***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: Innovations in periradicular surgery for failed treatment of ortho grade root canal disease have been well-documented . We know of no prospect i ve studies that have compared success rates of conventional methods with these presumed advances . In this prospect i ve r and omised trial we compare the use of an ultrasonic retrotip with a microhead bur in the preparation of a retro grade cavity . Outcome was estimated clinical ly by estimation of pain , swelling , and sinus , and radiographically by looking at infill of bone and retro grade root filling 2 weeks and 6 months postoperatively . Both methods used other surgical techniques including microinstruments to place the retro grade root filling . The success rate of the ultrasonic method was higher ( all patients , n=26 ) than that of the microhead method ( n=19 of 21 ) . A larger study with longer follow up is required to consoli date this evidence OBJECTIVE R and omized clinical prospect i ve study to evaluate the application of MTA and IRM as retro grade sealers in surgical endodontics . STUDY DESIGN One hundred single-rooted teeth were surgically treated . After r and omization , MTA or IRM was used as a retrosealer . Radiographs were taken 1 week , 3 months , and 1 year postoperatively . Assessment was performed by 2 independent assessors 1 year after surgery . Both treatment groups were homogeneous in their composition , and clinical features and radiographic findings were classified according to Rud 's classification . RESULTS Complete healing was observed in 64 % of the MTA-treated teeth vs 50 % of the IRM-treated teeth . Incomplete healing was seen in 28 % ( MTA ) vs 36 % ( IRM ) , and unsatisfactory in 6 % ( MTA ) vs 14 % ( IRM ) . Only 1 failure was seen ( MTA ) . No statistically significant differences were found between the 2 retrofilling material s. CONCLUSION As root-end filling material s in this clinical prospect i ve r and omized design on single rooted teeth , MTA and IRM had the same clinical effectiveness This article covers a 4-year study that reports 320 cases in which endodontic surgery was performed for residual apical lesions or lesions that could not be treated in a conventional way . Four groups of 80 teeth each were formed and they were followed up after a 12-month interval . The first group comprised cases treated with a micro bur , retro grade filling and IRM ; the second , cases treated at the apical and radicular portions with a CO2 laser ; the third , cases in which the retro grade cavity was prepared with an ultrasonic device instead of a micro bur ; and the fourth group comprised cases treated in a similar way to the second group , i.e. , cases treated at the apical and radicular portions , but with a CO2 laser instead of a micro bur . After 12 months , the results showed a better prognosis with ultrasonic treatment . Regardless of technique , the CO2 laser did not improve the healing process OBJECTIVE To evaluate the pain experience following root-end resection and filling with Mineral Trioxide Aggregate or Intermediate Restorative Material . STUDY DESIGN Referred adult patients recruited using strict entry criteria were r and omly allocated to receive either material . A st and ardized surgical technique was employed . Postoperative instructions and a pain question naire were given to each patient to record the severity of their pain at 3 time intervals-3 - 5 hours , 24 hours , and 48 hours after surgery-on a st and ard visual analog scale ( VAS ) . Patients were also asked to record consumption of any self-prescribed analgesics , the type , and dosage . RESULTS At 3 - 5 hours after surgery , regardless of the material used , 90 % of all patients experienced some level of postoperative pain . Twenty-four hours after surgery 82 % of patients experienced pain , as did 72 % after 48 hours . Thirty-seven percent of patients did not take any analgesics at all . In order of popularity , the analgesics taken were ibuprofen , acetaminophen , and acetaminophen plus codeine phosphate . The VAS measurements were reduced over time in both treatment groups ( P < .001 ) . There was no statistically significant difference in the proportion of subjects taking analgesics in each treatment group . Patients who used analgesics showed higher median VAS measurements at all time periods ( P < .05 ) . CONCLUSIONS There was no significant difference in the pain experienced by both treatment groups . The postoperative pain was of a relatively short duration , at its maximum intensity early in the postoperative period but progressively decreased with time . Even if pain relief medication was needed , nonprescription analgesics were adequate and effective OBJECTIVES This prospect i ve r and omized study compared the outcome of retreatment and surgical intervention in root canal treated teeth with nonhealing periradicular pathosis . STUDY DESIGN One such tooth from each of 38 patients was r and omly allotted to retreatment or root-end resection and root-end filling . Treatment outcome after 1 year was evaluated and compared clinical ly and radiographically . RESULTS The success rate for surgery was higher than for conventional retreatment , but the difference was not statistically significant . CONCLUSIONS For management of nonhealing periradicular pathosis associated with root canal treated teeth , surgical intervention should be considered as an alternative to retreatment . In cases with a similar prognosis for both modes of treatment , the choice should be governed by consideration of intrinsic and extrinsic factors INTRODUCTION The purpose of the present study was to evaluate the clinical outcomes of endodontic microsurgery when super ethoxy-benzoic acid ( Super EBA ; Harry J. Bosworth , Skokie , IL ) and mineral trioxide aggregate ( MTA ) were used as root-end filling material s in a prospect i ve r and omized controlled study . METHODS Of the 388 teeth eligible for endodontic microsurgery , 128 teeth were excluded from the study , and 260 teeth were r and omly assigned to either the Super EBA group or the MTA group with equal numbers using the " minimization method . " Endodontic microsurgical procedures were performed according to the Yonsei protocol reported in a previous study and were carried out by a single operator . The patients were followed up at 3 , 6 , and 12 months . The primary outcome measure was the change in the apical bone density at 12 months , and the secondary outcome measures were the presence of clinical symptoms or abnormal findings at 12 months . RESULTS A total of 192 teeth were examined at the 12-month follow-up ; 102 teeth were in the Super EBA group , and 90 were in the MTA group . The overall success rate was 94.3 % , with a success rate of 95.6 % ( 86/90 teeth ) for MTA and 93.1 % ( 95/102 teeth ) for Super EBA . The statistical analysis of the success rate results did not show any significant difference between the groups ( P = .472 ) . CONCLUSIONS In this prospect i ve r and omized controlled study , there was no significant difference in the clinical outcomes of endodontic microsurgery when Super EBA and MTA were used as root-end filling material OBJECTIVE The purpose of this study was to evaluate the potential benefit of an ultrasonic device in apical surgery on the outcome of treatment . STUDY DESIGN A r and omized prospect i ve design was used in a st and ardized treatment protocol . Patients were allocated to treatment with an ultrasonic device ( P-Max Newtron ) or treatment with a bur in an otherwise similar protocol . One year after treatment the results were evaluated by 2 oral and maxillofacial surgeons who were blinded for the therapy . RESULTS Out of a total group of 399 patients who were included in the study , adequate follow-up could be obtained in 290 patients . The overall success rate in the ultrasonic group was 80.5 % and in the group treated with a bur 70.9 % ( P = .056 ) . In molars , the difference in success rate was significant ( P = .02 ) . CONCLUSION The use of an ultrasonic device in apical surgery improved the outcome of treatment . In molars this effect was significant AIM To assess the success rate of the root-end filling material , Mineral Trioxide Aggregate ( MTA ) . METHODOLOGY Referred adult patients were recruited using strict entry criteria and r and omly allocated to receive MTA or IRM . A st and ardized surgical technique was employed : the root end was resected perpendicularly and a root-end cavity was prepared ultrasonically and filled . A radiograph taken immediately after surgery was compared with those taken at 12 and 24 months . Customised film holders and the paralleling technique were used ; radiographs were assessed by two trained observers using agreed criteria . The results from 122 patients ( 58 in IRM group , 64 in MTA group ) after 12 months and 108 patients ( 47 in IRM group , 61 in MTA group ) for the 24-month review period were analysed using the chi2 test . RESULTS The highest number of teeth with complete healing at both times was observed when MTA was used . When the numbers of teeth with complete and incomplete ( scar ) healing , and those with uncertain and unsatisfactory healing were combined , the success rate for MTA was higher ( 84 % after 12 months , 92 % after 24 months ) compared with IRM ( 76 % after 12 months , 87 % after 24 months ) . However , statistical analysis showed no significant difference in success between material s ( P > 0.05 ) at both 12 and 24 months . CONCLUSIONS In this study , the use of MTA as a root-end filling material result ed in a high success rate that was not significantly better than that obtained using IRM AIM To compare healing responses to periosteal sliding grafts and polyglactin 910 periodontal mesh used as guided tissue regeneration ( GTR ) material s/techniques when both periapical and periradicular bone loss are present . METHODOLOGY Thirty patients with suppurative chronic apical periodontitis with apicomarginal communication were selected and allocated r and omly into two groups according to the barrier technique to be used during periradicular surgery : periosteal graft group ( n = 15 ) and bioabsorbable membrane group ( n = 15 ) . Clinical and radiological evaluations were completed prior to surgery , a week later and every 3 months after surgery up to 12 months to measure the periodontal pocket depth ( PD ) , clinical attachment level ( CAL ) , gingival margin position ( GMP ) , size of periapical lesion , percentage reduction of the periapical rarefaction , and periapical healing . RESULTS Both groups showed highly significant ( P < 0.001 ) reductions in periodontal PD , CAL and size of periapical lesion at 12 months whilst GMP was unaltered . No significant difference between the experimental groups was evident for these parameters , or for the percentage reduction of size of the periapical lesion and clinical -radiographic healing . CONCLUSION Guided tissue regeneration applied to apicomarginal defects using sliding periosteal grafts and use of bioabsorbable membranes led to similar enhancements of the clinical outcome of periradicular surgery in terms of periapical healing , gain of periodontal support , PD reduction and minimal recession of the gingival margin The purpose of this prospect i ve clinical study was to assess the rate of healing of periapical bony defects created at the time of endodontic periapical surgery  by measuring the densitometric ratio change in periapical osseous tissues , after periapical endodontic surgery was performed , by using or not using Guidor bioresorbable membrane material . Periapical surgeries were performed on 25 patients where nonsurgical root canal therapy had failed and a periapical lesion was present . For inclusion in the study , the osseous defect to be analyzed had to be confined to the apical area , with bone covering the entire root surface coronally , and an intact lingual cortical plate had to be present . A series of radiographs at the 3- , 6- , and 12-month recalls were compared with the radiograph taken immediately after surgery by using digital imaging and a densitometric ratio that gave a numerical estimation of osseous healing . Using repeated-measure ANOVA , it was shown that there was no statistical difference between the rate of healing in those cases where a Guidor resorbable membrane was used and those cases where no membrane was used . The results suggest that placement of a guided tissue membrane over the bony opening created during an endodontic periapical surgical procedure has no beneficial effect on the rate of healing and the added expense to the patient would not be warranted in these cases PURPOSE The introduction of microsurgical instruments and magnification devices has brought advantages in root-end management and the application of root-end filling material s. The main purpose of this prospect i ve clinical study was to monitor the outcome of ultrasonic root-end preparation using magnification loupes or an endoscope . Tooth location and the presence of post restoration were also examined as potentially affecting the outcome . MATERIAL S AND METHODS Teeth treated surgically showed a periradicular lesion of strictly endodontic origin . A total of 59 patients were included in the study , according to specific selection criteria . Following the reflection of a full mucoperiosteal tissue flap , residual soft tissues were curetted , root ends were resected , and root-end cavities were prepared ultrasonically with a zirconium nitrate tip , and zinc oxide EBA-reinforced cement root-end fillings were placed . Thirty-two root-end management procedures were performed using magnification loupes and 39 using an endoscope . All cases followed for a period of 1 year were classified into 3 groups ( success , uncertain healing , and failure ) according to radiographic and clinical criteria . RESULTS Of the 71 teeth evaluated at 1-year follow- 
    Output:
    
Available evidence does not provide clinicians with reliable guidelines for treating periapical lesions .