Vol. 112 No. 2 August 2011

ENDODONTOLOGY Editor: Larz S.W. Spångberg

Super-EBA and IRM as root-end fillings in periapical surgerywith ultrasonic preparation: a prospective randomizedclinical study of 206 consecutive teethDan-Åke Wälivaara, DDS,a Peter Abrahamsson, DDS,b Maria Fogelin, DDS,c andSten Isaksson, MD, DDS, PhD,d Halmstad, SwedenMAXILLOFACIAL UNIT, HALMSTAD HOSPITAL

Objective. This study evaluated the treatment outcome after periapical surgery with the use of 2 different retrograderoot-filling materials and the influence of 3 pre- and perioperative variables on the periapical healing.Study design. Two hundred six teeth in 164 patients were randomly allocated to receive either IRM or Super-EBA as aretrograde root-end seal. The teeth were reviewed 12 months after surgery. The influence of lesion size, lesion type,and orthograde root filling quality on healing was analyzed.Results. One hundred ninety-four teeth in 153 patients were reviewed. Radiologic evaluation and clinical examinationrevealed 91% success rate for the IRM group and 82% for the Super-EBA group. There was no statistical significancein the healing outcome between the 2 groups (Fisher exact test). The analyzed pre- and perioperative variables had nosignificant influence on the treatment outcome (Z test).Conclusions. Both retrograde materials tested in this study can serve as a root-end seal in periapical infected teeth,according to the results of the healing outcome after 12 months’ follow-up. (Oral Surg Oral Med Oral Pathol Oral

Radiol Endod 2011;112:258-263)

Periapical surgery is an advantageous treatment methodwhen faced with a tooth with a failed previous orthograderoot-filling procedure. Conventional endodontic treatmentis reported to succeed in 79%-96% of cases.1,2 If it fails,revision of the orthograde root filling should be consid-ered first. This procedure is reported to have a 62%success rate,2 but in many cases the revision of the ortho-grade root filling has to be performed by removing aprosthetic crown or post, a procedure which can be a riskfactor in causing root fracture. In such cases a periapicalsurgical procedure is beneficial despite the quality of theorthograde root filling. The causal factors of failed con-

aConsultant in Oral and Maxillofacial Surgery.bConsultant in Oral and Maxillofacial Surgery.cConsultant in Oral and Maxillofacial Radiology.dProfessor in Oral and Maxillofacial Surgery.Received for publication Nov 9, 2010; returned for revision Dec 16,2010; accepted for publication Jan 6, 2011.1079-2104/$ - see front matter© 2011 Mosby, Inc. All rights reserved.

doi:10.1016/j.tripleo.2011.01.016

258

ventional endodontic treatment may be bacterial leakagefrom the coronal direction due to insufficient root-fillingor residual infective material more likely in the maincanal. Remaining bacterial material in the lateral canals,usually in the apical part of the root, could also be a causeof a persistent apical periodontitis. The main goal is toperform a resection of the apical portion of the root of �3mm, which reduces up to 93% of the lateral canals,3

followed by a preparation of the root-canal using an ul-trasonic technique and a retrograde apical seal of the canalwith a retrograde root-filling material. The use of ultra-sonic retrotips when cleaning the root canal has beenreported to result in a cleaner and well centered prepara-tion compared with a traditional round-bur technique4 andhigher healing figures in clinical studies.5,6 IRM, Super-EBA, and mineral trioxide aggregate are the most com-monly used materials for retrograde fillings, and both invivo and in vitro studies have been reported.7-11 We havepreviously published studies with IRM and thermoplasti-cized gutta-percha as retrograde root-filling materials inconjunction with an ultrasonic preparation technique.12,13

One of the first publications reporting the use of Super-

OOOOEVolume 112, Number 2 Wälivaara et al. 259

EBA as a retrograde root-filling material revealed goodsealing ability and biocompatibility.14 A clinical prospec-tive study with a 1-year follow-up concluded that perira-dicular surgery on molar teeth with Super-EBA gives apredictable treatment outcome with a success rate up to96%.15 A long-term follow-up study on all types of teethshowed 91.5% healing 5-7 years after periapical surgerywith Super-EBA as a retrograde seal.16

The aim of the present prospective study was to eval-uate and analyze the outcome of periapical surgery with aretrograde ultrasonic cleaning technique in conjunctionwith the use of 2 different retrograde root-filling materials,IRM and Super-EBA. This study included consecutivepatients referred to the department for an apical surgeryprocedure on all types of teeth. The second aim was to seeif 3 different parameters—the quality of the orthograderoot-filling, type of lesion (granuloma or cyst) ,and lesionsize—had an influence on the treatment outcome. Thestudy was approved by the human ethical committee at theUniversity of Lund, Sweden.

MATERIAL AND METHODSTwo hundred six consecutive teeth in 164 patients

(99 women and 65 men), the majority living a maxi-mum of 40 km from the hospital, were included in thestudy between September 2006 and December 2008.All teeth were included except those with obvious rootfractures or advanced periodontal disease (e.g., apicalmarginal communications). The included teeth wererandomly allocated into 2 groups receiving either IRM(99 teeth) or Super-EBA (107 teeth) as a retrograderoot-end filling. The randomization procedure was per-formed using a standard randomization table.

Preoperative examinationBefore surgery, a radiographic examination was per-

formed with 2 intraoral radiographs in different angles,together with a clinical examination. The quality of theorthograde root-filling judged from radiographs was notan inclusion criterion for participating in the study, butrather all teeth were included. The pre- and perioperativevariables noted were type of coronal restoration, presenceand type of post in the root canal, presence of periodontalpockets �5 mm, type of lesion (cyst or granuloma) setfrom a perioperative assessment, presence of intact buccalcortical bone, and the status of the root-filling judged fromthe radiograph (Table I). All patients were carefully in-formed about the study and the intended procedure. Thepatients could at any time terminate their participation inthe study. No financial compensation was given to thepatients except a free-of-charge 1-year follow-up.

Surgical procedureAll surgical procedures were performed by 2 surgeons

using �2.3 magnification operating loupes. Local anes-

thesia of 3.6-5.4 mL 2% lidocaine with adrenaline wasinjected into the operating field as both infiltration and/orID nerve blocks depending on the region. A full-thicknessmucoperiosteal buccal flap was raised over the affectedtooth. The bony periapical area was exposed using a roundbur. Enucleation of the granuloma or cyst from the peri-apical area was followed by a 3–4-mm slightly obliqueresection of the root with a fissure bur. The root canal wasprepared and cleaned with ultrasonic root-end cavity prep-aration of 3 mm in depth (Sybron Endo; EMS; and dia-mond-coated retrotips; EndoMark). All preparations in thealveolar bone, the apicectomies, and the ultrasonic prep-aration were performed under constant saline solutionirrigation. To achieve hemostasis in the operating field, asmall gauze soaked with 1% adrenaline was packed intothe bone cavity for 2-3 minutes. The canal was thenthoroughly dried with 70% alcohol and endodontic paperpoints. The prepared canals were filled with handspatu-lated IRM or Super-EBA (Bosworth). The flap was su-tured with Vicryl 4-0 sutures. Two intraoral radiographswere taken immediately after the operation.

Clinical and radiographic evaluationAfter a minimum of 1 year (range 12-21 months,

average 13.1 months) radiographic and clinical exam-inations were performed. The clinical reviews of thepatients were made by 1 of 4 independent surgeonsaccording to a protocol. Registration of clinical findingssuch as tenderness on percussion, tenderness on palpa-tion of the crown and/or in the apical area, gingivalswelling, and presence of a fistula or an apicomarginal

Table I. Pre- and perioperative protocolVariable Comment

Type of restoration Filling or crown/bridge restorationNumber of

affected/treatedcanals

Presence of root-canalpost

Composite, screw-post, or cast

Presence of pockets �6 mmType of lesion Granuloma or cyst set from a

clinical evaluationSize of the lesion Graduated from a clinical evaluation

of the diameter of the lesion intothree groups: 1) �5 mm; 2) 5-9mm; 3) �9mm

Buccal bone status Presence of buccal bone coverage ofthe tooth

Quality of the orthograderoot filling

Evaluated on the preoperativeradiograph as complete,incomplete, shortage, or overfilled

Type of retrograderoot-end filling

IRM or Super-EBA

Perioperativehemostasis

Sufficient or insufficient

communication was recorded as a failure.

OOOOE260 Wälivaara et al. August 2011

All radiographs were reviewed independently by the 2operating surgeons and a maxillofacial radiologist, with asubsequent joint discussion if there was any disagreementabout the findings. Measurements and classifications ac-cording to previously reported models for healing afterperiapical surgery17,18 were performed. The following 4different classifications were used: 1) complete healing; 2)incomplete healing (scar tissue); 3) uncertain healing; and4) unsatisfactory healing. The second group, incompletehealing (scar tissue) could be regarded as success at the1-year follow-up.19 Groups 1 and 2 were recorded assuccess and groups 3 and 4 as failures.

For a successful outcome no clinical or radio-graphic findings showing signs of remaining infec-tion should be present. The collected and registeredinformation was analyzed. Success and failure ratesfor each material and the results between differentareas in the mouth were calculated. The possibleinfluence on the treatment outcome of 3 pre-/periop-erative parameters was also analyzed: lesion size,lesion type, and orthograde root filling quality.

RESULTSOne hundred ninety-four teeth (96 IRM and 98 Super-

EBA) in 153 patients were assessed. The drop-outs were8 teeth (2 IRM and 6 Super-EBA) in 7 patients. Four teeth(1 IRM and 3 Super-EBA) were excluded owing to rootfractures discovered during the follow-up period.

IRM groupOf the 96 followed teeth in the IRM group, the radio-

logic assessment placed 82 teeth in group 1, completehealing (Fig. 1); 8 teeth in group 2 (Fig. 2), incompletehealing (scar tissue); 5 teeth in group 3, uncertain healing(Fig. 3); and 1 tooth in group 4, unsatisfactory healing.Following the final clinical and radiologic examinations, atotal of 9 failures were recognized. The success and failurerates were calculated on 96 teeth, with success in 87 teeth(90.6%) and failure in 9 (9.4%; Table II).

Super-EBA groupOf the 98 followed teeth in the Super-EBA group, the

radiologic assessment placed 72 teeth in group 1, completehealing; 10 teeth in group 2, incomplete healing (scar tissue);12 teeth in group 3, uncertain healing; and 4 teeth in group 4,unsatisfactory healing. After the clinical and radiologic ex-amination results, there were a total of 18 failures. Thesuccess and failure rates were calculated on 98 teeth with 80successful teeth (81.6%) and 18 failures (18.4%; Table II).

Overall treatment resultsThe distribution of success and failure numbers

among different types of teeth, retrograde material type,

and upper and lower jaw are presented in Table II.

Distribution and influence of pre-/perioperativevariables

The results of the number of different lesion size,lesion type, and quality of the orthograde root filling

Fig. 1. Tooth 36 with an affected distal root in a 22-year-oldman treated with IRM: (A) preoperative, (B) postoperative, and(C) at follow-up showing complete healing (group 1).

for the reviewed teeth are presented in Tables III and

OOOOEVolume 112, Number 2 Wälivaara et al. 261

IV. These 3 variables were statistically analyzedaccording to their possible influence on the treatmentoutcome.

Statistical analysisFisher exact test was used for a statistical analysis

regarding the differences in healing between the ret-rograde materials. There was no statistical signifi-

Fig. 2. Tooth 23 in a 73-year-old man treated with Super-EBAincomplete healing (scar tissue; group 2).

Fig. 3. Tooth 31 in a 42-year-old man treated with IRM: (uncertain healing (group 3).

cance between the 2 groups (IRM and Super-EBA)

regarding the healing outcome as it applied to alltypes of teeth; P � .096. When looking for differenttypes of teeth and the breakdown into maxillary andmandibular teeth (Table II) there was a significantdifference in the healing result between the materialgroups (IRM and Super-EBA) for maxillary molars;P � .024.

There was no statistical significance for the influ-

reoperative, (B) postoperative, and (C) at follow-up showing

operative, (B) postoperative, and (C) at follow-up showing

: (A) p

A) pre

ence on the healing result, taking either both mate-

OOOOE262 Wälivaara et al. August 2011

rials together or each material separately, when look-ing at the lesion type, lesion size, or the orthograderoot filling quality. The variable tests were per-formed with Z test.

DISCUSSIONThe overall result in this study was high considering the

entry requirements. Both material groups had relativelyhigh success figures: 90.6% for the IRM group and 81.6%for the Super-EBA group. There is no statistically signif-icant difference between the 2 groups when comparing alltypes of teeth. This could be explained by the fact that the

Table II. Outcome for different types of teeth in themaxilla and mandible in both material groups and sta-tistical result of the difference in healing between the 2material groups, n (%)

IRM (n � 96) Super-EBA (n � 98)

P valueSuccess Failure Success Failure

IncisorUpper 16 (94.1) 1 (5.9) 15 (93.8) 1 (6.2) 1.000Lower 4 (66.7) 2 (33.3) 0 1 (100) .429

CanineUpper 5 (83.3) 1 (16.7) 5 (100) 0 1.000Lower 3 (100) 0 1 (50.0) 1 (50.0) .400

PremolarUpper 17 (89.5) 2 (10.5) 15 (83.3) 3 (16.7) .660Lower 9 (90.0) 1 (10.0) 8 (80.0) 2 (20.0) 1.000

MolarUpper 16 (100) 0 14 (70.0) 6 (30.0) .024*Lower 17 (89.5) 2 (10.5) 22 (84.6) 4 (15.4) 1.000Total 87 (90.6) 9 (9.4) 80 (81.6) 18 (18.4) 0.096

*P � .05.

Table III. Distribution of lesion size and lesion typeamongst the 194 followed teethLesion size n Cysts, n (%) Granulomas, n (%)

�5 mm 56 1 (1.8) 55 (98.2)5-9 mm 102 11 (10.8) 91 (89.2)�9 mm 36 12 (33.3) 24 (66.7)Total 194 24 (12.4) 170 (87.6)

Table IV. Distribution of the preoperative quality ofthe orthograde root-fillings amongst the 194 reviewedteeth

Radiographic status n (%)

Complete (dense and 2 mm from apex) 36 (18.6)Uncomplete, shortage or overfilled 158 (81.4)Total 194

total number of teeth in the studied material is too small in

relation to the achieved difference between the 2 groups,although there was a power estimation before implemen-tation of the study of 80%, with a difference of 15% (90%vs. 75%, according to the literature) between success andfailure giving 100 teeth in each group. A statisticallysignificant difference was shown when comparing resultsin upper molars, which is explained by the lack of failuresin the IRM upper molar group. The figures for IRM aresimilar to the results from other studies, despite differentinclusion criteria and preparation techniques.7-9 The IRMresults in the present study are even higher compared withone earlier study where IRM showed a success of 76%after 12 months’ follow-up.8 That study furthermore in-cluded only a single anterior tooth, 1 root of a premolar, orthe mesiobuccal root of an upper molar for each partici-pating patient. No lower molars were included in thatstudy. Compared with the results for IRM in our ownpreviously published studies, our success rate has in-creased steadily, from 80% to 85%12,13 and, in the presentstudy, 91%. This may be due to the learning curve amongthe performing surgeons, such as the assistant’s ability tohandle the material.

Conversely, the explanation of the slightly lower suc-cess rate for Super-EBA may be explained by the shortertime Super-EBA has been used compared with IRM, byboth the 2 surgeons and the assistant nurses. Anothercause is a possible difference in consistency of Super-EBA compared with IRM. When mixing Super-EBAaccording to the manufacturer’s manual with a powder-liquid ratio of 2:1, as it was performed in this study, thematerial was found to be slightly too soft compared withIRM when inserting it into the prepared root canal. Thisresulted in a reduced height of the retrograde root filling,with the risk of a concomitant increase in rapid leakage.The long-term prognosis for the retrograde seal is thenimpaired. The consistency could probably have been al-tered by increasing the powder-liquid ratio, but we wantedto use the material according to the manufacturer’s direc-tions. Von Arx et al. reported 96% success on 25 molarstreated with ultrasonic root-end preparation and Super-EBA as a retrograde root-end seal.15 This is a high successrate but the sample is rather small compared with thepresent study. Another study comparing Super-EBA andamalgam as retrograde root-fillings in conjunction with aconventional round-bur technique reported a slightly in-creased success rate for Super-EBA (57%) after a 3-yearfollow-up.20 The results in that particular study were prob-ably dependent on the choice of preparation technique.6

In the present study, no histologic examination wasperformed to divide the apical lesions into granulomas orcysts. This was simply assessed on the basis of the clinicalevaluation of the lesion during the surgery together withthe preoperative radiographic findings. According to the

literature, the true diagnosis should be performed by the

OOOOEVolume 112, Number 2 Wälivaara et al. 263

help of histology with a proper sectioning technique.21

However, despite the lack of histologic evaluation of thelesions in the present study, the distribution of granulomasand cysts, according to our assessment, 87.6% and 12.4%,respectively, corresponds well with the reported incidencein the literature.21 The incidence of cysts increases withthe increasing size of the apical lesion.22 This fact wasconfirmed in the present study (Table III). The overalltreatment outcome in our material was not significantlyinfluenced by the presence of either a granuloma or a cyst.

The importance of a good orthograde endodontictreatment for a successful surgical treatment outcomehas been proposed, including a tight filling of the rootcanal.23 However, the present study did not suggest thatthe quality of the orthograde root filling would affectthe treatment outcome after a 12-month follow-up, buta long-term follow-up may alter that statement.

CONCLUSIONSThe results of this study show that both tested materials

can serve as satisfactory retrograde root-filling materialsaccording to outcome figures. A slight bias in favor ofIRM was found, but the figures for Super-EBA might beimproved by an alteration of the mixing powder/liquidratio to get a more plastic consistency. However, whatevermaterial is used by the surgical team, they must be con-fident in its handling and management. Finally, the influ-ence of the quality of the orthograde root filling, the lesionsize, and type of lesion is not a significant factor on thefinal treatment outcome.

The authors thank Andrew Brown, Visiting Specialist inOral and Maxillofacial Surgery, Länssjukhuset, Halmstad,for his input and discussion.

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Reprint requests:Dan-Åke WälivaaraMaxillofacial UnitHalmstad Hospital 13SE-301 85 HalmstadSweden

dan-ake.valivaara@regionhalland.se