Side-vented Needle Research Articles

Velocity and wall shear stress of 18% EDTA irrigation solution flow in the removal of Ca(OH)2 with computational fluid dynamic analysis

Introduction: Ethylene Diamine Tetra Acetic Acid (EDTA) 18% irrigation solution is one of the chelating agents that able to remove calcium hydroxide (Ca(OH)2) from the root canal wall. Failure of root canal treatment can be caused by the presence of residual calcium hydroxide in the root canal wall, thus blocking the bond between the medication and root canal filling material with the root canal wall. This study was aimed to observe the EDTA 18% flow in removing the Ca(OH)2 using CFD analysis. Methods: This research was descriptive. Cleanliness of the root canal wall from Ca(OH)2 medicament using EDTA 18% irrigation was analysed using the CFD method with test specimens in the form of resin blocks made according to the characteristics of the root canal. The irrigation needle used was side-vented with a position of 3 mm from the apical tooth. Stage analysis of root canal geometry was performed using Computational Fluid Dynamics (CFD) analysis to observe the characteristics of irrigation solutions in root canals in 3D. Results: The streamlined characteristics of EDTA 18% irrigation solution showed a unique behaviour due to the features of the side-vent shaped irrigation needle. Irrigation flow in the crown area of the inlet (side-vented irrigation needle) showed low velocity so that the fluid flow when exiting the inlet was more towards the apical than the outlet (root canal orifice). Conclusion: Velocity and wall shear stress of EDTA 18% showed the results validation conformity between experimental and CFD, that the maximum velocity of EDTA 18% is 19 ms-1 and EDTA 18% wall shear stress is 1.56 KPa for calcium hydroxide removal observed from the CFD study. Keywords: Computational fluid dynamics, EDTA 18%, calcium hydroxide (Ca(OH)2), velocity, wall shear stress

“Efficiency of removal of debris from root canal system with help of different irrigation system:” An in vitro scanning electron microscope study

Aims and Objectives: The aim of this study was to determine the efficiency of EndoActivator, passive ultrasonic irrigation, side-vented needle, and syringe irrigation for removal of dentinal debris (smear layer) in root canals prepared with same master apical file sizes. Materials and Methods: Forty mandibular premolars with mature apices (extracted) were selected for this study. Each tooth was decoronated 2mm coronal to the cementoenamel junction with a diamond disk to facilitate straight-line access for instrumentation. Apical patency was determined by inserting an ISO # 08 K-file. Working length was determined by placing a size 15 K-file into the canal until it appeared at the apical foramen; this length was measured and the working length was set at 1mm short of this measurement. The roots were sealed with yellow sticky wax (DPI) to avoid apical extrusion during irrigation. The root canals were prepared to size 40, 0.02 taper, using step-back technique. After each instrument change, manual irrigation was performed with 2-mL NaOCl (3%) using a 26-gauge syringe. Then, a total of 40 samples were randomly distributed into four groups. According to group, root canals were irrigated with EndoActivator, passive ultrasonic irrigation, side-vented needle, and syringe irrigation. The roots were spilt and sent laboratory for examination under scanning electron microscope. Results: Ultrasonic irrigation had highest removal of the smear layer than the other irrigation systems followed by EndoActivator, side-vented needle, and syringe irrigation. Conclusion: Ultrasonic irrigation resulted in better removal of the smear layer in the apical third of root canals than EndoActivator, side-vented needle, and conventional needle irrigation.

Effect of simulated intraosseous sinusoidal pressure on NaOCl extrusion

IntroductionThe present study examined the effects of irrigant flow rate and simulated intraosseous sinusoidal pressure on the rate of NaOCl extrusion from the apical terminus of a faux root canal. MethodsAn extrusion setup was designed to enable irrigant extrusion to be opposed by 30 mm Hg simulated intraosseous pressure. The faux canal apex was opposed by atmospheric + 30 mm Hg pressure (experimental) or atmospheric pressure only (control group). Using five irrigant delivery rates (15.6 8.0, 4.0, 3.4 or 3.0 mL/min), the extrusion rates of 2% NaOCl from the faux apex were measured in both groups (n = 16). Data were analysed with two-factor ANOVA and pairwise comparisons at α = 0.05. Correlation between NaOCl delivery rates and extrusion rates in both groups were analysed with the Pearson product-moment procedure. ResultIrrespective of the presence or absence of simulated sinusoidal pressure, NaOCl extrusion rates were positively-correlated with irrigant flow rates. For the factor “irrigant flow rates”, significant differences in NaOCl extrusion rates were identified among all flow rates (p < 0.05), except for the pairwise comparison between 4.0 and 3.4 mL/min in the control. For all irrigant flow rates, NaOCl extrusion rate was significantly lower in the presence of 30 mm Hg simulated sinusoidal pressure than that obtained in the absence of opposing pressure (p < 0.05). ConclusionIn the presence of 30 mm Hg simulated intraosseous pressure, NaOCl delivered via a side-vented needle inserted to 1 mm short of working length may be prevented from extrusion when its flow rate is ≤ 3.0 mL/min. Clinical SignificanceWhen opposed by intraosseous sinusoidal pressure, NaOCl delivered via a side-vented needle inserted to 1 mm short of working length may be prevented from extrusion when its flow rate is ≤ 3.0 mL/min.

Apically extruded debris associated with different instrumentation systems and irrigation needles

Aim Of this study is to compare apically extruded debris associated with canal shaping using 2Shape, ProTaper Universal and Reciproc systems using two different irrigation needle tips, open-ended and side-vented. Patients and methods Sixty freshly extracted human mandibular premolars were randomly divided into six groups (n = 10) as follows; group 1 and 2, 2Shape system was used in root canal preparation, in groups 3 and 4, ProTaper Universal preparation system was used, but In groups 5 and 6, Reciproc preparation was performed. In groups 1, 3 and 5 irrigation was done with open-ended needle while in groups 2, 4 and 6 side-vented needle was used. One Eppendorf tube for each tooth was weighed with an electronic weighing machine before instrumentation procedures. During instrumentation, irrigation was performed after every instrument with 1 ml distilled water. On completion of the preparation, teeth were removed from the Eppendorf tubes. All of the tubes were incubated at 37°C for 15 days, to evaporate the irrigant. After the incubation period, the tubes were weighed again. The difference between initial and final tubes weights was calculated, and statistical evaluation was performed using two-way analysis of variance at 5% level of significance. Results A statistically significant difference was observed between all groups (P≤0.05). The highest mean extruded debris value was recorded with group 3 while the lowest value was recorded with group 6. Open-ended needles were associated with significantly more extruded debris than side-vented needles regardless of the instrumentation system used (P≤0.05). Conclusion All the tested rotary instruments resulted in extrusion of debris beyond the apical foramen to an extent but Reciproc system is associated with less amount of apically extruded debris in comparison with 2Shape, ProTaper Universal systems. Side-vented needles extruded significantly less debris than open-ended needles.

Cleaning Efficacy of Root Canal Irrigation with Positive and Negative Pressure System.

Introduction:The purpose of this study was to analyze the differences between irrigant replacement in the positive and negative pressure irrigation systems regarding root canal cleaning efficacy. Methods and Materials:A total of 27 extracted single-root mandibular premolars with 18-20 mm root canal length were decoronated and equally divided into three groups (n=9) based on the irrigation system used: positive irrigation with side-vented needle as the control group (C), positive irrigation with an open-ended needle as the first group (T1) and negative irrigation as the second group (T2). The root canals were irrigated with 2.5% NaOCl between each instrumentation, followed by a final irrigation with 5 mL of sterile distilled water. The irrigation replacements were monitored by means of computational fluid dynamic (CFD), while a scanning electrone microscope (SEM) was used to observe the smear layers and plug evaluations after the teeth had been sectioned longitudinally and buccolingually halves subsequently cut in apical third area. The result was analyzed using the Kruskal Wallis, Mann Whitney and Spearman correlation tests. The level of significance was set at 0.05. Result:Irrigant replacement in the negative pressure irrigation system tends to produce a greater effect in reaching the apical end compared to in the positive pressure irrigation system. This resulted in significantly superior smear layer removal in the apical third area (P<0.05). Conclusion: The irrigation solution exchange of the negative pressure irrigation system is more capable of reaching the apical end compared to the positive pressure irrigation system, resulting in a higher sanitation level in the apical third of the root canal.

Comparisons by microcomputed tomography of the efficiency of different irrigation techniques for removing dentinal debris from artificial grooves.

Aim:The aim of this study was compare the capacity of different irrigation protocols for debris removal from artificial grooves and assess the effectiveness of Easy Clean used in different kinematics by means of micro-CT.Methodology:Fifty acrylic prototyped maxillary incisors were instrumented and included in a muffle. The specimens were longitudinally sectioned, and a longitudinal groove was made on the inner surface of the root canal in one of hemisections, and the dentin debris was inserted into the grooves. The specimens were divided into five groups (n = 10): G1: Conventional with open-ended needle; G2: Conventional with double side-vented needle; G3: Easy Clean in reciprocating movement; G4: Easy clean in continuous rotation (ECCR); and G5: Passive ultrasonic irrigation (PUI). All specimens were scanned using microcomputed tomography before and after the irrigation technique and calculated the volume (mm3) of dentin debris. The paired t-test and post hoc Tukey test were the statistical tests used, with significance set at 5%.Results:There were no significant difference (P > 0.05) between PUI and ECCR. ECCR was significantly (P < 0.05) more effective than the groups of conventional irrigation techniques.Conclusions:PUI and ECCR favored the removal of a larger volume of dentin debris from the groove.

Numerical and analytical investigation of irrigant penetration into dentinal microtubules

Irrigation is one of the most important steps in root canal therapy. Sodium hypochlorite is inserted into the root canal to eliminate bacteria and dissolve necrotic tissue. Dentinal tubules are micrometer sized channels along the dentin thickness. An irrigant should have the ability to penetrate into these tubules to remove bacteria residing in them. The difference between the concentrations of the inserted irrigant and the dentinal tubule fluid is the main factor of penetration. This study attempts to model dentinal tubules with precise dimensions and to study the time dependent irrigant penetration into them by using Computational Fluid Dynamics (CFD). The effects of needle type and position in the dentinal tubule were also considered. The results showed that concentration distribution would be different when the tubule was modeled as a frustum compared to the cylindrical shape tubule. Dentinal tubule curvature, however, did not have a noticeable effect in irrigant penetration. It was also concluded that when the needle working length is 3 mm, concentration can be considered constant at the tubule's entrance for tubules located at more than 1 mm from the apex. Moreover, by irrigating the root canal with a side-vented needle instead of an open-ended one, the concentration would be less for the tubules located in the apex region. Analytical solutions for different cases were also obtained, and their predictions were found to be in good agreement with the numerical results. Therefore, the presented analytical solutions can be directly used to obtain irrigant concentration in tubules with no need for additional computer simulations.

Comparison of different irrigation and agitation methods for the removal of two types of calcium hydroxide medicaments from the root canal wall: an in-vitro study.

Background and aimComparison of different irrigation and agitation methods for the removal of two types of calcium hydroxide medicaments from the root canal walls.MethodsFifty extracted single rooted teeth were selected for this study. After decoronation, the root canals of these teeth were prepared to the size F3 (30 no.) using rotary ProTaper file system. These samples were randomly divided into four groups. Group 1 (n=20) were filled completely with water based calcium hydroxide (CH), Group 2 (n=20) were filled with oil based CH using lentulo spiral, Group 3 (n=5) - the positive control group received the CH as intracanal medication, but no subsequent removal, Group 4 (n=5) - the negative control did not receive CH placement. Further on, Group 1 and Group 2 were divided into four sub-groups (n=5). In sub-group A we performed conventional syringe irrigation with side-vented needle sub-group B) manual dynamic agitation, sub-group C sonic agitation using endoactivator, sub-group D passive ultrasonic irrigation (PUI). Roots were split longitudinally into mesial and distal halves. Digital images of the root canal walls were acquired by a Dental Operating Microscope (DOM) and assessed by using a scoring criteria at different thirds (coronal, middle and apical) of the root canal as follows: score 1, score 2, score 3, and score 4. Data were analyzed applying one-way analysis of variance (ANOVA) and Tukey’s multiple comparison tests at a 95% confidence interval (P < 0.05).ResultsStatistically significant differences were not found between the experimental groups and the negative group in any one third of the root canal (P>0.05). However, a difference did exist between the experimental groups and the positive control group (P<0.05). None of the experimental groups totally removed CH substances from root canal walls.ConclusionAmong all experimental groups, removal of CH was best achieved by sonic agitation using endoactivator followed by passive ultrasonic irrigation (PUI), manual dynamic agitation and conventional syringe irrigation with side-vented needle.

Evaluation of the Effect of Needle Tilting Angle on Irrigant Flow in the Root Canal Using Side-Vented Needle by an Unsteady Computational Fluid Dynamics Model

Aim: The Irrigant flow dynamics has strong influence on the root canal cleaning effectiveness. The aim of this study was to evaluate the effect of needle tilting angle on irrigant flow inside a prepared root canal during final irrigation with a side-vented needle using a validated Computational Fluid Dynamics (CFD) model.&#x0D; Methodology: To analyze the irrigant flow a CFD model with tilting angles of 0 and 2 degrees was created. The irrigant flow in the apical root canal was simulated. Computations were carried out for two selected flow rates of 0.26 and 0.78 mL/s to evaluate the velocity and turbulence quantities along the solution domain.&#x0D; Results: In addition to velocity and pressure distribution at the apex, wall shear stress distribution, vorticity and turbulent intensity results were obtained for needle tilting angle of 0 and 2 degrees. In the case of turbulent flows where the flow rate was higher, irrigation is better; however, higher apical pressures were observed for both tilting angles. Although the effect of tilting angle of two degrees for laminar flow was slightly better than zero degrees, the effect of tilting was significant for the turbulent flow case. Wall shear stress distribution, vorticity and turbulent intensity results were consistent with each other.&#x0D; Conclusions: A small tilting angle of 2 degrees had an effect on irrigation effectiveness which could be clearly observed from the wall shear stress, vorticity and velocity distribution results. The velocity distribution results obtained at the symmetry plane should be evaluated with the wall shear stress values together to observe the complete fluid dynamics structure inside the root canal. &#x0D; How to cite this article: Adiguzel O, Gokcen MG, Olcay AB. Evaluation of the Effect of Needle Tilting Angle on Irrigant Flow in the Root Canal Using Side-Vented Needle by an Unsteady Computational Fluid Dynamics Model. Int Dent Res 2016;6:1-8. &#x0D; Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Apical Extrusion of Debris and Irrigants Using Different Irrigation Needles.

This study evaluated the influence of irrigation tip, root canal curvature and final apical diameter on periapical debris and irrigant extrusion during root canal instrumentation. After being classified as mildly or moderately curved, the mesiobuccal root canals of 90 human molars were instrumented. The teeth were allocated into three groups according to the used needle type: a flat open-end needle (Group 1), a side-vented needle (Group 2) or a double side-vented needle (Group 3). The amount of extruded material after instrumentation was calculated for each group. The differences in irrigant and debris extrusion between the experimental groups were analyzed with the Mann-Whitney U test. Irrigation tips and final instrument diameter differences were analyzed with the Kruskal-Wallis test. Multiple groups were compared using the Mann-Whitney U-test with a Bonferroni correction at α=0.05. The amount of extruded material from the double side-vented needle was significantly less than the open-ended flat needle (p=0.008), but there was no difference compared to the side-vented needle (p=0.929). The results showed no effect of root curvature and final apical diameter on the amount of irrigant and debris extrusion (p>0.05). The double side-vented needles generated the least material extrusion to the periapical tissues. Irrigation needle type had the greatest influence on periapical irrigant and debris extrusion and the double side-vented needles may be safely used during endodontic therapy.

QUALITY OF SINGLE CONE AND GUTTA CORE OBTURATION IN CURVED ROOT CANALS AFTER NEEDLE OR DIODE LASER IRRIGANT ACTIVATION USING CONE BEAM COMPUTED TOMOGRAPHY AND STEREOMICROSCOPE

Objective: The purpose of this study was to assess the quality of single cone and gutta core obturation in curved root canals of the mandibular molars after needle and diode laser activation of both ethylenediaminetetraacidic acid (EDTA) and sodium hypochlorite (NaOCl) irrigation using cone beam computed tomography (CBCT) and stereomicroscope. Methods: A total of twenty –four extracted human mandibular molars with root canal curvature more than 20 degrees and type IV anatomic configuration in the mesial roots were selected for this study. Canals in mesial roots were prepared with ProTaper next instruments up to x3 and equally divided into two experimental groups (n=12) according to final one minute activation for each of 5 ml 2.5% NaOCl and 5 ml 15% EDTA using; side-vented needle (group1) or 980 nm diode laser (group2). After preparation, the mesial canals were randomly obturated with either single-cone gutta-percha (sub group A) or gutta core Obturator (subgroup B). Obturated canals were scanned with cone beam computed tomography; images were used to assess the quality of obturation at different canals levels. The roots were subsequently sectioned at 2, 4, 6, 8 and 12 mm levels from the apex for analyses of the percentage of gutta percha filled area (PGFA) and percentage of sealer filled area (PSFA) using stereomicroscope to examine the root sections. The areas of gutta percha and sealer for each segment of the root were measured using Image J software. Kruskal-Wallis test was used to analyze data. Results: Both cone beam and digital stereomicroscopic data indicated that canals obturated with gutta core after irrigant activation had the highest PGFA. The Gutta core and diode laser acti- vation group produced significantly higher PGFA and lower PSFA at different root canal levels 4,6 and 8 mm levels of the root canal (P < .05) than all other groups at the same levels (P < .05). Single cone and EDTA has the lowest PGFA and highest PSFA (P < .05). Conclusions: The results reinforced that 980-nm Diode activated irrigation improved the qual- ity of obturation of the mesial root canals in mandibular molars by using gutta core or single cone. Variation in root canal obturation technique and irrigation activation influenced the percentage of gutta percha filled area and percentage of sealer filled area.

Apical Extrusion of Sodium Hypochlorite using Various Mechanical Activators

ABSTRACT Aim To evaluate the volume of sodium hypochlorite extruded from the apex on using various mechanical activators. Materials and methods Forty extracted single-rooted mandibular premolar teeth were taken. Standardized access opening with chemicomechanical preparation till protaper F3 was done with 2 mL of 5.25% sodium hypochlorite in between instrumentation of each file. The apical patency was checked with 10 K file. The teeth were then divided into four groups: Group I (n = 10) activation was done with #20 side-vented needle; group II (n = 10) activation was done with GP cones; group III (n = 10) activation was done with Irrisafe tips; group IV (n = 10) activation was done with endoactivator. As much as 10 mL of 5.25% sodium hypochlorite has been used with each group to activate the irrigant. The extruded sodium hypochlorite during activation with various systems was been collected in prepared apparatus. The obtained samples were analyzed for sodium ion concentration. Evaluation of the volume of sodium hypochlorite extruded from the apex was analyzed using absorption spectrometry. Then the above results were then statistically analyzed. Results Varying amount of apical extrusion was seen among the above study groups. Minimum amount of apical extrusion was seen with endoactivator. Maximum amount of apical extrusion was seen with needle irrigation followed by GP cones. How to cite this article Vangala A, Doshi SR, Aparadh A, Hegde V. Apical Extrusion of Sodium Hypochlorite using Various Mechanical Activators. World J Dent 2016;7(3):146-149.

Evaluation of 4 Different Irrigating Systems for Apical Extrusion of Sodium Hypochlorite

IntroductionThe aim of this study was to evaluate NaOCl apical extrusion by using negative apical pressure (EndoVac), sonic agitation (EndoActivator), side-vented needle (Max-i-Probe), and photon induced photoacoustic streaming (PIPS 10 mJ and PIPS 20 mJ) laser irrigation in an in vitro gel model. MethodsExtracted mandibular and maxillary central incisors (n = 18) were prepared to size 35/.04 and 55/.04, respectively. Teeth were mounted in transparent containers with clear acrylic and suspended in a color-changing pH-sensitive gel, creating a closed system. By using a crossover design, each tooth was sequentially irrigated by using 6% NaOCl with each device following manufacturers' recommendations. Each tooth served as its own control. Pre-irrigation and post-irrigation buccal and proximal view photographs served to measure the longest distance of extrusion and were analyzed with ImageJ software. Mean results were analyzed by using Kruskal-Wallis and Dunn post hoc test (P < .05). ResultsThere were no significant differences between EndoVac, EndoActivator, and the passive extrusion groups. The EndoVac and EndoActivator groups produced significantly less extrusion than PIPS irrigation. Max-i-Probe extrusion results were more variable than those of EndoActivator but had no significant difference. Across all irrigation systems, there were no significant differences with respect to apical preparation size. ConclusionsUnder the in vitro conditions of this study, no difference was found between the 10 mJ and 20 mJ PIPS laser groups. EndoVac demonstrated significantly less potential for apical extrusion than PIPS and Max-i-Probe, whereas apical preparation size did not significantly affect extrusion of irrigant. The potential for apical extrusion of endodontic irrigants should be a consideration when selecting a system for final irrigation.

Evaluation of the Effect of Needle Position on Irrigant Flow in the C-shaped Root Canal Using a Computational Fluid Dynamics Model

IntroductionThe purpose of this study was to investigate the effect of the orientation of a side-vented needle on the irrigant flow pattern in a C-shaped root canal system using computational fluid dynamics and to evaluate the real-time replacement of irrigant in the lateral canal (LC). MethodsA mandibular second molar with a complete C-shaped canal system was chosen for this study. The root canals were prepared and scanned, and then the images were exported to design software. A 30-G, side-vented irrigation needle was positioned with the open notch facing the lateral canal (case A) and rotated 90°, 180°, and 270° clockwise (cases B, C, and D, respectively). The flow pattern, irrigant replacement, velocity distribution, wall stress distribution, and apical pressure in the canal were analyzed. ResultsMost of the irrigant flowed to the canal outlet from the adjacent instrumented canal space with different trajectories in the 4 cases. The concentration of scalar immediately below the tip of the needle was exchanged quickly; the length of the cleared zone extended 3 mm beyond the tip of the needles. The depth of circulation in the LC in all cases increased during the first 0.2 seconds. After that, the exchange of irrigant reached a stable phase. Irrigant penetration in the LC was greatest in cases A and B (<1.1 mm). Apical pressure in case B was significantly lower than in other groups. ConclusionsThe scalar concentration can be used to evaluate the replacement of irrigant in the root canal over time. Orientation of the opening of the side-vented needle influences the flow pattern, velocity, apical wall pressure, and penetration into the LC.

A comparison of different irrigation/agitation methods for the removal of calcium hydroxide medicament from the root canal walls

Aim: To compare the removal efficiency of calcium hydroxide (CH) medicament from the root canal walls with different irrigation/agitation methods. Materials and Methods: Forty human mandibular premolars were selected. Root canals of these teeth were prepared up to F4 file using ProTaper rotary system and then filled with CH. All root specimens were stored at 37΀C and 100% relative humidity for 7 days. Teeth were randomly divided into four different groups (n = 10). For the removal of the medicaments from the canal walls, roots were subjected to the final irrigation/agitation methods used as follows: Conventional syringe irrigation with side-vented needle (Group 1), passive ultrasonic irrigation (PUI; Group 2), manual dynamic agitation (Group 3), and apical negative pressure irrigation (Group 4). The negative control did not receive CH placement. The positive control received the intracanal medication, but no subsequent removal. Roots were split longitudinally into two halves. Digital images of the root canal walls were acquired by a digital camera and assessed for residual amount of medicament. Cervical, middle, and apical third of each canal was assessed by using a scoring system. Data were analyzed using one-way analysis of variance (ANOVA) and Tukey's multiple comparison tests, at 95% confidence interval (P 0.05). However, there were statistically significant differences between the experimental groups and the positive control (P < 0.05). None of the experimental groups totally removed CH medicaments from root canal walls. Conclusions: In the limitations of this in vitro study, all experimental groups produced similar removal efficiency in terms of canal cleanliness.

A comparative study of the debridement efficacy and apical extrusion of dynamic and passive root canal irrigation systems

BackgroundRoot canal irrigation carries a risk of extrusion of irrigant into the periapical tissues which can be associated with pain, swelling, and tissue damage. Studies have shown less extrusion with sonic or apical negative pressure devices compared with syringe and side-port needle or passive ultrasonic irrigation with continuous irrigant flow. This study aimed to evaluate the effectiveness of the EndoVac irrigation system, regarding 1) debris removal and 2) the control of apically extruded irrigating solution.MethodsFifty extracted human single-rooted teeth were used in this study. The teeth were then randomly divided into three experimental groups according to the type of irrigation used and one control group. In group 1, irrigation was performed using the EndoVac irrigation system. In group 2, irrigation was performed using a 30-gauge, tip-vented irrigation needle. In group 3, irrigation was performed using a 30-gauge, side-vented irrigation needle. The control group received instrumentation with no irrigation to serve as a control for cleaning efficiency. Root canal instrumentation was performed using the Profile NiTi rotary system with a crown-down technique. All of the experimental teeth were irrigated with the same amount of 5.25% sodium hypochlorite. The amount of extruded irrigating solution was then measured by subtracting the post-instrumentation weight from the pre-instrumentation weight using an electronic balance. The cleanliness of debris removal was evaluated using scanning electron microscopy.ResultsEndoVac irrigation had the least amount of extrusion followed by the side-vented and tip-vented method. The difference between the groups was statistically significant (P <0.01). As for the cleaning results, the debris collection in the EndoVac and tip-vented groups was the least in the apical third. In the control and the side-vented groups, the debris was the greatest in the apical third, but this difference was not significant among the three experimental groups.ConclusionsThe EndoVac irrigation system extruded significantly less irrigant solution than either needle irrigation system. Debris collection was the least in the apical third for the EndoVac irrigation system. No significant difference was found in the cleaning efficiency among the three irrigation systems.

Irrigation dynamics associated with positive pressure, apical negative pressure and passive ultrasonic irrigations: a computational fluid dynamics analysis.

Complexities in root canal anatomy and surface adherent biofilm structures remain as challenges in endodontic disinfection. The ability of an irrigant to penetrate into the apical region of a canal, along with its interaction with the root canal walls, will aid in endodontic disinfection. The aim of this study was to qualitatively examine the irrigation dynamics of syringe irrigation with different needle tip designs (open-ended and closed-ended), apical negative pressure irrigation with the EndoVac® system, and passive ultrasonic-assisted irrigation, using a computational fluid dynamics model. Syringe-based irrigation with a side-vented needle showed a higher wall shear stress than the open-ended but was localised to a small region of the canal wall. The apical negative pressure mode of irrigation generated the lowest wall shear stress, while the passive-ultrasonic irrigation group showed the highest wall shear stress along with the greatest magnitude of velocity.

Wall shear stress effects of different endodontic irrigation techniques and systems

ObjectivesThis study examined débridement efficacy as a result of wall shear stresses created by different irrigant delivery/agitation techniques in an inaccessible recess of a curved root canal model. MethodsA reusable, curved canal cavity containing a simulated canal fin was milled into mirrored titanium blocks. Calcium hydroxide (Ca(OH)2) paste was used as debris and loaded into the canal fin. The titanium blocks were bolted together to provide a fluid-tight seal. Sodium hypochlorite was delivered at a previously-determined flow rate of 1mL/min that produced either negligible or no irrigant extrusion pressure into the periapex for all the techniques examined. Nine irrigation delivery/agitation techniques were examined: NaviTip passive irrigation control, Max-i-Probe® side-vented needle passive irrigation, manual dynamic agitation (MDA) using non-fitting and well-fitting gutta-percha points, EndoActivator™ sonic agitation with medium and large points, VPro™ EndoSafe™ irrigation system, VPro™ StreamClean™ continuous ultrasonic irrigation and EndoVac apical negative pressure irrigation. Débridement efficacies were analysed with Kruskal–Wallis ANOVA and Dunn's multiple comparisons tests (α=0.05). ResultsEndoVac was the only technique that removed more than 99% calcium hydroxide debris from the canal fin at the predefined flow rate. This group was significantly different (p<0.05) from the other groups that exhibited incomplete Ca(OH)2 removal. ConclusionsThe ability of the EndoVac system to significantly clean more debris from a mechanically inaccessible recess of the model curved root canal may be caused by robust bubble formation during irrigant delivery, creating higher wall shear stresses by a two-phase air–liquid flow phenomenon that is well known in other industrial débridement systems.

Efficacy and Safety of Various Active Irrigation Devices When Used with Either Positive or Negative Pressure: An In Vitro Study

IntroductionThe purpose of this in vitro study was to evaluate and compare the efficacy and safety of different devices available for canal cleansing. MethodsThe following systems were tested: passive ultrasonic irrigation, EndoVac (Discus Dental, Culver City, CA), and the irrigation ultrasonic needle (ProUltra PiezoFlow Irrigation Ultrasonic Needle; Dentsply Tulsa Dental Specialties, Tulsa, OK) used in both the injection mode (IUNI) and the aspiration mode (IUNA). In the control group, traditional irrigation with a syringe and side-vented needle was used. A resin model was used with 4 lateral canals (respectively at 2, 5, 8, and 11 mm from the apical foramen) filled with bovine pulp stained with fuchsin. The model also included a 2-mm chamber in communication with the apex, again filled with bovine pulp, which enabled the measurement of the extrusion of NaOCl beyond the apex. ResultsWith regard to efficacy, the most effective systems were found to be those using the ultrasonic needle, either in aspiration or injection modes; EndoVac was the least effective. Conversely, IUNI was found to bring the highest risk with regard to the extrusion of sodium hypochlorite beyond the apex. EndoVac was the safest but only by a slight margin compared with IUNA and passive ultrasonic irrigation. ConclusionsBased on this study, the system that best reconciles efficacy and safety appears to be IUNA.

Canal and Isthmus Debridement Efficacy of the VPro EndoSafe Negative-pressure Irrigation Technique

IntroductionThis study compared canal and isthmus debridement efficacies between side-vented needle irrigation (SNI) and the VPro EndoSafe (VPro) negative-pressure device (Vista Dental, Racine, WI) in mesial roots of mandibular first molars with narrow isthmuses in a closed-canal design. MethodsTwenty teeth with narrow isthmuses were selected using micro–computed tomography scanning. Collagen solution was reconstituted with 1% NH4OH to simulate debris and injected into canals via vacuum. Canals were instrumented to size 40/.04. Final irrigation was performed with 17% EDTA and 6% NaOCl using SNI with a 30-G needle or the VPro system. Roots were demineralized, and Masson trichrome–stained sections were prepared at 1.2 to 3.2 mm from the anatomic apex for a total of 6 canal levels. Debris-filled areas within the canals and isthmuses were measured using ImageJ software (National Institutes of Health, Bethesda, MD) and statistically analyzed using repeated-measures analysis. ResultsThere was no significant difference between techniques and debridement efficacy among the 6 levels within the canal (P = .108). The debridement efficacy at 1.6 mm differed significantly from that at 3.2 mm. VPro had significantly more debris at isthmus levels 2.0 and 2.4 mm than SNI (P = .009). A significant difference was observed between the canal and the isthmus (P < .001). Neither VPro nor SNI removed debris completely from the apical third or isthmus. ConclusionsVPro EndoSafe did not differ significantly from SNI in the overall debridement efficacy in the apical third of mesial roots of mandibular first molars.