Abstract

The effects of repairing the perforated sinus membrane with collagen membrane are unknown. The purpose of this pilot study was to clinically, histologically, and histomorphometrically evaluate the results of repairing the perforated sinus membrane with resorbable collagen membrane. A split-mouth design was followed in the current study. Five subjects requiring bilateral sinus grafting were included in the study, where one site was accidentally perforated during sinus augmentation procedures and the other site was not perforated. The perforated sites were repaired with a resorbable collagen membrane. Dental implants were placed at a second stage and biopsies were harvested from both sinuses. New bone formation was measured for all sites. Implant survival was recorded at second-stage surgery. Nonperforated sites demonstrated significantly more bone formation (34.40%) than perforated sites (12.80%) (P = .016). Implant survival at second-stage surgery was significantly inferior in perforated sites (54.5%) when compared with nonperforated sites (100%) (P = .0146). The study demonstrated that perforation and repair of the Schneiderian membrane can compromise new bone formation and implant survival rate.

EFFECTS OF SEALING THE PERFORATED SINUSMEMBRANE WITH A RESORBABLE COLLAGENMEMBRANE: A PILOT STUDY IN HUMANSCLINICALPeriklis Proussaefs, DDS, MSJaime Lozada, DDSJay Kim, PhDKEY WORDSResorbable collagen membraneSealing perforated sinus membranePeriklis Proussaefs, DDS, MS, is anassistant professor in the Graduate Program inImplant Dentistry, Loma Linda University,Loma Linda, CA 92350, and has a privatepractice emphasizing implant and prostheticdentistry in Santa Clarita, CA.Jaime Lozada, DDS, is a professor and thedirector of the Graduate Program in ImplantDentistry, Loma Linda University, LomaLinda, CA 92350.Jay Kim, PhD, is a professor in Biostatisticsand Education Services, Loma LindaUniversity, Loma Linda, CA 92350.The effects of repairing the perforated sinus membrane with collagen membraneare unknown. The purpose of this pilot study was to clinically, histologically, andhistomorphometrically evaluate the results of repairing the perforated sinusmembrane with resorbable collagen membrane. A split-mouth design wasfollowed in the current study. Five subjects requiring bilateral sinus graftingwereincluded in the study, where one site was accidentally perforated during sinusaugmentation procedures and the other site was not perforated. The perforatedsites were repaired with a resorbable collagen membrane. Dental implants wereplaced at a second stage and biopsies were harvested from both sinuses. Newbone formation was measured for all sites. Implant survival was recorded atsecond-stage surgery. Nonperforated sites demonstrated significantly more boneformation (34.40%) than perforated sites (12.80%) (P 5 .016). Implant survival atsecond-stage surgery was significantly inferior in perforated sites (54.5%) whencompared with nonperforated sites (100%) (P 5 .0146). The study demonstratedthat perforation and repair of the Schneiderian membrane can compromise newbone formation and implant survival rate.INTRODUCTIONntal implants offer apredictable treatmentmodality for the totallyor partially edentulouspatient.1,2 After the introductionof sinus-graftingtechniques3,4 implant placement andprosthetic rehabilitation of the resorbedposterior maxilla has become avalid treatment option.5-8Several grafting materials havebeen used to augment the antral space,including autografts,3,4,9-12 demineralizedfreeze-dried bone (DFDBA) powder,5,13-15 hydroxyapatite,5,8,12,16-18 andcombinations of these.5,8,12,19-22 Regardlessof the type of graft that is used,the sinus augmentation procedure involveselevation of the Schneiderianmembrane and placement of the graftmaterial at the space underneath thereflected membrane.3 The most commoncomplication during sinus graftsurgery is tearing or perforating the sinusmembrane (SM).23 If membraneperforation occurs, the opening can beJournal of Oral Implantology 235A PILOT STUDY IN HUMANS USING RESORBABLE COLLAGEN MEMBRANE IN A PERFORATED SINUSTABLE 1Subject distribution*Subject Age645612365587845Average 64.24.3 SD*N/A indicates not applicable.sealed with a piece of resorbable collagenmembrane.18,23-25Even though it has been clinicallyrecommended, there is no study toevaluate the potential of sealing theperforated SM. A study was designedto clinically, histologically, and histomorphometricallyevaluate the effectsof sealing the perforated SM with a resorbablecollagen membrane.MATERIALS AND METHODSFive human subjects were included inthis pilot study (Table 1). A splitmouthdesign was followed. Subjectswho received bilateral sinus graftingprocedure and had the SMaccidentallyperforated in 1 side only were includedin the study. All subjects were asked torespond to the corresponding informedconsent approved by the InstitutionalReview Board for Humanstudies at Loma Linda University.Inclusion criteriaThe inclusion criteria were as follows:1. Patients with bilateral atrophic posteriormaxillary region with heightof residual bone 0-4 mm (SA-4)23 asmeasured through panoramic andtomographic radiographs.2. Subjects who received bilateral sinusgrafting and had the SM perforatedin 1 side only.3. Good oral hygiene.Exclusion criteriaExclusion criteria were as follows:1. Smoking or alcohol consumption.236 Vol. XXIX/No. Five/2003Healing Period ofGraft Material (Months) Sex88FM1497FFFN/A 9.21.62. Acute or recurrent sinusitis at any ofthe 2 maxillary sinuses.3. Uncontrolled systemic disease.For all subjects, a healing period of8-14 months was allowed before implantsurgery. During implant surgery,the bone quality was recorded (Type I-IV) and a biopsy was taken from thegrafted area.Pre- and postoperative medicationBefore surgery, subjects received 500mg of amoxycillin (Novopharm, Toronto,Canada). Following surgery, subjectswere prescribed amoxycillin (500mg 3 times a day for 10 days) and ibuprofen(800 mg 3 times a day for atleast 3 days).Surgical procedureThe subjects were given the option toproceed with (a) local anesthesia alone,(b) local anesthesia in conjunction withoral sedation, and (c) local anesthesiain conjunction with IV sedation.The sinus augmentation procedurefollowed the technique described byTatum4 and Smiler et al.18 Briefly, a supracrestalincision was made from canineor first premolar area to the ipsilateralmaxillary tuberosity region. Fullthickness mucoperiosteal flaps wereraised and the lateral wall of the sinuswas exposed. A rectangular osteotomywas made with a #4 round bur (ACESurgical Supply Inc, Brockton, Mass).The inferior osteotomy was 5 mmabove the sinus floor. The superior osteotomywas left intact to allow infractureof the lateral sinus wall. The SMwas carefully elevated. A portion of theantral space was filled with bovinebone mineral (Bio-Oss, Osteohealth Co,Shirley, NY).For areas where the SM was perforatedduring reflection (Figure 1), aresorbable collagen membrane wastrimmed and placed at the site of theperforation prior to the insertion of thegraft material (Figures 2 and 3). Themucoperiosteal flaps were repositionedand sutured with horizontal mattressand single interrupted sutures. Implantswere placed after a period of 8to 14 months. Bone quality (Type I-IV)was recorded during implant placement.26 Second-stage surgery followedafter a 6- to 9-month healing period.Radiographic evaluationIn all cases, panoramic radiographswere taken before and after the sinusgrafting procedure (Figures 4 and 5)and after placement of the implants.Implant survivalImplant survival was recorded at second-stage surgery (SSS). Implant mobilitywas evaluated by placing a healingabutment and bimanual use of 2hand instruments. In addition, the Perio-Test Unit was used to assess implantmobility.27 Mobility more than 11 dictatedimplant failure. Symptoms ofpain or sensitivity to percussion aswell as clinical signs of infection wererecorded as implant failures.There were instances where bonegraft appeared soft and inadequateto offer primary stability during implantplacement. During statisticalanalysis, these cases were recordedas failures.Biopsy procedureA healing time of 8 to 14 months wasallowed before proceeding to implantsurgery. The biopsy sample was harvestedwith a 2-mm internal-diametertrephine bur (ACE Surgical Supply Inc)starting from the alveolar crest andending at the most superior part of thegraft. The site of biopsy was the areawhere the original bone has the leastFIGURES 1-5. FIGURE 1. Perforation of the sinus membrane is observed. FIGURE 2. A resorbable collagen membrane is placed to repair thesinus membrane. Bio-Oss is subsequently added as graft material against the collagen membrane. FIGURE 3. The Bio-Oss particles areplaced into the sinus. FIGURE 4. Panoramic radiograph before the sinus-graft procedure. FIGURE 5. Panoramic radiograph after performingbilateral sinus graft. The left sinus had been perforated. Some graft material appears to have escaped into the sinus area (black arrow).In the other side, a sharp line (white arrow) defines the upper margin of the graft material that now represents the floor of the sinus.height. The trephine bur was used asthe first drill during the osteotomypreparation for implant placement.Subsequently, an hydroxyapatite-coatedthreaded root-form implant (Steri-Oss; Nobel Biocare, Yorba Linda, Calif)was placed according to the manufacturer'sprotocol. The specimens werefixed in 10% buffered formalin.Histologic processingThe specimens were dehydrated in alcoholand embedded in specializedresin (Technovit 7200 VLC; Kulzer,Periklis Proussaefs et alWehrheim, Germany). Initial midaxialsections of 200 mm were made bymeans of the cutting-grinding system(Exact Medical Instruments, OklahomaCity, Okla). The sections were thenground to 40 to 50 mm and werestained with Stevenel's blue and VanJournal of Oral Implantology 237A PILOT STUDY IN HUMANS USING RESORBABLE COLLAGEN MEMBRANE IN A PERFORATED SINUSBone quality of grafted area and implant survival until second-stage surgeryPerforated SideBoneQuality SubjectImplantsPlacedImplantsPlannedTo Be PlacedIVIIIIVIVIV1234522223Gieson' s picro-fuchsin for histomorphometricanalysis and light fluorescentmicroscopy.28,29Histomorphometric evaluationHistomorphometric evaluation wasperformed by one investigator (P.P.) byusing a computer-assisted linear analysisprogram, Ribbon, developed atLoma Linda University.30 This programuses a series of systematicallyspaced horizontal lines (each 2 pixelswide), 1 by 1, on a vertically orientedimage selected for analysis. In thisstudy, the lines were spaced 50 pixelsapart in the object plane and the firstline was placed randomly within 50pixels of the top of the image. Keyboardentries and cursor clicks recordedthe lengths of the line segments thatcrossed the various types of tissue(bone, soft tissue, or residual bonegraftparticles). Intersections of lineswith residual bone-graft particles wererecorded as contacting bone or soft tissue,depending on the type of tissue atthe interface. For each histologic specimen,1 to 3 images were analyzed (dependingon the size of the specimen).Percent composition of the specimenwas given by the ratio of the sumof the lengths of line segments fallingon a given component (bone, soft tissue,graft particles) to the total lengthof lines analyzed. The percent of residualxenograft surface occupied by bonewas given by the ratio of the numberof line intersections with bone-particleinterfaces to the total number of graftxenograft surface intersections.All histomorphometric analysiswas performed by capturing an image238 Vol. XXIX/No. Five/2003TABLE 2BoneQualityImplantsPlannedTo Be PlacedFailures atSecond-Stage SurgeryIIIIIIIIIIIII1221300003under 32 magnification (Olympus Microscope,Model BH-2; McBain Instruments,Chattworth, Calif).Statistical analysisThe Mann-Whitney U test was used atsignificance level a 5 .05 to comparenew bone formation, connective tissue,residual graft (Bio-Oss) particles, andbone to Bio-Oss contact between perforatedsites (PS) and nonperforatedsites (NPS).A 2-sample test for binomial proportionswas used to compare implantsurvival rate between PS and NPS.RESULTSClinical evaluationNo immediate postoperative complication(infection, persistent pain, orbleeding) occurred in any of the sinusgraftprocedures. During implant surgery,2 patients (Table 2) that had perforationof the SM demonstrated inadequateconsistency of the graft materialin some areas, precluding primary stabilizationof dental implant. PS hadtypically Type IV bone quality (4 patients)while NPS had Type II or III.Radiographic evaluationNonperforated sites demonstrated asharp definition between grafted andnongrafted areas of the maxillary sinus(Figure 5). Perforated sinuses appear tohave graft particles beyond the bordersof the SM, lacking definition betweenthe grafted and nongrafted sinus area.Implant survivalThe NPS had 100% implant survivalrate until SSS, while PS had 54.5% sur-Nonperforated SideImplantsPlacedFailures atSecond-Stage Surgery221230000022123vival. The NPS had a significantly betterimplant survival rate (P 5 .0146).Histologic observationsThe NPS appeared to have enhancedbone formation (Figure 6). ResidualBio-Oss particles appeared in tightcontact with newly formed bone (Figures7 and 8). The PS had abundantconnective-tissue formation (Figure 9).Few areas with bone formation appearednot to be connected betweenthem. Even though there were areaswhere tight Bio-Oss to bone contactcould be seen (Figure 10), in the majorityof the cases, Bio-Oss particleswere surrounded by connective tissue.Histomorphometric analysisThe NPS had 34.40% bone formation,53.80% soft tissue, 12.40% residualgraft material, while 40.80% of the surfaceof the Bio-Oss particles was surroundedby bone (Table 3). The PS had12.80% bone formation, 63.00% soft tissue,24.20% residual Bio-Oss particles,while Bio-Oss to bone contact was16.00%. Bone formation was signifi-cantly more in NPS (P 5 .016) (Table4). Bio-Oss to bone contact was increasedin NPS as compared with PS(40.80 vs 16.00%) but the differencewas not statistically significant (P 5.095).DISCUSSIONThe current study demonstrated thatSM perforation may result in reducedbone formation and compromised implantsurvival. It can be hypothesizedthat bacterial penetration through thetorn membrane and mucous invasionFIGURES 6-10. FIGURE 6. Histologic overview, core harvested from the nonperforated side of subject 1 (original magnification 32). FIGURE7. Newly formed bone appeared to cover the majority of the specimen (black arrows). Residual Bio-Oss particles (white arrows) appearedin tight contact with bone (original magnification 34). FIGURE 8. At a higher magnification level, intimate bone (black arrows)-Bio-Oss(white arrows) contact can be observed (original magnification 310). FIGURE 9. Histologic overview, core harvested from the perforatedside of subject 2 (original magnification 34). FIGURE 10. The residual Bio-Oss particles (white arrows) appeared to be surrounded byconnective tissue. Little or no bone formation (black arrow) is observed (original magnification 310).into the grafted area23 may be the reasonsfor this compromised result. Inaddition, repair of the SM with a collagenmembrane does not preclude releaseof graft particles within the sinusspace through the torn site. Duringgraft placement and packing, the clinicianis unable to observe if membranerepair is adequate to resist pressureduring graft placement.No clinical study has evaluated thepotential and results when regraftingPeriklis Proussaefs et althe maxillary sinus. To the author's experience,once a sinus grafting procedurehas failed, a regrafting procedureoffers compromised results. Reflectionof the SM is difficult because of thepresence of irregular and sharp resid-Journal of Oral Implantology 239A PILOT STUDY IN HUMANS USING RESORBABLE COLLAGEN MEMBRANE IN A PERFORATED SINUSTABLE 3Histomorphometric analysisPerforated SideGraft Contact CT Bone Subject1539026016.0030361963024.20573875836263.001326611812.8012345AverageSD 16.90 11.88 17.36 7.85TABLE 4Mann-Whitney U-test*Parameter EvaluatedBone Statistically significant,nonperforated . perforatedStatistically nonsignificantStatistically nonsignificantStatistically nonsignificantSoft tissueResidual Bio-Oss particlesBone to Bio-Oss contact*PS indicates perforated site; NPS, nonperforated site.ual graft particles. Extensive perforationsof the SM occur in these cases.Proussaefs and Lozada31 have describeda technique to repair the perforatedSM. Briefly, collagenmembraneis placed internally into the sinus tosurround the entire internal surface ofthe maxillary sinus. The collagenmembraneis then folded externally at thearea of the window osteotomy to forma pouch (Loma Linda pouch) that isolatesand protects the graft material. Aclinical study is needed to validate theuse of this technique.However, it needs to be acknowledgedthat the number of subjects ofthis pilot study was limited. Eventhough the differences between PS andNPS offered statistically significant resultsregarding new bone formationand implant survival rate, a largersample size is needed before definitiveconclusions can be made.CONCLUSIONSIn summary, the preliminary results ofthis pilot study demonstrated that perforationand repair of the SM duringsinus grafting offers reduced bone formationand implant survival rate. Anincreased sample size is needed to val-240 Vol. XXIX/No. Five/2003Nonperforated SideGraft Contact CT Bone5470111834132412.40474875613853.80374921273834.40274240.8022.95 9.02 14.41 10.81PS vs NPS P Value.016.421.095.095idate the results of this preliminary report.ACKNOWLEDGMENTSThe authors would like thank MichaelRohrer, DDS, MS, for the histologicprocessing of the specimens and HariPrasad, BS, MDT, for his technical assistanceduring the histologic processing.They would also like to thank MacOjano, DDS, for his contribution. Thefirst author is much obliged to GloriaValencia, DDS, Cert Pros, for her overallassistance and support.REFERENCES1. Adell R, Eriksson B, Lekholm U,Branemark P-I, Jemt T. A long-term follow-up study of osseointegrated implantsin the treatment of totally edentulousjaws. Int J Oral Maxillofac Implants.1990;5:347-359.2. Lekholm U, Van Steenberghe D,Hermann I, et al. Osseointegrated implantsin the treatment of partiallyedentulous jaws. 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