A two-year report of a comparative randomized controlled trial on the treatment of upper central incisors with periapical lesions

ORIGINAL

ARTICLE/ARTICOLO

ORIGINALE

A

two-year

report

of

a

comparative

randomized

controlled

trial

on

the

treatment

of

upper

central

incisors

with

periapical

lesions

Risultati

a

due

anni

di

un

trial

clinico

controllato

randomizzato

comparativo

sul

trattamento

di

incisivi

centrali

superiori

con

lesione

periapicale

Daniele

Angerame

*

,

Matteo

De

Biasi

,

Vittorio

Franco

,

Lorenzo

Bevilacqua

,

Attilio

Castaldo

a

DentalClinic,UniversityClinicDepartmentofMedical,SurgicalandHealthSciences,UniversityofTrieste, Trieste,Italy

b

PrivatePractice,Rome,Italy

Received28October2016;accepted23December2016 Availableonline15February2017

KEYWORDS

Periapicallesion; Integratedendodontic techniques;

Carrierbasedsystems; Healing.

Abstract

Aim: Toevaluatethetwo-yearsuccessrateofprimaryrootcanaltreatmentperformedwithtwo integratedshapingandfillingsystemsonuppercentralincisorswithchronicperiapicalpathosis. Methodology: Thetrialenrolled60 patientswithanuntreatedmaxillarycentralincisor pre-sentingachronicperiapicallesionsmallerthan5mmindiameter,whowererandomlyassignedto twotreatmentgroups:G1(n=30),Revo-S/OneStepObturator;G2(n=30)GTX/GTXObturator. Thepatientsunderwentsingle-sessionrootcanaltreatmentsbyanexperiencedendodontistand werefollowedupfortwoyears.Theclinicalevaluationentailedpercussionandpalpationtests. Twoindependentexaminersratedtheradiographichealingonthebasisofapreviouslydescribed scale.Comparabilitybetweengroupsintermsofbaselineclinicalparameterswastestedwitha

Peer review under responsibility of Societa` Italiana di Endodonzia.

* Correspondingauthorat:UniversityofTrieste,DentalClinic,UniversityClinicalDepartmentofMedical,SurgicalandHealthSciences,Piazza

Ospedale 1, I-34125 Trieste, Italy.

E-mail: d.angerame@fmc.units.it(D. Angerame).

Availableonlineatwww.sciencedirect.com

ScienceDirect

jo ur na l h o m ep a ge : w w w.e ls e v i er.c o m / lo c at e /gi e

http://dx.doi.org/10.1016/j.gien.2017.01.001

1121-4171/ß2017Societa` ItalianadiEndodonzia.ProductionandhostingbyElsevierB.V.ThisisanopenaccessarticleundertheCCBY-NC-ND

Introduction

Inthemanagementoftheperiapicalpathosisofendodontic origin,thepurposeoftherootcanaltreatmentistoremove the necrotic tissue, as well as microorganisms from the endodonticsystem,thereby promotingthehealingof peri-apical tissues.1 To contribute to the successof root canal treatment, both an effective chemo-mechanical cleaning andatight three-dimensional seal oftherootcanalfilling shouldbeachieved.

Shapingandfillingtechniqueshaverecentlyundergonea process of simplification. An example of such trend is the decreaseofthenumber ofinstrumentsthatmodern rotary systemsarecomposedof.2Further,fillingtechniquesinvolving

carrier-basedsystemsprovidetheclinicianwiththe possibi-litytofillthewholerootcanalwiththermoplasticised gutta-perchainasinglestep.Fillingtechniquesperformedinfewer stepsmay beadvantageous—especially forneophytes and non-specialists—assimplifiedsystemsseemtobelessprone tocauseerrorsintheoperativeprocedure.Thisissupported bythefindingsofa microtomographicstudy,whichshowed howrootfillingsperformed bynoviceswith thecontinuous waveofcondensationtechniquecontainedhigheramountof voidsandtooklongertimes.3_{Inaddition,manufacturersand}

dealersofferintegrated endodonticssystems,in whichthe sizeofthefillinginstrumentsmatchesthatofshapingfiles. BothRevo-S(Micro-Mega,Besanc¸on,France)andGTXrotary files(DentsplyTulsaDentalSpecialties,Tulsa,OK,USA)canbe

PAROLECHIAVE Lesioneperiapicale; Tecnicheendodontiche integrate; Sistemicarrier-based; Guarigione.

Mann-Whitneytest(age,apicalgauging)andx2test(tendernesstopercussionandpalpation). Thecomparisonofclinicaldataandradiographichealingscoresbetweenthegroupsandamong timepointswascarriedoutwithnon-parametricstatisticalmethods(p<0.05).

Results: Thetwogroupswerecomparableintermsofbaselineclinicalparameters.Allpatients wereavailableforthere-evaluationaftertwoyears.Onlyonepatientpergroupwaspositiveto theclinicaltestsatthefinalrecall.Animprovementofradiographichealingscoresalongthe follow-up period wasobserved. After two years, thelesionswere scored astotally healed, partiallyhealedandnothealedin93.3%,3.3%and3.3%ofcasesinG1andin93.3%,0%and6.7%of casesinG2,withoutpointingoutstatisticallysignificantdifferencesbetweengroups. Conclusions: Boththetwotestedintegratedshapingandfillingsystemsprovedtobeeffective forthetreatmentofuppercentralincisorswithperiapicalpathosis.Whenmonitoringthehealing ofperiapicallesions,follow-uptimeslongerthanoneyearmayberequiredtoobservecomplete healing.

ß2017Societa` ItalianadiEndodonzia.ProductionandhostingbyElsevierB.V.Thisisanopen accessarticleundertheCCBY-NC-NDlicense(http://creativecommons.org/licenses/by-nc-nd/ 4.0/).

Riassunto

Obiettivi: Valutareiltassodisuccessoadueannideltrattamentoendodonticodiincisivicentrali superioriaffettidalesioneperiapicaleeseguitoconduesistemiintegratidistrumentazionee otturazione.

Materialiemetodi: Lostudiohacoinvolto60pazienticonunincisivomascellarecentralenon trattatoconlesioneperiapicale(diametro5mm),iqualisonostatiattribuiticasualmentea due gruppi di trattamento: G1 (n=30), Revo-S/One Step Obturator; G2 (n=30) GTX/GTX Obturator.Ipazientisonostatisottopostiatrattamentiendodonticiinsingolasedutaaopera diunendodontistaeseguitineltempoperdueanni.Lavalutazioneclinicae` consistitaneltestare ladolorabilita` allapalpazioneeallapercussione.Dueesaminatoriindipendentihannovalutatola guarigioneradiograficafacendoriferimentoaunascaladescrittainprecedenza.La compara-bilita` traigruppiinterminidiparametricliniciinizialie` stataverificatacontestMann-Whitney (eta`,gaugingapicale)ex2(sensibilita` apalpazioneepercussione).Ilconfrontodeidaticlinicie deipunteggiradiograficitraiduegruppietraitempisperimentalie` statocondottocontestnon parametrici(p<0,05).

Risultati: Iduegruppisonorisultatiparagonabiliinterminidiparametriclinicialbaseline.Tuttii pazientisisonoripresentatiallarivalutazionea2anni.Unsolopazientepergruppohariportato dolorabilita` aitestclinicialcontrollofinale.E` statoosservatounmiglioramentodeipunteggi radiograficiduranteilfollow-up.Dopodueannilelesioniperiapicalisonostateclassificatecome guarite,ridotteindimensionienonguariterispettivamentenel93,3%,3,3%e3,3%deicasiinG1e nel93,3%,0%e6,7%deicasiinG2,senzarilevaredifferenzestatisticamentesignificativetrai gruppi.

Conclusioni: Entrambiisistemiintegratidistrumentazioneeotturazionetestatisonorisultati efficacineltrattamentodellapatologiaperiapicalediincisivicentralisuperiori.Ilmonitoraggio delle lesioni periapicali puo` richiedere un follow-up maggiore di un anno per osservare la guarigionecompleta.

usedincombinationwithdedicatedcarrier-basedobturators, theOne-StepObturator(CMSDentalApS,Copenhagen, Den-mark)andGTXObturator(DentsplyTulsaDentalSpecialties), respectively.Thesealingability4_{andthepreliminaryclinical}

performanceon different tooth types2 of these integrated systemshas alreadybeen a matter of study, attestingthe plausibilityofconsideringthesesystemsavalidalternativeto traditionalmorecomplextechniques.

Thepresentpaperistheupdatedreportofthefindingsof apreviouslypublishedtrial,5whichassessedtheearlysuccess rateof theroot canaltreatment ofupper centralincisors with chronic periapical pathosis making use of the two aforementionedsystems.Thechoiceoffocusingexclusively onsuchtoothtypeisintendedtoassesstheclinical perfor-manceofthesesimplifiedsystemsonteeththataregenerally characterisedbya wide, straightcanal.Even ifextremely rareaberrations fromthemostcommon rootcanal config-urationhavebeen described,6,7 thethoroughcleaning and sealingofthewideapicalregionofmaxillarycentralincisors is the only true challenge that the clinician faces when treatingthese teeth.Thepresentstudyposes thequestion whetherthetestedsystems canbeeffectiveinteeth with non-vital pulp, periapical lesion and such anatomy of the apicalthird,despitetheirintrinsicsimplicity.

Materials

and

methodology

The study setup and the methodological aspects of the presenttrialhavealreadybeendescribedindetailformerly.5

The present randomised controlled trial designed with twoparallelgroupswasconductedandreportedaccording totherecommendationsoftheCONSORTstatement guide-lines8 _{andtheprinciplesofthelastupdateoftheHelsinki}

Declaration.Afterbeinginformedontheobjectiveandthe designofthestudy,allthepatientsassessed foreligibility gavetheirconsentfortheinvolvementinthestudybysigning adedicatedform.

Eligibilitycriteria

Thestudy enrolled male andfemale adultsubjects at the DentalClinicoftheUniversityofTriestebetweenAugust2014 andFebruary2015,whoneededtherootcanaltreatmentof anupper centralincisor diagnosedwith chronic periapical lesionwithadiameter5mmontheperiapicalradiograph. Theexclusion criteriawere:patientswith physicalor psy-chologicaldisabilities,inability to understandinstructions, severe systemic disorders (i.e. non-controlled diabetes, immunologic diseases, malignant neoplastic processes). Fromatotalof70subjectsassessedforeligibility,60patients wereenrolledinthetrial.5Anindependentoperator,blindto thecharacteristicsofthetrialotherthanitsdesign, gener-atedtherandomsequencebystratifiedblocked randomiza-tionusing a freesimulation software.9 The patients were unawareoftheexperimentalgroupofassignment.Blinding theoperatorperformingthesingle-sessionrootcanal treat-mentswasnotfeasible.

Interventions

A single experienced endodontist treated all enrolled patients.Field isolationwas achieved by means ofrubber

dam.Acompositeresinbuild-uprestorationwasmadeincase ofsuboptimalsealoftherubberdam.Amanualsize10Kfile (Dentsply Maillefer, Ballaigues, Switzerland) was used to scout the root canal and check the coronal and apical patency,thenitwasconnectedtoanelectronicapexlocator (RootZX,MoritaCo.,Tokyo,Japan)todeterminethe elec-tronicworkinglength.Inthetwogroups,alltheoperative proceduresexcludingtheshapingandfillingprotocolswere keptstandardised.Theirrigationprotocolconsistedof2.5ml rinses after each shaping instrument with 5.25% sodium hypochlorite(Niclor5,Ogna,Muggio`, Italy).

The rotary files were mountedon an endodontic hand-piececonnectedtoadedicatedmotor(TecnikaVisionS,ATR, Pistoia,Italy),whichwassetinaccordancewiththe indica-tions suggestedby themanufacturers. The canalshaping/ fillingprotocolswerethefollowing:

Group1(G1,n=30):therootcanalwasshapedwiththe standard sequence of rotary Revo-S instruments (Micro-Mega): SC 1 (25/.06), SC 2 (25/.04), and SU (25/.06). Afterwards, theapex wasgauged withmanualNi-Ti files (MityTurbo,JSDental,Ridgefield,CT,USA)andaccordingly enlargedwithfinishingfilesAS30(30/.06),AS35(35/.06) or AS 40 (40/.06). Manual refinement was performed if necessary.Therootcanalwasdriedwithpaperpointsand thecanalwallsweresmearedwitheugenol-free endodon-tic sealer (Sicura-Seal, Dentalica, Milan, Italy) using a sterile paper point.Making useofdedicated forceps, an obturatorof theOne-StepObturatorsystem(CMSDental ApS,Copenhagen,Denmark)matchingtheapical prepara-tionsizewas insertedintotheOne-StepObturator Oven (CMSDentalApS)toreachadequategutta-percha thermo-plasticisationandthenintroducedintotherootcanal1mm shorter of the working length. After ten seconds, the handle of the obturator was bent andcut at the orifice levelwithaburmountedonahighspeedhandpiece. Group2 (G2,n=30):therootcanal wasshaped withGT

SeriesXrotaryfiles(DentsplyTulsaDentalSpecialties)inthe order:20/.04,20/.06,30/.04,30/.06.Theapicalgauging wasperformedasdescribedinG1andtheapexwasfinished with.06or0.8taperedGTSeriesX files.Oncedried,the canalwallsweresmearedwithSicura-Sealsealer.Thefilling procedure followed the same principles described above and was carried out with GT Series X Obturators and a Thermaprepoven(DentsplyTulsaDentalSpecialties).

Clinicalevaluation

Asingleoperatorwhowasnottheoneperforming theroot canal treatmentsgathered all anamnestic data concerning thegeneralandoralhealthbyinterviewingthepatientsand performed the clinical evaluation wearing 4 magnifying loupes.Thepresenceofbaselineclinicalsignswasnotedas abinarydatuminadedicatedelectronicspreadsheet,after testingthetendernesstopercussionorpalpationofthebuccal sulcusintheapicalareaofthedesignatedtooth.Theclinical recallvisitswerescheduledafter6,12,18and24months.

Radiographiccentering andexamination

with a paralleling technique. The X-ray source was kept constant duringthe wholeduration of the trial, using the same device (2200 Intraoral X Ray System, Kodak Dental Systems, Rochester, NY, USA) set at 70kVp, 10mA, and 0.20s exposure time. All the images were registered in ‘‘Endo’’ mode to enhance readability.10 _{The images taken}

into examination in the radiographic healing assessment were the postoperative control radiograph, which served as baseline, andthe radiographs takenat the recall visits after6,12,18and24months.

Two blind examiners with 19 and 23 years of clinical experience in Endodontics unaware of the study design and purpose were calibrated according to a previously describedscaledevelopedtoscorethehealingofperiapical lesions.11 _{In a blind fashion, they were then asked to}

score the follow-up radiographs according to such scale, by attributing each of them to one of the following categories:

1.healing:normaltrabecularboneandphysiological period-ontalligamentwidth;

2.improvement:decreaseofthelesionsize;

3.failure:increaseoflesionsizeorabsenceofchangesfrom theinitialstatus;

4.unreadableradiograph.

The evaluationtook place in multiple sessions immedi-atelyafterthecollectionoftheradiologicalimagesandafter at least 1 month.12 In case of disagreement between the judgementoftheevaluators,theworstofthetwoscoreswas assumed.

Statistical analysis

Boththesensitivitytotheclinicaltestsandtheradiographic scorewereregardedmainoutcomemeasuresofthepresent trial.Allcollected dataweremanagedwith theStatistical PackageforSocialSciencesv.15(SPSSInc.,Chicago,IL,USA). Thecomparabilityofbaselineparametersofthetwogroups was testedbymeansof aMann—Whitneytest (age,apical diameter)andax2test(sensitivitytopercussionand palpa-tion).Radiographichealing scoresandclinicalexamination parameters (percussion and palpation) were compared between groupswith the Mann—Whitneytest and x2test, respectively.Withingroups,changes overtime interms of positivitytoclinicaltestswereassessedwithaCochran’sQ test,andintermsofradiographichealingwith aFriedman test and a Wilcoxon test with Bonferroni correction for pairwisecomparisons.Thelevelofsignificancewassetat5%. Thelevelof intra-andinter-observeragreement ofthe ratingofradiographichealinghadbeenpreviouslyevaluated withkappastatisticswithquadraticweightingandreported tobeexcellent.5Theimputedrelativedistancesbetweenthe ordinalcategoriesservedas abasisfor weighting: healing-improvement,1;improvement-failure,2.

Results

Table1reportsacomparisonbetweengroupswithregardto

anamnestic variables, operative data and clinical para-meters. The two groups were comparable at baseline, as nostatisticallysignificantdifferencesintermsofage,apical

diameter, and tenderness to percussionor palpation tests T

wereobserved.Nopatient drop-outsorvoluntary withdra-wals wereregistered, andall the recruited patients were availableforre-evaluationduringthefollow-upperiod.

Throughoutthewholetrial,patientsreportingsymptoms beforeandafterthetreatmentwereaminority,rangingfrom 3.3%to10%.Attheendoftheobservationperiod,onlyone patientpergroupwaspositivetotheclinicaltests,whileall the other subjects were symptom-free. On average, the prevalenceoftendernesstopercussionandpalpation symp-tomsdidnotchangeover timeandwas similarin thetwo groups(p>0.05).

Despiteminordifferencesintheoutputofthestatistical analysis,inthetwogroups theradiographic healingscores followedasimilartrendofconstantimprovementduringthe 24monthsofobservation,asportrayedinFig.1.Asubstantial portionofsubjects(43%)presentedcompleteradiographic healingalreadyatthesix-monthrecall.Afteroneyear,this subset underwent almost a two-fold increase (p<0.01), becauseofthefurtherreductionofpartiallyhealedlesions, withmorepatientsbeingclassifiedastotallyhealed. Differ-ently,theimprovementbetweenthescoresattributedafter 12 and 18 months was statistically significant only in G2 (p<0.05).Between18and24 months,thefrequenciesof the scores remained constant (p>0.05), evidencing two-yearsuccessratesabove90%irrespectiveoftheintegrated system.Inthecomparisonbetweentheradiographichealing observed in the two experimental groups, the statistical analysisdidnotrevealanysignificantdifference.

Discussion

Thepresentstudydemonstratedthatadoptingasimplified approachwith integrated techniquesfor thetreatment of uppermaxillaryincisorswithperiapicalpathosiscanleadto highsuccessrates.Indeed,93%ofpatientswereclassifiedas healedattheendofthefollow-upperiod.Thisdatummaybe consideredsomehowunforeseen because,eventhoughthe rootcanaltreatmentcanbe successfulinapercentage of casesthatrangesbetween75%and97%accordingtoprimary andsecondarystudies,13—15thesuccessrateusuallydropsin presenceofperiapicallesion.Further,theclinical effective-nessofcarrier-based fillingtechniquesinpresenceof peri-apical lesion hasbeen questioned, as the success rate of endodontictreatmentscarriedoutwithNi-Tirotaryfilesand Thermafil obturation may be one-half that obtainable in

teeth with vital pulps.16 _{The relatively low success rates}

reportedbyGaglianiandco-workers16(48.2%)arereasonably ascribable to the characteristics of the sample, which includedalltypesofteeth,evenmolarteeth,whose treat-ment entails more challenging tasks than upper anterior teeth. Further,thechoiceoffirst-generationNi-Ti shaping instruments, namely the Profile system, might have influ-enced the effectiveness of thetreatment since its instru-mentshavenegativerakeanglesthatcouldpossiblyworsen theperformanceoftherotaryfileincaseofinfectedcanals. Moregenerally,arecentprospectivestudy13 demonstrated thatthesuccessrateoftherootcanaltreatmentofatooth withperiapical radiolucencyisreduced asmuchas8—13%, compared to the case in which the lesion is absent. The findingsofthepresentstudymaysuggestthatwhendealing withteeththatposenopeculiarhindrancetoastandardised andsimplifiedtreatmentbecauseoftheirregularanatomy and good accessibility, highly satisfactory results may be obtainedwith relativelyscarceeffortandwith techniques withintherangeofgeneraldentistsorinexperienced opera-tors.

Surprisingly, itappears thatthetopic ofthe speedand patternofperiapicalhealinghasbeentakeninto considera-tion by literature only marginally, with only few studies following up endodontically treated teeth with periapical pathosis to monitor the initial stages of the radiographic healing.17,18Instead,theearlyassessmentoftheperiapical healingprocessisprobablyoneofthemostrelevantissues fromaclinicalpointofview,sinceboththeclinicianandthe patientareinterestedinobtainingreliableinformationabout theprognosisofthetooth,inordertoconcludethe restora-tivetreatmentassoonaspossible.Basedonarandom-effects meta-analysis,theweighted-pooledsix-monthsuccessrate of healing has been reported to be 29.6%.19 Moreover, a follow-upperiodlastingatleastoneyearhasbeenadvocated tovisualizesubstantialhealing.20,21Thetrendofperiapical healingevidencedinthepresentstudyatteststhatagreater portion of patientscan beconsideredtotally healed after halfayear(43%)andthat12monthsmaybeinsufficientto detect all the cases that are going to achieve complete resolution, as a total of 10 improved lesions (17% of the whole sample) disappeared after 18 months. Despite the improvement of the radiographic scores between the 12-monthand18-monthtimepointswasstatisticallysignificant only in G2, the global trend of radiographic healing was comparablein thetwo groupsandthedifference was

determined by onlyone subject stillclassified as partially healedinG1after18months.Moreinterestingly,theabsence ofdifferencesbetweenthehealingscoresattributedtothe radiographsatthe18-and24-monthrecallsmaysuggestto assume oneyearandahalf aslandmarkto safely endthe follow-upperiod.Anothernoteworthyfindingisthefactthat —with theonlyexceptionofonesubjectinG1(3% ofthe partially healed patients) — all the patients classified as partiallyhealed reachedthe statusofcompleteperiapical resolution,thusconfirmingthepreliminaryhypothesis pos-tulatedinthesix-monthreportofthepresenttrialon the prognostic relevance of the detection of an early sign of ongoinghealing.5_{Giventhecompletehealingofalmostthe}

totality(97%)ofthelesionsalreadyclassifiedasreducedin sizeafter6months,itmightbespeculatedthatitwouldbe possibletoproceedwiththeearlyrehabilitationofmaxillary incisorswithreducedlesionafter6monthsinthecaseswhen thisisneeded,allthemoresoconsideringthattheonlylesion notcompletelyhealedremainedstationaryafter2years.A potentialendodonticfailurewillbetreatedwith an ortho-gradeorretrograderetreatment. Forfuture researches,it willbechallengingtoinvestigateatwhichextentthelesion reductionafter6monthscanbesafelyconsidereda guaran-tee of complete/partially complete future healing in all typesofteeth.

Astotheevaluationofsymptomsovertime,nosignificant changesoftheprevalenceofpatientspositivetotheclinical tests were observed. Strictly considering the criteria of success adopted, a total of 2 patients (3% of the whole sample)werereportingtendernesstopercussionand palpa-tionand,sincetheywerenotshowinganyradiographicsigns oflesionreduction,shouldbeconsideredtreatmentfailures. However, even if the possibility to be subjected to non-surgicalorsurgicalendodonticretreatment wasofferedto these individuals, they declared themselves unwilling to receivesuchtherapygiventheabsenceofmajor complica-tionsorspontaneoussymptoms.

Themostfrequentlyusedand,maybe,themostcriticised ratingscalefortheperiapicalstatusistheperiapicalindex (PAI).21_{Itsapplicationtoalltoothtypeshasneverbeenfully}

validatedoraccepted,becausePAIwasdevelopedon radio-graphic and histological findings of maxillary incisors,22 wheretheproperanalysisoftheradiographisnotimpeded bythickcorticalplatesorunfavourablepositionsoftheroot tip.22_{ThescalebyKatebzadehetal.}11_{adoptedinthepresent}

studyhadits validity previously testedbymeans ofkappa statisticswithquadraticweighting.5_{Theexcellentinter-and}

intra-observer agreement that has been reported can be explainedby thesimplicityofthecategoriesof thislatter scale,whichdifferunmistakeablyonetoanotherand,unlike PAIscores,werespecificallydesignedtomonitorthehealing ofanexisting periapicallesion.Katebzadeh’sscalefollows the same intuitive principles of everyday clinical activity, during which clinicians classify a lesionas disappearedor decreased/unvaried/increasedinsize.Onemethodological aspectthatisessentialtoensurereliabilityofthereadingsis thestandardisationofthefilmpositioningandimage acquisi-tion.Whilestandardisingthephasesofimageacquisitionand filtering is fairly easy, a little more effort is required to customisethefilmholderwithaputtysiliconeregistration; thisprocedure,thoughnotcompulsoryintheclinical prac-tice,isessentialintheresearchsetting.

Thetwotestedintegratedshapingandfillingsystemsare examplesoftheendeavourmadebymanufacturersto pro-videclinicianswithpredefinedsequencesofoperativesteps thataimatreducingthepossibilitytointroduceerrorsand not being operator-dependent. The present study proved thatthesesystems arecapableof valuableclinical perfor-mance,whichcanreachthatoftraditionalapproaches,and laysthegroundforfutureinvestigationsonothertoothtypes.

Conclusions

Theendodontictreatmentsperformedonmaxillarycentral incisors with periapical lesionwith the integratedshaping andfillingsystemstestedinthepresenttrialallowedfor93% two-year success rate, without differences between the experimentalgroups.Oneandahalfyearswereasufficient follow-uptimeperiodtodetectthecompletehealingofthe vastmajorityofthecasesscoredaspartiallyhealedatthe previous recall examinations. Allbut one the lesions that werepreliminarilyclassifiedasreducedinsizereachedthe statusofthecompletehealing.

Conflict

of

interest

Theauthorshavenoconflictsofinteresttodeclare.

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