Comparison of EASYDO ACTIVATOR, passive ultrasonic, and needle irrigation techniques on the treatment of apical periodontitis: a study in rats.

OBJECTIVES: To evaluate the long-term therapeutic effect of EASYDO ACTIVATOR, passive ultrasonic irrigation, and needle irrigation in experimental apical periodontitis in rats. MATERIALS AND METHODS: Sprague-Dawley male rats were used to produce periapical lesions. The pulp chambers of the bilaterally first mandibular molars were exposed and left open for 21 days. The rats were divided into four groups according to different irrigation protocols. Seven days after irrigation, the mandibles were removed for micro-CT, histological, and immunohistochemical analysis. Serum levels of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) were assessed by enzyme-linked immunosorbent assays (ELISA). Statistical data were analyzed by one-way analysis of variance (ANOVA) with LSD tests. RESULTS: The passive ultrasonic irrigation and EASYDO ACTIVATOR groups had the smallest apical lesions compared to the other groups (P < 0.05), while the needle irrigation group had smaller lesions than the control group (P < 0.05). The EASYDO ACTIVATOR group had less inflammation infiltration compared to the control and needle irrigation groups (P < 0.05). The control and needle irrigation groups had more TNF-α expression compared to the passive ultrasonic irrigation and EASYDO ACTIVATOR groups (P < 0.05). The lowest IL-6 expression was observed in the EASYDO ACTIVATOR group. The EASYDO ACTIVATOR group had the lowest serum level of TNF-α than other groups (P < 0.05). IL-6 expression was significantly lower in the EASYDO ACTIVATOR group in comparison with the control and needle irrigation groups (P < 0.05). CONCLUSIONS: EASYDO ACTIVATOR can significantly reduce the apical lesions and decrease the inflammatory response around the periapical area. CLINICAL RELEVANCE: EASYDO ACTIVATOR is recommended for clinical application.

Effect of apical size on apical pressure during syringe-needle and multisonic negative pressure irrigation.

Apical pressure during root canal irrigation is regarded as a key factor affecting the risk of irrigant extrusion. The aim of this study was to examine the effect of apical size on the apical pressure by positive and negative pressure syringe-needle and multisonic negative pressure irrigation. An extracted maxillary first molar with two separate buccal roots, one palatal root and four canals was selected. The roots of the molar were fixed in a specially made apparatus to acquire the apical pressure of the four root canals separately. The apical sizes tested were from sizes 10, 30, 40, 50, 60, 70, 80, 90, 110. Multisonic negative pressure irrigation protocol was as recommended by the manufacturer (45 mL/min), syringe-needle irrigation was done using 30-G side-vented needle 3 mm from the working length at 5 mL/min as a conventional positive pressure irrigation (SNI), and as negative pressure irrigation (NPSNI) using suction. Apical pressure by SNI was measured also at 10 mL/min with an open-ended 30G needle, for the smallest and largest apical sizes. Apical pressures by SNI stayed positive, except when suction was used (NPSNI). The apical pressure by multisonic negative pressure irrigation remained negative in all situations. With increasing apical size, apical pressure by SNI decreased, whereas with multisonic negative pressure irrigation and NPSNI, it was not affected by apical size. Large apical size did not result in higher apical pressure values compared to small apical sizes.

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

AIM AND OBJECTIVE: 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. MATERIALS AND METHODS: 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. RESULT: 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. CONCLUSION: Diode laser disinfection showed the highest reduction of microbial count compared to ultrasonic activated and conventional needle irrigation with 2.5% NaOCl group. CLINICAL SIGNIFICANCE: 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.

Sonic irrigant activation for root canal disinfection: power modes matter!

BACKGROUND: Sonic irrigant activation has gained widespread popularity among general dentists and endodontists alike in recent years. This in vitro study aimed to evaluate the impact of three power modes of a sonic activation device (EDDY) on its antimicrobial effectiveness in infected root canals. METHODS: The root canals of straight, human roots (n = 120) were prepared to size 40/.06. In a short-term infection experiment, the root canals were inoculated with different microbial species for three days. The following irrigation protocols, using 4 ml of normal saline as irrigant, were performed: negative control, manual rinsing, sonic irrigant activation at power modes "low", "medium" and "high". In a second, long-term experiment, testing the same irrigation protocols, inoculation lasted 21 days and sodium hypochlorite was used as irrigant. Sequential infection control samples were assessed using culture assays. The statistical analysis included one-way analysis of variance of log10-scaled counts of colony-forming units (CFU) with post-hoc comparisons using Bonferroni corrections and Chi2 tests (α = 0.05). RESULTS: In the short-term experiment, the sonic irrigation protocols decreased the number of CFUs by 1.88 log10 units compared with the negative control (p < 0.001). The power modes "medium" and "high" achieved the most effective reduction of the microbial load. In the long-term experiment, microbial regrowth occurred after 7 days unless the device was used at its highest power setting. CONCLUSIONS: The power modes of the sonic irrigation device have a significant impact on the effectiveness for endodontic disinfection. The sonic irrigation device should always be used at the highest power setting in order to maximize its antimicrobial effectiveness.

Comparative Evaluation of the Efficacy of Novel Root Canal Irrigation Techniques on Reduction of Enterococcus faecalis Count: An In Vitro Study.

AIM AND OBJECTIVE: To compare the effectiveness of three irrigation systems, namely, Endovac system, Max I probe, and Navitip FX, in reduction of Enterococcus faecalis population from the root canal using agar diffusion method. MATERIALS AND METHODS: Sixty extracted intact human permanent maxillary anterior teeth were selected for this study. In group I, root canals were irrigated using brush covered 30-gauge NaviTipFX. Ultradent in group II root canals was irrigated using brush covered 30-gauge Max-I-Probe Dentsply. In group III, root canals were irrigated using Endoactivator, Dentsply. In group IV, root canal was irrigated by using the Endovac system Sybronendo. The steps followed in the study include preparation of specimen, contamination of the samples followed by conduction of testing procedures with implementation of appropriate irrigation protocols, and sampling procedures. RESULTS: Data were subjected to statistical analysis to interpret the significant differences among various irrigation systems. One-way analysis of variance, Post hoc Tukey tests were used for statistical analysis in the present study. Among the experimental groups, group IV showed statistically significant difference in reduction of E. faecalis. There were no statistical differences between them in reduction of E. faecalis in group I and group II compared and represented in Tables 1 and 2. CONCLUSION: All four irrigation delivery systems have been found to be effective in the reduction of E. faecalis. Endovac showed comparable efficacy in reduction of colony-forming units to that of other delivery systems used in the study. The result has to be validated with in vivo studies and clinical trials of larger sample size. CLINICAL SIGNIFICANCE: Selection of appropriate irrigation system capable of disinfection of canal complexities in apical third with less adverse effects is essential for good clinical success of endodontic treatment.

Comparison of sodium hypochlorite extrusion by five irrigation systems using an artificial root socket model and a quantitative chemical method.

OBJECTIVES: This is to compare the volumes of irrigant apically extruded by five irrigation systems in an artificial socket model simulating clinical conditions. MATERIALS AND METHODS: Twenty extracted human single-rooted teeth were enlarged to size 40/04 and then embedded in silicone impression material. The root canal space was irrigated with nominal 3% sodium hypochlorite (NaOCl) using standard needle irrigation (SNI) with a 30-gauge notched needle, EndoActivator (EA), XP Endo Finisher (XP Endo), EndoVac (EV), and photon-induced photoacoustic streaming (PIPS). Extruded NaOCl was collected, reacted with taurine to form taurine-monochloramine, and absorbance of taurine-monochloramine was measured at 252 nm using a spectrophotometer. The five irrigation systems were compared with repeated measures ANOVA and pairwise comparisons. RESULTS: The EV group had very low extrusion (mean ± SD = 0.12 ± 0.2 µL) and differed significantly from the other four groups (P ≤ 0.001). Larger volumes of irrigant were extruded in the other irrigation groups. There were no significant differences in the extruded volumes among the SNI (7.4 ± 3.4 µL), EA (7.0 ± 6.1 µL), and XP Endo (7.8 ± 4.1 µL) groups (P = 1). The PIPS group had the highest mean extruded volume (12.9 ± 6.8 µL) and differed significantly from SNI (P = 0.030), EV (P < 0.0005), and EA (P = 0.02), but not XP Endo (P = 0.154). CONCLUSION: Under the in vitro conditions of this study, irrigant extrusion appears unavoidable unless negative pressure irrigation such as EV is used. PIPS extrudes more irrigant than other systems, while SNI, EA, and XP Endo extrude similar volumes of irrigant. CLINICAL RELEVANCE: The findings help clinicians select the optimal irrigation system to avoid irrigant extrusion.

A promising approach utilising photothermal energy to disinfect the root canal system: An in vitro investigation.

This study aimed to assess root canal disinfection through various irrigation protocols, including a novel photothermal system called 'LEAP'. Mandibular premolars were infected with Enterococcus faecalis and divided into five groups for different treatments: Group 1: standard needle irrigation; Group 2: passive ultrasonic irrigation; Group 3: GentleWave; Group 4: LEAP; and Group 5: Group 1 + Group 4. Microbial counts were measured before (S1) and after disinfection (S2) using colony-forming units (CFU) and confocal laser scanning microscopy (CLSM). Results revealed a significant reduction in bacterial counts for all groups (p < 0.05). While the percentage of dead bacteria near the canal wall (0-50 µm) did not differ significantly, at 50-150 µm, LEAP and SNI + LEAP exhibited significantly higher bacterial reduction than other groups (p < 0.05). The findings indicate that LEAP is comparable to existing irrigation devices in the main root canal and notably superior in tubular disinfection.

Efficacy of Different Irrigation Needles and Ultrasonic Activation on Calcium Hydroxide Removal: A Micro-CT Study Using 3D-Printed Endodontic Models.

INTRODUCTION: The aim of this study was to evaluate the efficacy of different irrigation needles and passive ultrasonic activation in removing Ca(OH)2 from an endodontic model that duplicated a root canal configuration of a human natural tooth. METHODS: An extracted human maxillary premolar was subjected to root canal preparation and scanned with microcomputed tomography. A 3-dimensional reconstruction model of the natural tooth was printed to endodontic models using a polyjet printer. The root canals of the models were filled with Ca(OH)2 paste and divided into 2 groups based on the irrigation protocol: conventional syringe-needle irrigation (conventional group) and passive ultrasonic irrigation (PUI) group. Each group was subdivided into 3 groups (n = 10) according to the type of needle: half-cut, side-vented, and TruNatomy irrigation needle. Microcomputed tomographyimaging was used to assess the percentage of reduction of Ca(OH)2. Data were analyzed using two-way analysis of variance test (α = .05). RESULTS: The side-vented and TruNatomy irrigation needles showed significantly higher percentage reductions than the half-cut needle (P < .05) in the conventional irrigation group. The PUI group showed significantly higher percentage reductions of Ca(OH)2 than the conventional group regardless of the type of needle (P < .05). However, no significant difference was found among the needles in the PUI group. CONCLUSIONS: The type of irrigation needle and the use of PUI influenced the removal efficacy of Ca(OH)2. PUI enhanced the removal of Ca(OH)2 regardless of the type of irrigation needle.

Comparative Evaluation of Bacterial Reduction by Laser-Activated Irrigation Technique (LAI) With Conventional Needle Irrigation (CNI) in Single-Rooted Teeth With Pulpal Necrosis: A Single-Blinded Randomized Controlled Trial.

Aim  To compare the bacterial reduction in single-rooted teeth with pulpal necrosis after laser-activated irrigation technique (LAI) and conventional needle irrigation (CNI). Methodology In this clinical trial (CTRI/2021/09/047767), 32 patients with pulpal necrosis were enrolled. Under complete aseptic conditions, access cavity preparation was done and the baseline sample S1 was collected from the root canal using paper points. After chemo-mechanical preparation they were allocated into two groups, following block randomization; Group A - CNI with 27 gauge side-vented needle, Group B - LAI with pulsed Er,Cr:YSGG (erbium, chromium:yttrium-scandium-gallium-garnet) (2780 nm) laser. After irrigant activation, canals were dried and a second sample S2 was taken using paper points. Microbial analysis using quantitative polymerase chain reaction (qPCR) was done to quantify the bacterial reduction among the two groups. Inter-group and intra-group analysis was done using the independent student t-test and Bonferroni test, respectively. The data was represented in terms of quantification cycle (Cq) values, which are inversely proportional to the microbial count.  Results There was no significant difference in S1 between the two groups (mean difference=0.0205; p=0.912). There was a significant difference in S2 between the two groups for the organisms (mean difference=0.8042; p=0.000). The mean percentage of bacterial reduction in CNI was 10.82% and in LAI it was 25.92%.  There was a significant difference in S1 through S2 within the two groups for the organisms (p=0.000). The mean difference of Cq value is high for LAI compared to CNI (1.3494).  The fold change was calculated by taking the ΔCq value and ΔΔCq value after the logarithmic transformation of the Cq value. LAI showed lower levels of DNA at S2 similar to CNI. There is no significant difference in mean fold change between CNI and LAI (p=0.564).  Conclusion This clinical trial concluded that both LAI and CNI were effective in bacterial reduction. There was greater bacterial reduction with LAI (25.92%) than with the CNI (10.82%) in single-rooted teeth with pulpal necrosis using qPCR analysis.

Effect of SWEEPS and PIPS techniques on dye extrusion in photodynamic therapy procedure after root canal preparation.

AIM: The aim of this study is to measure and compare the amount of apical extrusion of the methylene blue as photosensitizer using Laser-activated irrigation(LAI) techniques (SWEEPS, PIPS) and photodynamic therapy (PDT). MATERIALS AND METHODS: 40 single-rooted premolar teeth were selected and their root canals were cleaned and prepared. The photosensitizer, Methylene blue (MB), was used as dye which applied inside the root canals and the access cavities. Then the teeth were randomly allocated to 4 groups. Different techniques (SWEEPS, PIPS, PDT) were used in 3 groups. One group received no activation. Data related to the concentration of the extruded methylene blue was measured using ultraviolet and visible (UV-Vis) absorption spectroscopy. Absorption peak intensity of MB in the wavelength of 668 nm was considered as the concentration index according to Beer Lambert law. Taking into account the normal distribution of this data, one-way ANOVA analysis was used to evaluate the effects of the independent variables on the amount of apical extrusion of the irrigant. RESULTS: Based on the results of ANOVA analysis, there was no significant difference between the amounts of apical extrusion of MB between different groups (p = 0.628) CONCLUSION: Using SWEEPS and PIPS techniques, despite diffusion of the photosensitizer, didn't lead to any difference in the amount of apical extrusion. Therefore, these LAI techniques can be used safely for root canal irrigation.

Comparative Study Assessing the Canal Cleanliness Using Automated Device and Conventional Syringe Needle for Root Canal Irrigation-An Ex-Vivo Study.

The success of endodontic treatment relies on both apical and coronal sealing. To achieve a good three-dimensional seal, the removal of the smear layer becomes mandatory. This study aims to assess the difference in debris accumulation and smear layer formation while using automated root canal irrigation and conventional syringe needle irrigation. Single-rooted human mandibular premolar teeth (n = 30) which were indicated for orthodontic extractions were selected. An endodontic access cavity was prepared, and a glide path was created. Based on the irrigation protocol decided upon for the study, the teeth were randomly allocated into three study groups, namely Group 1, where the manual syringe needle irrigation method was adopted; Group 2, in which automated root canal irrigation was undertaken; and Group 3, in which teeth remained un-instrumented as it was considered the Control group. The teeth were decoronated at the cement-enamel junction (CEJ) and were subjected for scanning electron microscopy (SEM) examination. Debris and smear layers were viewed in 1000× magnification and scored. A statistically significant (p < 0.05) lower mean debris and smear layer score (p < 0.05) was observed in both study groups when compared with the control group. However, no significant difference (p > 0.05) in the debris and smear layer was observed between the manual syringe needle irrigation and automated irrigation, although automated irrigation devices can be a potential alternative. The present study concluded that the efficacy of smear layer removal remained the same with both automated irrigation and manual syringe irrigation.

Comparative Evaluation of Efficacy of Different Irrigating Needles and Devices in Removal of Debris from Apical Third of Root Canal: An In-vitro SEM Study.

BACKGROUND: Irrigants were required to eliminate the microbes and debris from the intraradicular space and must have direct contact with the entire root canal wall. Therefore, different irrigation methods have been proposed to deliver the irrigant as close as possible to the remote areas of the root canal. AIM: The aim of the present study is to evaluate the cleaning efficacy of single-beveled needle, side-vented needle, endovac, and endo-irrigator plus in the removal of debris from apical third of root canal by Scanning Electron Microscope. MATERIALS AND METHODS: Forty single-rooted freshly extracted human permanent mandibular premolars were collected. Root canals were cleaned and instrumented till X2 (25/06) with rotary Protaper Next at working length 1 mm short of the apex. Teeth were randomly divided into four equal groups: Group 1 (n = 10): Endovac, Group 2 (n = 10): Endo irrigator plus, Group 3 (n = 10): Side-vented needle, and Group 4 (n = 10): Single-beveled needle. Irrigation was done with 5.25% NaOCl, followed by 17% ethylenediaminetetraacetic acid. Samples were sectioned and examined under SEM at apical levels. STATISTICAL ANALYSIS: Analysis of variance followed by Tukey's post hoc test was performed. RESULTS: The level of debris removal efficacy is as follows: Endovac > Endo-irrigator plus > Side-vented needle ~ Single-beveled needle. CONCLUSION: Endovac showed the maximum number of debris removal and has better cleaning efficacy in the apical areas of the root canal, followed by Endo irrigator plus, Side-vented needle and Single-beveled needle.

Examining the Effect of Gravity on Different Irrigation Systems: An In vitro Study.

BACKGROUND: Periapical extrusion is frequently observed during endodontic therapy. It can lead to acute injury of periapical tissues, resulting in interappointment pain or swelling. The effect is pronounced in teeth with immature apex, which are more susceptible to the extrusion of irrigant. The aim of this study was to evaluate the effect of gravity on the apical extrusion of irrigating solution with different irrigation protocols in single-rooted premolars. METHODOLOGY: A total number of 80 permanent single-rooted teeth (premolars) with same working length (WL) were divided into two main groups: Group A: Penetration depth of irrigation syringe to 2 mm from the WL and Group B: Penetration depth of irrigation syringe to 4 mm from the WL. Each group was subdivided into four subgroups. (n = 10). The extruded debris and irrigants were weighed, and the data were statistically analyzed by the analysis of variance and the Tukey test. RESULTS: Irrespective of the irrigation technique used, the amount of irrigant extruded from the apex showed a statistically significant difference related to the effect of gravity (P < 0.05). There was no statistically significant difference observed between irrigation methods (P > 0.05). CONCLUSION: The degree of apical extrusion of irrigant was dependent on the type of irrigation technique and gravity. Greater caution should be taken during irrigation to prevent postoperative pain.

Antibacterial efficacy of an endodontic sonic-powered irrigation system: An in vitro study.

OBJECTIVE: To evaluate the efficacy of EDDY, a new sonic-powered irrigation system, in reducing intracanal bacteria load. METHODS: Thirty-eight instrumented, autoclaved single-rooted human premolars were inoculated with Enterococcus faecalis (ATCC-29212) for 21 days. Two teeth were used as negative control without bacterial contamination. For the bacteria-inoculated teeth, 6 were used as positive control without irrigation. The remaining 30 teeth were randomly divided into 2 groups (N = 15), using 3% NaOCl as irrigant: (A) 30-gauge syringe needle irrigation (SNI), (B) EDDY (VDW, Munich, Germany). Twelve teeth per group and 4 teeth in the positive control were evaluated for bacterial reduction using MTT assay. The remaining teeth were split for BacLight LIVE/DEAD staining to examine the percentages of live/dead bacteria present in the dentinal tubules from different canal locations (coronal, mid-root and apical portions of the canal space) using confocal laser scanning microscopy (CLSM). RESULTS: MTT assay indicated that both SNI and EDDY significantly reduced overall intracanal bacterial load compared with the positive control, with no significant difference between the two techniques. CLSM indicated that EDDY had better intratubular bacterial killing efficacy than SNI in the coronal and mid-root portions of the canal space only but not in the apical portion. In all canal locations (coronal, mid-root apical), both systems failed to eliminate bacteria that proliferated deep within the dentinal tubules. CONCLUSION: With the use of 3% NaOCl, sonic-powered irrigant activation with EDDY tips did not provide additional advantage over SNI in killing Enterococcus faecalis from deep intraradicular dentin. CLINICAL SIGNIFICANCE: Both the sonic-powered root canal irrigant activation system and syringe needle irrigation can reduce intracanal bacteria load but are incapable of completely killing all bacteria that resided deep within the dentinal tubules of root canals infected with Enterococcus faecalis.

In Vitro Efficacy of XP-endo Finisher with 2 Different Protocols on Biofilm Removal from Apical Root Canals.

INTRODUCTION: The purpose of this study was to evaluate the effectiveness of the XP-endo Finisher (XPF; FKG Dentaire SA, La Chaux-de-Fonds, Switzerland) in biofilm removal in comparison with conventional needle irrigation (CNI) and passive ultrasonic irrigation (PUI) using an infected tooth model with an artificial apical groove. METHODS: Fifty-four extracted human single-rooted premolars were selected. Each tooth was split longitudinally into 2 halves, with a groove made in the apical segment of the canal wall. After growing mixed bacteria biofilm for 4 weeks, the split halves were reassembled and instrumented using Vortex Blue files (Dentsply Tulsa Dental, Tulsa, OK) to size 40/.06. The instrumented teeth were randomly assigned to 6 groups (n = 8) according to the final irrigation protocol. Three different techniques (CNI, PUI, and XPF) were performed each with either continuous irrigation or 3-step irrigation. Scanning electron microscopic images were taken to evaluate the amount of residual biofilm inside and outside the groove. RESULTS: Robust growth of biofilm was observed in each canal of the controls after 4 weeks. XPF showed the best biofilm removal efficacy inside and outside the groove followed by PUI and CNI (P < .05). The XPF 2 group using the 3-step protocol showed better antibiofilm efficiency than the XPF 1 group with continuous irrigation inside the groove (P < .05). CONCLUSIONS: The XP-endo Finisher, as an irrigation agitation technique, may help to remove biofilm from hard-to-reach areas in the root canal system. The 3-step irrigation protocol was more effective than continuous irrigation when XPF was used.

Influencia de los Diseños de Agujas Endodónticas en la Irrigación de Conductos Radiculares / Influence of Endodontic Needle Designs on Root Canal Irrigation

La irrigación del sistema de conductos radiculares con soluciones antibacterianas es considerada una parte esencial de la preparación químico-mecánica. Varios factores influyen en la eficacia de la irrigación del conducto radicular, incluyendo tamaño de la preparación apical y ensanchamiento, distancia de penetración de la aguja con respecto al ápice, flujo y volumen de sustancia de irrigante, dimensión de las agujas y la presencia de curvatura del conducto radicular. El tamaño de la preparación apical y la conicidad afectan el recambio del irrigante, el esfuerzo de corte en las paredes del conducto radicular y la presión en el foramen apical. La colocación de la punta de la aguja más cerca del ápice, permite un recambio de la solución más eficiente, resultando una mejor limpieza y desinfección del conducto radicular. La velocidad del irrigante, al lado de la aguja, en las paredes del conducto opuestas y frente a la salida de la aguja es dependiente del diseño de la aguja. El patrón de flujo y recambio del irrigante de las agujas con extremo abierto es diferente al de las agujas cerradas y las que logran mejor recambio de irrigante en la parte apical del conducto radicular también conducen a un aumento de la presión media en el foramen apical, lo que indica un mayor riesgo de extrusión del irrigante hacia el tejido periapical. El objetivo de esta revisión a la literatura, es evaluar los diferentes diseños de agujas y su influencia en la irrigación del sistema de conductos radiculares.

Root canal irrigation with antibacterial solutions is considered an essential part of the chemical-mechanical preparation. Several factors influence the efficacy of root canal irrigation, including apical preparation size and taper, needle penetration distance from the apex, flow and volume of irrigant substance, dimension of the needles and the presence of curvature of the root canal. The apical preparation size and the taper affect irrigant replacement, shear stress on the root canal walls, and pressure on the apical foramen. Placing the tip of the needle closer to the apex, allows more efficient solution exchange, resulting in better cleaning and disinfection of the root canal. The velocity of the irrigant, next to the needle, on the opposite canal walls and in front of the needle outlet is dependent on the design of the needle. The flow and irrigant replacement pattern of open ended needles is different from needles with closed tip. The needles that achieve better irrigant exchange in the apical part of the root canal also lead to an increase in mean pressure in the apical foramen which indicates a greater risk of extrusion of the irrigant into the periapical tissue. The objective of this literature review is to evaluate the different needle designs and their influence on the root canal system irrigation.

Assessment of Apical Extrusion during Root Canal Irrigation with the Novel GentleWave System in a Simulated Apical Environment.

INTRODUCTION: This study assessed apical extrusion during treatment with GentleWave (GW; Sonendo Inc, Laguna Hills, CA), a conventional open-ended 30-G needle (CN), or Endovac (EV; SybronEndo, Orange, CA) in root canals enlarged to different dimensions with and without apical constriction. METHODS: Sixteen mandibular molars were mounted in an in vitro apparatus. Roots were immersed in a pressure-regulated chamber containing distilled water with pressure kept at 5.88 ± 0.15 mm Hg to simulate periapical back pressure. Mesiobuccal (curved ≤30°) and distal (straight) canals were instrumented to the working length (WL) as follows: minimal instrumentation (MI, #15/.04), traditional instrumentation (#35/.06), or overinstrumentation (OI, #35/.06, to the WL + 1 mm). Canals were tested 5 times each with distilled water using GW, CN (at WL-3 mm), or EV and the mass (g) of extruded water recorded. Extrusion frequency and mean extruded mass were compared for each canal, irrigation group, and canal instrumentation mode (Wilcoxon t test, P < .05). RESULTS: No extrusion occurred with GW and EV, whereas the frequency of extrusion with CN was 33%. Mean extruded water mass using CN ranged in mesial canals from 0.000 ± 0.000 g (OI) to 0.047 ± 0.098 g (MI) and in distal canals from 0.123 ± 0.191 g (MI) to 0.505 ± 0.490 g (OI). With traditional instrumentation and OI instrumentation, extruded mass in distal canals was significantly higher than in mesial canals (P < .002) and distal canals with MI (P < .020). CONCLUSIONS: Within this study's limitations, root canal treatment with GW and irrigation with EV was not associated with extrusion. Extruded irrigation mass using the open-ended 30-G needle depended on the canal type and enlargement. These results have to be interpreted with caution, and further investigations are warranted to evaluate the possibility of extrusion using GW in different tooth types and clinical situations.

In vitro study of different methods in the removal of calcium hydroxide from root canals / 口腔疾病防治

Objective@#To compare the efficacy of different methods in the removal of calcium hydroxide from root canals and to provide a reference for clinical treatment. @*Methods@# A total of 160 extracted single-rooted mandibular premolars were instrumented up to ProTaper Universal F4. The roots were split longitudinally, and standardized groove and depression models were prepared and filled with calcium hydroxide. The samples were randomly divided into 4 groups (n=40) according to different irrigation methods: syringe needle irrigation, passive ultrasonic irrigation, XP-endo finisher (XPF) irrigation, and M3-Max irrigation. Each group was then divided into 2 subgroups (n=20) according to the irrigation protocol: NaOCl and NaOCl+EDTA. Photos of grooves and depressions were taken under a microscope after irrigation, and the residual calcium hydroxide was scored to compare the removal effects of different irritation methods and solutions.@*Results@#In the groove and depression model, when sodium hypochlorite is used as the irrigation fluid, ultrasound irrigation, XPF and M3-Max are better than syringe needle irrigation in removing calcium hydroxide (P < 0.05); when sodium hypochlorite combined with EDTA flushing, the effect of removing calcium hydroxide with ultrasound irrigation, XPF and M3-Max is better than that of syringe needle irrigation (P < 0.05); but there is no statistically significant difference between ultrasound, XPF and M3-Max (P > 0.05); when compared with the use of sodium hypochlorite, the combined use of EDTA irrigation could enhance the effect of ultrasonic irrigation, XPF and M3 Max on the removal of calcium hydroxide (P < 0.05), but there was no significant improvement in the syringe needle irrigation group (P > 0.05). @*Conclusion @#Sodium hypochlorite combined with EDTA can enhance the effect of ultrasonic irrigation, XPF and M3 Max on the removal of calcium hydroxide, and there is no significant difference among these approaches, which are more effective than syringe needle irrigation.

Effectiveness of different irrigation systems on smear layer removal: A scanning electron microscopic study.

OBJECTIVES: To evaluate effectiveness of the apical negative pressure irrigation (EndoVac), passive ultrasonic irrigation (PUI), and conventional needle irrigation (CI) systems on smear layer (SR) removal. MATERIALS AND METHODS: Sixty single-rooted canines were prepared using NiTi rotary files and subjected to different irrigation regimens: EndoVac with NaOCl (Group 1) or NaOCl/EDTA (Group 2); PUI with NaOCl (Group 3) or NaOCl/EDTA (Group 4); CI with NaOCl (Group 5) or NaOCl/EDTA (Group 6). The roots were split longitudinally. SEM images were taken to evaluate the amount of residual SR. RESULTS: In Groups 1, 3, and 5, there was no removal of SR (P > 0.05). The coronal thirds within Groups 2, 4, and 6 were cleaned completely, but the middle and the apical thirds was achieved partially or completely (P > 0.05). CONCLUSION: Regardless of which irrigation system was used, the use of NaOCl alone failed to remove the SR. In NaOCl/EDTA combination groups, the SR was removed partially or completely and no statistical significance. This study demonstrated that in order to remove the SR should be used EDTA solution for final irrigation in the root canal, regardless of the technique in each of the three.

Mycoplasma hominis Septic Arthritis of the Hip Developed in the Postpartum Period / 대한정형외과학회잡지

Septic arthritis of the hip is rarely caused by Mycoplasma hominis. It rarely develops in a patient during the postpartum period. However, delayed treatment of septic arthritis of the hip may lead to serious sequelae; therefore, it is important for clinicians not to overlook patients with the disease. This case illustrates the clinical steps in diagnosis and treatment of M. hominis septic arthritis of the hip.