and scanning electron microscopy.ResultsIn specimen prepared using PIPS irrigation, the ATP was reduced by more than 98%. When the root canal taper was 0.02, the size #25 root canals had a higher percentage of dead bacteria than the size #10 root canals in all regions (P < 0.05) in the PIPS group. When the root canal width was #25, the 0.02 taper group had a higher percentage of dead bacteria than the 0.06 taper group in the apical region (P < 0.05), except coronal and middle regions (P > 0.05). PIPS irrigation results in a greater percentage of dead bacteria and reduction of ATP in size #10/.02 root canals than CNI in size #25/.06 root canals in three regions (P < 0.05).ConclusionIncreasing the width from #10 to #25 improves the bactericidal effect of PIPS in the root canal. Increasing the taper of the root canal from 0.02 to 0.06 at size #25 did not affect the bactericidal effects of PIPS. PIPS resulted in more dead bacteria in specimen with smaller tapers and root canal widths than CNI. PIPS can be used to clean the smear layer in the coronal region and open the dentin tubules.Clinical significance: Activation of irrigants with PIPS brought about significant bacterial reduction smaller tapers and width root canals compared to CNI, which was beneficial to prevent excessive loss of tooth tissue and conserve the structural integrity of teeth.

First pre-filled pen device with highly purified human menopausal gonadotropin (HP-hMG, Menopur) in liquid is shown to be bioequivalent to powder for reconstitution.

Objective: To determine whether serum human follicle-stimulating hormone (FSH) levels after single subcutaneous dosing of highly purified human menopausal gonadotropins (HP-hMG) in a liquid formulation and a powder formulation are bioequivalent. Materials and methods: This was a randomized, two-way, crossover, single-dose, bioequivalence trial comparing Menopur liquid injected by pre-filled pen, with Menopur powder injected by conventional syringe and needle. The primary endpoints were AUCt and Cmax of baseline-adjusted FSH. Pituitary-suppressed, healthy women were administered single subcutaneous injections of 450 IU Menopur liquid (600 IU/0.96 mL) and 450 IU Menopur powder (by 2 subcutaneous injections of 225 IU in 1 mL) in a randomized order. The pharmacokinetic parameters of FSH and human chorionic gonadotropin (hCG) were assessed by non-compartmental methods with adjustment for endogenous pre-dose levels. Results: In total, 76 women were randomized, and 56 completed the trial. The mean FSH and hCG serum concentration-time profiles were comparable between the two HP-hMG formulations. The geometric mean ratios and 90% confidence intervals of FSH for HP-hMG liquid versus HP-hMG powder were 1.12 (1.0562 – 1.1889) for AUCt and 1.17 (1.0946 – 1.2490) for Cmax, showing that the two formulations were bioequivalent. The incidence and severity of adverse events were similar between the two preparations, and both preparations were well tolerated. Conclusion: The 90% CIs for the geometric mean ratios of serum FSH AUCt and Cmax were both within 0.8000 – 1.2500, thus the two formulations are bioequivalent.

Generating an optical needle with prescribed length and polarization direction through reversing the radiation pattern from a spatial ULS antenna

Unlike the conventional optical needle directed along the optical axis, we propose an approach to generate an optical needle with prescribed polarization direction and length by inversely focusing the radiation pattern from a spatial uniform line source (ULS) antenna in a 4Pi focusing system. The spatial ULS antenna situated at the foci of the 4Pi configuration is employed to obtain the required illumination at the pupil plane for creating the above optical needle through the use of a time-reversal holographic methodology. Numerical results show that the spatial polarization direction of the created optical needle is consistent with that of the spatial ULS antenna, that its length is approximately equal to the length of the ULS antenna, and that the transverse size of the optical needle is over its extent. The proposed method is more flexible than traditional methods for customizing the optical needle with prescribed characteristics.

Dispersion profile of a needle-free jet injection depends on the interfacial property of the medium.

Injections into or through the skin are common drug or vaccine administration routes, which can be achieved with conventional needles, microneedles, or needle-free jet injections (NFJI). Understanding the transport mechanism of these injected fluids is critical for the development of effective drug administration devices. NFJI devices are distinct from traditional injection techniques by their route and time scale, which relies on a propelled microjet with sufficient energy to penetrate the skin surface and deliver the drug into the targeted region. The injected fluid interacts with multiple skin tissue layers and interfaces, which implies that the corresponding injection profile is dependent on their mechanical properties. In this study, we address the lack of fundamental knowledge on the impact of these interfaces on the injection profiles of NFJI devices.

Anesthetic Infiltration with Microcannulas

Local anesthetics have been used since ancient times in medical surgeries and aesthetic procedures. Lidocaine is the most commonly used local anesthetic agent. The infiltration techniques include using small caliber needles and low-volume syringes. The conventional needles have three parts: the hub

Efficacy of Sonic Versus Ultrasonic Irrigation in Debris Removal from the Root Canal System: A Systematic Review

Introduction: The aim of this study was to systematically review the debridement efficacy of ultrasonic irrigation compared with sonic irrigation during the endodontic treatment. Methods: An electronic search was undertaken on Cochrane Library, Medline, ScienceDirect and Scopus for articles published between January 2010 and January 2021 using appropriate Mesh terms and key words. The inclusion criteria were systematic reviews or in vitro controlled trials on permanent mature teeth or models simulating the root canal system involving a sonic or ultrasonic irrigation group and a control group of conventional needle irrigation. Two reviewers independently selected articles to include according to the inclusion criteria, extracted data from the articles and assessed the methodological quality of the included studies. The data items were arranged in tables. Results: From 811 studies, 17 in vitro studies and 3 systematic reviews were included. EndoActivator and EDDY were the most sonic devices used, whereas several ultrasonic devices were tested for passive ultrasonic irrigation. Debris removal was assessed either on root canal walls or isthmuses or both. The risk of bias and quality of the selected studies were qualified as moderate to high according to the JBI (Joanna Briggs Institute) and the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) checklists. Overall, the findings confirmed superiority of the two agitation techniques over conventional irrigation and most of the studies showed no significant differences between sonic and ultrasonic irrigation in debris removal, however a moderate level of evidence showed superiority of ultrasonic irrigation. Conclusion: It may be concluded that sonic and ultrasonic activation of the irrigants are beneficial in hard tissue debris removal when compared to conventional needle irrigation, yet, the current data could not find significant differences between the two techniques.

Endoscopic ultrasound-guided fine-needle biopsy histology with a 22-gauge Franseen needle and fine-needle aspiration liquid-based cytology with a conventional 25-gauge needle provide comparable diagnostic accuracy in solid pancreatic lesions.

Background and AimFine‐needle biopsy (FNB) needles obtain more core samples and support the shift from cytologic to histologic evaluation; however, recent studies have proposed a superior diagnostic potential for liquid‐based cytology (LBC). This study compared the diagnostic ability of endoscopic ultrasound (EUS)‐guided FNB histology with a 22‐gauge Franseen needle (22G‐FNB‐H) and fine‐needle aspiration (FNA) LBC with a conventional 25‐gauge needle (25G‐FNA‐LBC).MethodsWe analyzed 46 patients who underwent both 22G‐FNB‐H and 25G‐FNA‐LBC in the same lesion during the same endoscopic procedure. This study evaluated the diagnostic ability of each needle, diagnostic concordance between needles, and incremental diagnostic effect of both needles compared to using each needle alone.ResultsThe agreement rate for malignancy between both techniques was 93.5% (kappa value = 0.82). There was no significant difference in the diagnostic ability of both methods. 22G‐FNB‐H and 25G‐FNA‐LBC provided an incremental diagnostic accuracy in two (4.3%) cases and one (2.2%) case, respectively.ConclusionOur study demonstrated that the diagnostic accuracy of 25G‐FNA‐LBC and 22G‐FNA‐H for solid pancreatic lesions were comparable. A conventional 25‐gauge needle that punctures lesions with ease can be used in difficult cases and according to the skill of the endoscopist.

Self-sealing hyaluronic acid-coated 30-gauge intravitreal injection needles for preventing vitreous and drug reflux through needle passage

Self-sealing hyaluronic acid (HA)-coated self-sealing 30-gauge needles exhibiting instant leakage prevention of intravitreal humor and injected drug were developed in this study. Ninety New Zealand rabbits were used in this study. We assessed dye regurgitation in intravitreal ICG dye injections using HA-coated needles (HA needle group) and conventional needles (control group). Vitreous humor levels of anti-vascular endothelial growth factor (VEGF) were compared between groups one, three, and seven days after intravitreal bevacizumab (0.016 mL) injections. Expression levels of inflammatory cytokines in the aqueous humor and vitreous humor, including prostaglandin E2 (PGE2), interferon-γ, tumor necrosis factor-α, interleukin (IL)-1β, IL-4, IL-6, IL-17, and IL-8, were compared between HA needle, control, and normal (in which intravitreal injection was not performed) groups following 12 intravitreal injections over a period of one week. In the HA needle group, HA remained at the injection site and blocked the hole after intravitreal injection. Dye regurgitation occurred significantly less frequently in the HA needle group (16.7%) than the control group (55.6%) after intravitreal ICG dye injection. Meanwhile, vitreous anti-VEGF levels were markedly higher in the HA needle group than the control group one and three days after intravitreal bevacizumab injections. After 12 intravitreal injections, expression levels of aqueous and vitreous IL-8 significantly increased in the control group compared to the HA needle and normal groups. Conversely, there were no significant differences in the expression of the other seven cytokines among the three groups. Intravitreal injections using HA-coated self-sealing 30-gauge needles can block the outflow of vitreous humor and drugs through the needle passage.

Comparison of Histological Sample Volumes among Various Endoscopic Ultrasound-Guided Biopsy Needles.

Endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) enables easy and accurate pathological assessment. Here, we compared and assessed the area of samples on glass slides for three needle types: a 19-gauge Franseen needle (Acquire, Boston Scientific, Natick, MA, USA), a 22-gauge Franseen needle, and a 19-gauge fine-needle aspiration (FNA) needle (EZ Shot 3 Plus; Olympus, Tokyo, Japan). Among patients with suspected pancreatic cancer, with a ≥20 mm tumor located in the pancreatic body and tail, and who underwent EUS-FNA or FNB between June 2018 and March 2020, 10 were randomly selected to test each needle. The areas of histological tissue and blood clot samples were measured using the BZ-X800 imaging software (Keyence Corporation, Osaka, Japan). Baseline patient characteristics and pathological sample data showed no significant differences among the needles. The 19-gauge Franseen needle obtained significantly more histological tissue samples than the 19-gauge conventional needle (p = 0.010) and 22-gauge Franseen needle (p = 0.008). Conversely, there was no significant difference between the 19-gauge conventional needle and 22-gauge Franseen needle (p = 0.838) in this regard. The 19-gauge Franseen needle could collect more samples than the other needles, contributing to giving a more precise pathological diagnosis and more information, including genomic profiling.

Debris Removal by Activation of Endodontic Irrigants in Complex Root Canal Systems: A Standardized In-Vitro-Study

Aim of the study was to develop a standardized model system to investigate endodontic irrigation techniques and assess the efficiency of different activation methods on the removal of hard tissue debris in complex root canal systems. Mesial roots of mandibular molars were firstly scanned by micro-computed tomography (µCT) and allocated to three groups of irrigant activation: sonic activation (EDDY, VDW, Munich, Germany), laser activation (AutoSWEEPS, FOTONA, Ljubljana, Slovenia) and conventional needle irrigation (control). Roots were fixed in individual 3D-printed holders to facilitate root canal enlargement under constant irrigation with NaOCl (5%). To enable standardized quantification of remaining debris, BaSO4-enriched dentine powder was compacted into the canals, followed by another µCT-scan. The final irrigation was performed using 17% ethylenediaminetetraacetic acid (EDTA) and 5% sodium hypochlorite (NaOCl) with the respective activation method, and the volume of remaining artificial debris was quantified after a final µCT-scan. The newly developed model system allowed for reliable, reproducible and standardized assessment of irrigation methods. Activation of the irrigant proved to be significantly more effective than conventional needle irrigation regarding the removal of debris, which persisted particularly in the apical third of the root canal in the control group. The efficiency of irrigation was significantly enhanced with laser- and sonic-based activation, especially in the apical third.

Comparison of Antimicrobial Efficacy of Diode Laser, Ultrasonic Activated and Conventional Irrigation with 2.5% NaOCl during RCT: An Interventional Study

The aim and objective of the study was to evaluate and compare the antimicrobial efficacy of a diode laser irradiation, ultrasonic activated and conventional irrigation with 2.5% NaOCl on obligatory and facultative anaerobic bacteria in single-rooted canals. Total of 60 permanent maxillary and mandibular single-rooted (single canal) anterior teeth were selected. First microbial sample (S1) was collected after access opening and working length determination, using a sterile paper point. Cleaning and shaping were performed, with each instrument change accompanied by irrigation using 2 mL 2.5% NaOCl. After cleaning and shaping, disinfection protocol using diode laser (group1), ultrasonic activated irrigation with 2.5% NaOCl (group 2) and conventional irrigation with 2.5% NaOCl (group 3) was performed and second microbial sample (S2) was obtained. The colony characters of each type of growth on each media were noted and the organisms were identified using standard biochemical reactions. Gram-positive and gram-negative facultative anaerobe were predominantly isolated from the culture, and the highest reduction of the microbial count was seen in diode laser group with 60.92% followed by the ultrasonic group with 47.22% reduction and least reduction was observed in conventional irrigation with the ultrasonic group with 37.97%. The results were statistically significant with p-value <0.05. Diode laser disinfection showed the highest reduction of microbial count compared to ultrasonic activated and conventional needle irrigation with 2.5% NaOCl group. This study will help us to choose wisely between various irrigating methods and protocols. Diode laser in our study has shown superior disinfection of the root canals compared to others.