title: Effectiveness of various irrigation activation protocols and the self-adjusting file system on smear layer and debris removal. Root canal debridement efficacy of different final irrigation protocols. Effect of passive ultrasonic irrigation and manual dynamic irrigation on smear layer removal from root canals in a closed apex in vitro model. Radiographic healing after a root canal treatment performed in single-rooted teeth with and without ultrasonic activation of the irrigant: a randomized controlled trial. A comparative study of the debridement efficacy and apical extrusion of dynamic and passive root canal irrigation systems Efficacy of four different irrigation techniques combined with 60°C 3% sodium hypochlorite and 17% EDTA in smear layer removal 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. Evaluation of smear layer removal after use of a canal brush: an SEM study. Effect of apical size and taper on volume of irrigant delivered at working length with apical negative pressure at different root curvatures. Efficacy of a new brush-covered irrigation needle in removing root canal debris: a scanning electron microscopic study. A Scanning electron microscopic evaluation of intracanal smear layer removal by two different final irrigation activation systems Efficacy of irrigation systems on penetration of sodium hypochlorite to working length and to simulated uninstrumented areas in oval shaped root canals. In vivo efficacy of three different endodontic irrigation systems for irrigant delivery to working length of mesial canals of mandibular molars. A comparative study of the removal of smear layer by three endodontic irrigants and two types of laser. Smear layer removal with passive ultrasonic irrigation and the NaviTip FX: a scanning electron microscopic study. Comparison of irrigant penetration up to working length and into simulated lateral canals using various irrigating techniques. The efficacy of dynamic irrigation using a commercially available system (RinsEndo) determined by removal of a collagen 'bio-molecular film' from an ex vivo model. Efficacy of the self-adjusting file system on cleaning and shaping oval canals: a microbiological and microscopic evaluation.
abstract: 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 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 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 INTRODUCTION The aim of this study was to compare the outcome of a root canal treatment with and without additional ultrasonic activation of the irrigant . METHODS Single-rooted teeth with radiographic evidence of periapical bone loss were r and omly assigned to 2 treatment groups . In both groups syringe irrigation was performed , and in one group the irrigant was also activated by ultrasound . Ten to 19 months after treatment , the teeth were examined by using periapical radiography ( PA ) and cone-beam computed tomography ( CBCT ) . Area and volume of the periapical lesions were measured , and the outcome was presented in 4 categories : absence , reduction or enlargement of the radiolucency , or uncertain . Lesions were classified as reduced or enlarged when the change in size of the radiolucency was 20 % or more . RESULTS The recall rate was 82 % , and 84 teeth were analyzed . CBCT detected significantly more post-treatment lesions than PA ( P = .038 ) , but the percentages of absence and reduction of the radiolucency together revealed by CBCT and PA were similar ( P = .383 ) . The CBCT results showed that absence of the radiolucency was observed in 16 of 84 teeth ( 19 % ) and reduction of the radiolucency in 61 of 84 teeth ( 72.6 % ) , but there was no significant difference between the results of the 2 groups ( P = .470 ) . Absence and reduction of the radiolucency together were observed in the ultrasonic group in 39 of 41 teeth ( 95.1 % ) and in the syringe group in 38 of 43 teeth ( 88.4 % ) . CONCLUSIONS Root canal treatments with and without additional ultrasonic activation of the irrigant contributed equally to periapical healing Background Root canal irrigation carries a risk of extrusion of irrigant into the periapical tissues which can be associated with pain , swelling , and tissue damage . Studies have shown less extrusion with sonic or apical negative pressure devices compared with syringe and side-port needle or passive ultrasonic irrigation with continuous irrigant flow . This study aim ed to evaluate the effectiveness of the EndoVac irrigation system , regarding 1 ) debris removal and 2 ) the control of apically extruded irrigating solution . Methods Fifty extracted human single-rooted teeth were used in this study . The teeth were then r and omly divided into three experimental groups according to the type of irrigation used and one control group . In group 1 , irrigation was performed using the EndoVac irrigation system . In group 2 , irrigation was performed using a 30-gauge , tip-vented irrigation needle . In group 3 , irrigation was performed using a 30-gauge , side-vented irrigation needle . The control group received instrumentation with no irrigation to serve as a control for cleaning efficiency . Root canal instrumentation was performed using the Profile NiTi rotary system with a crown-down technique . All of the experimental teeth were irrigated with the same amount of 5.25 % sodium hypochlorite . The amount of extruded irrigating solution was then measured by subtracting the post-instrumentation weight from the pre-instrumentation weight using an electronic balance . The cleanliness of debris removal was evaluated using scanning electron microscopy . Results EndoVac irrigation had the least amount of extrusion followed by the side-vented and tip-vented method . The difference between the groups was statistically significant ( P < 0.01 ) . As for the cleaning results , the debris collection in the EndoVac and tip-vented groups was the least in the apical third . In the control and the side-vented groups , the debris was the greatest in the apical third , but this difference was not significant among the three experimental groups . Conclusions The EndoVac irrigation system extruded significantly less irrigant solution than either needle irrigation system . Debris collection was the least in the apical third for the EndoVac irrigation system . No significant difference was found in the cleaning efficiency among the three irrigation systems 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 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 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 INTRODUCTION The purpose of this investigation was to determine the effect that apical preparation size and preparation taper have on the volume of irrigant delivered at the working length for different canal curvatures using apical negative pressure irrigation . METHODS One hundred fifty-five human teeth ( 55 maxillary canines and 100 m and ibular molars ) were used in this study . Root canals were prepared with rotary instruments to a size 35.04 and separated into 3 experimental groups according to their degree of curvature : group A ( n = 50 ) included canal curvatures ranging from 0 ° to 10 ° , group B ( n = 50 ) from 11 ° to 30 ° , and group C ( n = 50 ) from 31 ° to 65 ° . Sample s of each curvature group were further r and omized to experimental subgroups according to the apical size and taper as follow : 35.06 , 40.04 , 40.06 , 45.04 , and 45.06 . The apical third was irrigated using a microcannula and the volume of NaOCl suctioned at the working length under negative pressure was measured over a period of 30 seconds using a fluid recovery trap . Positive controls consisted of measuring the maximum volume of 5.25 % NaOCl capable of being suctioned by the microcannula from an open glass vial over 30 seconds . Negative control was the volume of irrigant aspirated by the microcannula with a preparation size of 25.04 over 30 seconds . RESULTS The volume of irrigant was significantly greater when the apical preparation size increased from 35.06 to 40.04 . As the apical preparation taper increased further from 40.04 to 40.06 , the volume of irrigant significantly improved in group B , but it was not significant in group A. Apical preparation sizes greater than 40.06 did not show an increase of the volume of irrigant aspirated . CONCLUSIONS The degree of root canal curvature decreased the volume of irrigant at the working length for a given apical size and taper . An apical preparation of 40.06 significantly increased the volume and exchange of irrigant at the working length regardless of curvature 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 : 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 ) 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 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 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 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 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 To compare the efficacy of three irrigation protocol s using an established ex vivo bio-molecular film model . METHODOLOGY Thirty human teeth with single straight canals were r and omly allocated to three groups [ static , manual-dynamic , automated-dynamic ( RinsEndo ] ; each with a sub-group ( n = 5 ) for needle position at 4 or 10 mm short of the working length ( WL ) . The root canals were prepared to apical size 40 , taper 0.08 . The teeth were split longitudinally into two halves and a st and ard coat of stained-collagen was applied to the canal surfaces . The re-assembled teeth were irrigated using one of the protocol s with the irrigation needle at one of two positions . Digital images of the canal surfaces , before and after irrigation with 18 mL of 2.5 % NaOCl , were used to score surface coverage with stained-collagen using image-analyses ( ipWin4 ) . The data were analysed using linear regression models . RESULTS The canal area covered with stained-collagen was significantly ( P < 0.001 ) less after dynamic irrigation ( manual/automated ) compared with static irrigation ; but automated-dynamic irrigation was significantly ( P = 0.037 ) less effective than manual-dynamic irrigation . The ' orientation of needle port ' , ' corono-apical level of canal ' and ' apical extent of needle placement ' were significant ( P < 0.001 ) factors influencing efficacy of irrigation . Residual collagen was most evident in the coronal third . Deeper penetration of the needle tip result ed in significantly ( P < 0.001 ) more effective collagen removal . CONCLUSIONS Automated-dynamic irrigation was significantly more effective ( 16 % ) than static irrigation but significantly less effective ( 5 % ) than manual-dynamic irrigation . Irrigation was more effective ( 7 % ) when the needle was placed closer to WL 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
target: IATs improve intracanal cleanliness across a substantial portion of the canal , and therefore , their use is recommended throughout root canal preparation .
background: AIMS To establish whether irrigant activation techniques ( IATs ) result in greater intracanal smear layer and debris removal than conventional needle irrigation ( CNI ) .