Bacterial reduction with nickel-titanium rotary instrumentation. Effect of three nickel-titanium rotary file techniques on infected root dentin reduction. A retrospective study of endodontic treatment outcome between nickel-titanium rotary and stainless steel hand filing techniques. 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. Comparison of canal transportation and centering ability of twisted files, Pathfile-ProTaper system, and stainless steel hand K-files by using computed tomography. Ex vivo study on root canal instrumentation of two rotary nickel-titanium systems in comparison to stainless steel hand instruments. Alignment efficiency of superelastic coaxial nickel-titanium vs superelastic single-stranded nickel-titanium in relieving mandibular anterior crowding: a randomized controlled prospective study. Alleviation of mandibular anterior crowding with copper-nickel-titanium vs nickel-titanium wires: a double-blind randomized control trial. Improved quality of root fillings provided by general dental practitioners educated in nickel-titanium rotary instrumentation. Nickel-titanium rotary instrument fracture: a clinical practice assessment. [Safety and efficacy of gastrointestinal anastomosis with nickel titanium compression anastomosis clip]. Influence of the NiTi rotary system on the debridement quality of the root canal space. Nickel content of as-received, retrieved, and recycled stainless steel brackets. Clinical study of single-visit root canal treatment with a nickel-titanium (Ni-Ti) rotary instrument combined with different ultrasonic irrigation solutions for elderly patients with chronic apical periodontitis. The timing of significant arch dimensional changes with fixed orthodontic appliances: data from a multicenter randomised controlled trial. Efficiency, behavior, and clinical properties of superelastic NiTi versus multistranded stainless steel wires: a prospective clinical trial. A randomized clinical trial investigating pain associated with superelastic nickel–titanium and multistranded stainless steel archwires during the initial leveling and aligning phase of orthodontic treatment
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 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 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 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 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 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 OBJECTIVE To clinical ly evaluate the alignment efficiency of 0.016-inch coaxial superelastic nickel-titanium ( NiTi ) and 0.016-inch superelastic NiTi in the lower anterior region over a period of 12 weeks . MATERIAL S AND METHODS A sample of 24 patients requiring lower anterior alignment were included in this single-center , single-operator , double-blind clinical trial and were r and omly allocated into two groups of 12 patients . The type of wire selected for each patient was not disclosed to the provider or to the patient . Comparison of pretreatment characteristics of the archwire groups revealed no discrimination between two sample s , thus verifying the r and om allocation of the intervention . An initial alginate impression of the lower arch was followed by impressions at 4- , 8- , and 12-week intervals . Casts were measured using the coordinate measuring machine to denote the degree of alignment . Duplicate readings of the cast series were taken to assess measurement variation . RESULTS A statistically significant difference ( P < .05 ) in the mean values of tooth movement demonstrated the superior aligning efficiency of coaxial superelastic NiTi over single-str and ed superelastic NiTi in relieving lower anterior crowding . The measurement error recorded was within acceptable limits , with range values within 95 % limits of agreement . CONCLUSION Coaxial superelastic NiTi wire proved superior to single-str and ed NiTi in its efficiency in relieving lower anterior crowding over a 12-week period INTRODUCTION The purpose of this study was to investigate the efficiency of copper-nickel-titanium ( CuNiTi ) vs nickel-titanium ( NiTi ) archwires in resolving  crowding of the anterior m and ibular dentition . METHODS Sixty patients were included in this single-center , single-operator , double-blind r and omized trial . All patients were bonded with the In Ovation-R self-ligating bracket ( GAC , Central Islip , NY ) with a 0.022-in slot , and the amount of crowding of the m and ibular anterior dentition was assessed by using the irregularity index . The patients were r and omly allocated into 2 groups of 30 patients , each receiving a 0.016-in CuNiTi 35 degrees C ( Ormco , Glendora , Calif ) or a 0.016-in NiTi ( ModernArch , Wyomissing , Pa ) wire . The type of wire selected for each patient was not disclosed to the provider or the patient . The date that each patient received a wire was recorded , and all patients were followed monthly for a maximum of 6 months . Demographic and clinical characteristics between the 2 wire groups were compared with the t test or the chi-square test and the Fisher exact test . Time to resolve crowding was explored with statistical methods for survival analysis , and alignment rate ratios for wire type and crowding level were calculated with Cox proportional hazards multivariate modeling . RESULTS The type of wire ( CuNiTi vs NiTi ) had no significant effect on crowding alleviation ( 129.4 vs 121.4 days ; hazard ratio , 1.3 ; P > 0.05 ) . Severe crowding ( > 5 on the irregularity index ) showed a significantly higher probability of crowding alleviation duration relative to dental arches with a score of < 5 ( 138.5 vs 113.1 days ; hazard ratio , 2.2 ; P=0.02 ) . CONCLUSIONS The difference of the loading pattern of wires in laboratory and clinical conditions might effectively eliminate the laboratory-derived advantage of CuNiTi wires AIM To test the hypothesis that an increased utilization of nickel-titanium rotary instrumentation ( NTRI ) by general dental practitioners will lead to an increased frequency of good quality root fillings . A second aim was to determine whether the educational format would exert influence on the quality . METHODOLOGY Dentists were assigned at r and om to three intervention groups : a 4-h lecture  ( L-group , n = 40 ) ; a 4-h lecture plus a full day h and s-on course  ( LH-group , n = 40 ) ; or a control group receiving no instruction ( n = 68 ) . The control group received education later on in the study . Radiographs of two root filled molar teeth per dentist were selected at r and om before the start of the education program and after a 6-month clinical learning period . Using length , seal and shape of root-fillings a 5-level variable was created . RESULTS The rate of good quality root fillings increased after the introduction of NTRI . Calculated over all types of roots the frequency of excellent ( score 1 ) root fillings increased from 31 % to 51 % ( P = 0.006 ) in the L-group and from 27 % to 47 % ( P = 0.016 ) in the LH-group . The frequency of low quality root-fillings ( score 5 ) dropped in the L-group from 22 % to 16 % ( P = 0.29 ) and in the LH-group from 13 % to 9 % ( P = 0.48 ) . No statistically significant difference was seen among the controls . CONCLUSIONS When NTRI technology replaced manual stainless steel techniques the rate of good quality root fillings increased . A significant drop in the rate of low quality root fillings was not found 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 OBJECTIVE To assess the safety and efficacy of gastrointestinal anastomosis with nickel titanium shape memory alloy compression anastomosis clip . METHODS We r and omized 51 patients to undergo gastrointestinal anastomosis with stapler ( n=25 ) and nickel titanium compression anastomosis clip ( n=26 ) respectively . The following parameters were recorded to evaluate the safety and efficacy : mean hospitalization time , anastomotic complication , first post-operation flatus and bowel movement , and extrusion of the clip . RESULTS Anastomotic complications such as leakage , stenosis and obstruction were not observed in both groups . There were no significant differences in the first post-operation flatus time and bowel movement time between the 2 groups ( P>0.05 ) . The clip was expelled with stool within 9 - 15 d. CONCLUSION Compression anastomosis clip is safe and effective OBJECTIVE The present study was design ed to test the null hypothesis that there is no significant difference in debridement quality promoted by 3 nickel-titanium ( NiTi ) rotary systems . STUDY DESIGN Sixty-seven vital m and ibular molars that were prospect ively collected in vivo were used . The teeth were extracted and then pulp tissue fixed by 10 % formalin . The use of different NiTi rotary systems result ed in 3 experimental groups with 20 specimens each : G1 : Hero 642 ; G2 : K3 ; and G3 : ProTaper Universal . Afterward , the specimens were histologically prepared and serial 0.5 microm cross-sections were obtained every 0.2 mm from the 1 - 3 mm apical levels . The remaining pulp tissue was assessed using a morphometric approach . The cross-sectional area of each root canal and remaining pulp tissue were measured ( mcirom(2 ) ) . Thus , the percentages of remaining pulp tissue area were calculated for each root canal . RESULTS Overall , the pooled data obtained from all levels revealed a variable amount of remaining pulp tissue for all experimental groups . Remaining pulp tissue existed in every specimen . However , the Kruskal-Wallis H test was unable to show significant differences among the experimental groups ( P > .05 ) for the pooled data from all levels . CONCLUSIONS The present study did not find a significant difference in the quality of canal debridement between different NiTi rotary systems , because an adequate tapered shape is obtained The purpose of this study was to investigate the composition of as-received , retrieved , and recycled stainless steel brackets .  New , used , and recycled br and -matched , slot size-matched , and prescription-matched appliances were subjected to scanning electron microscopy and energy dispersive electron probe micro analysis . Elemental analysis was performed on r and omly selected surface bracket base and wing areas , and metal content was statistically analyzed with the 2-way ANOVA and the Tukey test , with treatment ( as-received , retrieved , and recycled ) and bracket regions ( base and wing ) serving as discriminating variables ( alpha = 0.05 ) . The results showed that there was no difference in the surface composition of the base ; however , surface area-wing analysis indicated that nickel content was decreased in retrieved and recycled specimens , implying that an ionic release effect occurred in vivo . Differences were noted between bracket base and wing with respect to elemental composition for the same brackets , implying that the base and wings are manufactured from different alloys The study involved 300 elderly patients with chronic periapical periodontitis . The patients were r and omly assigned into three groups . The treatment for group A used a Mtwo Ni-Ti rotary instrument combined with ultrasonic irrigation of a 2.5 % NaOCl solution . The group B used the same instrument combined with ultrasonic irrigation of an active silver ion antibacterial solution . The group C used the same instrument combined with syringe irrigation of a 2.5 % NaOCl solution . The root canal fillings were performed immediately after canal preparation . Twenty-four hours after the procedure , patients self-assessed pain levels according to the VAS table . The three groups returned after seven days so their postoperative acute reactions could be evaluated clinical ly . After six and twelve months , efficacy was evaluated . The self-assessed pain levels for group A and B were significantly lower than group C. The incidence of postoperative acute reactions after seven days for group A and B were significantly lower than those of group C. The effective rates after six and twelve months did not differ among these groups . The single-visit root canal treatment with a nickel-titanium rotary instrument combined with ultrasonic irrigation for elderly patients with chronic periapical periodontitis achieved short and long term efficacy and stability OBJECTIVES To identify the timing of significant arch dimensional increases during orthodontic alignment involving round and rectangular nickel-titanium ( NiTi ) wires and rectangular stainless steel ( SS ) . A secondary aim was to compare the timing of changes occurring with conventional and self-ligating fixed appliance systems . METHODS In this non- primary publication , additional data from a multicenter r and omised trial initially involving 96 patients , aged 16 years and above , were analysed . The main pre-specified outcome measures were the magnitude and timing of maxillary intercanine , interpremolar , and intermolar dimensions . Each participant underwent alignment with a st and ard Damon ( Ormco , Orange , CA ) wire sequence for a minimum of 34 weeks . Blinding of clinicians and patients was not possible ; however , outcome assessors and data analysts were kept blind to the appliance type during data analysis . RESULTS Complete data were obtained from 71 subjects . Significant arch dimensional changes were observed relatively early in treatment . In particular , changes in maxillary inter-first and second premolar dimensions occurred after alignment with an 0.014 in . NiTi wire ( P<0.05 ) . No statistical differences in transverse dimensions were found between rectangular NiTi and working SS wires for each transverse dimension ( P>0.05 ) . Bracket type had no significant effect on the timing of the transverse dimensional changes . CONCLUSIONS Arch dimensional changes were found to occur relatively early in treatment , irrespective of the appliance type . Nickel-titanium wires may have a more profound effect on transverse dimensions than previously believed . CLINICAL SIGNIFICANCE On the basis of this research orthodontic expansion may occur relatively early in treatment . Nickel-titanium wires may have a more profound effect on transverse dimensions than previously believed OBJECTIVE To investigate efficiency , behavior , and properties of superelastic NiTi vs multistr and ed stainless steel wires in Begg and preadjusted edgewise appliance ( PEA ) under moderate to severe crowding conditions . MATERIAL AND METHODS Ninety-six participants ( 48 male , 48 female ) , aged 12 - 18 years old ( mean age = 15.2 ± 1.95 ) , with moderate ( ≤ 6 mm ; mean = 5.3 ± 0.48 ) to severe ( > 6 mm ; mean = 7.9 ± 0.66 ) initial crowding were distributed into four groups : superelastic NiTi PEA ( n = 24 ) , superelastic NiTi Begg ( n = 24 ) , multistr and ed ( coaxial ) stainless steel PEA ( n = 25 ) , and multistr and ed ( coaxial ) stainless steel Begg ( n = 23 ) . In this study , 0.16-inch superelastic ( austenitic active ) NiTi and 0.175-inch multistr and ed ( six str and ed , coaxial ) stainless steel wires were used in a 0.022-inch slot ( Roth prescription ) PEA and Begg appliance with a follow-up of six weeks . RESULTS Analysis of variance revealed no significant difference in reduction of crowding  between superelastic NiTi PEA and multistr and ed ( coaxial ) stainless steel PEA groups , but reduction in crowding was significantly greater in the superelastic NiTi Begg group compared with the multistr and ed ( coaxial ) stainless steel Begg group with F ( 3 , 44 ) = 8.896 , P < .001 , and effect size ( ω ) 0.57 in moderate crowding and F ( 3 , 44 ) = 122.341 , P < .001 , and effect size ( ω ) 0.93 in severe crowding . Linear regression demonstrated significant ( P < .05 ) positive correlation between amount of initial crowding and reduction in crowding in all groups except the multistr and ed ( coaxial ) stainless steel Begg group , wherein a negative correlation did exist . CONCLUSION Superelastic NiTi performed significantly better than multistr and ed ( coaxial ) stainless steel wire in the Begg appliance . However , in PEA , there was no significant difference Objective To investigate and compare the effects of superelastic nickel – titanium and multistr and ed stainless steel archwires on pain during the initial phase of orthodontic treatment . Design A double-blind two-arm parallel design stratified r and omized clinical trial . Setting A single centre in India between December 2010 and June 2012 . A total of 96 participants ( 48 male and 48 females ; 14.1±2.1 years old ) were r and omized ( stratified on age , sex and initial crowding ) to superelastic nickel – titanium or multistr and ed stainless steel archwire groups using a computer-generated allocation sequence . Methods We compared 0.016-inch superelastic nickel – titanium and 0.0175-inch multistr and ed stainless steel wires in 0.022-inch slot ( Roth prescription ) preadjusted edgewise appliances . The follow-up period was 14 days . Outcome was assessed with a visual analogue scale at baseline and 32 pre-specified follow-up points . Data was analyzed using mixed-effects model analysis . Results One participant was lost to follow up and 10 were excluded from the analysis due to bond failure or incomplete question naire answers . Ultimately , 85 participants ( 42 males and 43 females ; 14.1±2.0 years old ) were analysed for the final results . No statistically significant difference was found for overall pain [ F value = 2.65 , degrees of freedom ( df ) = 92.6 ; P = 0.1071 ] . However , compared to multistr and ed stainless steel wires , pain in subjects with superelastic nickel – titanium archwires was significantly greater at 12 h ( t = 2.34 ; P = 0.0193 ) , as well as at day 1 in the morning ( t = 2.21 , P = 0.0273 ) , afternoon ( t = 2.11 , P = 0.0346 ) and at bedtime ( t = 2.03 , P = 0.042 ) . Conclusion For overall pain , there was no statistically significant difference between the two wires . However , subjects with superelastic nickel – titanium archwires had a significantly higher pain at peak level
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 .
Introduction This systematic review evaluated the effectiveness of  nickel‐titanium ( NiTi ) rotary files compared to stainless‐steel ( SST ) h and files .