Effectiveness of various irrigation activation protocols and the self-adjusting file system on smear layer and debris removal. A Scanning electron microscopic evaluation of intracanal smear layer removal by two different final irrigation activation systems Smear Layer Evaluation on Root Canal Preparation with Manual and Rotary Techniques using EDTA as an Irrigant: A Scanning Electron Microscopy Study. Efficacy of four different irrigation techniques combined with 60°C 3% sodium hypochlorite and 17% EDTA in smear layer removal Root canal debridement efficacy of different final irrigation protocols. Efficacy of the self-adjusting file system on cleaning and shaping oval canals: a microbiological and microscopic evaluation. Effect of passive ultrasonic irrigation and manual dynamic irrigation on smear layer removal from root canals in a closed apex in vitro model. The effect of German chamomile (Marticaria recutita L.) extract and tea tree (Melaleuca alternifolia L.) oil used as irrigants on removal of smear layer: a scanning electron microscopy study. A comparative study of the debridement efficacy and apical extrusion of dynamic and passive root canal irrigation systems Smear layer removal with passive ultrasonic irrigation and the NaviTip FX: a scanning electron microscopic study. Scanning electron microscope study on the efficacy of root canal wall debridement of hand versus Lightspeed instrumentation. A comparative study of the removal of smear layer by three endodontic irrigants and two types of laser. Comparison of the effectiveness of three irrigation techniques in reducing intracanal Enterococcus faecalis populations: an in vitro study. Apical extrusion of intracanal debris and irrigant following use of various instrumentation techniques. Effect of removal of the smear layer on apical microleakage. 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 smear layer removal after use of a canal brush: an SEM study. Efficacy of a new brush-covered irrigation needle in removing root canal debris: a scanning electron microscopic study.
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 : The aim of this study was to compare smear layer removal at apical 1 mm level after final irrigation activation with an EndoVac system and Max-I probe . Material s and Methods : Fifty freshly extracted maxillary central incisors were r and omly divided into two groups after completing cleaning and shaping with ProTaper rotary files . In one group , final irrigation was performed with an EndoVac system while in the other group final irrigation was performed with a 30 gauge Max-I probe . 3 % sodium hypochlorite and 17 % ethylenediaminetetracetic acid were used as final irrigants in all teeth . After instrumentation and irrigation , the teeth were sectioned longitudinally into buccal and palatal halves and viewed under a scanning electron microscope for evaluation of the smear layer . Statistical analysis was performed using the Kruskal Wallis and Mann-Whitney U tests . Results : The EndoVac group showed significantly better smear layer removal compared with the Max-I probe at the apical 1 mm level . Conclusion : An apical negative pressure system ( EndoVac ) results in better debridement at apical 1 mm when compared with side-vented closed ended needle irrigation ( Max-I probe ) 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 Background Efforts to improve the efficacy of smear layer removal by applying irrigant activation at the final irrigation or by elevating the temperature of the irrigant have been reported . However , the combination of such activation protocol s with 60 ° C 3 % sodium hypochlorite ( NaOCl ) has seldom been mentioned . The aim of this study was to compare the efficacy in smear layer removal of four different irrigation techniques combined with 60 ° C 3 % NaOCl and 17 % EDTA . Methods Fifty single-rooted teeth were r and omly divided into five groups ( n = 10 ) according to the irrigant agitation protocol s used during chemomechanical preparation(Dentsply Maillefer , Ballaigues , Switzerl and ): a side-vented needle group , a ultrasonic irrigation ( UI ) group , a NaviTip FX group , an EndoActivator group , and a control group ( no agitation ) . After each instrumentation , the root canals were irrigated with 1 mL of 3 % NaOCl at 60 ° C for 1 minute , and after the whole instrumentation , the root canals were rinsed with 1 mL of 17 % EDTA for 1 minute . Both NaOCl and EDTA were activated with one of the five irrigation protocol s. The efficacy of smear layer removal was scored at the apical , middle and coronal thirds . The Data were statistically analyzed using SAS version 9.2 for Windows ( rank sum test for a r and omised block design and ANOVA ) . Results No significant differences among the NaviTip FX group , EndoActivator group and control groups , and each of these groups showed a lower score than that of UI group ( P < 0.05 ) . Within each group , all three thirds were ranked in the following order : coronal > middle > apical ( P < 0.05 ) . In the coronal third , the NaviTip FX group was better than UI group . In the middle and apical third , the differences were not significant among any of the groups . Conclusions Even without any activation , the combination of 60 ° C 3 % NaOCl and 17 % EDTA  could remove the smear layer effectively , similar to NaviTip FX or EndoActivator , and these three protocol s were more effective than UI . However , regardless of different types of irrigation technique applied , complete removal of the smear layer was not achieved , particularly in the apical third 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 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 AIM To compare the effect of passive ultrasonic irrigation with manual dynamic irrigation on smear layer removal from root canals using a closed apex in vitro model . METHODS The root canals of 45 freshly-extracted human single-rooted m and ibular premolar teeth were prepared by the Pro-Taper rotary system to an apical preparation of F4 size . Prepared teeth were r and omly divided into three groups ; two experimental groups and one control group ( n = 15 ) on the basis of the type of activation of final irrigation as follows : ( a ) Group A , 3 % sodium hypochlorite ( NaOCl ) and 17 % ethylenediaminetetraacetic acid ( EDTA ) , no activation received ; ( b ) Group B , 3 % NaOCl and 17 % EDTA , ultrasonic activation with a small file ; and ( c ) Group C , 3 % NaOCl and 17 % EDTA , manual activation with a master gutta-percha point . The prepared teeth were decoronated and split into two halves longitudinally , and observed under a scanning electron microscope to assess the removal of the smear layer . RESULTS In the apical-third region , the mean smear scores for groups B and C were significantly less than those of Group A ( control group ) ( P < 0.05 ) . CONCLUSION Both activation techniques are important adjuncts in removing the smear layer , with manual dynamic activation being a simpler , safer , and more cost-effective technique AIM To compare the cleaning effectiveness of chamomile hydroalcoholic extract and tea tree oil to 2.5 % sodium hypochlorite ( NaOCl ) solution as an intracanal irrigant for the removal of the smear layer . METHODOLOGY Forty extracted , single-rooted , mature , permanent , human teeth were allocated at r and om into one of three experimental groups of ten teeth and two control groups of five teeth . For each tooth , the pulp chamber was accessed and the canal prepared using K-type files and Gates-Glidden burs , using a step-back technique ; the apical stop was prepared to a size 30 . Each canal was subsequently irrigated with one of the following solutions : distilled water ( as a negative control ) , 2.5 % NaOCl + 17 % ethylenediamine tetraacetic acid ( EDTA ) ( as a positive control ) , chamomile or tea tree oil or 2.5 % NaOCl . Each tooth was split longitudinally and prepared for examination by scanning electron microscopy ( SEM ) . The quantity of smear layer remaining on the three levels of each canal ( coronal , middle and apical ) was examined using magnifications of 2000 and 5000x . The data were analysed using nonparametric Kruskal-Wallis and Mann-Whitney U-tests . RESULTS The most effective removal of smear layer occurred with the use of NaOCl with a final rinse of 17 % EDTA ( negative control ) followed by the use of a chamomile extract . Chamomile extract was found to be significantly more effective than distilled water and tea tree oil ( P < 0.008 ) . The use of a 2.5 % NaOCl solution alone , without EDTA and that of tea tree oil , was found to have only minor effects . There was no statistical difference between distilled water , 2.5 % NaOCl and tea tree oil . CONCLUSIONS The efficacy of chamomile to remove smear layer was superior to NaOCl alone but less than NaOCl combined with EDTA 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 The aim of this study was to compare the effect of continuous , intermittent passive ultrasonic irrigation ( PUI ) and active scrubbing of irrigants with NaviTip FX ( Ultradent , South Jordan , UT ) in removing smear layer . STUDY DESIGN Forty single-rooted teeth were r and omly divided into 5 test groups and subjected to final irrigation with 17 % EDTA followed by 2.5 % NaOCl for 1 minute each using different activation methods : no activation ( control ) , brushing with NaviTip FX , continuous PUI with irrigant delivered at pulp chamber , continuous PUI with irrigant delivered through the ultrasonic unit , and intermittent PUI . Specimens were examined under scanning electron microscope , and the data were analyzed using Friedman 2-way analysis of variance , Kruskal-Wallis , and Mann-Whitney U tests . RESULTS NaviTip FX and intermittent PUI showed significantly lower smear score than other groups at the 3 mm level ( P < .05 ) . CONCLUSIONS Both brush and intermittent ultrasonic activation were effective in the removal of smear layer from the apical third AIM The aim of this in vitro study was to compare the efficacy of root canal wall debridement following h and versus LightSpeed instrumentation . METHODOLOGY Twenty recently extracted single-rooted teeth were paired and r and omly placed into two treatment groups of 10 teeth each . In group 1 , a step-back instrumentation without initial coronal flaring with stainless steel Hedstroem files was used ; group 2 was instrumented with Ni-Ti LightSpeed instruments . Both groups had the same irrigation regimen : 2.5 % NaOCl and a 15 % EDTA solution . The teeth were then decoronated and each root split longitudinally into two halves to be examined using the scanning electron microscope ( SEM ) . The presence of superficial debris and smear layer was evaluated by a st and ardized grading system , and the result ing scores su bmi tted to nonparametric statistics . RESULTS Under the conditions of this study , the removal of superficial debris was generally excellent with both canal preparation techniques . Both techniques result ed in variable presence of residual smear layer , with a canal wall covered by smear layer as the predominant characteristic . Generally , the amount of smear layer was greater in the apical than in the middle third of the root , however , this difference was statistically significant ( P < 0.005 ) only in h and -instrumented teeth . The use of LightSpeed instruments was associated with significantly more ( P < 0.05 ) smear layer presence in the middle region of the root when compared with h and instrumentation . In addition , less smear layer was present in the apical region following LightSpeed instrumentation than stainless steel h and files , but this difference was not statistically significant . Differences in debridement between the two halves of the same root were more evident with LightSpeed than manual instrumentation , however , there was no statistical significance . CONCLUSIONS It may be inferred that the choice between h and and LightSpeed instrumentation should be based on factors other than the amount of root canal debridement , which does not vary significantly according to the instruments used 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 INTRODUCTION Several irrigation techniques have been recently introduced with the main objective of improving root canal disinfection . This in vitro study aim ed at comparing the intracanal bacterial reduction promoted by chemomechanical preparation with 3 different irrigation techniques . METHODS Root canals from extracted teeth were contaminated with Enterococcus faecalis ATCC 29212 for 7 days and then r and omly distributed into 3 experimental groups of 20 teeth each : group 1 , conventional irrigation with NaviTip needles inserted up to 3 mm short of the working length ; group 2 , same as group 1 , but supplemented with final irrigant activation by the EndoActivator system ; and group 3 , irrigation with the EndoVac system . NaOCl and ethylenediaminetetraacetic acid ( EDTA ) were the irrigants used in all experimental groups . The overall preparation time was kept constant for the groups , but the total volume ranged from 20 mL ( groups 1 and 2 ) to 43 mL ( group 3 ) . The control group was irrigated with saline solution ( total volume , 43 mL ) . Sample s taken before and after chemomechanical procedures were cultured , and the colony-forming units ( CFUs ) were counted . RESULTS Reduction in the bacterial population s was highly significant for all groups . The 3 experimental groups with NaOCl and EDTA as irrigants were significantly more effective than the control group with saline in reducing CFU counts . There were no significant differences between the 3 techniques tested . CONCLUSIONS There was no evident antibacterial superiority of any of the irrigation techniques evaluated in the present in vitro model OBJECTIVE The purpose of this study was to compare in vitro the amount of debris and irrigant extruded apically from extracted teeth , using manual technique and crowndown pressureless technique by K3 , RaCe , and FlexMaster instruments . STUDY DESIGN Sixty human single-rooted m and ibular premolar teeth were r and omly assigned to 4 groups , 15 teeth each . The teeth in 4 groups were instrumented until the working length with RaCe , K3 , FlexMaster , and K-type stainless steel instruments respectively .  Debris and irrigant extruded from the apical foramen were collected into vials and the amounts were determined . The data obtained were analyzed using Kruskal-Wallis 1-way analysis of variance and Mann-Whitney U tests , with alpha = 0.05 as the level for statistical significance . RESULTS No statistically significant difference was observed among the groups in terms of debris extrusion ( P > .05 ) . On the other h and , a statistically significant difference was observed between K3 and manual technique groups in terms of irrigant extrusion ( P < .05 ) . The difference between other groups was not statistically significant ( P > .05 ) . CONCLUSION Based on the results , all instrumentation techniques produced extruded debris and irrigant ; however , the engine-driven nickel-titanium systems were associated with less apical extrusion and irrigant It has been shown previously that the smear layer created during instrumentation of the root canal promotes apical microleakage . The purpose of the present study was to investigate the effect of removal of the smear layer on apical microleakage , using the fluid filtration method . Thirty-six single-rooted human premolar teeth were used . Six of the teeth were selected r and omly as controls , and the remaining 30 teeth were r and omly divided into two groups of 15 teeth each . For the first group ( group 1 ) teeth were irrigated with NaOCl only ( smear layer not removed ) . In the second group ( group 2 ) the teeth were irrigated with 15 % EDTA , followed by NaOCl to remove the smear layer . Both groups were filled with thermoplasticized gutta-percha ( Obtura II ) using glass-ionomer cement as sealer . All teeth were stored at 37 degrees C and 100 % humidity for 2 days . Apical microleakage of the filled root canal was measured by the fluid filtration technique . Hydraulic conductance was measured by the movement of an air bubble in a capillary tube after a pressure of 200 mm Hg was applied to the system . The mean microleakage rate of group 1 and group 2 were 13.0 ( SD + /- 5.1 ) and 16.9 ( SD + /- 15.3 ) nl/s , respectively . Removal of the smear layer caused significantly more apical microleakage ( p < 0.05 , Student 's t test ) than when the smear layer was left intact 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 OBJECTIVE The objective of this study was to evaluate smear layer removal after using the new CanalBrush ( Coltene/Whaledent GmbH+Co . KG , Germany ) . STUDY DESIGN Twenty extracted maxillary anterior teeth were r and omly divided into 2 equal groups . The canals of the teeth in each group were instrumented with ProTaper Universal rotary files ( Dentsply Maillefer , Switzerl and ) . Following each file use , the root canals in both groups were irrigated with 5.25 % NaOCl and 15 % EDTA . At the end of instrumentation , the canals in group 2 were flushed with 15 % EDTA , then a CanalBrush was used for 30 seconds , and a final irrigation was conducted with 5.25 % NaOCl . All teeth were processed for scanning electron microscopy ( SEM ) , and the removal of the smear layer was examined in the apical , middle , and coronal thirds . Analyses of SEM images were performed by 2 independent evaluators in a blinded manner and using a 4-point scoring system . RESULTS The middle and apical thirds of the root canals in group 2 showed lower average scores than those in group 1 , but the difference was not statistically significant . There was no significant difference in the coronal score between the groups ( P > .05 ) . CONCLUSIONS Irrigating with brushing tended to produce cleaner canal walls , but irrigating brushing was not significantly better than irrigation alone in removing the smear layer on the canal walls 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
IATs improve intracanal cleanliness across a substantial portion of the canal , and therefore , their use is recommended throughout root canal preparation .
AIMS To establish whether irrigant activation techniques ( IATs ) result in greater intracanal smear layer and debris removal than conventional needle irrigation ( CNI ) .