title: Postoperative pain after the application of two different irrigation devices in a prospective randomized clinical trial. Ability of chemomechanical preparation with either rotary instruments or self-adjusting file to disinfect oval-shaped root canals. The in vivo evaluation of hand/rotary/ultrasound instrumentation in necrotic, human mandibular molars. Hard tissue debris removal from the mesial root canal system of mandibular molars with ultrasonically and laser-activated irrigation: a micro-computed tomography study Evaluation of Root Canal Debridement of Human Molars Using the GentleWave System. The effect of passive ultrasonic activation of 2% chlorhexidine or 5.25% sodium hypochlorite irrigant on residual antimicrobial activity in root canals. Radiographic healing after a root canal treatment performed in single-rooted teeth with and without ultrasonic activation of the irrigant: a randomized controlled trial. A comparative study of the debridement efficacy and apical extrusion of dynamic and passive root canal irrigation systems Comparative evaluation of postoperative pain after using endodontic needle and EndoActivator during root canal irrigation: A randomised controlled trial. Clinical study of single-visit root canal treatment with a nickel-titanium (Ni-Ti) rotary instrument combined with different ultrasonic irrigation solutions for elderly patients with chronic apical periodontitis. Apical extrusion of sodium hypochlorite using different root canal irrigation systems. In vivo debridement efficacy of ultrasonic irrigation following hand-rotary instrumentation in human mandibular molars. Influence of an apical negative pressure irrigation system on bacterial elimination during endodontic therapy: a prospective randomized clinical study. An in vivo evaluation of the efficacy of ultrasound after step-back preparation in mandibular molars. In vivo efficacy of three different endodontic irrigation systems for irrigant delivery to working length of mesial canals of mandibular molars. In vivo antibacterial efficacy of ultrasound after hand and rotary instrumentation in human mandibular molars. Effect of continuous ultrasonic irrigation on postoperative pain in mandibular molars with nonvital pulps: a randomized clinical trial Cleaning efficacy of an apical negative-pressure irrigation system at different exposure times. The Effect of Apical Positive and Negative Pressure Irrigation Methods on Postoperative Pain in Mandibular Molar Teeth with Symptomatic Irreversible Pulpitis: A Randomized Clinical Trial The Effect of Different Irrigation Agitation Techniques on Postoperative Pain in Mandibular Molar Teeth with Symptomatic Irreversible Pulpitis: A Randomized Clinical Trial The efficacy of dynamic irrigation using a commercially available system (RinsEndo) determined by removal of a collagen 'bio-molecular film' from an ex vivo model.
abstract: INTRODUCTION The extrusion of irrigation solutions beyond the apical constriction may result in postoperative pain .  Sodium hypochlorite can cause severe tissue irritation and necrosis outside the root canal system if extruded into the periodontal ligament ( PDL ) space . Different delivery techniques were discussed to reduce this potential risk . The aim of this study was to compare the postoperative level of pain after root canal therapy using either endodontic needle irrigation or a negative apical pressure device . MATERIAL AND METHODS In a prospect i ve r and omized clinical trial , 110 asymptomatic single-rooted anterior and premolar teeth were treated endodontically with two different irrigation techniques . The teeth were r and omly assigned to two groups . In the MP group ( n = 55 ) , procedures were performed using an endodontic irrigating syringe ( Max-i-Probe ; Dentsply Rinn , Elgin , IL ) . The EV group ( n = 55 ) used an irrigation device based on negative apical pressure ( EndoVac ; Discus Dental , Culver City , CA ) . Postoperatively , the patients were prescribed ibuprofen 200 mg to take every 8 hours if required . Pain levels were assessed by an analog scale question naire after 4 , 24 , and 48 hours . The amount of ibuprofen taken was recorded at the same time intervals . RESULTS During the 0- to 4- , 4- to 24- , and 24- to 48-hour intervals after treatment , the pain experience with the negative apical pressure device was significantly lower than when using the needle irrigation ( p < 0.0001 [ 4 , 24 , 48 hours ] ) . Between 0 and 4 and 4 and 24 hours , the intake of analgesics was significantly lower in the group treated by the negative apical pressure device ( p < 0.0001 [ 0 - 4 hours ] , p = 0.001 [ 4 - 24 hours ] ) . The difference for the 24- to 48-hour period was not statistically different ( p = 0.08 ) . The Pearson correlation coefficient revealed a strongly positive and significant relationship for the MP group ( r = 0.851 , p < 0.001 ) and the EV group ( r = 0.596 , p < 0.0001 ) between pain intensity and the amount of analgesics . CONCLUSION The outcome of this investigation indicates that the use of a negative apical pressure irrigation device can result in a significant reduction of postoperative pain levels in comparison to conventional needle irrigation INTRODUCTION Oval-shaped root canals might represent a great challenge for proper disinfection . This study compared the capability of a newly developed instrument , the self-adjusting file ( SAF ) , and rotary nickel-titanium ( NiTi ) instrumentation to eliminate Enterococcus faecalis population s from long oval root canals of extracted human teeth . As a secondary purpose , the ability of a modification in sampling technique to recover bacteria lodged in recesses of oval canals was evaluated . METHODS Long oval canals from m and ibular incisors and maxillary second premolars were infected with E. faecalis ( ATCC 29212 ) for 30 days and then r and omly distributed into 2 experimental groups . In group 1 , canals were prepared up to a 40/04 rotary BioRaCe instrument by using irrigation with NaviTip needles ; in group 2 , canals were prepared by using the SAF system with continuous irrigation . NaOCl and ethylenediaminetetraacetic acid were used as irrigants . Bacteriologic sample s were taken before ( S1 ) and after preparation ( S2a and S2b ) . RESULTS Reduction in the bacterial population s was highly significant in both groups ( P < .001 ) . Preparation of long oval canals with the SAF was significantly more effective than rotary NiTi instrumentation in reducing intracanal E. faecalis counts ( P = .01 ) . Frequency of positive cultures in S2 sample s was 11 of 20 ( 55 % ) for rotary instrumentation and 4 of 20 ( 20 % ) for SAF instrumentation ( P = .048 ) . S2b sample s ( modified method ) yielded more positive sample s than S2a ( 12/40 vs 5/40 ) , but this difference reached no statistical significance ( P > .05 ) . CONCLUSIONS The SAF system was significantly more effective than rotary NiTi instrumentation used with syringe/needle irrigation in disinfecting long oval root canals in vitro . A modified sampling technique might be necessary for oval canals This in vivo , prospect i ve , r and omized , single-blinded study histologically compared biofilm/necrotic debridement efficiency of a h and /rotary technique versus a h and /rotary/1 min ultrasound technique in the mesial roots of necrotic , human m and ibular molars . The h and /rotary group consisted of 20 mesial roots . The h and /rotary/ultrasound group consisted of 20 mesial roots  prepared with the same h and /rotary technique followed by 1 min of ultrasonic irrigation , per canal , utilizing an ultrasonic needle in a MiniEndo unit . Following extraction , histologic preparation and staining , 0.2 mum cross-sections from the 1- to 3-mm apical levels were evaluated for percentage of biofilm/necrotic debris removal . Cleanliness results at the 1- , 2- and 3-mm levels for the h and /rotary and h and /rotary/ultrasound techniques , respectively , were : Canals , 80 % versus 95 % , 92 % versus 99 % , and 95 % versus 100 % ; Isthmuses , 33 % versus 83 % , 31 % versus 86 % , 45 % versus 91 % . Statistical analysis revealed mean percent canal and isthmus cleanliness values to be significantly higher for h and /rotary/ultrasound technique at all levels evaluated This study is to investigate the efficacy of different irrigant activation techniques on removal of accumulated hard tissue debris ( AHTD ) in mesial roots of human m and ibular molars . Extracted human m and ibular molars with an isthmus between the mesial root canals were selected based on micro-CT ( μCT ) scans . The mesial canals were instrumented to an apical diameter ISO30 using ProTaper rotary files . Teeth were r and omly assigned to three irrigant activation groups ( n = 10 ) : ultrasonically activated irrigation ( UAI ) using a size 20 Irrisafe for 3 × 20 s , laser-activated irrigation ( LAI ) with an Er : YAG laser ( 2940 nm ) and plain 300 μm fiber tip inside the canal ( 20 mJ , 20 Hz , 3 × 20 s ) , and laser-activated irrigation with identical parameters with a 400 μm photon-induced photoacoustic streaming ( PIPS ) tip held at the canal entrance . All teeth were scanned with μCT before and after instrumentation and after irrigant activation . After reconstruction and image processing , the canal system volume filled with hard tissue debris before and after irrigant activation was calculated . Changes in hard tissue debris volumes were compared between groups using one-way ANOVA . The percentage volume of hard tissue debris ( vol% ) was significantly lower after irrigant activation in all groups . Although the lowest debris values were observed in the laser groups , no significant differences in the vol% of accumulated hard tissue debris after activation were observed between groups . Accumulated hard tissue debris was reduced significantly in all activation groups . Ultrasonically and laser-activated irrigation regimens performed similarly in this respect . None of the tested methods was able to render the root canal systems free of debris INTRODUCTION Studies using conventional endodontic protocol s show insufficient cleaning of root canal systems , often result ing in persistent infection and treatment failure . The GentleWave System ( GWS ; Sonendo , Inc , Laguna Hills , CA ) has been shown to result in a higher tissue dissolution rate in a study using bovine muscle . The purpose of this study was to compare the debridement efficacy of the GWS with a traditional method for cleaning root canals . METHODS Forty-five freshly extracted molars were r and omly separated into 3 treatment groups ( n = 15/group ) : group 1 , no treatment ; group 2 , conventional rotary instrumentation and needle irrigation ; and group 3 , minimal instrumentation and the GWS treatment . Roots were prepared per st and ard histologic tissue processing after hematoxylin-eosin staining ; sections were microscopically examined , and the percentage of soft tissue and debris remaining within the canals was morphometrically calculated . Images of the apical and middle regions of the roots were blindly analyzed . RESULTS Significant differences ( Welch 's t test ) were found between groups 2 and 3 in both apical ( P = .0015 ) and middle ( P = .0179 ) regions of the mesial roots of m and ibular molars and mesiobuccal roots of maxillary molars . Groups 2 and 3 result ed in cleaning 67.8 % and 97.2 % of the mesiobuccal and mesiolingual root canals of m and ibular molars and the mesiobuccal canals of maxillary molars , respectively , whereas the results were similar among groups 2 and 3 in the apical and middle regions of distal roots . Groups 2 and 3 revealed significantly less debris than group 1 ( P < .005 ) . CONCLUSIONS The GWS showed a significantly greater cleaning capacity and reduction in residual debris within the mesiobuccal and mesiolingual canals of m and ibular molars and the mesiobuccal canals of maxillary molars than those cleaned conventionally Ninety-four single-canal roots were prepared using the step-down technique . Forty-two canals were irrigated with 2 % chlorhexidine , 42 canals with 5.25 % sodium hypochlorite ( NaOCl ) , and 10 control canals  with phosphate-buffered saline ( PBS ) . The chlorhexidine and NaOCl groups were each then equally divided into a final irrigation group and a 1-min passive ultrasonic irrigation group . Canals were enlarged with a Parapost drill . The apical 3 - 5 mm was covered with nail polish . Canals were rinsed with PBS , dried , refilled with PBS , and stored . At 6 h , 20 microl of fluid was pipetted from each canal and placed into wells on agar plates , which were inoculated with Streptococcus sanguinis . The plates were incubated , and zones of inhibition were measured . Sampling was repeated at 24 , 48 , 72 , 96 , 120 , 144 , and 168 h. Residual antimicrobial activity with 2 % chlorhexidine was statistically significantly superior to 5.25 % NaOCl with irrigation alone and with final passive ultrasonic activation ( p < 0.001 ) . Chlorhexidine experimental groups demonstrated residual antimicrobial activity for as long as 168 INTRODUCTION The aim of this study was to compare the outcome of a root canal treatment with and without additional ultrasonic activation of the irrigant . METHODS Single-rooted teeth with radiographic evidence of periapical bone loss were r and omly assigned to 2 treatment groups . In both groups syringe irrigation was performed , and in one group the irrigant was also activated by ultrasound . Ten to 19 months after treatment , the teeth were examined by using periapical radiography ( PA ) and cone-beam computed tomography ( CBCT ) . Area and volume of the periapical lesions were measured , and the outcome was presented in 4 categories : absence , reduction or enlargement of the radiolucency , or uncertain . Lesions were classified as reduced or enlarged when the change in size of the radiolucency was 20 % or more . RESULTS The recall rate was 82 % , and 84 teeth were analyzed . CBCT detected significantly more post-treatment lesions than PA ( P = .038 ) , but the percentages of absence and reduction of the radiolucency together revealed by CBCT and PA were similar ( P = .383 ) . The CBCT results showed that absence of the radiolucency was observed in 16 of 84 teeth ( 19 % ) and reduction of the radiolucency in 61 of 84 teeth ( 72.6 % ) , but there was no significant difference between the results of the 2 groups ( P = .470 ) . Absence and reduction of the radiolucency together were observed in the ultrasonic group in 39 of 41 teeth ( 95.1 % ) and in the syringe group in 38 of 43 teeth ( 88.4 % ) . CONCLUSIONS Root canal treatments with and without additional ultrasonic activation of the irrigant contributed equally to periapical healing Background Root 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 aim ed to evaluate the effectiveness of the EndoVac irrigation system , regarding 1 ) debris removal and 2 ) the control of apically extruded irrigating solution . Methods Fifty extracted human single-rooted teeth were used in this study . The teeth were then r and omly 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 . Results EndoVac 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 . Conclusions The 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 The purpose of this study was to evaluate and compare the postoperative level of pain after activation of irrigants using EndoActivator with conventional needle irrigation during root canal therapy . In this prospect i ve r and omised clinical trial , 72 symptomatic irreversible pulpitis patients were selected . Based on block r and omisation after routine root canal preparation , patients were assigned to two groups . In group EN , procedures were performed with endodontic irrigating needle ( n = 36 ) while group EA received activation using EndoActivator ( n = 36 ) in the final irrigation protocol . All the participants were called through phone at 8 , 24 and 48 h to analyse pain score using visual analogue scale . Those patients who developed pain were prescribed ibuprofen 200 mg . Pain score and frequency of tablet intake were recorded and statistically analysed . Results showed that group EA result ed in significantly less postoperative pain and analgesics intake than group EN . In conclusion , within the limitations of this study , the activation of irrigants using EndoActivator can be considered an effective method for reducing postoperative pain The study involved 300 elderly patients with chronic periapical periodontitis . The patients were r and omly assigned into three groups . The treatment for group A used a Mtwo Ni-Ti rotary instrument combined with ultrasonic irrigation of a 2.5 % NaOCl solution . The group B used the same instrument combined with ultrasonic irrigation of an active silver ion antibacterial solution . The group C used the same instrument combined with syringe irrigation of a 2.5 % NaOCl solution . The root canal fillings were performed immediately after canal preparation . Twenty-four hours after the procedure , patients self-assessed pain levels according to the VAS table . The three groups returned after seven days so their postoperative acute reactions could be evaluated clinical ly . After six and twelve months , efficacy was evaluated . The self-assessed pain levels for group A and B were significantly lower than group C. The incidence of postoperative acute reactions after seven days for group A and B were significantly lower than those of group C. The effective rates after six and twelve months did not differ among these groups . The single-visit root canal treatment with a nickel-titanium rotary instrument combined with ultrasonic irrigation for elderly patients with chronic periapical periodontitis achieved short and long term efficacy and stability INTRODUCTION Root canal irrigation carries a risk of extrusion of irrigant into the periapical tissues . The objective of this study was to compare different irrigation systems in matched pairs of teeth prepared to an apical size of 35.06 and 50.06 by measuring the frequency and extent of apical extrusion of sodium hypochlorite ( NaOCl ) into a simulated periapical environment . The null hypothesis was tested that there is no difference between systems . METHODS Bilaterally matched pairs ( n = 10 ) of single-canal extracted human anterior teeth were instrumented to an apical size of either 35.06 or 50.06 . Teeth were embedded in a gel containing the pH-sensitive dye M-cresol purple that changes from yellow at pH 7.4 to purple at pH 9 . Root canals were irrigated with 6 % NaOCl ( pH 11 ) by using EndoActivator ( EA ) , EndoVac ( EV ) , Rispi-Sonic/MicroMega 1500 ( MM ) , passive ultrasonic irrigation ( PUI ) , and syringe irrigation with a slot-tipped needle ( SN ) , so that each tooth underwent all irrigation procedures in a r and omized crossover design . Apical extrusion was evaluated by image analyses . RESULTS The frequency of extrusion was less in teeth with apical preparation size 35.06 ( 36 % ) compared with 50.06 ( 60 % ) ( P = .014 ) and was dependent on the irrigation system in 35.06 ( P = .039 ) but not 50.06 groups . In the 35.06 group the frequency of extrusion was less for EV than for MM and SN ( both P = .029 ) . The extent of extrusion was less for MM compared with PUI ( P = .024 ) and SN ( P = .046 ) in the 35.06 group and greater for SN compared with all other systems in the 50.06 group ( P < .05 ) . The null hypothesis was rejected . CONCLUSIONS The frequency of apical extrusion of NaOCl was dependent on the type of root canal irrigation system and apical preparation size . The extent of extrusion depended on the irrigation system , with syringe and slotted-needle irrigation result ing in the greatest extent of extrusion This study histologically compared the in vivo debridement efficacy of h and /rotary canal preparation versus a h and /rotary/ultrasound technique in mesial root canals of vital m and ibular molars . Group 1 consisted of 16 teeth prepared with a h and /rotary technique  whereas group 2 consisted of 15 teeth  prepared in similar fashion but followed by 1 min of ultrasonic irrigation , per canal , utilizing an ultrasonic needle in a MiniEndo unit . Five uninstrumented m and ibular molars served as histologic controls . After extraction and histologic preparation , 0.5 microm cross-sections , taken every 0.2 mm from the 1- to 3-mm apical levels , were evaluated for percentage of tissue removal . Nonparametric analysis revealed mean percent canal and isthmus cleanliness values to be significantly higher for group 2 at all levels evaluated , except one . In conclusion , the 1 min use of the ultrasonic needle after h and /rotary instrumentation result ed in significantly cleaner canals and isthmuses in the mesial roots of m and ibular molars INTRODUCTION Recent in vitro studies that use an apical negative pressure irrigation system , EndoVac , have demonstrated promising results in the production of debris-free root canals , while also preventing potential extrusion of irrigants into the periapical region . We conducted a r and omized , controlled , prospect i ve clinical study to determine whether the use of EndoVac irrigation ( EndoVac group ) was more efficient compared with st and ard needle irrigation ( control group ) in obtaining canals from which microbes could not be cultivated . METHODS Routine endodontic therapy was performed in 48 patients with necrotic , single-rooted , single-canal teeth . The patients were r and omly assigned to either the EndoVac group ( n = 25 ) or control group ( n = 23 ) . Irrigation with either method was carried out with 0.5 % sodium hypochlorite . After surface disinfection , before instrumentation and on completion of chemomechanical preparation , intracanal microbial sample s were obtained and cultured under anaerobic conditions . The frequency of microbial cultivability by using either irrigation system was analyzed . RESULTS The frequency of obtaining culture-negative root canals was 90.9 % and 82.6 % for the control group and EndoVac group , respectively . There was no significant difference in the antimicrobial efficacy of either control group or EndoVac group ( Fisher exact test , P = .665 ) . Furthermore , no significant association between study variables and the irrigation systems ' antimicrobial efficacy was found ( P > .05 ) . CONCLUSIONS The results of this prospect i ve in vivo study demonstrate that the antimicrobial efficacy of EndoVac irrigation is comparable to that of st and ard irrigation This study histologically compared the in vivo debridement efficacy of the step-back preparation versus a step-back/ultrasound preparation in the mesial root canals of vital m and ibular molars . Group 1 consisted of 17 teeth prepared with a step-back technique using intermittent irrigation with 5.25 % sodium hypochlorite . Group 2 consisted of 17 teeth prepared with a step-back technique as in group 1 followed by 3 min of ultrasonic instrumentation per canal utilizing a # 15 Endosonic file in an Enac unit set at 3.5 . An additional 6 ml/canal of 5.25 % sodium hypochlorite was used during the ultrasonic preparation .  Eight uninstrumented m and ibular molars served as histological controls . Following extraction and histological preparation , 0.2-microns cross-sections from the 1- to 3-mm apical levels of the canal and isthmus were evaluated for percentage of tissue removal using an Olympus CUE-2 Image Analysis System . Factorial analysis of variance indicated canal and isthmus cleanliness values were significantly higher , at all 11 apical levels , with the ultrasonic technique . Sample values at the 1- , 2- , and 3-mm levels for the step-back and step-back/ultrasonic techniques , respectively , were : canal , 64 % versus 92 % , 81 % versus 97 % , and 90 % versus 99.9 % ; isthmus , 2 % versus 46 % , 15 % versus 60 % , and 16 % versus 83 % INTRODUCTION Many in vitro studies have debated over the ability of different irrigant delivery and /or agitation systems to reach the apical third of curved root canals ; however , little is known about irrigant penetration in vivo . Therefore , the purpose of this study was to compare the efficacy of the conventional endodontic irrigation needle , passive ultrasonic irrigation ( PUI ) , and a negative pressure system for irrigant delivery to working length ( WL ) of mesial canals of m and ibular molars . METHODS Thirty mesial canals of 30 vital m and ibular first or second molars were r and omly assigned into 3 groups ( n = 10 ) : ( 1 ) Monoject syringe with 27-gauge needle ; ( 2 ) PUI with IrriSafe tip ; and ( 3 ) EndoVac system . All canals were treated following the same preparation protocol to size 35/0.04 by using 5.25 % NaOCl as irrigant during preparation procedure . Before obturation , canals were irrigated with 1 mL of a radiopaque solution by using the assigned irrigation system , and a digital radiograph was taken by using a parallel technique . With the aid of image editing software the distance between WL and maximum irrigant penetration was measured . RESULTS Mean distances for Monoject , PUI , and EndoVac groups were 1.51 mm , 0.21 mm , and 0.42 mm , respectively . Analysis of variance test showed statistically significant differences between groups ( P < .001 ) . Tukey honestly significant difference test showed statistically significant differences between the Monoject group and the other 2 groups ( P < .001 ) but no significant differences between PUI and EndoVac groups ( P = .06 ) . CONCLUSIONS PUI and EndoVac are more effective than the conventional endodontic needle in delivering irrigant to WL of root canals The purpose of this prospect i ve , r and omized , single-blind study was to compare the in vivo antibacterial efficacy of a h and /rotary technique versus a h and /rotary/ultrasound technique in mesial root canals of necrotic m and ibular molars . The h and /rotary group consisted of 16 mesial roots prepared with a h and /rotary technique .  The h and /rotary/ultrasound group consisted of 15 mesial roots prepared similarly , followed by 1 minute of ultrasonic irrigation per canal with an ultrasonic needle in a MiniEndo unit and 15 mL/canal of 6.0 % sodium hypochlorite . Canals were sample d before and after instrumentation and after 1 minute of ultrasonic irrigation . Sample s were incubated anaerobically on reduced blood agar for 7 days at 37 degrees C , and colony-forming units ( CFUs ) were counted . The addition of 1 minute of ultrasonic irrigation result ed in significant ( p = .0006 ) reduction in CFU count and positive cultures ( p = .0047 ) . Logistic regression analysis indicated the addition of ultrasonic irrigation was 7 times more likely to yield a negative culture AIM To evaluate via a r and omized clinical trial the effect of continuous ultrasonic irrigation ( CUI ) on  postoperative pain in m and ibular molars with nonvital pulps . METHODOLOGY Seventy m and ibular molars with nonvital pulps and apical periodontitis were treated endodontically using two different irrigation techniques . The patients were r and omly allocated to one of two groups , CUI ( n = 35 ) and syringe irrigation ( SI ) ( n = 35 ) . The CUI group received irrigant activation using a Proultra Piezoflow ultrasonic needle as the final irrigation protocol , whilst in the SI group , the final irrigation was performed using 27-gauge needle . All the patients were prescribed ibuprofen 400 mg to be taken every 8 h , if required . Postoperative pain using a visual analog scale and analgesic intake were recorded everyday for 7 days . Data were analysed using chi-Square , Mann-Whitney and multiple linear regression tests . RESULTS Mean postoperative pain was lower in the CUI as compared to SI group , but the difference was significant on the first day only ( P = 0.032 ) . The overall 24-h pain prevalence was 41.4 % . CUI had a lower incidence of pain ( 31.4 % ) as compared to the SI group ( 51.4 % ) , but the difference was not significant ( P > 0.05 ) . No significant difference was observed in analgesic consumption between the groups ( P > 0.05 ) . Regression analysis revealed a significant association of mean postoperative pain at 24 h with the irrigant protocol ( P = 0.017 ) and preoperative pain ( P = 0.000 ) . CONCLUSION A significant difference was observed between CUI and syringe irrigation on the first postoperative day following chemo-mechanical preparation . However , the benefit observed was not clinical ly relevant OBJECTIVE Recent studies have shown that the apical negative-pressure irrigation system EndoVac ( Discus Dental ) produces better disinfection and cleanliness at the apical third of root canals than current irrigation methods using positive pressure . The aim of this histologic study was to compare the EndoVac system at two different exposure times to the traditional positive-pressure irrigation technique for root canal cleaning efficacy and to measure the volume of irrigation at the apical third . METHOD AND MATERIAL S Fifty extracted human incisors , canines , and premolars ( with one canal ) were used . All teeth were stored in sterile saline and then r and omly assigned to one of three experimental groups of 15 each . All teeth were cleaned and shaped at working length using Profile Series 29 ( Dentsply Tulsa ) to a size 6 ( ISO size 36 ) or larger depending on the first instrument to bind at the apical third . After working length was reached with the master apical file , apical irrigation was accomplished with 6 % sodium hypochlorite ( NaOCl ) over a predetermined time for each group as follows : group 1 , EndoVac for 210 seconds ; group 2 , EndoVac for 150 seconds ; group 3 , traditional positive-pressure irrigation for 210 seconds . The amount of debris left in the canals was quantified at 1 and 3 mm from working length . RESULTS No statistical differences were found at 3 mm from working length . At 1 mm from working length , an overall test of association was significant when comparing across the three groups ( P = .03 ) . CONCLUSION The apical negative-pressure irrigation system EndoVac has the potential to achieve significantly better root canal cleaning at the apical third of root canals and in less exposure time than required with traditional positive-pressure irrigation Introduction : This study compared the effect of conventional needle irrigation ( positive pressure ) and the EndoVac system ( Discus Dental , Culver City , CA ) ( negative pressure ) on postoperative pain in m and ibular molar teeth with symptomatic irreversible pulpitis . Methods : One hundred sixteen patients with symptomatic irreversible pulpitis were selected . Teeth were r and omly assigned to 2 groups according to the irrigation methods performed during root canal preparation . In group 1 , root canal irrigation was performed using a syringe and a 31‐G side‐port needle ( NaviTip ; Ultradent , South Jordan , UT ) . In group 2 , the EndoVac system was used for irrigation . Teeth were then obturated with gutta‐percha and a resin‐based sealer using the cold lateral compaction technique .  The presence of postoperative pain was assessed after 6 , 24 , 48 , and 72 hours and 1 week . Results : At 6‐ , 24‐ , and 48‐hour time intervals , group 1 patients reported more intense postoperative pain than patients in group 2 ( P < .05 ) . There was no significant difference between the 2 groups at the other time intervals ( P > .05 ) , and in both groups the intensity of postoperative pain decreased over time . Conclusions : Apical positive pressure irrigation caused greater postoperative pain after endodontic therapy of m and ibular molar teeth with symptomatic irreversible pulpitis compared with the apical negative pressure irrigation system Introduction This study compared the effect of several final irrigation agitation techniques ( sonic agitation , passive ultrasonic irrigation , and manual dynamic agitation [ MDA ] ) in comparison with needle irrigation on postoperative pain in m and ibular molar teeth with symptomatic irreversible pulpitis . Methods One hundred sixty‐eight patients with a single tooth diagnosed as symptomatic irreversible pulpitis were selected . Teeth were r and omly assigned to 4 groups based on the final irrigation methods . In group 1 ( needle irrigation ) , irrigation was conducted without agitation with a side‐port needle ; in group 2 , sonic agitation was used ; in group 3 , passive ultrasonic irrigation was used ; and in group 4 , MDA was used . Teeth were then obturated with gutta‐percha and a resin‐based sealer using the cold lateral compaction technique .  The presence of postoperative pain was assessed after 6 , 24 , 48 , and 72 hours and 1 week . Results At the 6‐ and 24‐hour time intervals , group 4 patients reported more intense postoperative pain than those patients in groups 1 , 2 , and 3 ( P < .05 ) . There was no significant difference among the groups at the other time intervals ( P > .05 ) , and in all groups the intensity of postoperative pain decreased over time . Conclusions MDA caused greater postoperative pain after endodontic therapy in m and ibular molar teeth with symptomatic irreversible pulpitis compared with the other methods in the first 24 hours AIM To compare the efficacy of three irrigation protocol s using an established ex vivo bio-molecular film model . METHODOLOGY Thirty human teeth with single straight canals were r and omly allocated to three groups [ static , manual-dynamic , automated-dynamic ( RinsEndo ] ; each with a sub-group ( n = 5 ) for needle position at 4 or 10 mm short of the working length ( WL ) . The root canals were prepared to apical size 40 , taper 0.08 . The teeth were split longitudinally into two halves and a st and ard coat of stained-collagen was applied to the canal surfaces . The re-assembled teeth were irrigated using one of the protocol s with the irrigation needle at one of two positions . Digital images of the canal surfaces , before and after irrigation with 18 mL of 2.5 % NaOCl , were used to score surface coverage with stained-collagen using image-analyses ( ipWin4 ) . The data were analysed using linear regression models . RESULTS The canal area covered with stained-collagen was significantly ( P < 0.001 ) less after dynamic irrigation ( manual/automated ) compared with static irrigation ; but automated-dynamic irrigation was significantly ( P = 0.037 ) less effective than manual-dynamic irrigation . The ' orientation of needle port ' , ' corono-apical level of canal ' and ' apical extent of needle placement ' were significant ( P < 0.001 ) factors influencing efficacy of irrigation . Residual collagen was most evident in the coronal third . Deeper penetration of the needle tip result ed in significantly ( P < 0.001 ) more effective collagen removal . CONCLUSIONS Automated-dynamic irrigation was significantly more effective ( 16 % ) than static irrigation but significantly less effective ( 5 % ) than manual-dynamic irrigation . Irrigation was more effective ( 7 % ) when the needle was placed closer to WL
target: Results showed that mechanical active irrigation reduces post-operative pain .
  It improved debridement , canal/isthmus cleanliness .
  It also improved delivery of irrigant up to working length .
  Bacterial count was more with active irrigation , though not significant .
  There is no effect on long-term periapical healing .
  Conclusion It may be concluded that mechanical active irrigation devices are beneficial in reducing post-operative pain and improving canal and isthmus cleanliness during Endodontics
background: Objective Irrigant activation has been cl aim ed to be beneficial in in vitro and clinical studies .
  This systematic review aims to investigate the clinical efficiency of mechanically activated irrigants and conventional irrigation .