Antimicrobial efficacy of two irrigation techniques in tapered and nontapered canal preparations: an in vitro study. A comparative study of the debridement efficacy and apical extrusion of dynamic and passive root canal irrigation systems Cleaning efficacy of an apical negative-pressure irrigation system at different exposure times. Influence of an apical negative pressure irrigation system on bacterial elimination during endodontic therapy: a prospective randomized clinical study. Microbiological evaluation of different irrigation protocols on root canal disinfection in teeth with apical periodontitis: an in vivo study. Different pharmacological solutions in intracanal irrigation. Postoperative pain after the application of two different irrigation devices in a prospective randomized clinical trial. Efficacy of a new brush-covered irrigation needle in removing root canal debris: a scanning electron microscopic study. Comparison of irrigant penetration up to working length and into simulated lateral canals using various irrigating techniques. Comparative evaluation of adjunctive oral irrigation in diabetics. Effectiveness of various irrigation activation protocols and the self-adjusting file system on smear layer and debris removal. Smear Layer Evaluation on Root Canal Preparation with Manual and Rotary Techniques using EDTA as an Irrigant: A Scanning Electron Microscopy Study. Radiographic comparison of three methods for nasal saline irrigation. 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 Final Irrigation Regimens Affect Fracture Resistance Values of Root-filled Teeth. Ability of chemomechanical preparation with either rotary instruments or self-adjusting file to disinfect oval-shaped root canals. Root canal debridement efficacy of different final irrigation protocols.
The aim of this in vitro study was to determine whether irrigation with apical negative pressure was more effective than traditional positive-pressure irrigation in eradicating Enterococcus faecalis from preshaped root canals . Fifty-four extracted m and ibular molars were instrumented to produce either a non-tapered or tapered preparation , sterilized , inoculated with E. faecalis for 30 days , and then r and omly assigned into the following groups : group 1 - -non-tapered preparation and negative-pressure irrigation , group 2 - -non-tapered preparation and positive-pressure irrigation , group 3 - -tapered preparation and positive-pressure irrigation , and group 4 - -tapered preparation and negative-pressure irrigation .  Mesial canals were sample d before and after final irrigation and sample s incubated aerobically for 48 hours at 37 degrees C. Scanning electron microscopic analysis confirmed dense bacterial colonies in the positive control , consistent with biofilm formation . A statistically significant difference was evident when comparing apical negative-pressure irrigation to positive-pressure irrigation ( p=0.004 ) . There was no statistically significant difference in colony-forming units ( CFUs ) between sizes # 35 and # 45 , nor between tapered and non-tapered preparation . The results of this in vitro study showed that apical negative-pressure irrigation has the potential to achieve better microbial control than traditional irrigation delivery systems 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 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 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 The present in vivo study was design ed to evaluate the efficacy of apical negative pressure irrigation ( ANP ) , passive ultrasonic irrigation ( PUI ) and positive pressure irrigation ( PP ) in the reduction of intracanal bacteria of dogs ' teeth with pulp necrosis and apical periodontitis . Eighty root canals were r and omly distributed into 3 experimental and 2 control groups according to the irrigation delivery system : group ANP ( n=20 ) , group PUI ( n=20 ) , group PP ( n=20 ) , group PC ( positive control - sterile saline irrigation ; n=10 ) and group NC ( negative control - vital pulps not subjected to bacterial inoculation ; n=10 ) . The first sample ( S1 ) was collected at baseline , and the second sample ( S2 ) was collected after the disinfection protocol s. All sample s were seeded in culture media for anaerobic bacteria . CFU counts were analyzed statistically by the Kruskal-Wallis , Dwass-Steel-Critchlow-Fligner post-hoc and Chi-square followed by Tukey like multiple comparisons for proportions ( α=0.05 ) . All experimental groups were effective in reducing Gram-positive bacteria compared with PC ( p<0.05 ) . Regarding the reduction of Gram-negative bacteria , group ANP was significantly better than PP ( p<0.05 ) . No statistically significant difference could be found between PP and PUI ( p>0.05 ) . In dog 's teeth with apical periodontitis , the use of ANP and PUI can be considered promising disinfection protocol s as both delivery systems promoted a significant bacterial reduction Irrigation of root canals during endodontic therapy is an important step . Sodium hypochlorite ( NaOCl ) , hydrogen peroxide ( H2O2 ) , chlorhexidine ( CHX ) and normal saline are commonly used intracanal irrigants to disinfect and clean the root canals . This prospect i ve study was set to observe the efficacy of normal saline ( 0.9 % NaCl ) irrigation with sequential irrigation of 3 % H2O2 , 5.2 % NaOCl and 0.9 % NaCl .  A total number of 228 dental patients were screened and 104 patients fulfilling the inclusion criteria were enrolled for the endodontic therapy of mature permanent teeth for the period of one year . Two treatment groups were constituted in which patients were r and omly allocated equally in each treatment group . Post-obturation pain , swelling , analgesic use and eight weeks post-obturation radiological evaluation of the patients were carried out as the measurement of clinical and radiological success of the endodontic treatment . No statistically significant differences were observed in the measured treatment outcomes between two groups . However , studies involving larger sample size and longer post-obturation follow up are recommended for the further either confirmation or rejection of present findings 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 The usefulness of NaviTip FX , a brush-covered irrigation needle , in endodontic therapy has never been reported . Therefore , the purpose of this investigation was to evaluate the cleaning efficacy of this new brush-covered irrigation needle , the NaviTip FX .  Thirty single-rooted teeth were r and omly divided into two equal groups and instrumented using the crown-down technique with 0.04 taper ProFile . Following each file use , the canals were irrigated with 1 ml of 5.25 % NaOCl using the NaviTip FX needle for group 1 or using the same needle without the brush for group 2 . At the end of instrumentation , the roots were cut longitudinally and each half was divided into three equal parts . The specimens were then routinely prepared for scanning electron microscopic evaluation . The results showed that using the NaviTip FX produced cleaner coronal thirds of instrumented root canals compared to the control group . On the other h and , the middle and apical thirds were not statistically significantly different between the two groups . Further development of this irrigation technique to improve cleanliness of the apical and middle thirds is required before the NaviTip FX can be recommended for routine use during root canal therapy AIM To evaluate the effect of an apical negative pressure system , a passive ultrasonic irrigation system and a combination of both apical negative pressure and passive ultrasonic irrigation on the penetration of the  irrigating contrast solution ( ICS ) up to working length and into simulated lateral canals . METHODOLOGY The root canals of 64 single-rooted teeth were instrumented using the ProTaper rotary system . In each sample , three simulated lateral canals were created at 2 , 4 and 6 mm levels from the root apex using a 06-size C+ file ( Dentsply Maillefer , Ballaigues , Switzerl and ) . Sample s were r and omly assigned into 4 experimental groups ( n = 16 ) : group I - conventional needle irrigation , group II - passive ultrasonic irrigation , group III - apical negative irrigation system and group IV - combination of passive ultrasonic irrigation and apical negative pressure irrigation system . To examine irrigating solution penetration , Indian ink was mixed with 5.25 % NaOCl and delivered into the root canals . Sample s were then assessed by direct observation of the images taken using Canon EOS rebel T3 . The depth of penetration of ICS up to the working length and into the simulated lateral canals was analysed using chi-squared tests . RESULTS The combination ( ANP and PUI ) and ANP group had significantly deeper ICS penetration up to the working length ( P < 0.001 ) . The combination ( ANP and PUI ) and the PUI group exhibited significantly greater ICS penetration into lateral canals at the 6 mm level ( P < 0.001 ) . At the 4 and 2 mm levels , the combination of ANP and PUI had significantly greater ICS penetration into the lateral canals than the other groups ( P < 0.001 ) . CONCLUSIONS The combination of ANP and PUI was the only group able to achieve irrigating contrast solution penetration both up to the working length and into lateral canals AIM The purpose of this study was to assess the response of diabetics to scaling and root planing treatment and subgingival oral irrigation as adjunctive therapy . METHOD A total of 52 type 1 and 2 diabetics ( mean age 51.3+/-14 ) with adult periodontitis were r and omized to two groups . Treatment included ultrasonic scaling and scaling and root planing in both groups ( control and test ) plus subgingival water irrigation 2x daily for the test group . Assessment s were made prior to and at 6 and 12 weeks after treatment . Parameters measured were modified gingival index ( MGI ) , probing pocket depth ( PPD ) , plaque index ( PI ) , clinical attachment level ( CAL ) , and bleeding on probing ( BOP ) . Systemic measurement of Reactive Oxygen Species ( ROS ) generation , cytokines ( TNF-alpha , IL-1beta , IL-10 , and PGE2 ) , and glycated hemoglobin ( HbA1C ) . RESULTS After treatment , analysis of data showed that both groups had clinical and systemic improvement . The test group had a statistically significant reduction for MGI , PI , and BOP compared to controls ( p<0.03 ) at 12 weeks and for ROS generation at 12 weeks ( p<0.012 ) . Unlike controls , systemic analysis of cytokines showed a statistically significant reduction from baseline for IL-1beta at 6 weeks and PGE2 at 6 and 12 weeks ( p<0.05 ) within test group . CONCLUSION These results suggest that scaling and root planing and adjunctive therapy may be of value in establishing a healthy periodontium in diabetics The purpose of the present study is to evaluate smear layer generation and residual debris after using self-adjusting file ( SAF ) or rotary instrumentation and to compare the debris and smear layer removal efficacy of the SAF cleaning/shaping irrigation system against final agitation techniques . One hundred and eight maxillary lateral incisor teeth were r and omly divided into nine experimental groups ( n = 12 ) , and root canals were prepared using ProTaper Universal rotary files , with the exception of the SAF instrumentation group . During instrumentation , root canals were irrigated with a total of 16 mL of 5 % NaOCl . For final irrigation , rotary-instrumented groups were irrigated with 10 mL of 17 % EDTA and 10 mL of 5 % NaOCl using different irrigation agitation regimens ( syringe irrigation with needles , NaviTip FX , manual dynamic irrigation , CanalBrush , EndoActivator , EndoVac , passive ultrasonic irrigation ( PUI ) , and SAF irrigation ) . In the SAF instrumentation group , root canals were instrumented for 4 min at a rate of 4 mL/min with 5 % NaOCl and received a final flush with same as syringe irrigation with needles . The surface of the root dentin was observed using a scanning electron microscope . The SAF instrumentation group generated less smear layer and yielded cleaner canals compared to rotary instrumentation . The EndoActivator , EndoVac , PUI , and SAF irrigation groups increased the efficacy of irrigating solutions on the smear layer and debris removal . The SAF instrumentation yielded cleaner canal walls when compared to rotary instrumentation . None of the techniques completely removed the smear layer from the root canal walls INTRODUCTION The aim of any root canal treatment is to achieve a canal free of micro organisms , residual pulp remnants , debris and smear layer for the long term success of the procedure . Manual and automated instrumentation techniques along with proper irrigation regime is used to arrive at the aforementioned goal . Many authors focused on the preparation capabilities of various manual and rotary instruments but very few investigators stressed on the actual cleaning abilities of these instruments . AIMS AND OBJECTIVES This study was undertaken to evaluate the cleaning efficiency of manual K flex files and rotary Pro File systems in the root canals using a scanning electron microscope . MATERIAL AND METHODS Thirty single rooted m and ibular first premolars were divided into two groups and r and omized ( the manual group-M and the ProFile group-P ) with respect to the preparation technique . The Manual group was h and instrumented with stainless steel K- Flexofiles by means of a conventional filing technique . The Pro File group was instrumented according to the manufacturer 's instructions using a rotary h and piece . All canals were shaped and cleaned under frequent irrigation with EDTA . Final irrigation was carried out with 3 mL of normal saline solution to neutralize the action of the irrigant . The roots were split , one half of each tooth was selected for further SEM technique analysis and examined under the scanning electron microscope . The canal walls were quantitatively evaluated for the amount of debris and smear layer . The apical , middle and coronal regions of the canal surface , were grade d ( 1 - 5 ) for debris and smear layer . A statistical analysis was performed using a Mann-Whitney Rank Sum test . ProFile performed least effective cleaning . Manual K-Flexofiles led to a grooved pattern . RESULTS AND CONCLUSION A statistically significant difference was observed ( p<0.05 ) between the two instrumentation techniques concerning the amount of debris and smear layer at the apical level . The manually filed canals had less debris and smear layer than those using a rotary technique . It was concluded from this study that none of the instrumentation techniques employed , produced the canal walls which were free of surface debris and smear layer . The manual instrumentation technique was better in cleaning the canals compared to the ProFile rotary Ni-Ti instruments despite the step-back technique used for manual instrumentation . How to cite this article : Manjunatha M , Kini A , Sudhakar V , Sunil K V C , Hiremath V K , Shah A. Smear Layer Evaluation on Root Canal Preparation with Manual and Rotary Techniques using EDTA as an Irrigant : A Scanning Electron Microscopy Study . J Int Oral Health 2013 ; 5(1):66 - 78 OBJECTIVE To compare intranasal distribution of saline solution delivered by three popular methods for nasal saline irrigation . STUDY DESIGN Prospect i ve , controlled comparison . METHODS Eight healthy adult volunteers received nasal irrigation with 40 mL of isotonic , nonionic contrast material immediately before having coronal computed tomography to visualize distribution of solution in the paranasal sinuses . For each study subject , three methods of irrigation were used : irrigation using positive-pressure irrigation , irrigation using negative-pressure irrigation , and irrigation using a nebulizer . For each subject , three-dimensional computer reconstructions of the irrigated paranasal sinus airspaces were used to compare contrast solution volume and distribution achieved by the three methods . RESULTS Of the three methods used , two methods , positive-pressure and negative-pressure irrigation , distributed contrast solution widely to ethmoid and maxillary sinuses , but distribution of contrast solution was more uniform using positive-pressure irrigation than using negative-pressure irrigation . The nebulization method distributed contrast solution poorly and result ed in a significantly lower volume of retained contrast solution ( P < .05 ) . CONCLUSION Judged solely on the basis of solution distribution in the nasal sinuses , nasal irrigation is effective when either positive-pressure or negative-pressure irrigation is used but is ineffective when a nebulizer is used 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 The purpose of this study was to compare the effect of different final irrigation solutions on fracture resistance values ( FRVs ) of endodontically treated teeth . METHODS Eighty extracted decoronated human incisors were used . Ten r and omly selected roots were used as the negative control group . The remaining roots were prepared by the ProTaper system ( Dentsply Maillefer , Ballaigues , Switzerl and ) up to F2 . Ten prepared roots were selected as the positive control . The other prepared roots were divided into 6 ( n = 10 ) groups according to the final irrigation solution used : 5 mL saline , 17 % EDTA , EDTA with a surfactant ( REDTA ) , chlorhexidine , QMix ( Dentsply Tulsa Dental Specialties , Tulsa , OK ) , and BioPure MTAD ( Dentsply Tulsa Dental Specialties ) . In all groups , the final irrigation was performed for 1 minute except for the BioPure MTAD group ; in this group , it was applied for 5 minutes according to the manufacturer 's instructions . The specimens were filled with a single gutta-percha cone and AH 26 sealer ( Dentsply , De Trey , Konstanz , Germany ) . After being stored under 37 ° C and 100 % humidity for a week , the specimens were loaded in a vertical direction at 1 mm/min speed until they were vertically fractured . The results were analyzed by the Kruskal-Wallis and Siegel Castellan tests . RESULTS The negative control group showed the highest FRV . There were statistically significant differences between the negative and positive control groups ( P < .05 ) . Specimens irrigated with REDTA and QMix showed a higher FRV compared with the positive control group ( P < .05 ) . Specimens exposed to chlorhexidine and BioPure MTAD showed a lower FRV compared with the negative control group ( P < .05 ) . CONCLUSIONS Root canal preparation weakens the tooth . The final irrigation regimen has an impact on the FRV . A short time exposure to irrigation solutions ( REDTA and QMix ) that include surfactants probably contributed to the higher FRV , instead of a long time exposure as done with BioPure MTAD 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 AIM To compare the smear layer and debris removal effectiveness of four root canal irrigation protocol s as well as their effectiveness in removing remaining soft tissues in curved root canals . METHODOLOGY The mesiobuccal and mesial root canals of 107 extracted human maxillary and m and ibular molars were instrumented using Mtwo rotary NiTi instruments then r and omly divided into four groups according to a final rinse protocol : Group 1 ( n = 28 ) - manual agitation of 1 % NaOCl and 15 % EDTA ; Group 2 ( n = 26 ) - CanalBrush agitation of 1 % NaOCl and 15 % EDTA ; Group 3 ( n = 26 ) - 3 % H(2 ) O(2 ) alternated with 1 % NaOCl ; Group 4 ( n = 27 ) - passive ultrasonic agitation of 1 % NaOCl and 15 % EDTA . All irrigation protocol s were performed in a closed system . Eleven roots per group were prepared and histologically stained ( H&E ) to assess percentage of remaining pulpal tissues in the apical thirds . The remaining specimens were split longitudinally and examined under scanning electron microscope at ×2000 magnification to assess smear layer and debris removal . Image Pro Plus 6.0 software was used to analyse smear layer and remaining pulp tissue . Debris presence was scored by two blinded investigators using a five-point scale . Data were analysed using Univariate analysis of variance ( GenStat 13 , α = 0.05 ) . RESULTS CanalBrush and passive ultrasonic irrigation were equally effective with significantly less smear layer and debris than manual agitation and H(2 ) O(2 ) alternated with NaOCl ( P < 0.05 ) . The H(2 ) O(2 ) alternated with NaOCl protocol was significantly more effective in removing pulp tissue remnants in the apical level than manual agitation ( P = 0.009 ) and passive ultrasonic irrigation ( P = 0.01 ) . CONCLUSIONS CanalBrush was as effective as passive ultrasonic irrigation in smear layer and debris removal . Alternating H(2 ) O(2 ) with NaOCl was effective in removing soft tissues from root canal complexities . Further studies are required to evaluate effectiveness of this regimen taking into account irrigant volume differences and effect of root canal system configuration
Inconclusive results were reported about the cleaning and disinfection accomplished by the two irrigation methods .
There is insufficient evidence to cl aim general superiority of any one of these methods .
The aim of this study was to systematic ally review and critically analyse the published data on the treatment outcome ( primary outcome ) and on the  cleaning and disinfection of root canals  ( secondary outcomes ) achieved by negative pressure irrigation as compared to syringe irrigation .