bioabsorbable root analogue for closure of oroanatral communication - thoma et al_________bibl 36

8/10/2019 Bioabsorbable Root Analogue for Closure of Oroanatral Communication - Thoma Et Al_________BIBL 36

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ORAL AND MAXILLOFACIAL SURGERY Editor: James R. Hupp

Bioabsorbable root analogue for closure of oroantral communications aftertooth extraction: A prospective case e cohort studyKaya Thoma, DMD, a Gion F. Pa jarola, DMD, b Klaus W. Gr atz, MD, DMD, c

and Patrick R. Schmidlin, DMD, d Zurich, SwitzerlandUNIVERSITY OF ZURICH CENTER OF DENTAL AND ORAL MEDICINE

Objective. To assess the clinical capacity of a bioabsorbable root analog to close oroantral perforations after extraction.Study design. In this prospective casee cohort study, 20 consecutive patients with oroantral communications greater

than 2 mm were treated with a bioabsorbable root analog (RootReplica). Patients were followed up clinically andradiographically for 3 months to monitor the healing process.Results. Root replicas could be placed in 14 patients, whereas 6 patients required the socket to be covered with a buccal slidingap. In the latter cases, fragmentary roots or overly large defects prohibited replica fabrication or accurate tting of the analog,respectively. Healingwas uneventful in allpatients,and epistaxis, swelling,or pain wasobservedonly in patients treated withaps.Conclusions. The method described is a valuable alternative method with which to close oroantral communications butcannot be performed in all patients because of technical limitations.(Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006;101:558-64)

Oroantral perforations occur occasionally after theextraction of upper teeth because of the anatomicalproximity of the roots to the sinus. The incidence rangesfrom 0.31% to 4.7%. 1-3 Although perforations with adiameter of less than 2 mm mayheal spontaneously afte rthe formation of a blood clot and secondary healing, 4

larger orices require closure of the defect to avoidinfection and stula formation. 5

Many techniques have been proposed to seal thesocket from the oral environment. Different ap designsthat cover these defects have been reported; 6-8 however,they each have disadvantages. Buccal sliding apsreduce the vestibular sulcus and therefore hamper pros-thetic treatments. Palatal aps produce a denuded area

that requires secondary healing. The use of ller mate-rials in combination with guided bone regeneration(GBR)/guided tissue regeneration (GTR) techniquesis no real alternative, because primary closure to covermembranes is still challenging andmay lead to theprob-lems described. On the other hand, graft material mayeasily be dislocated into the sinus and is thereforecontraindicated. The use of nonporous hydroxyapatiteblocks (which are carved and tapered with diamondsunder water cooling until friction is achieved) to closestulas has been reported. 9 Transplanted natural thi rdmolars have also been used to close perforations. 10

Suhonen and coworkers introduced the idea of applyingchairside custom-made bioabsorbable root analogs intoextractionsocket s as immediate implants to preserve thealveolar process. 11,12

This study assessed the suitability of these b-tricalcium phosphate root analogs (RootReplica, De-gradable Solutions AG, Schlieren, Switzerland) to closeoroantral communications. Patients were followed for3 months to evaluate healing.

MATERIAL AND METHODSThis study was a prospective clinical investigation.

All procedures and materialswere approved by the localethics committee. We proposed to treat 20 consecutive

a Dr. med. dent., Postgraduate Student, Clinic for Cranio-Maxillofa-cial Surgery and Oral Surgery, Zurich, Switzerland.b Dr. med. dent., Senior research fellow, Clinic for Cranio-Maxillofa-cial Surgery and Oral Surgery, Zurich, Switzerland.c Dr. med.dent., Professorand Chairman, Clinic for Cranio-Maxillofa-cial Surgery and Oral Surgery, Zurich, Switzerland.d Dr. med. dent., Senior research fellow, Clinic for Preventive Dentis-try, Periodontology and Cariology, Zurich, Switzerland.Received for publication May 17, 2005; returned for revision Jul 13,2005; accepted for publication Aug 17, 2005.1079-2104/$ - see front matter

2006 Mosby, Inc. All rights reserved.doi:10.1016/j.tripleo.2005.08.017

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patients with sinus perforations larger than 2 mm,immediately after tooth extraction, with a root analog.Other selection criteria for inclusion were that patientsbe systemically healthy, with no clinical or radiologicalsigns of acute or chronic sinusitis. Subjects wereexcluded if they did not meet the inclusion criteria,

were pregnant or lactating, or were medicated withantibiotics. Smokers were not excluded from the study.Informed consent was obtained from all patients.

If a perforation occurred after extraction, the perfora-tion was rst veried by using a blunt probe and/orthe Valsalva maneuver ( Fig. 1). Granulation tissue wascarefully removed and the socket was rinsed with sterilesaline solution ( Fig. 2, A, B). Socket depth was mea-sured by using a periodontal probe. The perforationdiameter was assessed with specially devised roundedprobes of known diameter that measured the perforationat its smallest diameter ( Fig. 2, C ). The oroantral com-munication was classied accordingly. The patient biton a sterile swab during the fabrication of the root ana-log, which takes about 10 minutes. To produce the rootanalog, the extracted root was rst cleared of soft tissuewith a curette, and rinsed with 3% H 2 O2 and then withsterile saline solution. To produce a mold of the ex-tracted tooth root, the chamber of a small heating device(RootReplicator, Degradable Solutions AG) was lledwith impression material (RootReplica, DegradableSolutions AG) and the extracted tooth was pressedinto it (Fig. 2, D). After the impression material hadset, the tooth was removed and the mold was precutabout two thirds in height at opposite ends to alloweasy demolding of the root analog. The mold was thenreplaced in the heating device and the rst biomaterial,consisting of free-owing granules of synthetic phasepure b-tricalcium phosphate coated with polylactide(RootReplica Granules, Degradable Solutions AG),was poured into the mold ( Fig. 2, E ). After a heating pe-riod of about 1 minute, the granules condensed to forma solid but porouscopyof the extracted tooth root. A sec-ond component, consisting of pure polylactide powder(RootReplica Membrane, Degradable Solutions AG),was poured onto the surface of the root analog andcondensed to form an integrated membrane on the cor-

onal end of the root analog. A heated condenser(HeatCondenser, Degradable Solutions AG) was thenused to seal the surface. The mold was removed fromthe heating device, and after a short cooling period,the root analog was removed from the mold ( Fig. 2, F ).The swab was taken from the patient and the extractionsite rinsed with sterile saline solution. Fresh bleedingwas induced by curetting the extraction site. The replicawas placed in the socket and carefully pushed up untilfriction and proper seating were achieved ( Fig. 2, G).Suturing was only performed if necessary, for example,

when the extraction was performed with ap surgicalremoval or to adapt papillae. The soft tissues werecompressed to achieve a good coagulum andadaptation,and a radiograph was taken.

In patients in whom no root analog could be placed,a buccal sliding ap was made. No antibiotics wereadministered to any patient. Mefenamic acid (Ponstan,Pzer, Zu rich, Switzerland) was prescribed as an anal-gesic. Patients were told not to blow their nose duringthe rst weeks. Control appointments were made after1, 2, and 3 weeks. Any sutures were removed after2 weeks. Patients were followed clinically and radio-graphically for 3 months to monitor the healing process.Photographs were taken at all visits to document softtissue healing.

RESULTSAn overview of the patients, the baseline measure-

ments of theextraction site, and the treatmentmodalitiesare emphasized in Table I . The mean age of the patientswith oroantral communications was 38 6 11 years.Eleven men and 9 women were treated. Ten patientswere smokers. Extractions were mainly performed forcaries (n = 14) and endodontic problems (n = 5). Onetooth was extracted fororthodontic reasons (buccal non-

occlusion). Ten perforations had a diameter of 2-3 mm,whereas theother10 sockets hadperforations larger than3 mm. Mean socket depth was 12.5 6 3.7 mm. In therecruitment period from August 2004 to December2005, 1823 extractions were performed. Eleven extrac-tions had an oroantral communication of less than 2mm and were excluded from the study. Thus, includingthe patients in this study, 31 perforations to the sinuswere observed, constituting an incidence of 1.7%.

In 6 patients, no root replica could be inserted(Table II ). The reasons were (1) a large maceration of the

Fig. 1. Especially designed test probe with a standard diame-ter used to determine and measure the perforation at its small-est diameter.

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bone in 1 patient, (2) fracture of themaxillary tuberosityin 2 patients, and (3) complicated extractions withmultiple root fragments in 3 patients ( Fig. 3). In thesepatients, a buccalsliding apwasmade ( Fig. 4 ). Healingwas uneventful except for swelling and postoperativepain, which was observed in all 6 patients. One patient(patient 14) showed epistaxis.

A replica could be placed in 14 patients ( Table II ).Noadditional treatment or medication was required. Heal-ing was complete after 2 weeks and no complicationsarose. In all cases, the replicas were retained in situ,except in 1 patient from whom it was completely lostafter 5 days (patient 17). In 4 patients, the coronal thirdwas lost during the healing phase. In general, healing

Fig. 2. Tooth 25 (patient 2) with a deep carious lesion before extraction ( A), and the socket after extraction ( B). C , The proberevealed a perforation larger than 3 mm. An impression was made of the extracted tooth ( D) and a replica made ( E ). The porousreplica gave an exact copy of the extracted root ( F ) and perfectly sealed the socket after insertion ( G ).

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was uneventful in all 14 patients and no complicationswere observed ( Table II ). Soft tissue healing was un-eventful in all patients ( Fig. 5). No swelling or post-operative pain was observed.

Radiographic assessment of healing revealed no dis-tinct features ( Fig. 6). A corresponding decrease in radi-opacity was detected only in the 5 patients with clinical(partial) material loss. Round particles of the materialwere observed in the extraction area. No pathologicalchanges of the sinus were observed.

DISCUSSIONThe treatment of oroantral communications relies

on the establishment of a good physicochemical barrierthat allows uneventful healing and prevents infection.

Whereas small oroantral communications with a diam-eter of less than 2 mm usually heal spontaneously, largerdefects rarely heal spontaneously without adequate clo-sure, especially when they are larger than 5 mm or per-sist for more than 3 weeks. The traditional method of covering such defects is to usesoft tissues, that is, buccalor palatal aps or modications thereof. The inherentproblems associated with these techniques include, inthe short-term, postoperative pain and swelling (as con-rmed in this study), and in the long-term, scar forma-tion and changes in mucosal topography. In particular,

a reduction in the depth of the vestibular sulcus may sig-nicantly hamper prosthetic treatments.

Transplantation of upper third molars to close thesockets has been described. 10 This method allows theclosure of the oroantral communication and prosthetictreatment to be achieved in 1 procedure. However,the method is expensive and technique-sensitive. As analternative, the use of hydroxyapatite blocks has beenreported, which allowed the successful closure of oroantral stulas in 6 patients. 9 Clinically, the problemwas resolved in all patients without complications.However, all hydroxyapatite blocks became loose dur-ing the rst weeks in all patients and extrusion occurred.This was related not to infection but to a lack of osseo-integration, and was therefore considered a naturalphenomenon. The authors concluded that the blocks re-duced the sizes of the stulas, which then healed spon-taneously until the blocks were lost. In our study, only1 replica was lost during thehealing phase. Four replicas

showed partial loss of the coronal third of the implantlength, which did not affect healing.

In this study, neither bone formation nor quality wasassessed. The study mainly focused on whether thismethod is suitable and safe for the closure of oroantralperforations. However, from a biological perspective,there is evidence that the material undergoes hydro-lytic degradation and that new bone forms. This wasinvestigated in an animal study by using the samematerial. After an observation period of 60 weeks,the material was almost completely degraded. The

Table I. Overview of the patients. Baseline measure-ments of the extraction sites and treatment modalities

Patient Age(yr)

Sex(m/f)

Reasons for

extraction

Perforation(mm),

smallest diameter

Socket depth(mm) Sutures Smoker

1 30 f Caries 2-3 16 1 2 18 f Caries 4-5 11 13 28 f Endodontic 2-3 10 4* 46 m Caries 5-6 7 1 15 26 f Caries 2-3 15 16 47 f Endodontic 4-5 13 1 7 41 m Orthodontic 5-6 17 1 8* 56 m Caries 7-8 6 1 9* 27 m Caries 3-4 14 1 1

10 30 m Endodontic 4-5 16 111 44 m Caries 2-3 14 12 53 m Caries 2-3 14 1 113 56 f Caries 3-4 14 114* 37 m Caries 3-4 13 1 115 45 m Endodontic 2-3 15

16 44 f Endodontic 3-4 10 17 21 m Caries 4-5 12 118* 39 f Caries 3-4 12 1 119 29 m Caries 2-3 17 1 20* 45 f Caries 9-10 3 1

Data are given in chronological order. Sutures in patients treated with the rootanalogue were only used to adapt papillae; sockets were left open.*Patients treated with buccally advanced aps.

Table II. Complications during the observation period

Patient

Lossof

replica

Partialreplica

loss Epistaxis

Socket bleed-

ingSwell-

ing Sinusitis

Post-operative

pain

1 2 3 4* 1 15 1 6 7 8* 1 19* 1 1

10 1 11 12 1 13 1 14* 1 1 115 16 17 1

18* 1 119 20* 1 1 1

*Patients treated with buccally advanced aps.

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histological grade of bone formation was similar tothat at control sites. 13

In terms of soft tissueremodeling, wound healing wasuneventful and the vestibulum was not affected, whichis a clear advantage over closure with aps. No swellingor pain was reported in anypatient treated with a replica.These problems were more obvious in patients treatedwith conventional ap closure. Postoperative ailmentsin the latter patients probably arose from ap mobiliza-tion and periosteum slitting.

An important issue is whether defects of 3-5 mmwould have healed spontaneously without placementof the replica. This question could be answered only if an untreated control group, in whom no attempt wasmade to close the perforation, was included. The inci-dence of this condition is very low. Therefore, the statis-tical validity of any clinical evaluation of its treatment isnecessarily dubious. The studies of Von Wowern werepublished in the early 1970s and with fundamentalknowledge. Based on these results, as shortly presentedin the following sentences of our discussion, ethic alapproval would be impossible nowadays. Von Wowern 14

used a no-treatment control group of 9 patients withsinus perforation without root displacement, and 7 of

these formedan oroantral stula. Fistulas were observedin 7% of patients in whom sutures were used to connectthe buccal and palatal mucosae. In another study, 8% of sinus perforations failed to he al even after primary clo-sure with buccal sliding aps. 15

Ergonomic andeconomic factors mayalsoplay anim-portant role in primary wound treatment, including thecostsof thematerial andthetime for fabrication.Replicafabrication takesaround10 minutes. In thestudyby Rubinand Sanlippo, carving the prefabricated blocks took 20-30 minutes. The preparation, adaptation, and xation

of a ap also take a signicant amount of practice anddepend upon the skill of the operator and the clinicalsituation. No time data are available for this technique.

Within thelimitations ofourstudy, thefollowingconclu-sions canbedrawn.Thereplicatechnique isfastand easy. Itshows good clinical healing and integration into the hardand soft tissues. Postoperative pain and swelling are mark-edly reduced and thevestibular architecture is maintained.On the other hand, the feasibility of the replica technique

Fig. 3. Most common reasons for using ap surgical removalfor communication closure were multiple root fragments aftera complicated extraction, bone maceration, and tuberosityfractures, which do not allow a replica to be made or the stableplacement of a root analog.

Fig. 4. Bone condition after extraction of tooth 27 (patient20). A , A large area of macerated bone and a sinus perforationthat could not be occluded by a replica. A buccal sliding approcedure was therefore performed ( B), which induced goodclinical healing after 3 months ( C ).



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depends upon the integrity of the root after extractionand of thesurroundingbonybed. In this study, thereplicatechnique could be applied in 70% of extractions withoroantral communications. Technological improve-ments may lead to modications that increase this rate.

Further clinical studies are required to conrm thesuitability of this material and method in closing even

larger or chronic oroantral communications or stulas.If equally positive results are obtained, this methodmay become a valuable alternative for the treatment of oroantral communications.

The root replica materials and the instruments usedto prepare them were kindly provided by DegradableSolutions AG, Schlieren, Switzerland.

Fig. 5. A, Socket after extraction of tooth 27 from patient 13. B and C , The remaining part of the fractured basal sinus wall wasretained for replica fabrication. D, A tight t and coagulum formation were achieved. Healing was uneventful. Although the cor-onal part of the replica was coated with brin, no signs of inammation were observed ( E ) and complete coverage with epitheliumwas observed after 3 months ( F ).



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REFERENCES1. Beckedorf H, Sonnabend E. The incidence of maxillary sinus

perforations in teeth extractions. Zahnarztl Rundsch 1954;63:566-9.

2. Punwutikorn J, Waikakul A, Pairuchvej V. Clinically signicantoroantral communications e a study of incidence and site. Int JOral Maxillofac Surg 1994;23:19-21.

3. Hirata Y, Kino K, Nagaoka S, Miyamoto R, Yoshimasu H, Ama-gasa T. A clinical investigation of oro-maxillary sinus-perfora-tion due to tooth extraction. Kokubyo Gakkai Zasshi 2001;68:249-53.

4. Guven O. A clinical study on oroantral stulas. J Craniomaxillo-fac Surg 1998;26:267-71.

5. Kraut RA, Smith RV. Team approach for closure of oroantral andoronasal stulas. Atlas Oral Maxillofac Surg Clin N Am 2000;8:55-75.

6. Killey HC, Kay LW. An analysis of 250 cases of oro-antralstula treated by the buccal ap surgical procedure. Oral SurgOral Med Oral Pathol 1967;24:726-39.

7. Ziemba RB. Combined buccal and reverse palatal ap for clo-sure of oral-antral stula. J Oral Surg 1972;30:727-9.

8. Haanaes HR, Pedersen KN. Treatment of oroantral communica-tion. Int J Oral Surg 1974;3:124-32.

9. Zide MF, Karas ND. Hydroxylapatite block closure of oroantralstulas: report of cases. J Oral Maxillofac Surg 1992;50:71-5.

10. Kitagawa Y, Sano K, Nakamura M, Ogasawara T. Use of thirdmolar transplantation for closure of the oroantral communication

after tooth extraction: a report of 2 cases. Oral Surg Oral MedOral Pathol Oral Radiol Endod 2003;95:409-15.

11. Suhonen Suuronen R, Hietanen J, Marinello C, To rmala P.Custom made polyglycolic acid (PGA) - root replicas placedin extraction sockets of rabbits. Dtsch Z Mund Kiefer Gesicht-schir 1995;19:253-7.

12. Suhonen JT, Meyer BJ. Polylactic acid (PLA) root replica inridge maintenance after loss of a vertically fractured incisor.Endo Dent Trauma 1996;12:155-60.

13. Nair PNR, Luder HU, Maspero FA, Fischer JH, Schug J. Bio-compatibility of tricalcium phosphate root replica in porcinetooth-extraction sockets - a correlative histological ultrastruc-tural and x-ray microanalytical pilot study. J Biomat Appl2005 (in press).

14. von Wowern N. Frequency of oro-antral stulas after perforationto the maxillary sinus. Scand J Dent Res 1970;78:394-6.

15. von Wowern N. Correlation between the development of anoroantral stula and the size of the corresponding bony defect.J Oral Surg 1973;31:98-102.

Reprint requests:

Patrick R. Schmidlin, DMDPlattenstrasse 11CH - 8032 [email protected]

Fig. 6. Radiograph of patient 7 before extraction of tooth 28 ( A) and after 3 months ( B). The triangles indicate the border of thecoronal part of the replica. Patient 15 before extraction of tooth 26 ( C ) and after 3 months ( D). Note the partial loss of the replicamaterial indicated by the subcrestal triangles. In both cases, b-tricalcium phosphate granules are still visible as round radiopacities

in the extraction area.

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bioabsorbable root analogue for closure of oroanatral communication - thoma et al_________bibl 36

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