Remineralization Without Blood Clot

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Biologically Based Treatment of Immature PermanentTeeth with Pulpal Necrosis: A Case Series

Il-Young Jung, DDS, MS,* Seung-Jong Lee, DDS, MS,* and Kenneth M. Hargreaves, DDS, PhD

AbstractThis case series reports the outcomes of 8 patients(ages 9 14 years) who presented with 9 immaturepermanent teeth with pulpal necrosis and apical peri-odontitis. During treatment, 5 of the teeth were foundto have at least some residual vital tissue remaining inthe root canal systems. After NaOCl irrigation andmedication with ciprofloxacin, metronidazole, and mi-nocycline, these teeth were sealed with mineral trioxideaggregate and restored. The other group of 4 teeth hadno evidence of any residual vital pulp tissue. Thissecond group of teeth was treated with NaOCl irriga-tion and medicated with ciprofloxacin, metronidazole,and minocycline followed by a revascularization proce-dure adopted from the trauma literature (bleedingevoked to form an intracanal blood clot). In both groupsof patients, there was evidence of satisfactory postop-erative clinical outcomes (15 years); the patients wereasymptomatic, no sinus tracts were evident, apicalperiodontitis was resolved, and there was radiographicevidence of continuing thickness of dentinal walls, api-cal closure, or increased root length.(J Endod 2008;34: 876 887)

Key Words

Endodontics, immature permanent tooth, open apex,regenerative, revascularization, stem cell

Although contemporarynonsurgical endodontic procedures confer high degrees oclinical success(1, 2), the root canal system is obturated with synthetic materialpreventing any of the ad vantages that might ensue by regeneration of a functionpulp-dentin complex(3). This is a particular problem when treating the necrotic buimmature permanent tooth, where conventional treatment often lea ds to resolution of apical periodontitis, but the tooth remains susceptible to fracture(4) as a result of interruption of apical and dentinal wall development. Thus, one alternative appr would be to develop and validate biologically based endodontic procedures designrestore a functional pulp-dentin complex.

For more than 50 years, clinicians have evaluated biologically based method

restore a functional pulp-dentin complex in teeth with necrotic root canal systcaused primarily by trauma or caries. Although case series from the 1960s1970s ingeneral were not successful in producing this outcome (5, 6), it should be appreciatedthat they were performed without contemporary instruments or ma terials and without insight generated from the trauma or tissue engineering fields(7). More recent casereports, published during the last 15 years, have demonstrated that it is possiblhumans torestore a functional pulp-dentin complex in the necrotic immature permnent tooth(8 13). Human histologic studies have not yet been reported, so it is nknown whether these treatments truly recapitulate the normal pulp-dentin compHowever, these case studies provide some measure of achieving satisfactory funcoutcomes, because postoperative recalls indicate that the patient is asymptomaticsinus tracts are present, apical periodontitis is resolved, and there is radiograpevidence of continuing thickness of dentinal walls, apical closure, or developmeroot length.

Although case series do not provide definitive evidence to support a given tment modality, they do have the advantage of being conducted in actual patients anprovide greater insight than preclinical studies. Moreover, the results from case scan be used to identify potentially important parameters that can guide the desigfuture prospective clinical trials. For example, in nearly all published case seriepulpal regeneration, an effort was made to evoke an intracanal blood clot to trigtissue ingrowth. In this case series, we report conditions in which it was not neceto evoke intracanal bleeding to have continued root development.

Pulp Regeneration without Formation of a Blood ClotCase 1

A 10-year-old girl was referred to the Department of Conservative Dentistry

Dental Hospital of Yonsei University by an oral and maxillofacial surgeon for evaon the right second mandibular premolar (tooth #29). The girl had a history of swelof the right mandibular buccal vestibule, for which she received an incision for draprocedure at the Department of Oral and Maxillofacial Surgery 2 months earlierclinical examination, the patient was slightly symptomatic to percussion, and a tract was present that traced to the apex of tooth #29. The first and second premo were free of caries, but a fracture of an occlusal tubercle of tooth #29 was noted visual inspection. Periodontal probings were within normal limits for all teeth ilower right region. Diagnostic testing was inconclusive on cold and electric pulp tebut the patient reported sensitivity to percussion or palpation. Periradicular radgraphic examination revealed that tooth #29 had an incompletely developed apexa periradicular radiolucency (Fig. 1 A). The diagnosis of pulp necrosis and chronicapical abscess with a sinus tract was made for tooth #29.

From the *Department of Conservative Dentistry, YonseiUniversity School of Dentistry, Seoul, Korea; and Departmentof Endodontics, University of Texas Health Science Center atSan Antonio, San Antonio, Texas.

Address requests for reprints to Dr Seung-Jong Lee, De-partment of Conservative Dentistry, Yonsei University Schoolof Dentistry, 134 Shinchon-Dong, Sudaemun-Ku, Seoul, Korea120-752. E-mail address: [email protected]/$0 - see front matter

Copyright 2008 American Association of Endodontists.

doi:10.1016/j.joen.2008.03.023

Case Report/Clinical Techniques

876 Jung et al. JOE Volume 34, Number 7, July 2008
mailto:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]


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Figure 1. ( A) Radiographic image showing an incompletely developed apex and a periradicular radiolucency of tooth #29. Note the sinus tract that traceoftooth #29.( B ) Radiographicviewpresenting a gutta-perchacone tracing to tooth#29, anda periradicular radiolucencyassociated with tooth#28. (C ) Radiographfrom 60-day follow-up visit after both teeth were medicated with triantibiotic paste. The sinus tract is still traced to the apex of tooth #29. The thicknesfillingmaterialdoes notseemto beappropriatefor both teeth.( D) Theradiographdemonstratingcompleteresolution of theradiolucency andcontinueddevelopof the apex of both teeth at 6-month follow-up. ( E ) Follow-up at 5 years.


JOE Volume 34, Number 7, July 2008 Biologically Based Treatment of Immature Permanent Teeth with Pulpal Necrosis 877


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When the access cavity was made under rubber dam isolation, a purulent hemorrhagic exudate discharged from the canal. The tooth was left open until the discharge of the exudate had stopped. Afterthe exudate had almost stopped, a K-file was inserted into the canal.Thepatient did not complain of any sensation until the file tip was in themiddlepart of thecanal. In addition, a little resistanceby residual tissue was felt in the mid-portion of the canal, and the patient had a sensationof pain at that time. On the basis of these findings, the possibility was

raised that at least some vital pulp tissue remained in the canal, andtherefore we used a method similar to that reported by Iwaya et al. (8)in an attempt to achieve regeneration of the pulp tissue complex. Theroot canal was irrigated with 5% NaOCl for 10 minutes and dried withpaper points, and a mixture of ciprofloxacin, metronidazole, and mi-nocycline paste as describedby Hoshinoet al.(14) was introduced intothecanal with a lentulospiral. The accesscavity was closed with Caviton(GC, Aichi, Japan). No mechanical instrumentation wasperformeddur-ing the procedure.

The patient returned a week later, asymptomatic, reporting nopain postoperatively. However, the sinus tract was still present. Theaccess cavity was opened,and theroot canal was slowly flushed with 10mLof5.25%NaOCl,andirrigationwascontinuedfor15minutes.Unlike

the first visit, a mixture of erythromycin and Ca(OH)2 was placed intothe root canal. The patient returned 2 weeks later. The sinus tract wasstill present, and the patient complained of slight discomfort in tooth#28. A size #30 gutta-percha cone was threaded into the opening of thesinus tract, anda periapical radiograph wastaken. Radiographicexam-inationshowedthatasinustractwastracedtotheapexoftooth#29,anda periradicularradiolucency wassuspected aroundtooth #28(Fig.1 B ).The clinical examination revealed that moderate percussion pain wasassociated with teeth #28 and #29. Diagnostic testing was inconclusiveon cold and electric pulp testing on tooth #28. A diagnosis of pulpnecrosis and chronic apical periodontitis was made for tooth #28.

An access cavity was made on tooth #28, and the necrotic nature of the upper part of the root canal was confirmed. However, some vitalpulp tissue seemed to remain in the apical part of the canal becauseinsertion of a K-file to this point evoked a sensation of pain and somebleeding. The root canal was slowly flushedwith 10 mL of 5.25% NaOCland irrigated with the same solution for 15 minutes. The same proce-dure was performed on tooth #29. Both teeth were medicated with thetriantibiotic paste described by Hoshino et al. (14).

The patient returned 10 days later. The pain intensity had beenreduced, and the sinus tract was not present. To conduct a more de-tailed evaluation of the patient, the next appointment was made 2 weekslater. However, the patient failed to return for the appointment. Thepatient returned 50 days later, complaining of the reappearance of thesinustract and spontaneous pain. Thesinus tract was traced to the apex of tooth #29, and both teeth (teeth #28 and #29) were tender to per-cussion. The temporary filling material appeared to be intact, but theradiograph revealed the thickness of the material was not appropriatefor both teeth (Fig. 1C ). Because microleakage was a possibility, thecanal disinfection was repeated as before. A week later, the patient returned, and the sinus tract was closed. The canal was reirrigated withNaOCl, and Ca(OH)2 paste (Vitapex; Neo Dental Chemical Products,Tokyo, Japan) was placed, followed by Caviton temporary restoration.

At the 6-month recall, the patient was asymptomatic. The radio-graph showed complete resolution of the radiolucency, and continueddevelopment of the apex was also observed (Fig. 1 D). After removal of the Caviton and Ca(OH)2 paste, calcific barriers were evident in bothteeth by intracanal exploration with a #30 F-file. Permanent gutta-per-cha fillings were performed with Obtura (Obtura Corporation, Fenton,MO) and Sealapex (Kerr Co, Romulus, MI) followed by a bonded resin

restoration. At the 5-year follow-up, the patient continued to be asymtomatic, and closure of the apex and thickening of the dentinal wa were obvious in both teeth (Fig. 1 E ).

Case 2 A 10-year-old boy was referred to the Department of Conserva

Dentistry of the Dental Hospital of Yonsei University for evaluatitooth #29. The boy had reported slight discomfort in the lower rigregion for 1 month, but he was asymptomatic during the examinati visit. On clinical examination, a sinus tract was present that traced to tapex of tooth #29. The tooth was free of caries, but fracture of tocclusal tubercle wasnoted on visual inspection. Diagnostic testing winconclusiveoncoldand electricpulp testing, withsensitivitynotedapercussion or palpation. The periodontal probings were within normlimits for the tooth. Periradicular radiographic examination revealthat tooth #29hadan incomplete apex anda periradicularradiolucenc(Fig. 2 A). The diagnosis of pulp necrosis and chronic apical absces with a sinus tract was made for tooth #29.

When the access cavity was made, a purulent hemorrhagic exudadischarged from the access opening (Fig. 2 B ). After the control of theblood exudate with salineirrigation, there appeared to be some remaiing soft tissue in the root canal. The same regenerative technique moified from Iwaya et al. (8) and used in Case 1 was repeated for thispatient. The root canal was irrigated with 5.25% NaOCl and replaevery 5 minutes for a total of 30 minutes. A mixture of ciprofloxametronidazole, and minocycline paste was placed into the rootcan with a lentulo spiral, and the access cavity was closed with Cavi

The patient returned 11 days later. The patient was asymptomatand the sinus tract was resolved. The root canal was slowly flushed w10 mL of 5.25% NaOCl and continuously irrigated with the same stion for 15 minutes. The root canal was dried with paper points, amineral trioxide aggregate (MTA) (Dentsply Tulsa Dental, Tulsa, O was carefully placed over the tissue in the root canal followed by inmediate restorative material (IRM) (Caulk Dentsply, Milford, DE) (Fig.2C ).A radiograph taken 3 monthsafterMTAplacementrevealed a sli

increase of the thickness of the root canal wall and continued develoment of the apex (Fig. 2 D). The IRM was replaced with a bonded resinrestoration. At the 2-year follow-up, the patient continued to be asymtomatic, and closure of the apex and thickening of the dentinal wa were obvious (Fig. 2 E ).

Case 3 A 10-year-old boy was referred for evaluation and treatment of t

left mandibular second premolar (tooth #20). The patient reported throbbing pain in the lower left region for the preceding 10 days. Tpatients dentist had treated tooth #20 because of the presence of sweing around the tooth. Drainage was established by occlusal access aincisingthebuccalvestibuleadaybeforeourexamination.Atthetime

our examination, the tooth was moderately tender to percussion, anthe canal remained open with a cotton pellet and therefore exposedthe oral environment. A fluctuant swelling was present in the lingattached gingiva of the tooth, and the incision line on the buccal vebule also remained (Fig.3 A).A periodontal examination revealed prob-ingdepths of 3 mmor less. Radiographic examination showeda perirdicular radiolucency (Fig. 3 B ).

After rubber dam isolation, the cotton pellet was removed. Sligbleeding was evident from the canal, and there seemed to be some vtissue remaining in the apical half of the canal because insertion oK-file evoked a sensation of pain. The root canal was irrigated withsodium hypochlorite replaced every 5 minutes for a 30-minute perioThen a mixture of ciprofloxacin, metronidazole, and minocycline pa was introduced into the canal via a lentulo spiral.




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Figure 2. ( A) Radiographicimageshowing an incompletelydevelopedapex anda periradicular radiolucencyof tooth #29. Note thesinus tract that tracesof tooth #29. ( B ) Photograph of a purulent hemorrhagic exudate discharged from tooth #29. (C ) Radiograph presenting the placement of MTA. ( D) 3-month recallradiograph. A slightincreaseof thethickness of therootcanalwall andcontinued developmentof theapex areobserved.( E ) Two-year radiographshowing continuedroot development.




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Figure 3. ( A) Photograph demonstrating a fluctuant swelling in the lingual attached gingiva of tooth #20. ( B ) Radiograph showing a periradicular radiolucency associated with tooth #20. Note that the canal has remained open and therefore exposed to the oral environment. (C ) Radiograph presenting the placement of MTA andIRM.( D) Radiograph demonstrating a slight increase of thethickness of the root canal wall and theformationof dentinbridge under MTAat 2-month( E ) Ten-month radiograph showing complete resolution of the radiolucency and continued development of the apex.




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The patient returned 30 days later. The patient was asymptom-atic, and the sinus tract was resolved. However, when we removedthe intracanal dressing material, a slight amount of bleeding wasobserved. The root canal was irrigated with 5% NaOCl for 30 min-utes. Ca(OH)2 paste was placed into the canal. The patient returned40 days later. The patient was asymptomatic, and the radiographshowed resolution of the radiolucency. After rubber dam isolation,the root canal was slowly flushed with 10 mL of 5.25% NaOCl and

irrigated with same solution for 15 minutes. The root canal wasdried with paper points, and MTA was ca refully placed over thetissue in the root canal followed by IRM (Fig. 3C ). A radiographtaken 2 months after MTA placement showed that a slight increase of the thickness of the root canal wall and a mineralized bridge ap-peared to develop beneath the MTA (Fig. 3 D). At the 10-monthfollow-up, the patient continued to be asymptomatic, and continued

development of the apex was also observed. The IRM was replac with a bonded resin restoration (Fig. 3 E ).

Case 4 A 13-year-old boy was referred for evaluation and treatment of t

left second premolar. Before the visit to our clinic, the patient reportamoderatepaininthelowerleftregionandsoughtdentalcareinalocclinic. Thepatientsdentist at the local clinic thoughtthe pain origina

fromthenecrotic pulp of tooth #20and started the root canaltreatmen without local anesthesia. The dentist informed us that when he openthe pulp chamber, active hemorrhagic exudate discharged from thcanal. He tried to negotiate the distal canal but failed. At the time ofexamination, the tooth was asymptomatic and remained sealed wtemporary filling material. Clinical examination revealed periodonprobings 3 mmfor thetooth, and anabnormal finding suchasa sinus

Figure 4. ( A) Radiographic illustrating a large periapical radiolucency associated with the apex of tooth #20. ( B ) Radiograph presenting the placement of MTA andIRM. (C ) Two-month radiograph revealing some reduction in the periapical radiolucency. ( D) Radiograph demonstrating excellent periapical healing at 2-yeafollow-up.




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tract was not found. Periradicular radiographic examination revealedthat tooth #20 had a bifurcated apex and a periradicular radiolucency 10 mm in diameter (Fig. 4 A). When we removed the temporary fillingmaterial and observed the root canal system with an operating micro-scope, some tissue was found in apical third of the root canal. Copiousirrigation was performed with 5.25% NaOCl for 30 minutes, and a mixture of ciprofloxacin, metronidazole, and minocycline paste wasplaced into the canal with a lentulo spiral. The patient returned 2 weekslater and reported no postoperative pain. After rubber dam isolation,theroot canal systemwas slowlyflushed with10 mLof 5.25%NaOCl andirrigated with the same solution for 15 minutes. The root canal wasdried with paper points, andMTA was carefully placed over the tissue inthe root canal followed by IRM (Fig. 4 B ). A radiograph taken 2 monthsafter MTA placement showed that some reduction in the radiolucency was evident (Fig. 4C ). At the 2-year follow-up, the radiograph showedcomplete resolution of the radiolucency (Fig. 4 D).

Pulp Regeneration after Formation of a IntracanalBlood Clot

Case 5 A 10-year-old girl experienced painful symptoms in her mandib-

ular left second premolar that required evaluation and treatment. Herdentist informed her parents that there was a large cavity in the tooth.Root canal treatment was initiated, but she did not return to the localclinic at the next appointment. Instead, she presented at our clinic forcompletion of treatment of the tooth approximately 3 months later. Thecanal had remained open and exposed to the oral environment, but thetooth was asymptomatic. The periodontal probings were3 mm, andan abnormal finding such as a sinus tract was not observed. A radio-graph revealed a periradicular radiolucency around the incompletely formed apex of tooth #20 (Fig. 5 A). To prevent leakage during thetreatment or interappointment period, the tooth was restored with a bonded resin restoration.

Oneweeklater, thetoothwas isolated,and anaccess cavitywasmade.

A K-file was introduced into the canal until the patient felt some sensitivity,anda radiographwas taken(Fig.5 B ).Notactile resistancewasmetwith theK-fileuntil thepatientreportedsensitivity.Copiousirrigationwasperformed with 2.5% NaOCl for 30 minutes, and a mixture of ciprofloxacin, metroni-dazole, and minocycline paste was placed into the canal.

The patient returned a week later and reported no further experi-ence of pain. The root canal was slowly flushed with 10 mL of 2.5%NaOCl, and irrigation was maintained with same solution for 15 min-utes.A size#30 K-file was used to irritate the tissue gently tocreate somebleeding into the canal. The bleeding was left for 15 minutes so that theblood would clot. MTAwascarefullyplacedover theblood clot followedbyawetcottonpelletandCaviton(Fig. 5C ). Twoweeks later, thepatient returned, asymptomatic, and the Caviton and cotton pellet were re-placed with a bonded resin restoration. At the 12-month recall, thepatient was asymptomatic, and the radiograph showed complete reso-lution of the radiolucency, and the canal space occupied by blood clot was narrowed (Fig. 5 D). At the 24-month follow-up, the patient contin-ued to be asymptomatic, and continued thickening of the dentinal walls was obvious after radiographic examination (Fig. 5 E ).

Case 6 A 9-year-old girl was referred for evaluation and treatment of the

mandibularleft secondpremolar.Thechild hada lingualswelling of theleft mandibular area for 1 week before the appointment. On clinicalexamination, the patient was asymptomatic, and the tooth appearedintact without evidence of caries. Thetooth hadan open apex associated with a large radiolucency, and a lingual sinus tract was present that

tracedtotheapexoftooth#20(Fig.6 A). Periodontalprobings were3mm for all teeth in the lower left region. Diagnostic testing was incclusive with cold and electric pulp testing, but sensitivity was repoafter percussion or palpation. The tooth was isolated, and a purulehemorrhagic exudate discharged from the canal was evident when taccess cavity was made. The root canal system was irrigated with 2NaOCl for 30 minutes, the canals were then dried, and a mixtureciprofloxacin, metronidazole, and minocycline paste was placed by ing a lentulo spiral. The patient returned a week later and deniedhistory of postoperative pain. The root canal was slowly flushed witmLof 2.5%NaOCl. To evaluate whethervital tissue presentedin thecanal, a size #100 gutta-percha cone was introduced into the canuntil the patient reported some sensitivity. A radiograph was takand revealed that it had reached the open apex of the tooth (Fig. 6 B ).Because the presence of an open apex and thin dentinal walls greaincrease the risk of future fracture, the regenerative technique as dscribed in Case #5 was performed. A size #30 K-file was used to irrthe tissue gently to create some bleeding into the canal. The bleed was left for 15 minutes to permit blood clotting. MTA was carefplaced over the blood clot. However, the blood clot was so fragile tsome of MTA extruded into the apical third of the canal (Fig. 6C ). Two weeks later, the patient returned, asymptomatic, and the Caviton acotton pellet were replaced with a bonded resin restoration. At th6-month recall, the patient was asymptomatic, and the radiograpshowed complete resolution of the radiolucency, with some continudevelopment of theapexdetected (Fig. 6 D). At the24-month follow-up,the patient continued to be asymptomatic. Although the presenceextruded MTA was observed, it was evident that the dentinal wallsplayed continued thickening with closure of the apex (Fig. 6 E ).

Case 7 A 14-year-old girl was referred for evaluation on the lower right s

ond premolar. The girl had a history of swelling of the right mandibubuccalvestibule,for whichshe receivedanincisionfordrainageat theloclinica weekearlier.At the timeofour examination, the tooth had anop

apex associated with a radiolucency, and a buccal sinus tract was presthat traced to the apex of tooth #29 (Fig. 7 A). Periodontal probings were within normal limits for all teeth in the lower right region.

The tooth was isolated, an access cavity was made, copious irrition with 2.5% NaOCl was continued for 30 minutes, and an aquemixture of Ca(OH)2 was placed into the canal. A week later, the patienreturned, asymptomatic, and the sinus tract was resolved. The rocanal wasslowlyflushed with 10mLof 2.5%NaOCl. To evaluate wh vital tissue presented in the root canal, a size #100 gutta-percha co was introduced into the canal until the patient reported some sensatio A radiograph was taken at that point and revealed that the sensation wonly felt when the gutta-percha reached the open apex (Fig. 7 B ). A size#30 K-file was used to irritate the tissue gently to create some bleed

into the canal. The bleeding was left for 15 minutes so that the blo would clot. MTA was carefully placed over the blood clot (Fig 7C ).Three weeks later, the patient returned asymptomatic, and the Caviand cotton pellet were replaced with a bonded resin restoration. Thpatient returned 1 year later with no symptoms or sinus tract evideRadiographic examination revealed a greatly reduced periradicular rdiolucency (Fig. 7 D).

Case 8 A 10-year-old girl experienced painful symptoms in her maxill

right secondpremolar that required evaluationandtreatment. Herdentist initiated the root canal treatment on the tooth, but she did not gothe clinic at next appointment. Approximately 3 months later, she psentedatourclinicfortreatmentof thetooth. Onpresentation,the can




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Figure5. ( A)Radiographobtainedapproximately3 monthsafter theinitial treatmentatlocalclinic.A periradicular radiolucencyaroundthe incompletely formed#20canbeseen.( B ) Radiographdemonstrating a K-filecanbe introduced into thecanal withoutlocalanesthesia. (C ) Radiograph presenting theplacement ofMTA.The MT was carefully placed over the blood clot followed by a wet cotton pellet and Caviton. ( D) Twelve-month radiograph showing complete resolution of the radiolucency ancalcification of the canal space occupied by blood clot. ( E ) Radiograph demonstrating excellent periapical healing at 2-year follow-up.




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Figure 6. ( A) Periapical radiograph of tooth #20at initial presentation. A gutta-perchacone tracessinus tract to theperiradicular radiolucencyassociated#20. ( B ) Radiograph demonstrating a gutta-percha cone can be introduced into the canal easily without local anesthesia. (C ) Radiograph presenting the placement of MTA. Note that some of MTA extruded into the apical third of the canal. ( D) Six-month recall radiograph. The radiolucency has completely disappeared, acontinued root development can be seen. ( E ) Radiograph demonstrating thickening of the dentinal walls and closure of the apex at 2-year follow-up.




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was open to the oral environment, but the tooth was asymptomatic. Theperiodontal probings were within normal limits, and an abnormal find-ing such as a sinus tract was not found. A radiograph showed that a periradicular radiolucency was evident around the incompletely formed apex of the tooth (Fig. 8 A). The tooth was isolated, an accesscavity was made, copious irrigation was done with 2.5% NaOCl for 30minutes, and a mixture of ciprofloxacin, metronidazole, and minocy-cline paste was placed into the canal. At the next appointment (3 weekslater), the root canal was slowly flushed with 10 mL of 2.5% NaOCl andcontinuously irrigated with the same solution for 15 minutes under therubber dam isolation. A size #30 K-file was used to irritate the tissuegently to create some bleeding into the canal, but we failed to achievesufficient blood clot to support the MTA filling. Therefore, we usedCollatape (Sulzer Dental Inc, Plainsboro, NJ) as a matrix for the growth

of new tissue into the pulp space. Under the microscope, we couobserve thatblood wasoozingfrom theperiradicular tissueand wettithe Collatape. MTA was carefully placed over the Collatape followa wet cotton pellet and Caviton (Fig. 8 B ). A month later, the patient returned, asymptomatic, and the Caviton and cotton pellet were rplaced with a bonded resin restoration. At the 17-month recall, thpatient was asymptomatic, and the radiograph showed complete reslution of the radiolucency with continued apical closure (Fig. 8C ).

DiscussionThis case series described the outcomes of 8 patients who pr

sentedwith 9 immature permanent teeth with apicalperiodontitis. Mof these cases were associated with a dens evaginatus, where the t

Figure 7. ( A) Periapical radiograph of tooth #29 at initial presentation. A gutta-percha cone traces sinus tract to the periradicular radiolucency associated#29. ( B ) Radiograph demonstrating a gutta-percha cone can be introduced into the canal easily without local anesthesia. (C ) Radiograph presenting the placement of MTA. The MTA was carefully placed over the blood clot followed by a wet cotton pellet and Caviton. ( D) Radiograph demonstrating a reduced periradicularradiolucency at 1-year follow-up.




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occlusal tubercle might often fracture, predisposing the tooth to bacte-

rial infection and pulpal necrosis (15). The results indicated that it ispossible to treat thenecrotic and immature permanent tooth, leadingtoa postoperativepatientwho is asymptomaticwithoutevidence of a sinustract and a permanent tooth where apical periodontitis is resolved, andthere is radiographicevidence of continuing thicknessof dentinal walls,apical closure, or further development of root length. This biologicresult is remarkable, given the typically poor prognosis of thesecases (4) and the fact that contemporary treatment approachesincluding the use of MTA as an apical plug preclude further root development (16).

In the first 4 patients, treatment was administered without an at-tempt to trigger bleeding and the formation of an intracanal clot. It isinteresting to note that all 5 teeth had a preoperative diagnosis of pulpalnecrosis, and this was supported both by the clinical presentation (all

cases had a periradicular radiolucency, and cases #1#3 had either

sinus tract or an intraoral swelling) and by the lack of pain durinaccess without local anesthesia. The lack of responsiveness to cold aelectrical testing was not considered in the diagnosis, given the incoplete nature of the tooth development (17). Despite these preoperativediagnoses, some vitality was noted during treatment either by sensitto instrumentationwithin therootcanal systemor by thevisualor tactperception of soft tissue remaining within the root canal system. Thcaseswere treated byNaOCl irrigation followed byat least 1-weekplment of the triple antibiotic mixture of ciprofloxacin, metronidazoand minocycline, although case #1 did require additional treatment resolve the sinus tract. The postoperative recall periods of 1months5 years indicated increased thickening of the dentinal waand continual apical closure. Because at least some residual vittissue was believed to be present, these 4 cases could be classified

Figure 8. ( A) Radiograph obtained approximately 3 months after the initial treatment at local clinic. A periradicular radiolucency around the incompleapex of tooth #4 can be seen. ( B ) Radiograph presenting the placement of MTA. The MTA was carefully placed over Collatape followed by a wet cottoCaviton. (C ) Radiograph showing complete resolution of the radiolucency with continued apical closure at 17-month follow-up.




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apexogenesis, although it is not clear whether the continued apicaldevelopment was due to cells in the surviving pulp-dentin complex or to regenerated tissues originating from stem/progenitor cellslocated in the apical papilla (18).

In the second set of 4 patients, treatment was administered asabove,with theaddition of evoking an intracanal blood clot. These casesare distinctfrom the first set of4 cases bythe lackof evidenceof residual vital pulp tissue within the root canal system. The initiation of the bloodclot is thought to provide a fibrin scaffold with platelet-derived growthfactorsthat promotes regenerationof tissuewithintheroot canal system(9,19).Theclinicaloutcomesof 3 cases (cases#5, #6, and#8)are very similar to those observed in the first set of 4 patients, with 3 asymptom-atic patients returning for postoperative recall periods of 17 months2 years and radiographic evidence of increased thickening of the dentinal walls and continual apical closure. Case #7 showed some different clinicaloutcomes. Although apical periodontitis was resolved in the case, a narrowing of the canal space was not significant at 1-year follow-up.

Although the clinical outcomes of most cases were consistent withthe hypothesis of a functional restoration of biologic root development,the precise mechanisms and cellular source remain unknown. It hasbeen suggested that the radiographic evidence of increased root thick -ness might be due to ingrowth of dentin, cementum, or bone (13, 19).Thepresent findings do notdistinguishamongthese possibilities.We donote that other investigators have published human histologic stud-ies describing tissue changes in the pulp-dentin complex or peri-odontium after tooth extraction after various dental treatments (5,2022). Although this approach is clearly subject to considerableethical issues, including informed consent and strict inclusion cri-teria, human histologic studies would directly answer the questionof tissue identity after pulpal regeneration/revascularization proce-dures in patients.

The value of case reports is the demonstration of what is possiblein our patients. Reports from astute clinical practitioners have playedpivotal roles in advancing dental therapeutics including recognition of thepropertiesof fluoride(23), aswell as the adverse effects of bisphos-

phonates (24). The present study, combined with prior reports onregeneration/revascularization of the nonvital immature permanent tooth (813), constitute a growing case series suggesting that biologi-cally based treatmentapproaches might be of particular value in restor-ing root development and apical closure in these otherwise difficult cases. Importantly, the value of prospective randomized clinical tri-als is their ability to provide strong quantitative evidence for bothtreatment efficacy and the potential for adverse effects. This growingbody of case reports provides impetus for developing prospectiverandomized controlled trials evaluating these methods. Finally, if this biologic process can occur in the immature tooth, then it alsomight provide some insight into the conditions necessary to regen-erate a functional pulp-dentin complex in the nonvital fully formed

permanent tooth.

References1. SalehrabiR, Rotstein I. Endodontic treatmentoutcomes in a largepatientpopulati

in the USA: an epidemiological study. J Endod 2004;30:846 50.2. Marquis VL, Dao T, Farzaneh M, Abitbol S, Friedman S. Treatment outcome in

odontics: the Toronto Study. Phase III: initial treatment. J Endod 2006;32:299303. Murray PE, Garcia-Godoy F, Hargreaves KM. Regenerative endodontics: a revi

current status and a call for action. J Endod 2007;33:37790.4. Cvek M. Prognosis of luxated non-vital maxillary incisors treated with calcium

droxide and filled with gutta-percha: a retrospective clinical study. Endod DeTraumatol 1992;8:4555.

5. Nygaard-stby B. The role of the blood clot in endodontic therapy: an experimehistologic study. Acta Odont Scand 1961;19:32353.

6. Nygaard-stby B, Hjortdal O. Tissue formation in the root canal following premoval. Scand J Dent Res 1971;79:33349.

7. Hargreaves KM, Geisler TM, Wang Y, Henry M. Regeneration potential of the ypermanent tooth: what does the future hold? J Endod 2008 (in press).

8. Iwaya SI, Ikawa M, Kubota M. Revascularization of an immature permanent t with apical periodontitis and sinus tract. Dent Traumatol 2001;17:1857.

9. Banchs F, Trope M. Revascularization of immature permanent teeth with apiperiodontitis: new treatment protocol? J Endod 2004;30:196200.

10. Thibodeau B, Trope M. Pulp revascularization of a necrotic infected immature pmanent tooth: case report and review of the literature. Pediatr Dent 2007;29:475

11. Petrino JA. Revascularization of necrotic pulp of immature teeth with apical podontitis. Northwest Dentistry 2007;86:335.

12. ShahN, Logani A.Evaluationof revascularization to induce apexification/apexogin infected, non-vital immature teeth. Presented at IFEA Meeting, Vancouver, Canada; 2007.

13. Chueh LH, Huang GT. Immature teeth with periradicular periodontitis or abscundergoing apexogenesis: a paradigm shift. J Endod 2006;32:120513.

14. Hoshino E, Kurihara-Ando N, Sato I, et al. In-vitro antibacterial susceptibilitbacteria taken from infected root dentine to a mixture of ciprofloxacin, metronidzole and minocycline. Int Endod J 1996;29:12530.

15. Levitan ME, HimelVT. Densevaginatus: literature review, pathophysiology, andprehensive treatment regimen. J Endod 2006;32:19.

16. Pace R, Giuliani V, Pini Prato L, Baccetti T, Pagavino G. Apical plug technique mineral trioxide aggregate: results from a case series. IntEndod J 2007;40:47884

17. Fulling HJ, AndreasenJO. Influenceof maturationstatusand toothtype of permanteeth upon electrometric and thermal pulp testing. Scand J Dent Res 1976;8428690.

18. Sonoyama W, Liu Y, Yamaza T, et al. Characterization of the apical papilla anresiding stem cells from human immature permanent teeth: a pilot study. J Endo

2008;34:16671.19. Thibodeau B, Teixeira F, YamauchiM, CaplanDJ, TropeM. Pulp revascularizatioimmature dog teeth with apical periodontitis. J Endod 2007;33:6809.

20. Mellonig JT. Histologic and clinical evaluation of an allogeneic bone matrix fortreatment of periodontal osseous defects. International Journal of Periodontics &Restorative Dentistry 2006;26:5619.

21. Hartman GA, Arnold RM, Mills MP, Cochran DL, Mellonig JT. Clinical and hisevaluation of anorganic bovine bone collagen with or without a collagen barrieInternational Journal of Periodontics & Restorative Dentistry 2004;24:12735.

22. Yukna RA, Carr RL, Evans GH. Histologic evaluation of an Nd:YAG laser-assistattachment procedure in humans. International Journal of Periodontics & Restoative Dentistry 2007;27:57787.

23. Gordon SM, Dionne RA.The integration of clinical research intodental therapeutthe role of the astute clinician. J Am Dent Assoc 2004;135:153742.

24. Marx RE. Pamidronate (Aredia) and zoledronate (Zometa) induced avasculanecrosis of the jaws: a growing epidemic. J Oral Maxillofac Surg 2003;6

11157.


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Remineralization Without Blood Clot