title: Quality of life of endodontically treated versus implant treated patients: a University-based qualitative research study. Root Canal Cleaning Efficacy of Rotary and Hand Files Instrumentation in Primary Molars Reduction in intracanal bacteria during root canal preparation with and without apical enlargement. AMSTAR is a reliable and valid measurement tool to assess the methodological quality of systematic reviews. Smear Layer Evaluation on Root Canal Preparation with Manual and Rotary Techniques using EDTA as an Irrigant: A Scanning Electron Microscopy Study. An in-vitro Evaluation of canal transportation and centering ability of two rotary Nickel Titanium systems (Twisted Files and Hyflex files) with conventional stainless Steel hand K-flexofiles by using Spiral Computed Tomography. A prospective study of the factors affecting outcomes of nonsurgical root canal treatment: part 1: periapical health. A new methodology for the comparative study of the root canal instrumentation techniques based on digital radiographic image processing and analysis. Bacterial reduction with nickel-titanium rotary instrumentation. Apical Extrusion of Intracanal Debris Using Two Engine Driven and Step-Back Instrumentation Techniques: An In-Vitro Study A comparative study of biofilm removal with hand, rotary nickel-titanium, and self-adjusting file instrumentation using a novel in vitro biofilm model. A retrospective study of endodontic treatment outcome between nickel-titanium rotary and stainless steel hand filing techniques. Nickel-titanium rotary instrument fracture: a clinical practice assessment. Microbiological assessment of root canals following use of rotary and manual instruments in primary molars. Effect of three nickel-titanium rotary file techniques on infected root dentin reduction. Apical extrusion of intracanal debris and irrigant following use of various instrumentation techniques. Ex vivo study on root canal instrumentation of two rotary nickel-titanium systems in comparison to stainless steel hand instruments. Scanning electron microscope study on the efficacy of root canal wall debridement of hand versus Lightspeed instrumentation. Comparison of canal transportation and centering ability of twisted files, Pathfile-ProTaper system, and stainless steel hand K-files by using computed tomography. Rotary Mtwo system versus manual K-file instruments: efficacy in preparing primary and permanent molar root canals. Comparison among manual instruments and PathFile and Mtwo rotary instruments to create a glide path in the root canal preparation of curved canals.
abstract: INTRODUCTION Up-to- date studies comparing endodontic treatment versus implant-supported prosthesis have shown similar clinical outcome and survival rates . However , no data are available comparing both treatment modalities based on the patient 's perception of quality of life . This study was design ed to qualitatively describe and compare the quality of life of patients with restored , single endodontically treated teeth versus patients with single implant-supported fixed prostheses . METHODS Forty-eight patients agreed to participate in the study ( n = 24 from each treatment modality ) . Of those , 37 actually participated in the study : 17 were endodontically treated and 20 had an implant-supported prosthesis . Patients in each of the two groups were r and omly selected from the Graduate Endodontics and Graduate Periodontics Departments , respectively . Six focus group discussion s ( n = 3 per treatment group ) were held and audio-recorded for subsequent thematic analysis . Data were analyzed to identify common themes within each category and compared to assess any differences in quality of life between the two treatments . Additionally , a quality of life survey , the shortened version of the Oral Health Impact Profile ( OHIP-14 ) , was given before the discussion group and the responses analyzed . RESULTS The results obtained from this study show similar overall OHIP scores and show a high rate of satisfaction with both treatment modalities . Content analysis of the discussion groups revealed several themes and subthemes . The major themes were importance of overall health , financial implication s of the treatments , perception of the treatments and its outcomes , time since treatment , and follow-up dental visits . CONCLUSIONS The results help identify patients ' perception and concerns with each treatment modality and assist the clinician and patient in the selection of an optimal treatment for their given situation . In addition to the prognosis and outcomes , clinicians should consider patients ' perceptions and preferences as well as the influence each therapy may have on their quality of life , both short- and long-term . Overall , all the participants in this study were pleased with the treatment received and expressed a clear message to save their natural dentition whenever possible INTRODUCTION : Pulpectomy of primary teeth is commonly carried out with h and files and broaches ; a tricky and time consuming procedure . The purpose of this in vitro study was to compare the cleaning efficacy and time taken for instrumentation of deciduous molars using h and K-files and Flex Master rotary system . MATERIAL S AND METHODS : In this study , 68 canals of 23 extracted primary molars with at least two third intact roots and 7 - 12 mm length were selected . After preparing an access cavity , K-file size # 15 was introduced into the root canal and India ink was injected with an insulin syringe . Sixty sample s were r and omly divided in to experimental groups in group I ( n=30 ) , root canals were prepared with h and K-files ; in group II ( n=30 ) , rotary Flex Master files were used for instrumentation , and in group III 8 remained sample s were considered as negative controls . After clearing and root sectioning , the removal of India ink from cervical , middle , and apical thirds was scored . Data was analyzed using student 's T-test and Mann-Whitney U test . RESULTS : There was no significant difference between experimental groups cleaning efficacy at the cervical , middle and apical root canal thirds . Only the coronal third scored higher in the h and instrumented group ( P<0.001 ) . Instrumentation with Flex Master rotary files was significantly less time consuming ( P<0.001 ) . CONCLUSION : Although there was no difference in cleanliness efficacy at the apical and middle thirds , the coronal third was more effectively cleaned with h and files . Predictably , time efficiency was a significant advantage with rotary technique AIM To compare in vitro intracanal bacterial reduction using nickel-titanium rotary instruments with and without apical enlargement . METHODOLOGY Thirty-eight palatal roots of maxillary molar teeth , with mature apices were subdivided according to lengths and then r and omly assigned to two experimental and one control groups . The roots were sterilized and then reinfected with Enterococcus faecalis , which served as a bacteriological marker . All roots in the experimental groups were prepared in a step-down sequence with engine-driven GT rotary files at 350 rpm . In experimental group A ( n = 16 ) additional apical enlargement to ISO size 35 was performed . In group B ( n = 16 ) a serial step-back technique was followed with no apical enlargement . This was combined in groups A and B with irrigation with NaOCl and EDTA . In the control group ( group C , n = 6 ) irrigation only was carried out , with no mechanical preparation . Sample s were then taken from the root canals to determine the numbers of remaining bacteria . RESULTS In groups A and B , 15 ( 94 % ) and 13 ( 81 % ) specimens were rendered bacteria-free , respectively . In the control group C none of the specimens were bacteria-free . There was a significant difference ( P < 0.001 ) in the antibacterial effects of experimental and control regimens . There was , however , no significant difference ( P = 0.276 ) between the preparation methods used in the experimental groups . CONCLUSIONS There was no significant difference in intracanal bacterial reduction when Ni-Ti GT rotary preparation with NaOCl and EDTA irrigation was used with or without apical enlargement preparation technique . It may therefore not be necessary to remove dentine in the apical part of the root canal when a suitable coronal taper is achieved to allow satisfactory irrigation of the root canal system with antimicrobial agents OBJECTIVE Our purpose was to measure the agreement , reliability , construct validity , and feasibility of a measurement tool to assess  systematic review s ( AMSTAR ) . STUDY DESIGN AND SETTING We r and omly selected 30 systematic review s from a data base . Each was assessed by two review ers using : ( 1 ) the enhanced quality assessment question naire ( Overview of Quality Assessment Question naire [ OQAQ ] ) ; ( 2 ) Sacks ' instrument ; and ( 3 ) our newly developed measurement tool ( AMSTAR ) . We report on reliability ( interobserver kappas of the 11 AMSTAR items ) , intraclass correlation coefficients ( ICCs ) of the sum scores , construct validity ( ICCs of the sum scores of AMSTAR compared with those of other instruments ) , and completion times . RESULTS The interrater agreement of the individual items of AMSTAR was substantial with a mean kappa of 0.70 ( 95 % confidence interval [ CI ] : 0.57 , 0.83 ) ( range : 0.38 - 1.0 ) . Kappas recorded for the other instruments were 0.63 ( 95 % CI : 0.38 , 0.78 ) for enhanced OQAQ and 0.40 ( 95 % CI : 0.29 , 0.50 ) for the Sacks ' instrument . The ICC of the total score for AMSTAR was 0.84 ( 95 % CI : 0.65 , 0.92 ) compared with 0.91 ( 95 % CI : 0.82 , 0.96 ) for OQAQ and 0.86 ( 95 % CI : 0.71 , 0.94 ) for the Sacks ' instrument . AMSTAR proved easy to apply , each review taking about 15 minutes to complete . CONCLUSIONS AMSTAR has good agreement , reliability , construct validity , and feasibility . These findings need confirmation by a broader range of assessors and a more diverse range of review 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 The purpose of this in-vitro study was to compare canal transportation and centering ability of Twisted and Hyflex Rotary Files with stainless steel h and k-flexofiles by using Spiral Computed Tomography . MATERIAL S & METHODS A total of 90 freshly extracted human m and ibular single rooted Premolar teeth were selected . The crowns were flattened with steel disks and a final dimension of 18-mm WL was achieved for each tooth . Canals were divided r and omly into 3 groups of 30 teeth each . Group I : Hyflex files , Group II : Twisted files , Group III : stainless steel h and k-flexofiles . Three sections from apical , mid-root , and coronal levels of the canal were recorded . All the teeth were scanned before and after instrumentation by using Spiral Computed Tomography . RESULTS K-files showed highest transportation and less centered when compared to the Twisted and Hyflex rotary files . No significant difference was found between TF and Hyflex CM instruments . CONCLUSION TF and Hyflex files shaped curved root canals without significant shaping errors when compared to the H and stainless steel k-flexofiles . How to cite this article : Kumar BS , Pattanshetty S , Prasad M , Soni S , Pattanshetty KS , Prasad S. An in-vitro Evaluation of canal transportation and centering ability of two rotary Nickel Titanium systems ( Twisted Files and Hyflex files ) with conventional stainless Steel h and K-flexofiles by using Spiral Computed Tomography . J Int Oral Health 2013;5(5):108 - 15 AIM To investigate the probability of and factors influencing periapical status of teeth following primary ( 1 ° RCT x ) or secondary ( 2 ° RCT x ) root canal treatment .  METHODOLOGY This prospect i ve study involved annual clinical and radiographic follow-up of  1 ° RCT x ( 1170 roots , 702 teeth and 534 patients ) or 2 ° RCT x ( 1314 roots , 750 teeth and 559 patients ) carried out by Endodontic postgraduate students for 2 - 4 ( 50 % ) years . Pre- , intra- and postoperative data were collected prospect ively on customized forms . The proportion of roots with complete periapical healing was estimated , and prognostic factors were investigated using multiple logistic regression models . Clustering effects within patients were adjusted in all models using robust st and ard error . RESULTS proportion of roots with complete periapical healing after 1 ° RCT x ( 83 % ; 95 % CI : 81 % , 85 % ) or 2 ° RCT x ( 80 % ; 95 % CI : 78 % , 82 % ) were similar . Eleven prognostic factors were identified . The conditions that were found to improve periapical healing significantly were : the preoperative absence of a periapical lesion ( P = 0.003 ) ; in presence of a periapical lesion , the smaller its size ( P ≤ 0.001 ) , the better the treatment prognosis ; the absence of a preoperative sinus tract ( P = 0.001 ) ; achievement of patency at the canal terminus ( P = 0.001 ) ; extension of canal cleaning as close as possible to its apical terminus ( P = 0.001 ) ; the use of ethylene-diamine-tetra-acetic acid ( EDTA ) solution as a penultimate wash followed by final rinse with NaOCl solution in 2 ° RCT x cases ( P = 0.002 ) ; abstaining from using 2 % chlorexidine as an adjunct irrigant to NaOCl solution ( P = 0.01 ) ; absence of tooth/root perforation ( P = 0.06 ) ; absence of interappointment flare-up ( pain or swelling ) ( P = 0.002 ) ; absence of root-filling extrusion ( P ≤ 0.001 ) ; and presence of a satisfactory coronal restoration ( P ≤ 0.001 ) . CONCLUSIONS Success based on periapical health associated with roots following 1 ° RCT x ( 83 % ) or 2 ° RCT x ( 80 % ) was similar , with 10 factors having a common effect on both , whilst the 11th factor ' EDTA as an additional irrigant ' had different effects on the two treatments OBJECTIVE The objective of this study was to evaluate the utility of digital image processing and analysis procedures for the study and comparison of the efficiency of 2 root canal instrumentation techniques . STUDY DESIGN Forty m and ibular incisors with a single canal were r and omly divided into 2 groups of 20 teeth . A step-back technique was followed for the instrumentation of the root canals of Group 1 teeth using h and stainless steel Hedström files ( Dentsply Maillefer , Switzerl and ) , while a crown-down technique using ProFile engine-driven nickel-titanium instruments ( Dentsply Maillefer ) was followed for the instrumentation of the Group 2 root canals . Radiographs of each tooth were taken in bucco-lingual and mesio-distal projections , both before and after instrumentation , under constant conditions and by using a direct digital intraoral radiography system . The postoperative radiographs were digitally subtracted from their respective preoperative radiographs . A contrast enhancement process was applied to the result ant digital subtractive images . The enlargement of the root canals created by each instrumentation technique regarding the apical 6 mm was assessed through the application of region segmentation and area measurement processes . RESULTS Using this methodology no significant difference between the 2 preparation techniques was found in terms of configuration and enlargement of the root canals . CONCLUSIONS The application of this methodology provided the ability to ( 1 ) visualize dentin lost during root canal instrumentation , ( 2 ) simultaneously compare root canal morphology before and after instrumentation , and ( 3 ) quantitatively evaluate the enlargement of the root canal area induced by each of the instrumentation techniques The purpose of this study was to compare intracanal bacterial reduction on teeth instrumented with 0.04 tapered nickel-titanium ( NiTi ) rotary instrumentation to bacterial reduction when using a stainless-steel K-file step-back technique using sterile saline irrigation .  Forty-eight patients with apical periodontitis were r and omly assigned treatment type . The canals were sample d before , during , and after instrumentation . The sample s were incubated anaerobically for 7 days at 37 degrees C , colony-forming unit numbers calculated , and a log transformation performed to normalize the counts . Teeth exhibiting apical periodontitis were uniformly infected , whereas vital control teeth were not . A similar and uniform reduction occurred with progressive filing , regardless of technique ( p < 0.0001 ) . There was no detectable difference in colony-forming unit count after NiTi rotary or stainless-steel h and instrumentation ( p = 0.42 ) . Neither technique could predictably render canals free of bacteria . The results of this study indicate NiTi rotary and stainless-steel h and K-file step-back instrumentation techniques were not significantly different in their ability to reduce intracanal bacteria Objectives The purpose of this study was to compare in-vitro the amount of debris extruded apically from extracted teeth , using K3 , Protaper rotary instruments and manual step-back technique . Methods Forty five human single-rooted m and ibular premolar teeth were r and omly divided into 3 groups . The teeth in 3 groups were instrumented until reaching the working length with K3 , Protaper rotary instruments and K-type stainless steel instruments with manual step-back technique , respectively . Debris extruded from the apical foramen was collected into centrifuge tubes and the amount was determined . The data obtained were analyzed using Kruskal-Wallis one-way analysis of variance and Mann-Whitney U tests , with P=.05 as the level for statistical significance . Results Statistically significant difference was observed between K3 , Protaper and step-back groups in terms of debris extrusion ( P<.05 ) . Step-back group had the highest mean debris weight , which was significantly different from the K3 and Protaper groups ( P<.05 ) . The lowest mean debris weight was related to K3 group , which was significantly different from the Protaper group ( P<.05 ) . Conclusions : Based on the results , all instrumentation techniques produced debris extrusion . The engine-driven Ni-Ti systems extruded significantly less apical debris than step-back technique . However , Protaper rotary instruments extruded significantly more debris than K3 rotary instruments INTRODUCTION This study sought to present a st and ardized biofilm model in extracted teeth with an artificial apical groove to quantify the efficacy of h and , rotary nickel-titanium , and self-adjusting file ( SAF ) instrumentation in biofilm bacteria removal . METHODS Thirty-six extracted single-rooted teeth with oblong canals were selected . Each tooth was split longitudinally , and a 0.2-mm-wide groove was placed in the apical 2 to 5 mm of the canal . After growing mixed bacteria biofilm inside the canal under an anaerobic condition , the split halves were reassembled in a custom block , creating an apical vapor lock . Teeth were r and omly divided into 3 treatment groups ( n = 10 per group ) using the K-file , ProFile ( Dentsply Tulsa Dental Products , Tulsa , OK ) , and the SAF ( ReDent-Nova , Ra'anana , Israel ) . Irrigation consisted of 10 mL 3 % NaOCl and 4 mL 17 % EDTA .  Six teeth received no treatment . Areas inside and outside the groove were examined using a scanning electron microscope . RESULTS The scanning electron microscope showed a consistently thick layer of biofilm grown in the canals of the control group after 4 weeks . Within the groove , a smaller area remained occupied by bacteria after the use of the SAF compared with the ProFile and the K-file ( 3.25 % , 19.25 % , and 26.98 % , respectively ; P < .05 ) . For all groups , significantly more bacteria were removed outside the groove than inside ( P < .05 ) . No statistical differences were found outside the groove ( P > .05 ) . CONCLUSIONS Although all techniques equally removed bacteria outside the groove , the SAF reduced significantly more bacteria within the apical groove . No technique was able to remove all bacteria . This biofilm model represents a potentially useful tool for the future study of root canal disinfection AIM The purpose of this study was to compare the periapical healing of molar root canal treatment using two instrumentation techniques . METHODS A total of 225 maxillary and m and ibular first and second permanent molars endodontically treated by undergraduate or postgraduate students were r and omly selected from a computerized hospital data base of which 110 molars had been prepared using a hybrid rotary technique with nickel-titanium instruments ( group NR ) and 115 with h and stainless steel files ( group HF ) . Patients were recalled and the teeth were examined both clinical ly and radiographically for signs of periapical inflammation . RESULTS Some 19 % and 39 % of teeth in the NR and HF group , respectively , were judged to have some form of procedural errors . A higher rate of periapical healing was noted for NR ( 77 % ) than the HF group ( 60 % ) ( p < 0.05 ) . Factors contributing favorably to treatment outcome included the use of rotary technique , maxillary molar , experienced operator , and absence of preoperative radiolucent lesion . CONCLUSION There was a higher incidence of procedural errors and a lower success rate for primary root canal treatment of teeth prepared with stainless steel files compared with the use of NiTi instruments in a continuous reaming action AIM To prospect ively determine the incidence of nickel-titanium rotary instrument fracture in an endodontic clinical practice setting . METHODOLOGY Eleven second year endodontic residents , using four nickel-titanium rotary instrument systems ( ProFile , ProTaper , GTRotary and K3Endo )  according to the recommendations of the manufacturers , instrumented 3181 canals in 1403 teeth of 1235 patients , in a dental school post-graduate endodontic clinic , in 1 year . The incidence of instrument fracture was determined based on the number of instruments used . When fracture occurred , data were collected concerning the type , size , taper and prior use of the fractured instruments , the length and location of the fragment within the root canal and the curvature of the canal . RESULTS The overall incidence of instrument fracture was 0.39 % . The incidence of fracture for ProFile , ProTaper , GTRotary and K3Endo files was 0.28 % , 0.41 % , 0.39 % and 0.52 % , respectively . There was no statistically significant difference between instrument systems . The percentage of teeth in which instruments fractured was 1.9 % ( 0.28 % for anterior teeth , 1.56 % for pre-molars and 2.74 % for molars ) . A total of 26 instruments fractured , of which 23 had tapers of 0.06 or greater . Most of the fragments were located in the apical third of the root canal , and both the median and mode amongst the fragment lengths were 2 mm . CONCLUSIONS The low incidence of nickel-titanium rotary instrument fracture supports the continued use of these instruments in root canal treatment AIM To assess the microflora of root canals in primary molars following use of rotary NiTi files and conventional h and NiTi and stainless steel files . STUDY DESIGN This r and omized clinical trial consisted of a total of 60 first and second primary molars requiring root canal treatment , who were selected from children aged 5 - 9 years . Based on type of root canal instrumentation , the teeth were r and omly assigned to three groups of twenty teeth each ; Group A : Rotary NiTi files , Group B : H and NiTi files and Group C : H and stainless steel files . Following administration of local anesthesia , isolation with rubber dam was carried out . For the purpose of instrumentation and sampling , the palatal canal of maxillary molars and the distal canal of m and ibular molars were selected . Prior to sampling , the orifices of other canals in these teeth were sealed , so as to prevent any contamination . Instrumentation was carried out in each group using respective instruments along with intermittent saline irrigation . Root canal sample s were obtained both before and after instrumentation , using sterile absorbent paper points and transferred to a sterile vial with transport fluid . Serial dilutions were prepared and cultured on suitable agar media . Both aerobic and anaerobic microbial counts were made . Data obtained was subjected to statistical analysis using Wilcoxon signed rank test and one-way Analysis of variance . RESULTS In all three groups , there was a significant reduction in both aerobic and anaerobic mean microbial count following root canal instrumentation . ( p < 0.001 ) . CONCLUSION Rotary NiTi files were as efficient as conventional h and instruments in significantly reducing the root canal microflora OBJECTIVE This study compared the bacterial reduction of in vitro infected root canals after instrumentation by 3 nickel-titanium ( NiTi ) rotary files with different taper and diameter versus manual stainless steel files . STUDY DESIGN Sixty-four single-rooted human teeth were infected with a suspension of Streptococcus sanguis measured by optical density . Teeth were divided r and omly into 4 groups of 16 and prepared with Flexofiles , GT rotary files , HERO 642 , and ProFile . Bacterial samplings were performed before ( S1 ) , during ( S2-S3 ) , and after ( S4 ) instrumentation . RESULTS All techniques significantly reduced the number of bacterial cells in the root canals ( P < .05 ) . There was no significant difference between NiTi and manual instrumentation at S2 , S3 , or S4 . Concerning bacterial reduction , the results suggest that a manual stainless steel file preparation is as efficient as a NiTi rotary instrumentation . CONCLUSION Regardless of the root canal preparation technique , its taper , and diameter , the root dentin remained infected and was not bacteria-free at the end of the experiment 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 AIM To investigate instrumentation time , working safety and the shaping ability of two rotary nickel-titanium ( NiTi ) systems ( Alpha System and ProTaper Universal ) in comparison to stainless steel h and instruments . METHODOLOGY A total of 45 mesial root canals of extracted human m and ibular molars were selected . On the basis of the degree of curvature the matched teeth were allocated r and omly into three groups of 15 teeth each . In group 1 root canals were prepared to size 30 using a st and ardized manual preparation technique ; in group 2 and 3 rotary NiTi instruments were used following the manufacturers ' instructions . Instrumentation time and procedural errors were recorded . With the aid of pre- and postoperative radiographs , apical straightening of the canal curvature was determined . Photographs of the coronal , middle and apical cross-sections of the pre- and postoperative canals were taken , and superimposed using a st and ard software . Based on these composite images the portion of uninstrumented canal walls was evaluated . RESULTS Active instrumentation time of the  Alpha System  was significantly reduced compared with ProTaper Universal and h and instrumentation ( P < 0.05 ; anova ) . No instrument fractures occurred in any of the groups . The Alpha System revealed significantly less apical straightening compared with the other instruments ( P < 0.05 ; Mann-Whitney U test ) . In the apical cross-sections Alpha System result ed in significantly less uninstrumented canal walls compared with stainless steel files ( P < 0.05 ; chi-squared test ) . CONCLUSION Despite the demonstrated differences between the systems , an apical straightening effect could not be prevented ; areas of uninstrumented root canal wall were left in all regions using the various systems 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 INTRODUCTION The purpose of this study was to compare canal transportation and centering ability of 2 rotary nickel-titanium ( NiTi ) systems ( Twisted Files [ TF ] and Pathfile-ProTaper [ PP ] ) with conventional stainless steel K-files . METHODS Ninety root canals with severe curvature and short radius were selected . Canals were divided r and omly into 3 groups of 30 each . After preparation with TF , PP , and stainless steel files , the amount of transportation that occurred was assessed by using computed tomography . Three sections from apical , mid-root , and coronal levels of the canal were recorded . Amount of transportation and centering ability were assessed . The 3 groups were statistically compared with analysis of variance and Tukey honestly significant difference test . RESULTS Less transportation and better centering ability occurred with TF rotary instruments ( P < .0001 ) . K-files showed the highest transportation followed by PP system . PP system showed significant transportation when compared with TF ( P < .0001 ) . CONCLUSIONS The TF system was found to be the best for all variables measured in this study AIM To compare the cleaning ability and preparation time of rotary instruments ( Mtwo ) and conventional manual instruments ( K-file ) in preparing primary and permanent molar root canals . MATERIAL S AND METHODS Access cavities were prepared in 70 primary and 70 permanent teeth and  India ink was injected into 120 canals of selected molars . The teeth were r and omly divided into two main subgroups ( n=20 ) and three control groups ( n=10 ) . In each of these main subgroups , either the manual instrument ( K-file ) or the rotary system ( Mtwo ) was used to prepare root canals . After cleaning the canals and clearing the teeth , dye removal was evaluated with the help of a stereomicroscope . In addition , the time needed for root canal preparation was recorded by a chronometer . STATISTICAL ANALYSIS Statistical analyses were done using the Kruskal-Wallis , Mann-Whitney and t tests . RESULTS With regard to the cleaning ability of root canals , there were no significant differences between the K-file and Mtwo rotary system in primary and permanent teeth in the apical , middle or coronal third of the canals . Moreover , there were no significant differences between primary and permanent teeth prepared with K-files and rotary instruments . In all the groups , shorter times were recorded with the rotary technique . The working time was shorter in primary than in permanent teeth . CONCLUSION The Mtwo rotary system showed acceptable cleaning ability in both primary and permanent teeth , and achieved results similar to those of K-files in less time INTRODUCTION Nickel-titanium rotary instruments reduce procedural errors and the time required to finish root canal preparation . The goal of this study was to evaluate the occurrences of apical transportation and canal aberrations produced with different instruments used to create a glide path in the preparation of curved root canals , namely manual K-files ( Dentsply Maillefer , Ballaigues , Switzerl and ) and PathFile ( Dentsply Maillefer ) and Mtwo ( Sweden and Martina , Padua , Italy ) nickel-titanium rotary files . METHODS The mesial canals of 45 m and ibular first and second molars ( with curvature angles between 25 ° and 35 ° ) were selected for this study . The specimens were divided r and omly into 3 groups with 15 canals each , and canal preparation was performed by an endodontist using # 10 - 15 - 20 K-type stainless steel manual files ( group M ) , # 13 - 16 - 19 PathFile rotary instruments ( group PF ) , and # 10 - 15 - 20 Mtwo rotary instruments ( group MT ) . The double digital radiograph technique was used , pre- and postinstrumentation , to assess whether apical transportation and /or aberration in root canal morphology occurred . The initial and final images of the central axis of the canals were compared by superimposition through computerized analysis and with the aid of magnification . The specimens were analyzed by 3 evaluators , whose calibration was checked using the Kendall agreement test . RESULTS No apical transportation or aberration in root canal morphology occurred in any of the teeth ; therefore , no statistical analysis was conducted . CONCLUSIONS Neither the manual instruments nor the PathFile or Mtwo rotary instruments used to create a glide path had any influence on the occurrence of apical transportation or produced any canal aberration
target: Conclusions The results of this systematic review suggested that NiTi rotary instruments were associated with lower canal transportation and apical extrusion when compared to SST h and files , whereas both groups had similar outcomes in terms of success of therapy , amount of residual bacteria , and cleansing ability after treatment .
background: Introduction This systematic review evaluated the effectiveness of  nickel‐titanium ( NiTi ) rotary files compared to stainless‐steel ( SST ) h and files .