human
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: INTRODUCTION The extrusion of irrigation solutions beyond the apical constriction may result in postoperative pain .  Sodium hypochlorite can cause severe tissue irritation and necrosis outside the root canal system if extruded into the periodontal ligament ( PDL ) space . Different delivery techniques were discussed to reduce this potential risk . The aim of this study was to compare the postoperative level of pain after root canal therapy using either endodontic needle irrigation or a negative apical pressure device . MATERIAL AND METHODS In a prospect i ve r and omized clinical trial , 110 asymptomatic single-rooted anterior and premolar teeth were treated endodontically with two different irrigation techniques . The teeth were r and omly assigned to two groups . In the MP group ( n = 55 ) , procedures were performed using an endodontic irrigating syringe ( Max-i-Probe ; Dentsply Rinn , Elgin , IL ) . The EV group ( n = 55 ) used an irrigation device based on negative apical pressure ( EndoVac ; Discus Dental , Culver City , CA ) . Postoperatively , the patients were prescribed ibuprofen 200 mg to take every 8 hours if required . Pain levels were assessed by an analog scale question naire after 4 , 24 , and 48 hours . The amount of ibuprofen taken was recorded at the same time intervals . RESULTS During the 0- to 4- , 4- to 24- , and 24- to 48-hour intervals after treatment , the pain experience with the negative apical pressure device was significantly lower than when using the needle irrigation ( p < 0.0001 [ 4 , 24 , 48 hours ] ) . Between 0 and 4 and 4 and 24 hours , the intake of analgesics was significantly lower in the group treated by the negative apical pressure device ( p < 0.0001 [ 0 - 4 hours ] , p = 0.001 [ 4 - 24 hours ] ) . The difference for the 24- to 48-hour period was not statistically different ( p = 0.08 ) . The Pearson correlation coefficient revealed a strongly positive and significant relationship for the MP group ( r = 0.851 , p < 0.001 ) and the EV group ( r = 0.596 , p < 0.0001 ) between pain intensity and the amount of analgesics . CONCLUSION The outcome of this investigation indicates that the use of a negative apical pressure irrigation device can result in a significant reduction of postoperative pain levels in comparison to conventional needle irrigation INTRODUCTION Oval-shaped root canals might represent a great challenge for proper disinfection . This study compared the capability of a newly developed instrument , the self-adjusting file ( SAF ) , and rotary nickel-titanium ( NiTi ) instrumentation to eliminate Enterococcus faecalis population s from long oval root canals of extracted human teeth . As a secondary purpose , the ability of a modification in sampling technique to recover bacteria lodged in recesses of oval canals was evaluated . METHODS Long oval canals from m and ibular incisors and maxillary second premolars were infected with E. faecalis ( ATCC 29212 ) for 30 days and then r and omly distributed into 2 experimental groups . In group 1 , canals were prepared up to a 40/04 rotary BioRaCe instrument by using irrigation with NaviTip needles ; in group 2 , canals were prepared by using the SAF system with continuous irrigation . NaOCl and ethylenediaminetetraacetic acid were used as irrigants . Bacteriologic sample s were taken before ( S1 ) and after preparation ( S2a and S2b ) . RESULTS Reduction in the bacterial population s was highly significant in both groups ( P < .001 ) . Preparation of long oval canals with the SAF was significantly more effective than rotary NiTi instrumentation in reducing intracanal E. faecalis counts ( P = .01 ) . Frequency of positive cultures in S2 sample s was 11 of 20 ( 55 % ) for rotary instrumentation and 4 of 20 ( 20 % ) for SAF instrumentation ( P = .048 ) . S2b sample s ( modified method ) yielded more positive sample s than S2a ( 12/40 vs 5/40 ) , but this difference reached no statistical significance ( P > .05 ) . CONCLUSIONS The SAF system was significantly more effective than rotary NiTi instrumentation used with syringe/needle irrigation in disinfecting long oval root canals in vitro . A modified sampling technique might be necessary for oval canals This in vivo , prospect i ve , r and omized , single-blinded study histologically compared biofilm/necrotic debridement efficiency of a h and /rotary technique versus a h and /rotary/1 min ultrasound technique in the mesial roots of necrotic , human m and ibular molars . The h and /rotary group consisted of 20 mesial roots . The h and /rotary/ultrasound group consisted of 20 mesial roots  prepared with the same h and /rotary technique followed by 1 min of ultrasonic irrigation , per canal , utilizing an ultrasonic needle in a MiniEndo unit . Following extraction , histologic preparation and staining , 0.2 mum cross-sections from the 1- to 3-mm apical levels were evaluated for percentage of biofilm/necrotic debris removal . Cleanliness results at the 1- , 2- and 3-mm levels for the h and /rotary and h and /rotary/ultrasound techniques , respectively , were : Canals , 80 % versus 95 % , 92 % versus 99 % , and 95 % versus 100 % ; Isthmuses , 33 % versus 83 % , 31 % versus 86 % , 45 % versus 91 % . Statistical analysis revealed mean percent canal and isthmus cleanliness values to be significantly higher for h and /rotary/ultrasound technique at all levels evaluated This study is to investigate the efficacy of different irrigant activation techniques on removal of accumulated hard tissue debris ( AHTD ) in mesial roots of human m and ibular molars . Extracted human m and ibular molars with an isthmus between the mesial root canals were selected based on micro-CT ( μCT ) scans . The mesial canals were instrumented to an apical diameter ISO30 using ProTaper rotary files . Teeth were r and omly assigned to three irrigant activation groups ( n = 10 ) : ultrasonically activated irrigation ( UAI ) using a size 20 Irrisafe for 3 × 20 s , laser-activated irrigation ( LAI ) with an Er : YAG laser ( 2940 nm ) and plain 300 μm fiber tip inside the canal ( 20 mJ , 20 Hz , 3 × 20 s ) , and laser-activated irrigation with identical parameters with a 400 μm photon-induced photoacoustic streaming ( PIPS ) tip held at the canal entrance . All teeth were scanned with μCT before and after instrumentation and after irrigant activation . After reconstruction and image processing , the canal system volume filled with hard tissue debris before and after irrigant activation was calculated . Changes in hard tissue debris volumes were compared between groups using one-way ANOVA . The percentage volume of hard tissue debris ( vol% ) was significantly lower after irrigant activation in all groups . Although the lowest debris values were observed in the laser groups , no significant differences in the vol% of accumulated hard tissue debris after activation were observed between groups . Accumulated hard tissue debris was reduced significantly in all activation groups . Ultrasonically and laser-activated irrigation regimens performed similarly in this respect . None of the tested methods was able to render the root canal systems free of debris INTRODUCTION Studies using conventional endodontic protocol s show insufficient cleaning of root canal systems , often result ing in persistent infection and treatment failure . The GentleWave System ( GWS ; Sonendo , Inc , Laguna Hills , CA ) has been shown to result in a higher tissue dissolution rate in a study using bovine muscle . The purpose of this study was to compare the debridement efficacy of the GWS with a traditional method for cleaning root canals . METHODS Forty-five freshly extracted molars were r and omly separated into 3 treatment groups ( n = 15/group ) : group 1 , no treatment ; group 2 , conventional rotary instrumentation and needle irrigation ; and group 3 , minimal instrumentation and the GWS treatment . Roots were prepared per st and ard histologic tissue processing after hematoxylin-eosin staining ; sections were microscopically examined , and the percentage of soft tissue and debris remaining within the canals was morphometrically calculated . Images of the apical and middle regions of the roots were blindly analyzed . RESULTS Significant differences ( Welch 's t test ) were found between groups 2 and 3 in both apical ( P = .0015 ) and middle ( P = .0179 ) regions of the mesial roots of m and ibular molars and mesiobuccal roots of maxillary molars . Groups 2 and 3 result ed in cleaning 67.8 % and 97.2 % of the mesiobuccal and mesiolingual root canals of m and ibular molars and the mesiobuccal canals of maxillary molars , respectively , whereas the results were similar among groups 2 and 3 in the apical and middle regions of distal roots . Groups 2 and 3 revealed significantly less debris than group 1 ( P < .005 ) . CONCLUSIONS The GWS showed a significantly greater cleaning capacity and reduction in residual debris within the mesiobuccal and mesiolingual canals of m and ibular molars and the mesiobuccal canals of maxillary molars than those cleaned conventionally Ninety-four single-canal roots were prepared using the step-down technique . Forty-two canals were irrigated with 2 % chlorhexidine , 42 canals with 5.25 % sodium hypochlorite ( NaOCl ) , and 10 control canals  with phosphate-buffered saline ( PBS ) . The chlorhexidine and NaOCl groups were each then equally divided into a final irrigation group and a 1-min passive ultrasonic irrigation group . Canals were enlarged with a Parapost drill . The apical 3 - 5 mm was covered with nail polish . Canals were rinsed with PBS , dried , refilled with PBS , and stored . At 6 h , 20 microl of fluid was pipetted from each canal and placed into wells on agar plates , which were inoculated with Streptococcus sanguinis . The plates were incubated , and zones of inhibition were measured . Sampling was repeated at 24 , 48 , 72 , 96 , 120 , 144 , and 168 h. Residual antimicrobial activity with 2 % chlorhexidine was statistically significantly superior to 5.25 % NaOCl with irrigation alone and with final passive ultrasonic activation ( p < 0.001 ) . Chlorhexidine experimental groups demonstrated residual antimicrobial activity for as long as 168 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 
    Output:
    
agent
Results showed that mechanical active irrigation reduces post-operative pain .
It improved debridement , canal/isthmus cleanliness .
It also improved delivery of irrigant up to working length .
Bacterial count was more with active irrigation , though not significant .
There is no effect on long-term periapical healing .
Conclusion It may be concluded that mechanical active irrigation devices are beneficial in reducing post-operative pain and improving canal and isthmus cleanliness during Endodontics
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: INTRODUCTION The extrusion of irrigation solutions beyond the apical constriction may result in postoperative pain .  Sodium hypochlorite can cause severe tissue irritation and necrosis outside the root canal system if extruded into the periodontal ligament ( PDL ) space . Different delivery techniques were discussed to reduce this potential risk . The aim of this study was to compare the postoperative level of pain after root canal therapy using either endodontic needle irrigation or a negative apical pressure device . MATERIAL AND METHODS In a prospect i ve r and omized clinical trial , 110 asymptomatic single-rooted anterior and premolar teeth were treated endodontically with two different irrigation techniques . The teeth were r and omly assigned to two groups . In the MP group ( n = 55 ) , procedures were performed using an endodontic irrigating syringe ( Max-i-Probe ; Dentsply Rinn , Elgin , IL ) . The EV group ( n = 55 ) used an irrigation device based on negative apical pressure ( EndoVac ; Discus Dental , Culver City , CA ) . Postoperatively , the patients were prescribed ibuprofen 200 mg to take every 8 hours if required . Pain levels were assessed by an analog scale question naire after 4 , 24 , and 48 hours . The amount of ibuprofen taken was recorded at the same time intervals . RESULTS During the 0- to 4- , 4- to 24- , and 24- to 48-hour intervals after treatment , the pain experience with the negative apical pressure device was significantly lower than when using the needle irrigation ( p < 0.0001 [ 4 , 24 , 48 hours ] ) . Between 0 and 4 and 4 and 24 hours , the intake of analgesics was significantly lower in the group treated by the negative apical pressure device ( p < 0.0001 [ 0 - 4 hours ] , p = 0.001 [ 4 - 24 hours ] ) . The difference for the 24- to 48-hour period was not statistically different ( p = 0.08 ) . The Pearson correlation coefficient revealed a strongly positive and significant relationship for the MP group ( r = 0.851 , p < 0.001 ) and the EV group ( r = 0.596 , p < 0.0001 ) between pain intensity and the amount of analgesics . CONCLUSION The outcome of this investigation indicates that the use of a negative apical pressure irrigation device can result in a significant reduction of postoperative pain levels in comparison to conventional needle irrigation INTRODUCTION Oval-shaped root canals might represent a great challenge for proper disinfection . This study compared the capability of a newly developed instrument , the self-adjusting file ( SAF ) , and rotary nickel-titanium ( NiTi ) instrumentation to eliminate Enterococcus faecalis population s from long oval root canals of extracted human teeth . As a secondary purpose , the ability of a modification in sampling technique to recover bacteria lodged in recesses of oval canals was evaluated . METHODS Long oval canals from m and ibular incisors and maxillary second premolars were infected with E. faecalis ( ATCC 29212 ) for 30 days and then r and omly distributed into 2 experimental groups . In group 1 , canals were prepared up to a 40/04 rotary BioRaCe instrument by using irrigation with NaviTip needles ; in group 2 , canals were prepared by using the SAF system with continuous irrigation . NaOCl and ethylenediaminetetraacetic acid were used as irrigants . Bacteriologic sample s were taken before ( S1 ) and after preparation ( S2a and S2b ) . RESULTS Reduction in the bacterial population s was highly significant in both groups ( P < .001 ) . Preparation of long oval canals with the SAF was significantly more effective than rotary NiTi instrumentation in reducing intracanal E. faecalis counts ( P = .01 ) . Frequency of positive cultures in S2 sample s was 11 of 20 ( 55 % ) for rotary instrumentation and 4 of 20 ( 20 % ) for SAF instrumentation ( P = .048 ) . S2b sample s ( modified method ) yielded more positive sample s than S2a ( 12/40 vs 5/40 ) , but this difference reached no statistical significance ( P > .05 ) . CONCLUSIONS The SAF system was significantly more effective than rotary NiTi instrumentation used with syringe/needle irrigation in disinfecting long oval root canals in vitro . A modified sampling technique might be necessary for oval canals This in vivo , prospect i ve , r and omized , single-blinded study histologically compared biofilm/necrotic debridement efficiency of a h and /rotary technique versus a h and /rotary/1 min ultrasound technique in the mesial roots of necrotic , human m and ibular molars . The h and /rotary group consisted of 20 mesial roots . The h and /rotary/ultrasound group consisted of 20 mesial roots  prepared with the same h and /rotary technique followed by 1 min of ultrasonic irrigation , per canal , utilizing an ultrasonic needle in a MiniEndo unit . Following extraction , histologic preparation and staining , 0.2 mum cross-sections from the 1- to 3-mm apical levels were evaluated for percentage of biofilm/necrotic debris removal . Cleanliness results at the 1- , 2- and 3-mm levels for the h and /rotary and h and /rotary/ultrasound techniques , respectively , were : Canals , 80 % versus 95 % , 92 % versus 99 % , and 95 % versus 100 % ; Isthmuses , 33 % versus 83 % , 31 % versus 86 % , 45 % versus 91 % . Statistical analysis revealed mean percent canal and isthmus cleanliness values to be significantly higher for h and /rotary/ultrasound technique at all levels evaluated This study is to investigate the efficacy of different irrigant activation techniques on removal of accumulated hard tissue debris ( AHTD ) in mesial roots of human m and ibular molars . Extracted human m and ibular molars with an isthmus between the mesial root canals were selected based on micro-CT ( μCT ) scans . The mesial canals were instrumented to an apical diameter ISO30 using ProTaper rotary files . Teeth were r and omly assigned to three irrigant activation groups ( n = 10 ) : ultrasonically activated irrigation ( UAI ) using a size 20 Irrisafe for 3 × 20 s , laser-activated irrigation ( LAI ) with an Er : YAG laser ( 2940 nm ) and plain 300 μm fiber tip inside the canal ( 20 mJ , 20 Hz , 3 × 20 s ) , and laser-activated irrigation with identical parameters with a 400 μm photon-induced photoacoustic streaming ( PIPS ) tip held at the canal entrance . All teeth were scanned with μCT before and after instrumentation and after irrigant activation . After reconstruction and image processing , the canal system volume filled with hard tissue debris before and after irrigant activation was calculated . Changes in hard tissue debris volumes were compared between groups using one-way ANOVA . The percentage volume of hard tissue debris ( vol% ) was significantly lower after irrigant activation in all groups . Although the lowest debris values were observed in the laser groups , no significant differences in the vol% of accumulated hard tissue debris after activation were observed between groups . Accumulated hard tissue debris was reduced significantly in all activation groups . Ultrasonically and laser-activated irrigation regimens performed similarly in this respect . None of the tested methods was able to render the root canal systems free of debris INTRODUCTION Studies using conventional endodontic protocol s show insufficient cleaning of root canal systems , often result ing in persistent infection and treatment failure . The GentleWave System ( GWS ; Sonendo , Inc , Laguna Hills , CA ) has been shown to result in a higher tissue dissolution rate in a study using bovine muscle . The purpose of this study was to compare the debridement efficacy of the GWS with a traditional method for cleaning root canals . METHODS Forty-five freshly extracted molars were r and omly separated into 3 treatment groups ( n = 15/group ) : group 1 , no treatment ; group 2 , conventional rotary instrumentation and needle irrigation ; and group 3 , minimal instrumentation and the GWS treatment . Roots were prepared per st and ard histologic tissue processing after hematoxylin-eosin staining ; sections were microscopically examined , and the percentage of soft tissue and debris remaining within the canals was morphometrically calculated . Images of the apical and middle regions of the roots were blindly analyzed . RESULTS Significant differences ( Welch 's t test ) were found between groups 2 and 3 in both apical ( P = .0015 ) and middle ( P = .0179 ) regions of the mesial roots of m and ibular molars and mesiobuccal roots of maxillary molars . Groups 2 and 3 result ed in cleaning 67.8 % and 97.2 % of the mesiobuccal and mesiolingual root canals of m and ibular molars and the mesiobuccal canals of maxillary molars , respectively , whereas the results were similar among groups 2 and 3 in the apical and middle regions of distal roots . Groups 2 and 3 revealed significantly less debris than group 1 ( P < .005 ) . CONCLUSIONS The GWS showed a significantly greater cleaning capacity and reduction in residual debris within the mesiobuccal and mesiolingual canals of m and ibular molars and the mesiobuccal canals of maxillary molars than those cleaned conventionally Ninety-four single-canal roots were prepared using the step-down technique . Forty-two canals were irrigated with 2 % chlorhexidine , 42 canals with 5.25 % sodium hypochlorite ( NaOCl ) , and 10 control canals  with phosphate-buffered saline ( PBS ) . The chlorhexidine and NaOCl groups were each then equally divided into a final irrigation group and a 1-min passive ultrasonic irrigation group . Canals were enlarged with a Parapost drill . The apical 3 - 5 mm was covered with nail polish . Canals were rinsed with PBS , dried , refilled with PBS , and stored . At 6 h , 20 microl of fluid was pipetted from each canal and placed into wells on agar plates , which were inoculated with Streptococcus sanguinis . The plates were incubated , and zones of inhibition were measured . Sampling was repeated at 24 , 48 , 72 , 96 , 120 , 144 , and 168 h. Residual antimicrobial activity with 2 % chlorhexidine was statistically significantly superior to 5.25 % NaOCl with irrigation alone and with final passive ultrasonic activation ( p < 0.001 ) . Chlorhexidine experimental groups demonstrated residual antimicrobial activity for as long as 168 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 
    Output:
    