***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 : This single‐blind , r and omized controlled trial aim ed to evaluate whether foraminal enlargement ( FE ) with a continuous rotary system during endodontic treatment causes more postoperative pain than nonforaminal enlargement ( NFE ) . Methods : Seventy qualified patients were r and omized into 1 of 2 groups in a 1:1 ratio using a series of r and om numbers : the FE group and the NFE group . The patients were followed up for 7 days to evaluate between‐group differences in the outcome measures . The study participants were selected from among patients who had necrosis and apical periodontitis in the maxillary or m and ibular molar teeth . The primary outcome was to assess postoperative pain severity , and the secondary outcome was to evaluate analgesic consumption during the follow‐up period . Pain severity was evaluated for the first 7 days using a visual analog scale ( VAS ) . The VAS consisted of a 100‐mm line . Pain severity was assessed as no pain ( 0–4 mm ) , mild pain ( 5–44 mm ) , moderate pain ( 45–74 mm ) , and severe pain ( 75–100 mm ) . The quality of life of patients during the follow‐up period was assessed using a quality of life scale . The Student t test was used to identify statistically significant differences between the study groups ( P < .05 ) . Results : A significant difference was noted in postoperative pain in the first 2 days ; the FE group experienced more pain than the conventional NFE group ( P < .05 ) . In the FE group , 12 and 11 patients ( 34 % and 31 % ) had severe postoperative pain ( VAS score , > 74 mm ) on the first day and second day , respectively . VAS pain scores between the groups were not different ( P > .05 ) on other days . No significant difference was found in analgesic consumption between the groups ( P > .05 ) . Conclusions : On the basis of the VAS results , this r and omized controlled trial indicates that FE causes more pain on the first 2 days after an endodontic treatment Objectives The purpose of this prospect i ve , r and omized , double-blind study was to compare postoperative pain of root canal treatment in patients with asymptomatic m and ibular molar teeth with necrotic pulp and periapical lesion using three different instrumentation techniques : h and , multi-file rotary ( ProTaper Universal ) , and reciprocating single-file ( Wave-One ) instrumentation techniques . Material s and methods Ninety-six patients who fulfilled specific inclusion criteria were assigned to three groups according to the root canal instrumentation technique used : H and ( G1 ) , ProTaper Universal ( G2 ) , and Wave-One ( G3 ) . One-visit root canal treatment was carried out , and the severity of the postoperative pain was assessed by the Heft-Parker visual analogue scale 6 , 12 , 18 , 24 , 48 , and 72 h after treatment . Data were analyzed by Kruskal-Wallis , χ2 , Cochrane Q , one-way ANOVA , and Spearman ’s correlation analyses ( α = 0.05 ) . Results The patients in group 3 reported significantly lower postoperative pain levels at 6 , 12 , and 18 h compared with the patients in the two other groups ( P < .05 ) . In addition , the patients in group 2 reported significantly lower postoperative pain levels at 6 and 12 h compared with the patients in group 1 ( P < .05 ) . There were no significant differences in postoperative pain between the three groups at other time intervals ( P > .05 ) . The analgesic consumption was significantly higher in group 1 ( P < .05 ) , but no difference was seen between the two other groups ( P > .05 ) . Clinical relevance Postoperative pain was significantly lower in patients undergoing root canal instrumentation with the Wave-One file compared with the ProTaper Universal and h and files Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more The occurrence of new carious lesions is among the most detrimental side effects in subjects undergoing orthodontic therapy with fixed appliances . The present study evaluated the efficacy of repeated applications of a 40 % chlorhexidine varnish in this patient group with regard to long-term suppression of elevated mutans streptococci levels and the frequency and location of new carious lesions .  Thirty-three prospect i ve orthodontic patients age 11 to 18 harboring more than 105 mutans streptococci per ml saliva at the initial examination participated in the study . At baseline the previous carious involvement in each subject was recorded using the DMFS index , and extensive information on caries prevention was given . Using a r and om assignment 18 subjects were included in the test group while the remaining 15 subjects were assigned to the placebo group . From the time of b and ing until removal of the fixed appliances ( median : 21 months ) salivary mutans streptococci counts were recorded once every 8 weeks in both groups . At the same appointment all teeth and intraoral appliances in the test group were coated with a 40 % chlorhexidine varnish . Subjects in the placebo group were treated in the same way , using a placebo varnish with the same varnish base . After deb and ing , the DMFS score of each participant was recorded again . Analysis of the data revealed that mutans streptococci counts in the test group were only temporarily suppressed and were restored almost to baseline levels by the end of the study . In both groups a clinical ly relevant increase in the average DMFS score was recorded . Inter-group differences were not significant . ZusammenfassungDas Auftreten neuer kariöser Läsionen zählt zu den gravierendsten unerwünschten Nebenwirkungen kieferorthopädischer Therapie mit festsitzenden Geräten . In dieser Studie wurde untersucht , ob bei Patienten mit Multib and apparaturen die regelmäßige Applikation eines 40%igen Chlorhexidin-Lacks auf Zähne und inkorporierte Geräte hohe Mutans-Streptokokken-Zahlen langfristig zu supprimieren und die Entstehlung neuer kariöser Läsionen zu verhindern vermag.33 prospektive Multib and patienten i m Alter von elf bis 18 Jahren , die zum Zeitpunkt der Erstuntersuchung mehr als 105 Mutans-Streptokokken pro ml Speichel aufwiesen , nahmen an der Studie teil . Zu Studienbeginn wurden der bisherige Kariesbefall jedes Prob and en mit Hilfe des DMFS-Index ermittelt und die Prinzipien kariesprophylaktischer Mundhygiene sowie Ernährungslenkung intensiv mit dem Patienten besprochen . Dem Zufallsprinzip folgend wurden darauf 18 Prob and en der Chlorhexidin-Gruppe und 15 Prob and en der Plazebogruppe  zugeordnet . Während des Zeitraums der Bebänderung ( Medianwert : 21 Monate ) wurden in beiden Gruppen i m achtwöchigen Rhythmus der Kontrolluntersuchungen die Mutans-Streptokokken-Zahlen i m Speichel erneut bestimmt . In der Testgruppe wurden zudem alle Zähne und eingebrachten Geräte mit einem 40%igen Chlorhexidin-Lack überschichtet . Prob and en der Plazebogruppe erhielten einen  chlorhexidinfreien Plazebolack  auf identischer Lackbasis . Nach Entbänderung wurde bei allen Prob and en der DMFS-Wert erneut erfasst . Die Analyse der Date n zeigt , dass die Mutans-Streptokokken-Zahlen in der Chlorhexidin-Gruppe nur eine vorübergehende signifikante Absenkung erfuhren und sich am Studienende wieder dem Ausgangswert annäherten . In beiden Untersuchungstruppen kam es zu einer klinisch relevanten Zunahme des DMFS-Wertes . Unterschiede zwischen Test- und Plazebogruppe konnten nicht verifiziert werden The purpose of this prospect i ve study was to evaluate the incidence of postoperative pain after intracanal procedures based on an antimicrobial strategy . Data were examined from 627 teeth that had necrotic pulps or required retreatment . Information was obtained for each patient treated with regard to presence of preoperative pain . Occurrence of periradicular bone destruction detected by radiographs was also recorded . The operators consisted of undergraduate students , who were in their first year of clinical training . Root canals were instrumented and then medicated with a calcium hydroxide/camphorated paramonochlorophenol paste . No systemic medication was prescribed . Approximately 1 week after the initial appointment , patients were asked about the occurrence of postoperative pain and the level of discomfort was rated as no pain , mild pain , moderate pain , or severe pain . Data were statistically analyzed using the Chi-square test . Mild pain occurred in 10 % of the cases , moderate in 3.3 % , and severe ( flare-up ) in 1.9 % . Postoperative pain was significantly associated with the treatment of previously symptomatic teeth without periradicular lesions ( p < 0.01 ) . No other correlations were detected between the occurrence of postoperative discomfort and other clinical conditions . There was also no difference regarding the incidence of postoperative pain between treatment and retreatment ( p > 0.01 ) . The intracanal procedures used in this study to control root canal infections showed a small incidence of postoperative pain , particularly flare-ups , even performed by inexperienced undergraduate dental students INTRODUCTION The aim of this r and omized , controlled , prospect i ve clinical study was to determine if foraminal enlargement instrumentation during endodontic treatment is associated with more postoperative pain compared with st and ard nonenlargement instrumentation . METHODS Forty volunteers with a single root canal were diagnosed with asymptomatic necrosis with apical periodontitis and r and omized into 2 experimental groups ( ie , the control group and the foraminal enlargement group ) . Endodontic treatment was performed in a single visit , and volunteers were instructed to record pain intensity ( ie , none , slight , moderate , and severe ) . Scores from 1 to 4 were attributed to each kind of pain after 12 , 24 , and 48 hours . The Kolmogorov-Smirnov and Student 's t tests were used to determine significant differences at P < .05 . RESULTS No statistically significant age difference was found between the groups ( P > .05 , Student 's t test ) . Postoperative pain showed no statistically significant difference between the groups at any observation period ( P > .05 ) . Also , no significant difference was observed in the mean number of analgesic tablets used between the groups ( P > .05 ) . CONCLUSIONS The foraminal enlargement and nonenlargement techniques result ed in the same postoperative pain and necessity for analgesic medication . This may suggest that the use of foraminal enlargement should be performed for endodontic treatment previsibility without increasing postoperative pain INTRODUCTION The aim of this prospect i ve study was to evaluate the postoperative pain that followed root canal treatments performed with a single-file reciprocating system on asymptomatic uniradicular necrotic teeth with and without foraminal enlargements ( FEs ) . METHODS Forty-six volunteers were r and omly divided into 2 groups according to the established working lengths . The FE group had a working length of 0.0 mm from the apex , and the control group had a working length of 1.0 mm short of the apex . The treatments of both groups were performed with a Reciproc R40 ( VDW , Munich , Germany ) instrument . Both groups underwent the same treatment protocol with the exception of the established working length . The volunteers were instructed to record their pain ( none , mild , moderate , or severe ) on a visual analog scale at 24 hours , 72 hours , and 1 week after the procedures . The Kruskal-Wallis test was used to identify significant differences . RESULTS Overall , 82.22 % of the patients indicated no pain or mild pain . A greater proportion of the patients in the FE group reported mild pain compared with patients in the control group in the first 24 hours ( P < .05 ) . At 72 hours and 1 week , there were no statistically significant differences between the groups ( P > .05 ) . CONCLUSIONS FEs during endodontic treatments of asymptomatic necrotic , uniradicular teeth that were performed in single visits using the Reciproc R40 reciprocating file result ed in a low incidence of pain . After 24 hours , the FEs result ed in more patients reporting mild pain compared with the control group , but no differences were observed at 72 hours or 1 week INTRODUCTION The objective of the present study was to clinical ly compare the incidence of postoperative pain and the intake of analgesic medication ( frequency and quantity ) after endodontic treatment of posterior teeth using 2 reciprocating systems and a continuous rotary system . METHODS In a prospect i ve r and omized clinical study , 210 patients with vital teeth indicated for conventional endodontic treatment were treated by 5 specialists according to a pre-established protocol . The teeth were r and omly assigned to 1 of 3 groups ( n = 70 ) according to the instrumentation system used : ProTaper Next ( Dentsply Tulsa Dental Specialties , Johnson City , TN ) , WaveOne ( Dentsply Tulsa Dental Specialties ) , or Reciproc ( VDW , Munich , Germany ) . Treatments were performed in a single visit . After the visit , the patients were given a prescription for ibuprofen 400 mg to be taken every 6 hours if they experienced pain . Participants were asked to rate the intensity of the postoperative pain on a visual analog scale according to 4 classes ( no pain , mild pain , moderate pain , and severe pain ) after 24 hours , 48 hours , 72 hours , and 7 days . Patients were also asked to record 
    Output:
    
Limited data indicated that no significant difference was found in analgesic consumption , flare‐up , and swelling between the groups .
Conclusions Postoperative pain was higher in the FE group compared with conventional endodontic therapy in the first days after treatment in teeth with necrosis and apical periodontitis .
Five studies were included in the systematic review .Meta‐ analysis showed that foraminal enlargement provides higher pain in the first days .