This article presents the procedures that must be considered for periapical cyst repair after nonsurgical endodontic treatment. The case
of a periapical cyst associated to the left maxillary lateral incisor is reported. Nonsurgical root canal therapy was performed and lesion
healing was confirmed radiographically after 24 months. Differential diagnosis, endodontic infection control, apical foramen enlargement
and filling of the cystic cavity with a calcium hydroxide paste were important procedures for case resolution

Costa Junior, Edson Dias

Valois, Caroline Rodrigues Alves

Brazilian Dental Journal

This article presents the procedures that must be considered for periapical cyst repair after nonsurgical endodontic treatment. The case of a periapical cyst associated to the left maxillary lateral incisor is reported. Nonsurgical root canal therapy was performed and lesion healing was confirmed radiographically after 24 months. Differential diagnosis, endodontic infection control, apical foramen enlargement and filling of the cystic cavity with a calcium hydroxide paste were important procedures for case resolution.O objetivo do presente estudo foi apresentar os procedimentos a serem considerados para o tratamento endodôntico não-cirúrgico de cistos periapicais. Um caso de cisto periapical associado ao incisivo lateral superior esquerdo é relatado. Após o tratamento endodôntico não-cirúrgico, o reparo da lesão foi observado radiograficamente em 24 meses. Diagnóstico diferencial, controle da infecção endodôntica, alargamento do forame apical e preenchimento da cavidade cística com pasta de hidróxido de cálcio foram procedimentos relevantes para a resolução do caso

Valois, Caroline R.A.

Costa-Júnior, Edson Dias

Scientific Electronic Library Online - Brazil

Periapical cyst repair after nonsurgical endodontic therapy: case report

Repositório Institucional da Universidade de Brasília

Braz Dent J 16(3) 2005254 C.R.A. Valois and E.D. Costa-JúniorPeriapical Cyst Repair After NonsurgicalEndodontic Therapy - Case ReportCaroline R.A. VALOISEdson Dias COSTA-JÚNIORFaculty of Health Sciences, Department of Dentistry, University of Brasília (UnB), Brasília, DF, BrazilThis article presents the procedures that must be considered for periapical cyst repair after nonsurgical endodontic treatment. The caseof a periapical cyst associated to the left maxillary lateral incisor is reported. Nonsurgical root canal therapy was performed and lesionhealing was confirmed radiographically after 24 months. Differential diagnosis, endodontic infection control, apical foramen enlargementand filling of the cystic cavity with a calcium hydroxide paste were important procedures for case resolution.Key Words: endodontic therapy, periapical cyst, periapical pathosis.Correspondence: Dr. Edson D. Costa Jr., Faculdade de Odontologia, Universidade de Brasília (UnB), Campus Universitário, Asa Norte,70910-900 Brasília, DF, Brasil. Tel: +55-61-307-2632. e-mail: cravalois@uol.com.br/edsondias@opendf.com.brISSN 0103-6440lateral incisor. Intraoral clinical examination revealedthat the lateral incisor had esthetic restorations on themesial, distal and lingual surfaces. The buccal mucosapresented normal color and appearance. There was nogingival or extraoral swelling but a volumetric increasein the palate was observed. The patient deniedspontaneous pain but reported painful symptomatolgyupon percussion.The radiographic examination showed thepresence of external periapical resorption ofapproximately 1 mm length and a radiolucent lesion (15x 10 mm) surrounded by a tenuous radiopaque lineadjacent to the apex of tooth 22. Pulpal necrosis wasconfirmed by cold sensitivity testing done with Endo-Frost cold spray (Roeko, Langenau, Germany).After crown opening, a mucous and transparentexudate drained through the radicular canal. A sampleof this fluid was collected for cytological examination.The canal was instrumented at 1 mm from the apicalforamen according to the crown-down technique. Thememory instrument was a size 60 K-file (MailleferInstruments SA, Ballaigues, Switzerland). The canalwas irrigated with HCT20, an irrigating solutioncomposed of calcium hydroxide, tergentol and distilledwater (6), and filled with a paste prepared with 9 partsof calcium hydroxide and 1 part of zinc oxide in anINTRODUCTIONThe periapical cyst is originated from theepithelium in a granuloma and is frequently associated toan inflammatory response of the organism against along-term local aggression due to an endodontic infection.This condition is clinically asymptomatic but can resultin a slow-growth tumefaction in the affected region.Radiographically, the classic description of the lesion isa round or oval, well-circumscribed radiolucent imageinvolving the apex of the infected tooth (1).Although it has been demonstrated that thispathologic entity can represent 40 to 50% of all apicallesions (2), it is not yet well-established in the literaturewhether its treatment should be surgical or non-surgical.Some authors support that if the endodontic infection iseliminated, the immune system is able to promote lesionrepair, while other believe that surgical intervention isinvariably necessary (1-5).In this article, a case of periapical cyst healingafter nonsurgical endodontic treatment is reported.CASE REPORTA 42 year-old female patient was referred to ourclinic for endodontic treatment of the left maxillaryBraz Dent J (2005) 16(3): 254-258Braz Dent J 16(3) 2005Periapical cyst repair 255aqueous vehicle  (HCT20), using a lentulo drill. Canalentrance was sealed with a non-eugenol, pre-mixedtemporary filling material (Cimpat, Septodont, SaintMaur, France) and the access cavity was closed with arapid-setting zinc oxide and eugenol based cement(Pulpo-san, SS White, Rio de Janeiro, RJ, Brazil). Allprocedures were carried out under absolute isolation.The exfoliating cytology of the lesion’s fluid wascompatible with periapical cyst. The patient returned fora second visit and was informed about the diagnosis,tooth conditions and treatment options. She agreed tosign an informed consent form for nonsurgical rootcanal therapy and documentation of her case.The provisional restoration was removed and thecanal was irrigated with HCT20 and filled with intracanalmedication. A size 30 K-file (Maillefer Instruments SA)was introduced 3 mm beyond the radiographic apex(Fig. 1). At this moment, an abundant serum, purulentand hemorrhagic exudate flowed through the root canal.The calcium hydroxide paste was reapplied into thecanal and intentionally taken to the periapical regionusing a size 30 K-file as described above. All procedureswere carried out under absolute isolation.During the first month, the patient returned everyweek for control and, after that, monthly appointmentswere scheduled. The intracanal medication was renewedat each visit. One month after the beginning of thetreatment, the radiographic examination showed thatpractically all calcium hydroxide paste extruded into theperiapical lesion had been resorbed. Therefore, placementof intracanal dressing beyond the tooth apex wasrepeated, but this time greater paste volume was used tocompletely fill the cystic cavity (Fig. 2).During the following  three months of treatment,renewal of intracanal medication was associated toincrease of sensitivity to percussion and palatetumefaction. A fistula developed and persisted duringfour days. At the fifth month of follow-up, it wasobserved  absence of sensitivity to percussion, fistula,tumefaction and exudate drainage through the canal.Therefore, at the subsequent visits, there was no  longerneed to take the intracanal medication to the cysticcavity by advancing the file 3 mm beyond the apicalforamen. After fourteen months of treatment, periapicalradiographs showed a remarkable decrease of theradiolucency of the lesion and partial resorption of thecalcium hydroxide paste (Fig. 3).The root canal was chemomechanically prepared,obturated with gutta-percha cones (Dentsply Ind. Com.Ltda, Petrópolis, RJ, Brazil) and Sealer 26 cement(Dentsply Ind. Com. Ltda) using the lateral condensationtechnique. A definitive restoration was then placed.The patient returned for clinical and radiographiccontrols every 6 months during the first 2 years, andthen every 12 months during the following 3 years (Fig.4). Radiographic evidence of lesion healing was observedat the 24-month follow-up.DISCUSSIONIt is known that a pulpal infection originates andperpetuates periapical pathologic alterations. In addition,in the absence of aggressive agents, the immune systemhas mechanisms to promote the repair of tissues andstructures affected by pathologic processes (3).Therefore, the elimination of harmful agents from theroot canal system creates a propitious environment forrepair of a cystic lesion (3,5).Parendodontic surgeries may have directprocedural consequences that make nonsurgicalendodontic treatment preferable over them in cases ofperiapical cyst. Among the events that might be associatedto periapical surgical interventions are loss of bonesupport, possibility of damaging blood vessels andnerves irrigating and innervating teeth adjacent to thelesion, possibility of damaging anatomic structures,such as the mental foramen, inferior alveolar nerve and/or artery, nasal cavity and the maxillary sinus, productionof anatomic defects or scars, postoperative pain ordiscomfort, and refusal to undergo surgical procedures,especially pediatric patients (4,5).Studies have reported that periapical cysts arerefractory to non-surgical endodontic therapy (7,8).Nevertheless, the fact that these findings are associatedto other etiological factors, such as extraradicularinfection, presence of foreign bodies and cholesterolcrystals, has also been discussed in the literature (8).Furthermore, the way that the endodontic treatment isconducted should be discussed as well. Correct planningof the intervention in cases of periapical cyst is ofparamount importance for a successful therapy.The foremost step is to establish a differentialdiagnosis between periapical cyst and periapicalgranuloma. Several studies have shown the difficulty todistinguish radiographically these pathological entities(9,10). Biochemical procedures have also been describedBraz Dent J 16(3) 2005256 C.R.A. Valois and E.D. Costa-JúniorFigure 1. Radiograph showing a periradicular cyst associated tothe left maxillary lateral incisor. Note the intentional placementof an endodontic file beyond the apex into the cystic cavity.Figure 2. Radiograph taken 1 month after the beginning of thenonsurgical root canal therapy. Note the cystic cavity completelyfilled with the calcium hydroxide-based intracanal medication.Figure 3. Radiograph taken 14 months after the beginning of thenonsurgical endodontic therapy. Note a remarkable decrease ofthe lesion radiolucency with partial resorption of the paste.Figure. Radiograph taken 5 years after completion of thenonsurgical endodontic therapy. Note complete healing of theperiradicular cyst and resorption of the paste.Braz Dent J 16(3) 2005Periapical cyst repair 257for differencial diagnosis  (4,11). In the case reported inthis article, exfoliating cytology was the chosen methodto examine the lesion’s fluid because it has a simplifiedtechnique.Endodontic infection control is another crucialpoint to be addressed while planning the intervention.For elimination or maximum reduction of microorganismsin the root canal system, the professional should associatedebridment using endodontic files with efficient irrigatingsolution and intracanal medication. Moreover, patencyand elargement of the canals in case of necrotic teethwith periapical lesions will help eliminatingmicroorganisms from the apical foramen, thus preventingthe inflammatory process to perpetuate. Calciumhydroxide irrigants and dressings were selected becausethey reportedly provide excellent clinical and laboratorialresults (6,12,14,15). Calcium hydroxide was associatedto an aqueous vehicle to allow rapid release of Ca++ andOH. Zinc oxide was added to the paste to allow bettervisualization of the medication within the canal and thecystic cavity.Overextension of calcium hydroxide paste intocystic lesions, as performed in the case reported, hasbeen previously described (12,13,16). The benefits ofthis procedure include anti-inflammatory action throughhygroscopic properties forming calcium proteinatebridges and inhibiting phospholipase, neutralization ofacidic products such as hidrolases, which can affect theclastic activity, activation of the alkaline phosphatase,antibacterial effect and the destruction of the cysticepithelium, allowing conjunctive tissue invagination tothe lesion (12,13).Bhaskar (2) suggested that, during the endodontictherapy of teeth associated with periapical cysts, rootcanal instrumentation must be done slightly beyond theapical foramen. According to the author, this willproduce a transitory acute inflammation and destructionof the protective epithelial layer of the cyst, convertingit into a granulated tissue, which has better resolution.Although there is no scientific-based evidence thatsupport this assumption, in the case hereby presented,instrumentation beyond the apical foramen was carriedout because it would help eliminating microorganismsfrom the apical area, thus reducing the inflammatoryprocess. Moreover, it could also facilitate cyst resolutionthrough the relief of the intra-cystic pressure (1).The criteria used to establish the most adequatemoment for obturation of the root canal are associatedwith absence of spontaneous pain, sensitivity topercussion, exudate and edema, and the beginning ofradiographic regression of the lesion. Regarding thetime required for considering the therapy successful, atwo-year period has been considered a reasonableinterval (17). In the case described in this paper, thepatient was evaluated biannually and then every 12months up to 5 years of follow-up.Differential diagnosis, endodontic infectioncontrol, apical foramen enlargement and filling of thecystic cavity with a calcium hydroxide paste wereproved important procedures for successful nonsurgicalendodontic treatment of periapical cysts.RESUMOO objetivo do presente estudo foi apresentar os procedimentos aserem considerados para o tratamento endodôntico não-cirúrgicode cistos periapicais. Um caso de cisto periapical associado aoincisivo lateral superior esquerdo é relatado. Após o tratamentoendodôntico não-cirúrgico, o reparo da lesão foi observadoradiograficamente em 24 meses. Diagnóstico diferencial, controleda infecção endodôntica, alargamento do forame apical epreenchimento da cavidade cística com pasta de hidróxido decálcio foram procedimentos relevantes para a resolução do caso.REFERENCES1 . Shear M. Cistos da região bucomaxilofacial. 3th ed. São Paulo:Editora Santos; 1999.2 . Bhaskar SN. Nonsurgical resolution of radicular cysts. OralSurg 1972;34:458-468.3 . Maalouf EM, Gutmann JL. Biological perspectives on thenon-surgical endodontic management of perirradicularpathosis. Int Endod J 1994;27:154-162.4 . Morse DR, Bhambhani SM. A dentist’s dilemma: nonsurgicalendodontic therapy or periapical surgery for teeth withapparent pulpal pathosis and an associated periapicalradiolucent lesion. Oral Surg Oral Med Oral Pathol OralRadiol Endod 1990;70:333-340.5 . Shah N. Nonsurgical management of periapical lesions: aprospective study. Oral Surg Oral Med Oral Pathol OralRadiol Endod 1988;66:365-371.6 . Barbosa SV, Spangberg LS, Almeida D. Low surface tensioncalcium hydroxide solution is an effective antiseptic. IntEndod J 1994;27:6-10.7 . Nobuhara WK, Del Rio CE. Incidence of perirradicularpathoses in endodontic treatment failures. J Endod1993;19:315-318.8 . Nair PNR, Sjögren U, Figdor D, Sundqvist G. Persistentperiapical radiolucencies of root-filled human teeth, failedendodontic treatments and periapical scars. Oral Surg OralMed Oral Pathol Oral Radiol Endod 1999;87:617-627.9 . Mortensen H, Winther JE, Birn H. Periapical granulomas andcysts. An investigation of 1.600 cases. Scand J Dent Res1970;78:241-250.Braz Dent J 16(3) 2005258 C.R.A. Valois and E.D. Costa-Júnior10. Kizil Z, Energin K. An evaluation of radiographic andhistopathological findings in periapical lesions. J MarmaraUniv Dent Fac 1990;1:16-23.11. Morse DR, Patnik JW, Schacterle GR. Electrophoreticdifferentiation of radicular cysts and granulomas. Oral SurgOral Med Oral Pathol Oral Radiol Endod 1973;35:249-264.12. Sahli CC. L’hydroxide de calcium dans le traitmentendodontique des grandes lesions periapicales. Rev FranD’Endodoncia 1998;7:45-51.13. Souza V, Bernabe PFE, Holland R, Nery MJ, Mello W,Otoboni Filho JA. Tratamento não cirúrgico de dentes comlesões perirradiculares. Rev Bras Odont 1989;46:39-46.14. Çaliskan MK, Sem BH. Endodontic treatment of teeth withapical periodontitis using calcium hydroxide: a long-termstudy. Endod Dent Traumatol 1996;12:215-221.15. Siqueira Jr. JF, Lopes HP. Mechanisms of antimicrobialactivity of calcium hydroxide: a critical review. Int Endod J1999;32:361-369.16. Çaliskan MK, Türkün M. Periapical repair and apical closureof a pulpless tooth using calcium hydroxide. Oral Surg OralMed Oral Pathol Oral Radiol Endod 1997;84:683-687.17. Bender IB, Seltzer S, Soltanoff W. Endodontic success - areappraisal of criteria. Oral Surg Oral Med Oral Pathol OralRadiol Endod 1966;22:780-802.Accepted  June 27, 2004

Periapical cyst repair after nonsurgical endodontic therapy : case report

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Periapical cyst repair after nonsurgical endodontic therapy : case report

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