Cleaning efficacy of an apical negative-pressure irrigation system at different exposure times. A comparative study of the debridement efficacy and apical extrusion of dynamic and passive root canal irrigation systems Ability of chemomechanical preparation with either rotary instruments or self-adjusting file to disinfect oval-shaped root canals. Effectiveness of various irrigation activation protocols and the self-adjusting file system on smear layer and debris removal. Comparison of irrigant penetration up to working length and into simulated lateral canals using various irrigating techniques. Different pharmacological solutions in intracanal irrigation. Postoperative pain after the application of two different irrigation devices in a prospective randomized clinical trial. 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. Radiographic healing after a root canal treatment performed in single-rooted teeth with and without ultrasonic activation of the irrigant: a randomized controlled trial. Effect of irrigation technique for removal of triple antibiotic paste on bond strength of MTA to root dentin. Carisolv: an alternative to NaOCl in immature root canals? 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 Apical extrusion of sodium hypochlorite using different root canal irrigation systems. Smear Layer Evaluation on Root Canal Preparation with Manual and Rotary Techniques using EDTA as an Irrigant: A Scanning Electron Microscopy Study. In vivo efficacy of three different endodontic irrigation systems for irrigant delivery to working length of mesial canals of mandibular molars. Efficacy of the self-adjusting file system on cleaning and shaping oval canals: a microbiological and microscopic evaluation. Antimicrobial efficacy of two irrigation techniques in tapered and nontapered canal preparations: an in vitro study. A comparative study of the removal of smear layer by three endodontic irrigants and two types of laser. A bio-molecular film ex-vivo model to evaluate the influence of canal dimensions and irrigation variables on the efficacy of irrigation. Tissue response to root canal irrigation systems in dogs’ teeth with apical periodontitis Efficacy of irrigation systems on penetration of sodium hypochlorite to working length and to simulated uninstrumented areas in oval shaped root canals. An alternative regimen for root canal disinfection
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 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 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 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 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 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 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 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 This study evaluated the bond strength of mineral trioxide aggregate ( MTA ) to root canal dentin after the performance of various irrigation procedures to remove triple antibiotic paste ( TAP ) . A total of 56 single-rooted human m and ibular premolars were instrumented using a rotary system to size 40 and divided r and omly into a control group ( no intracanal dressing ) and three experimental groups ( TAP application for 28 days ) . TAP was then removed by rinsing with 10 mL 2.5 % NaOCl using three irrigation systems ( Vibringe sonic irrigation , CanalBrush , and syringe irrigation ) . The coronal and middle parts of root canals were then obturated with MTA . After storage for 1 week , each specimen was embedded in an acrylic block and sectioned horizontally ( 2-mm-thick slices ) at two levels ( coronal and middle ) . Bond strength of MTA to root canal dentin was assessed in 28 sample s per group via push-out test using a universal testing machine . Data from the four groups were compared using one-way analysis of variance . Tukey 's test was used for multiple comparisons . Push-out bond strength values were significantly higher in the control and Vibringe groups than in the CanalBrush and syringe irrigation groups ( p < 0.001 ) . TAP removal from root canals with the Vibringe irrigation system may increase the push-out bond strength of MTA compared with the use of the CanalBrush or syringe irrigation AIM To test the null hypothesis that Carisolv is no more effective than 1 % sodium hypochlorite in cleaning uninstrumented , immature root canals . METHODOLOGY A total of 240 uniform , immature ovine incisors were decoronated at the CEJ level and r and omly divided into four groups of 60 . After gross pulp extirpation , canals were flooded with normal saline ( negative control ) , 1 % NaOCl , Carisolv or 5 % NaOCl ( positive control ) and incubated for 10 min ( group 1 ) , 20 min ( group 2 ) , 30 min ( group 3 ) or 30 min , refreshing irrigant at 10 and 20 min ( group 4 ) . SEM photomicrographs of canal wall debris in the apical , middle and coronal thirds were scored against a 5-point scale . Internal consistency was assessed by kappa statistics . Debris scores for different irrigant regimes at different canal levels were analysed by non-parametric tests ( P < 0.05 ) . RESULTS Canals were consistently cleaner in the coronal and middle than apical thirds . NaOCl ( 5 % ) was consistently most effective . Carisolv and NaOCl ( 1 % ) were no more effective than normal saline in group 1 ( P > 0.05 ) , but significantly more effective than normal saline in groups 2 ( middle and apical 1/3 ) , 3 and 4 ( P < 0.05 ) . Carisolv and NaOCl ( 1 % ) had comparable activity in groups 1 , 2 ( middle and apical thirds ) and 3 , but NaOCl ( 1 % ) was significantly more effective than Carisolv in group 4 ( coronal and middle thirds ) . CONCLUSIONS 1 . The ovine incisor model presents opportunities to investigate irrigation regimes under controlled ex-vivo conditions . 2.NaOCl ( 5 % ) remains the most effective irrigant for rapid debris removal in immature root canals . 3 . Carisolv cleans pulp debris from the walls of immature root canals as effectively as NaOCl ( 1 % ) during static , unrefreshed wall contact for between 20 and 30 min . 4 . Refreshment of NaOCl ( 1 % ) enhances its cleaning ability above that of Carisolv 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 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 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 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 INTRODUCTION The shaping ability of root canal instruments is determined by a complex interrelationship of parameters such as cross-sectional design and the ability to remove debris and the smear layer . The self-adjusting file ( SAF ) consists of a hollow , flexible instrument in the form of a compressible , thin-walled , pointed cylinder . The aim of this study was to compare the SAF with the ProTaper rotary file system , evaluating debris and smear layer removal and the presence of bacteria by using microbiological and scanning electron microscopy ( SEM ) evaluation . METHODS Fifty maxillary premolars were inoculated with Enterococcus faecalis for 30 days and then r and omly distributed into 2 groups . Group 1 was prepared with ProTaper rotary instruments and irrigated with 30-gauge side-vented needles . Group 2 was prepared by using the SAF system with continuous irrigation . Bacteriologic sample s were taken before and after preparation . All sample s were then longitudinally split and analyzed under scanning electron microscopy . The scoring was carried out by 3 blinded evaluators . RESULTS In group 1 , 40 % of sample s had negative cultures with postinstrumentation sample s taken with paper points ( S2a ) and 45 % with postinstrumentation dentin sample s ( S2b ) . In group 2 , 20 % of sample s had negative cultures with S2a and 15 % with S2b . Intragroup analyses evaluating the reduction in the number of colony-forming units ( CFUs ) from S1 to S2a and S2b demonstrated both preparation techniques were highly effective ( P < .01 ) . Further reduction of CFUs was observed when comparing S2a and S2b in group 1 ( P < .05 ) , whereas no difference was observed in group 2 . Intergroup analysis demonstrated a statistically significant difference of CFUs at S2a and S2b ( P < .05 ) . SEM scores were consistent with the microbiology findings . CONCLUSIONS The SAF system does not allow control of the apical enlargement , thus limiting the ability of the irrigants to achieve effective and predictable disinfection 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 AIM The effects of three endodontic irrigants and two types of laser on a smear layer created by h and instrumentation were evaluated in vitro in the middle and apical thirds of root canals . METHODOLOGY Sixty human mature extracted m and ibular premolar teeth with a single root canal and a closed apex were distributed r and omly into five groups of 12 teeth each . Whilst cleaning and shaping up to a size 60 master apical file with a step-back technique , the root canals were irrigated with 3 mL of 5.25 % NaOCL and 3 % H2O2 , alternately , between each file size . Group 1 ( G1 ) were control specimens that were irrigated with a final flush of 17 % EDTA . The teeth in group 2 ( G2 ) were irrigated with a final flush of 6 % phosphoric acid , and group 3 ( G3 ) with 6 % citric acid . In the specimens of group 4 ( G4 ) the root canals were irradiated with a carbon dioxide ( CO2 ) laser , and specimens of group 5 ( G5 ) were irradiated using an Er : YAG laser . The teeth were split longitudinally and prepared for examination by scanning electron microscopy . RESULTS Control specimens ( G1 ) showed clean root-canal walls with open dentinal tubules in the middle one-third , but in some specimens thick smear layer was observed in the apical one-third . Specimens irrigated with a final flush of 6 % phosphoric acid ( G2 ) or 6 % citric acid ( G3 ) were cleaner than with 17 % EDTA , showing very clean root canal surfaces in the middle one-third but in the apical one-third the smear layer was not completely removed , especially at the openings of the dentinal tubules . The specimens irradiated with the CO2 laser ( G4 ) showed clean root-canal walls with the smear layer absent , charred , melted , recrystallized and glazed in both middle and apical thirds . The root-canal walls of the specimens irradiated with the Er : YAG laser ( G5 ) revealed an absent smear layer with open dentinal tubules in the middle and apical thirds . Statistical analysis showed no significant difference in the cleanliness of root-canal wall between G1 and G2 , and G1 and G3 . However , there were statistically significant differences ( P < 0.01 ) between G1 and G4 , and G1 and G5 in the cleanliness of the middle and apical one-thirds of the root canals . CONCLUSIONS Irrigation with 17 % EDTA , 6 % phosphoric acid and 6 % citric acid did not remove all the smear layer from the root-canal system . In addition , these acidic solutions demineralized the interbular dentine around tabular openings , which became enlarged . The CO2 laser was useful in removing and melting the smear layer on the instrumented root-canal walls and the Er : YAG laser was the most effective in removing the smear layer from the root-canal wall AIMS To devise an ex vivo model to test the efficacy of irrigation ( static/dynamic ) in removing a bio-molecular film from root canal walls . METHODOLOGY Forty human teeth with single straight canals were r and omly allocated to two groups for static ( n = 20 ) or dynamic ( n = 20 ) irrigation . The root canals were prepared to different apical sizes ( 20 , 40 ) and tapers ( 0.04 , 0.08 ) . The teeth were split longitudinally into two , stained collagen was applied to the canal surfaces and the tooth reassembled in a silicone matrix for dynamic or static irrigation . Digital images of the canal surface were taken before and after irrigation with 9 , 18 , 27 and 36 mL solution . The percentage of canal surface covered with stained collagen was quantified ( ipWin4 ) . The data were analysed using paired t-tests and linear regression models . RESULTS All the five explanatory variables : ' volume of irrigant used ' , ' mode of irrigation ' , ' orientation of open port of needle ' , ' corono-apical level of canal ' and ' root canal dimension ' had a significant ( P < 0.001 ) influence on outcome of irrigation . The corono-apical level of canal was the most dominating factor . After irrigation , the apical third had 19.9 % and 33.8 % less area covered with the bio-molecular film than the middle and coronal thirds respectively . CONCLUSIONS The stained collagen bio-molecular film could not be removed completely by either static or dynamic irrigation . Factors influencing removal , in rank order of decreasing priority , were : corono-apical level , apical size and taper of canal preparation , and dynamic/static irrigation Objectives The aim of this study was to compare the efficacy of apical negative pressure irrigation ( ANP ) and passive ultrasonic irrigation ( PUI ) with apical positive pressure irrigation ( PP — conventional irrigation ) in the periapical repair of dogs ’ teeth with apical periodontitis . Methods Forty-nine mesial and distal root canals of premolars of three dogs with experimentally induced periapical lesions were subjected to a single-session root canal treatment . The teeth were r and omly assigned to three groups : ANP , PUI , and PP ( control ) . After 180 days , the animals were euthanized , and the anatomic pieces were removed and subjected to histotechnical processing for morphological and morphometric histological analyses of hematoxylin and eosin (HE)-stained sections under conventional and fluorescence microscopy . Periapical lesion size before and 180 days after root canal treatment was measured by periapical radiographic examination . Tartrate-resistant acid phosphatase ( TRAP ) histoenzymology was performed for osteoclast counting and Brown and Brenn staining to assess bacteria . Data were analyzed statistically by the Kruskal-Wallis test ( α = 5 % ) . Result There were no statistically significant differences among the groups regarding periapical lesion size in the radiographic evaluation ( p = 0.91 ) . In the comparison of histopathological parameters , group ANP presented more homogeneous results . There was a statistically significant difference ( p = 0.02 ) between groups ANP and PP , with better results for group ANP in which milder infiltrate inflammatory was observed . No statistically significant difference ( p > 0.05 ) was found among the groups with respect to periodontal ligament space , presence of mineralized tissue resorption , size of the periapical lesions , and number of osteoclasts . Conclusion Although the three irrigation systems elicited similar periapical tissue response with respect to almost all evaluated parameters , ANP presented the mildest inflammatory infiltrate , suggesting an advantage over PP in the indication for clinical use . Clinical relevance Irrigation of the root canal systems is an extremely important step in root canal treatment . Therefore , it is of relevance to evaluate the efficacy of these systems by in vivo experimental models to provide scientific background for the clinical practice AIM To assess the ability of sodium hypochlorite ( NaOCl ) to penetrate simulated lateral canals and to reach working length ( WL ) when using the self-adjusting file ( SAF ) . METHODOLOGY Seventy single-rooted teeth with oval-shaped canals were used . Upon access , presence of a single canal was confirmed by direct visualization under a dental-operating microscope . Canal length and patency were obtained using a size 10 K-file and root length st and ardized to 18 mm . Pre-enlargement was restricted to the coronal one-third . The apical size of each canal was gauged at WL and sample s larger than size 30 were excluded . Canals were instrumented for 5 min using the SAF system while delivering a total of 20 mL of 5.25 % NaOCl and 5 mL of 17 % EDTA . Then , the apical diameters were st and ardized to size 35 using h and files . Four hundred and twenty simulated lateral canals were then created during the clearing process and roots coated with wax to create a closed system . All sample s were then cleared and r and omly assigned to four experimental groups : 1 ( n = 15 ) positive pressure ; 2 ( n = 15 ) SAF without pecking motion ; 3 ( n = 15 ) SAF with pecking motion ; 4 ( n = 15 ) apical negative pressure ( ANP ) irrigation and ( n = 10 ) control groups . Sample s were scored on the basis of the ability of the contrast solution to reach WL and permeate into the simulated lateral canals to at least 50 % of the total length . The Kruskal-Wallis test was used to analyse irrigant penetration and the Tukey test to determine statistical differences between groups ( P < 0.05 ) . RESULTS All sample s irrigated with ANP were associated with irrigant penetration to WL ( Table 1 ) . The differences between group 4 ( ANP ) and all other groups were significant in penetration to WL ( P < 0.05 ) . The pecking motion allowed for further penetration of the irrigant when using the SAF system but failed to irrigate at WL . None of the experimental groups demonstrated predictable irrigation of simulated lateral canals . CONCLUSIONS In this laboratory model , ANP was the only delivery system capable of irrigating consistently to full WL . None of the systems tested produced complete irrigation in artificial lateral canals Objective To compare the effect of a combination of 20 % citric acid solution and photo-activated disinfection with the use of 20 % citric acid and 2.25 % sodium hypochlorite solutions on bacterial load on the dentine walls in prepared canals in vivo . Subjects and methods Sixty-four r and omly selected cases were evaluated and allocated to one of two groups . In Group 1 , after gaining access to the root canal , bacterial load on the canal walls was sample d using endodontic files . A further sample was taken after apex location and initial widening of the canal had been completed and the photo-activated disinfection process carried out . A final sample was taken after completion of the canal preparation using citric acid and sodium hypochlorite solutions . In Group 2 , the initial sample was taken as described previously . A second sample was taken after conventional preparation using 20 % citric acid and sodium hypochlorite solutions as co-irrigants . A final sample was then taken after a subsequent PAD treatment . All sample s were cultured for facultative anaerobic bacteria . Results Of the canals treated in Group 1 only two of the 23 canals infected showed culturable bacteria after the use of citric acid and photo-activated disinfection . Of these two canals , one was free of culturable bacteria on completion of conventional treatment but the other still contained culturable bacteria . In Group 2 , four canals of the 23 infected initially , remained contaminated after conventional treatment . After subsequent photo-activated disinfection three of these four canals were free of culturable bacteria . Conclusion Results indicate that the use of a chelating agent acting as a cleaner and disrupter of the biofilm and photo-activated disinfection to kill bacteria is an effective alternative to the use of hypochlorite as a root canal cleaning system
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 .