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Vamsi A R, et al: Direct vs Indirect Sinus Elevation: A Literature ReviewReview articleDirect vs Indirect Sinus Elevation: A Literature ReviewSanthosh B Shenoy, Avaneendra Talwar, Biju Thomas, Amitha Ramesh, Anegundi RaghavendraVamsi*arvamsi2009@gmail.comAbstractThe placement of dental implants in the posterior maxilla is a challenging task for clinicians due to theinterference by maxillary sinus. The surgical techniques for enhancing the vertical alveolar bone height oraugmenting the sinus in the posterior part of the maxilla revealed high implant survival with a low incidence ofcomplications. However, the indications for the various surgical techniques are not the same, and the choice oftreatment should be based on a careful evaluation of the individual case. These can be grouped into direct andindirect techniques. Direct sinus augmentation refers to direct visualization and manipulation of the Schneiderianmembrane through a window created lateral to the sinus. An indirect sinus augmentation is a minimally invasiveprocedure that manipulates and elevates the membrane indirectly. Generally, the amount of bone gain with thedirect method is high compared to the indirect approach. Even though both techniques indications are different,they attract almost the same number of advantages and disadvantages. The ultimate choice of selection oftreatment depends on case selection and patient needs. This article reviews the differences between direct andindirect methods.Keywords: Dental implants, direct sinus lift, indirect sinus liftIntroductionDental implants are now regarded as predictablealternatives for replacing missing natural tooth/teeth compared to the conventional fixed prosthesis.However, there is a constant challenge faced by aclinician in restoring the posterior maxillary areabecause of the presence of maxillary sinus. Thiscould be related to the unfavourable pneumatizationSanthosh B Shenoy1, Avaneendra Talwar2, Biju Thomas3,Amitha Ramesh4, Anegundi Raghavendra Vamsi512345Additional Professor, Department of Periodontics, AB Shettymemorial institute of Dental Sciences, NITTE deemed to beuniversity, Derlakatte, Mangaluru, Karnataka - 575018.Reader, Department of Periodontics, AB Shetty memorialinstitute of Dental Sciences, NITTE deemed to be university,Derlakatte, Mangaluru, Karnataka - 575018Professor and Head, Department of Periodontics, AB Shettymemorial institute of Dental Sciences, NITTE deemed to beuniversity, Derlakatte, Mangaluru, Karnataka - 575018Professor, Department of Periodontics, AB Shetty MemorialInstitute of Dental Sciences, NITTE deemed to be university,Derlakatte, Mangaluru, Karnataka - 575018Postgraduate Student, Department of Periodontics, AB Shettymemorial institute of Dental Sciences, NITTE deemed to beuniversity, Derlakatte, Mangaluru, Karnataka - 575018* Corresponding Authorof the maxillary sinus, post-extraction resorptivepatterns, and the often-poor residual alveolar bonequality. These factors decrease the availabilityof bone for the placement of an implant in theprosthetically driven position. This can be achievedby augmenting the residual ridge either byhorizontal/vertical augmentation or in combination.Various techniques and methods have been triedand advocated to manipulate the sinus membranefor successful dental implants placement. All thesetechniques can be grouped broadly under twocategories - direct and indirect. To date, the directmethod is referred to as a gold standard in termsof gaining bone width.1 As with other methods,direct techniques have a considerably high amountof complications.2Sinus elevation is indicated in atrophic maxillacases or cases where a deficiency of ridge heightto place conventional implants. Many prospectivestudies have proven the high success rate of regularimplants with a height of 10-12mm. This makes thesinus augmentation a need in the posterior atrophicmaxilla.How to cite this article: Shenoy S B, Talwar A, Thomas B, Ramesh A, Vamsi A R. (2020). Direct vs Indirect Sinus Elevation: ALiterature Review. MJDS 5(2), 15-21.Manipal Journal of Dental Sciences October 2020 Volume 5 Issue 215
Vamsi A R, et al: Direct vs Indirect Sinus Elevation: A Literature ReviewPatient selection is a crucial factor in the selectionof a direct or indirect method. This article criticallyreviews the differences between the direct andindirect methods of augmenting sinus.Direct sinus liftTatum first demonstrated the direct sinus lift.It consists of osteotomies to create a bonywindow and either the medial rotation or removalof the bony window.3 Direct visualization andelevation of the sinus are done, hence the namedirect sinus lift. After the administration of localanaesthesia, posterior superior alveolar, infraorbital,subperiosteal anaesthesia through slow infiltration,greater palatine nerve block, an incision is made onthe crest from tuberosity to a point just anteriorto the anterior border of the sinus. The incisionis placed palatally, and a palatal flap elevation isgenerally avoided for better vasculature of theflap.4 A trapezoidal flap is made to allow adequatesinus exposure, and care should be taken to makesure that incisions are not placed in the area of thesinus window. Exposing the lateral wall of maxilla,a full-thickness flap is raised. A number 2 pencil isused to outline future osteotomies. This point allowscollecting or harvesting autogenous bone chips,which can be used for augmentation after membraneelevation. The osteotomes can be performed eitherby piezo surgery or by conventional burs. Betterresults with least postoperative complications havebeen reported from piezo surgery driven sinusaugmentation compared to traditional methods.5At this stage, four osteotomies in linear fashionare performed with round burs. Inferior horizontalosteotomy is done close to the antral floor, not morethan 2 to 3 mm above the floor. The osteotomy runsfrom the first or second molar area posteriorly to theextent of the antrum. The coronal outline of thewindow will depend on the position of the posteriorsuperior alveolar artery, height of the graft, andthe implant to be placed. When osteotomies areperformed, care must be taken to do so with a lighttouch and a gentle stroke not to perforate or tearthe membrane. This is followed by connectingthe superior horizontal osteotomy at the level ofthe planned augmentation height, and inferiorosteotomy with one anterior and one posterior16vertical osteotomy. The vertical osteotomies aremade parallel to the anterior border of the lateralnasal wall and maxillary tuberosity. The dorsaloutline depends on the number of implants to beplaced. Once the bony window and sinus membraneare exposed, the bone adherent is rotated mediallyor removed. If the bone is pushed inwards, thenit becomes the new sinus floor. The membrane isreleased by starting at the borders and then slowlyincreasing the amount of membrane elevation. Ifthe membrane elevation is excess in one region,perforations may occur. The membrane shouldbe elevated higher than the superior osteotomy.Membrane elevation should always be done onlyafter membrane release/detachment.6Care must be taken while the membrane is beingreleased or raised. The membrane should not beelevated more than 2 mm at each step to avoidmembrane tears. After every step, the membraneintegrity must be checked either by directvisualization or by the Valsalva manoeuvre. Thisstep is essential to prevent excessive pressure on theinserted bone graft.7 If there is an availability of 3–4 mm of residual alveolar bone of good quality, it ispossible to place implants simultaneously, otherwisethe implant should be deferred by 4 - 6 months.8Since the maxillary bone is a D3 and D4 bone,undersize the implant osteotomy site, protect thesinus membrane with a periosteal elevator to avoidthe damage from the drills. Sinus membrane shouldbe protected with a membrane. Implants are placedin the prepared osteotomy sites. There is diversifiedevidence regarding bone grafts.9 The choice of graftdepends purely on the clinician’s experience. Bonegrafts should be first placed in the least accessiblearea. Anterior and posterior sites are filled first,followed by the area along the medial sinus wall. Thebone graft should not be compacted too tightly as itprevents vascularization and can lead to the graft’sfailure. The resorbable membrane is placed over thewindow (collagen membrane or Platelet-rich Fibrin[PRF] membrane). Horizontal mattress sutures aregenerally used for flap closure. The incision ensuresadequate buccal and palatal attached tissue on eitherside. The infra-orbital nerve should be identified andprotected. If the height of the residual bone is lessManipal Journal of Dental Sciences October 2020 Volume 5 Issue 2
Vamsi A R, et al: Direct vs Indirect Sinus Elevation: A Literature Reviewthan 5 mm, the graft is allowed to consolidate overthe next six months. It is challenging to augment anisolated sinus by this method, and it may damage theadjacent teeth.Indirect techniqueIt is also called the osteotome technique or Crestalapproach or transalveolar approach or internal sinuslifting. In this method, sinus is elevated indirectly,i.e., a segment of bone adjacent to the membrane iselevated, which in turn elevates the membrane. Tatumfirst performed this method, and later, Summersillustrated an alternate crestal approach with taperedosteotomies of increasing diameters.10 The indirecttechnique is generally advised where the residualheight of the bone is greater than or equal to 6 mm.11After administrating LA, crestal incision is placedextending distally to expose the crest, and a fullthickness flap is elevated. Once the flap is reflected,osteotomy preparation with a pilot drill, keeping it2 mm short of the floor. A confirmatory radiographshould be taken by inserting a pilot drill. The drillsor set of osteotomes of varying dimensions canbe used in a sequential manner to enlarge the siteof osteotomy to the same level, i.e., 2 mm short ofthe sinus floor. In D3 and D4 bones, osteotomes aregenerally used to condense the bone and laterallyenhance bone density. Once the largest diameterdrill has expanded the implant site, particulate bonegrafts (commonly mixed with autogenous bone) areadded to the prepared osteotomy site as the graftingmaterial. Usually, composite bone graft composedof 25% autogenous and 75% hydroxyapatite graftis preferred.12 The graft is inserted in the osteotomysite before the fracturing the sinus floor. Anosteotome of smaller diameter than the implant isinserted into the osteotomy site and is gently tappedto fracture the sinus floor. Observe for the change insound while in sinus floor is being fractured. Whenthe floor fractures, a different pitch of the sound canbe heard. The change in the sound can be achievedby placing the final osteotome in the implant sitewith the bone graft. The augmented graft exertsforce onto the membrane, which elevates the sinusfurther. The bone graft can be inserted and tappedto achieve required amount of sinus membraneelevation. Proper care should be taken to ensurethat the membrane is within its stretching limit.The diameter of the final osteotome to be preparedshould be shorter than the implant diameter tobe inserted. If adequate primary stability is notachieved during the implant placed and if it is leftas is, there is a chance of implant displacing into theantrum.13 The primary stability of an implant for agiven bone quality depends on its macro design.Other minimally invasive techniques are listed inTable 1.Table 1: Other minimally invasive techniquesSl.AuthorMinimally Invasive TechniqueNo.ProposedFugazzotto,1 Modified trephine technique1999 14Antral membrane balloon2Soltan, 2012 15elevationMinimally invasive3 transalveolar sinus approachKher, 2014 16(MITSA)Minimally invasive trans crestal Pozzi and4– guided sinus lift techniqueMoy, 2014 17EG Meyer,5 Osseo-densification2014 18Postoperative instructions and carePost-surgical instructions should be given topatients in both verbal and written form. On theday of the procedure, the patients should be advisedto sleep with the head elevated. Patients should beadvised to be on a liquid diet and continue with thesoft diet for the next two weeks. Generally, somenasal bleeding is observed hours after surgery.Antibiotics and analgesics are advised along with1.2% chlorhexidine mouth wash. Patients shouldbe advised to avoid chewing from the surgical site,balloon blowing, blowing the nose, smoking, or anyother activity which creates negative pressure in theoral cavity for at least two weeks. If he/she doessneeze, the patient must open the mouth so thatthe pressure is not applied within the sinus. If anyswelling or bruising is observed, the patient shouldbe advised to apply ice pack gently over the face.17Direct vs indirect techniqueImplant survival rates following osteotome orlateral approaches when assessed radiographicallyand clinically with immediate and delayed implantManipal Journal of Dental Sciences October 2020 Volume 5 Issue 217
Vamsi A R, et al: Direct vs Indirect Sinus Elevation: A Literature Reviewplacement was 100% in both the groups.19 Thedecision of immediate or delayed placement iscompletely based on whether the primary stabilityis achieved. In cases where primary stability is notachieved, implants should be deferred by six months.There is no statistical difference between the primarystability achieved between both approaches.A comparative study on the indirect and directtechniques have found an increase in the boneheight, which was almost the same for the two-stage(median 12.7 mm) and single-stage (median 10mm) procedures.20The number of steps, period of edentulism, gender,or age does not influence the outcome in surgery.The width of the alveolar bone appears to differ andinfluence the outcome. The alveolar width seems toincrease when the height of RAB is reduced.21 Whenthere is an increase in alveolar width, implants withwider diameter can be placed, compromising height.This could be attributed to an increase in surfacearea with increasing implant diameter. Thus, it isa practical understanding that would be extremelyuseful to measure the outcome of the condition.Independent of the technique, there is a significantdifference between pre-surgical and post-surgicalbone quantity. The direct method always gives abetter increase in height than the indirect method.Residual bone height (RBH) might influence the rateof survival of implants. The implant survival ratefor RBH 4 mm was only marginally higher than forRBH 4 mm.22 The gold standard for bone grafts insinus augmentation is an autograft, but it is generallynot considered favourable graft material becauseit requires additional surgery site, the amount ofgraft collected is limited, patient discomfort, andrisk of complications. There is no substantial dataregarding other types of bone grafting, especiallyfor sinus elevations. A meta-analysis comparing theefficacy of bone grafts has not shown any differencesin marginal bone loss and survival rate betweenthe sites grafted with bone and non-grafted sites.Although no study was conducted concerning thecost-benefit ratio, it is evident that a sinus elevationwithout bone augmentation will be lower than withaugmentation.23 Survival of implants followingsinus elevation procedures demonstrated the rateof survival between 100% and 75% for graftedand non-grafted areas.24 Implants placed in themaxillary posterior ridge augmented using directsinus exhibited implant survival rate, marginal boneloss, and peri-implant clinical parameters similarto those of implants placed in the native bone. Butsinus augmented exhibited increased complications,as with any surgical intervention.sPost-operative pain is slightly more in the directgroup during the initial post-operative week, whichgradually diminished.26 Similar observationswere made in studies conducted by Kent et al. andWiltfang et al.27, 28Post-operative swelling is generally more in thedirect group than in the indirect group.26 Therewill be a subsequent improvement in the swellingone week postoperatively. Similar observations wererecorded by Rodoni et al. and Alkan et al.29, 30 Therewere much more severe complications like maxillarysinusitis, pain, swelling, and implant failures inpatients with preoperative sinus pathology. Thegingival status around augmented sinus wasevaluated by Zitzmann et al. and observed no signsof gingival inflammation around implants.31Bone gain is increased in the lateral approach case,but generally required broad intraoperative accessTable 2: Bone gain as shown by various studies.Direct TechniqueIndirect TechniqueStudyPre-operativebone heightPost-operativebone heightBone gainPre-operativebone heightPost-operativebone heightBone gainDaniel andRao(35)Pal (25)2.91 0.77Median: 2.54.5 mm12.09 0.83Median: 1213 mm9.5 mm12.09 1.32Median: 11.512mm5.5 mm8.5 mm5.68 0.87Median: 6.07.39 mm4.5 mmSM Balaji (21)3.94 0.4610.13 0.946.19 mm7.88 1.113.22 3.25.34 mm18Manipal Journal of Dental Sciences October 2020 Volume 5 Issue 2
Vamsi A R, et al: Direct vs Indirect Sinus Elevation: A Literature Reviewto the sinus. The bone gain was significantly higherin many studies, and it is the method of choice ifthe residual alveolar height is 6mm.26, 31 The bonegain, as shown by various studies, is listed in Table 2.Short implants have also been tried in the posteriorThe indirect method of augmentation is a relativelyconservative approach with minimal trauma to theadjacent soft and hard tissues, but the bone gain issignificantly low.32 Osseo densification is the latestaddition to this technique. The ballooning methodhas also been used for membrane elevation, whichhas potentially reduced the chances of perforation.bone gain would be possible with sinus grafting. InA recent study comparing direct sinus lift withzygomatic implants revealed relatively similarresults with more complications with zygomaticimplants.33maxilla with 4mm of RBH, in combination witha sinus lift. It was found that up to 3.8 mm of boneheight can be achieved without grafting, but morecomparison with longer or regular implants, shortimplants exhibited statistically significant prostheticcomplications.34, 35For the simultaneous placement of the implant in thedirect method, the minimum residual bone should bea minimum of 3 - 4mm to achieve adequate primarystability. The differences between direct and indirecttechnique are listed in Table 3.Table 3: Differences between direct and indirect TechniqueSl.Direct TechniqueNo.Indirect Technique1Invasive/TraumaticMinimally invasive2Also called open methodAlso called closed or Crestal method or osteotome ortransalveolar approach3Simultaneous implant placement is possible only ifthe residual bone height is more than 3-4 mmImplant placement can be done simultaneously4Can be performed in all cases.Can be performed if residual bone height is 6 mm.5Bone gain is more.Bone gain is less.6Higher chance of membrane tearFewer chances of membrane tear7Treatment duration is longTreatment duration is short8The patient might report of pain in the first week. Comparatively, there is no pain.9Gingival inflammation is relatively high in the firstGenerally, no gingival inflammation is seenweek10Mild post-operative swelling presentThe most common complication associated withsinus augmentation includes membrane perforation.Various materials, such as a resorbable membrane orPRF, are used to repair the membrane. In cases withsmaller defects (less than 2mm), the membrane isleft to heal.32, 36 Other complications include bleedingor dislodgment of the implant into sinus.37No post-operative swellingConclusionAny dental surgeon aims to use a simple, minimallyinvasive, cost-effective procedure with highpredictability. Advanced and invasive surgicaltechniques often prolong the treatment duration.The choice of various surgical techniques shouldcorrelate with the indications, patient expectationsabout the treatment, predictability of the treatmentchoice, and clinician’s experience.Manipal Journal of Dental Sciences October 2020 Volume 5 Issue 219
Vamsi A R, et al: Direct vs Indirect Sinus Elevation: A Literature ReviewReferences1. Simon BI, Greenfield JL. Alternative to the goldstandard for sinus augmentation: Osteotomesinus elevation. Quintessence International. Oct2011;1:42(9).2. Irinakis T, Dabuleanu V, Aldahlawi S.Complicationsduringmaxillarysinusaugmentation associated with interfering septa:a new classification of septa. The open dentistryjournal. 2017;11:140.3. Tatum JH. Maxillary and sinus implantreconstructions. Dental Clinics of NorthAmerica. 1986;30(2):207-29.4. Harris D, Horner K, Gröndahl K, Jacobs R,Helmrot E, Benic GI, et al. E.A.O. Guidelines forthe use of diagnostic imaging in implant dentistry2011. A consensus workshop organized by theEuropean Association for Osseointegration atthe Medical University of Warsaw. Clin OralImplants Res 2012;23:124353.5. Stacchi C, Troiano G, Berton F, Lombardi T,Rapani A, Englaro A, Galli F, Testori T, NevinsM. Piezoelectric bone surgery for lateral sinusfloor elevation compared with conventionalrotary instruments: A systematic review,meta-analysis and trial sequential analysis.International Journal of Oral Implantology.2020;1:13(2).6. Temmerman A, Hertelé S, Teughels W,Dekeyser C, Jacobs R, Quirynen M, et al. Arepanoramic images reliable in planning sinusaugmentation procedures? Clin Oral ImplantsRes 2011;22:18994.7. Stern A, Green J. Sinus lift procedures: anoverview of current techniques. Dental Clinics.2012;56(1):219-33.8. Bathla SC, Fry RR, Majumdar K. Maxillarysinus augmentation. Journal of Indian Societyof Periodontology. 2018;22(6):468.9. Kim YK, Yun PY, Kim SG, Lim SC. Analysis ofthe healing process in sinus bone grafting usingvarious grafting materials. Oral Surgery, OralMedicine, Oral Pathology, Oral Radiology, andEndodontology. 2009;107(2):204-11.10. Summers RB. A new concept in maxillaryimplant surgery: The osteotome technique.Compendium (Newtown, Pa). 1994;15(152):154156. 158 passim; quiz 1622011. Emmerich D, Att W, Stappert C. Sinus floorelevation using osteotomes: A systematic reviewand metaanalysis. J Periodontol. 2005;76:123751.12. Summers RB. Sinus floor elevation withosteotomes. J Esthet Dent. 1998;10:16471.13. Borgonovo A, Fabbri A, Boninsegna R, DolciM, Censi R. Displacement of a dental implantinto the maxillary sinus: case series. Minervastomatologica. 2010;59(1-2):45-54.14. Fugazzotto PA. Sinus floor augmentation at thetime of maxillary molar extraction: techniqueand report of preliminary results. InternationalJournal of Oral & Maxillofacial Implants.1999;14(4).15. Soltan M, Smiler D, Ghostine M, Prasad HS,Rohrer MD. Antral membrane elevation usinga post graft: A crestal approach. Gen Dent.2012;60:e8694.16. Kher U, Ioannou AL, Kumar T, Siormpas K,Mitsias ME, Mazor Z, et al. A clinical andradiographic case series of implants placedwith the simplified minimally invasive antralmembrane elevation technique in the posteriormaxilla. J Craniomaxillofac Surg 2014;42:19427.17. Pozzi A, Moy PK. Minimally invasive transcrestalguided sinus lift (TGSL): A clinical prospectiveproofofconcept cohort study up to 52 months.Clin Implant Dent Relat Res 2014;16:58293.18. Meyer EG, Huwais S. OsseodensificationIs A Novel Implant Preparation TechniqueThat Increases Implant Primary StabilityBy Compaction and Auto-Grafting Bone.San Francisco, CA: American Academy ofPeriodontology. 2014.19. Jurisic M, Markovic A, Radulovic M, BrkovicBM, Sándor GK. Maxillary sinus flooraugmentation: comparing osteotome withlateral window immediate and delayed implantplacements. An interim report. Oral Surgery,Oral Medicine, Oral Pathology, Oral Radiology,and Endodontology. 2008;106(6):820-7.20. Watzek G, Weber R, Bernhart TH, UlmCH, Haas HS. Treatment of patients withextreme maxillary atrophy using sinus flooraugmentation and implants: preliminary results.Int J Oral Maxillofac Surg 1998;27:428-34.21. Balaji SM. Direct v/s Indirect sinus liftin maxillary dental implants. Annals ofmaxillofacial surgery. 2013;3(2):148.Manipal Journal of Dental Sciences October 2020 Volume 5 Issue 2
Vamsi A R, et al: Direct vs Indirect Sinus Elevation: A Literature Review22. Yan M, Liu R, Bai S, Wang M, Xia H, ChenJ. Transalveolar sinus floor lift without bonegrafting in atrophic maxilla: A meta-analysis.Scientific reports. 2018;8(1):1-9.23. Jeong TM, Lee JK. The efficacy of the graftmaterials after sinus elevation: retrospectivecomparative study using panoramic radiography.Maxillofacial Plastic and ReconstructiveSurgery. 2014;36(4):146.24. Graziani F, Donos N, Needleman I, GabrieleM, Tonetti M. Comparison of implant survivalfollowing sinus floor augmentation procedureswith implants placed in pristine posteriormaxillary bone: a systematic review. Clin OralImplants Res. 2004;15(6):677-682. doi:10.1111/j.1600-0501.2004.01116.x25. Elangovan S. Dental Implant Survival inthe Bone Augmented by Direct Sinus Lift IsComparable to Implants Placed in the NativeBone. Journal of Evidence Based DentalPractice. 2020;20(1):101410.26. Pal US, Sharma NK, Singh RK, MahammadS, Mehrotra D, Singh N, Mandhyan D. Directvs. indirect sinus lift procedure: A comparison.National journal of maxillofacial surgery.2012;3(1):31.27. Kent JN, Block MS. Simultaneous maxillarysinus fl oor bone grafting and placementof hydroxylapatite-coated implants. J OralMaxillofac Surg. 1989;47:238-42.28. Wiltfang J, Schultze-Mosgau S, Merten HA,Kessler P, Ludwig A, Engel ke W. Endoscopic andultrasonographic evaluation of the maxillarysinus after combined sinus floor augmentationand implant insertion. Oral Surg Oral Med OralPathol Oral Radiol Endod 2000;89:288-91.29. Rodoni LR, Glauser R, Feloutzis A, HämmerleCH. Implants in the posterior maxilla: Acomparative clinical and radiologic study. Int JOral Maxillofac Implants 2005;20:231-7.30. Alkan A, Celebi N, Baş B. Acute maxillarysinusitis associated with internal sinus lifting:Report of a case. Eur J Dent 2008;2:69-72.31. Zitzmann NU, Schärer P. Sinus elevationprocedures in the resorbed posterior maxilla.Comparison of the crestal and lateral approaches.Oral Surg Oral Med Oral Pathol Oral RadiolEndod 1998;85:8-17.32. Woo I, Le BT. Maxillary sinus fl oor elevation:Review of anatomy and two techniques. ImplantDent 2004;13:28-32.33. Balaji SM, Balaji P. Comparative evaluation ofdirect sinus lift with bone graft and zygomaimplant for atrophic maxilla. Indian Journal ofDental Research. 2020;31(3):389.34. Nedir R, Nurdin N, Abi Najm S, El Hage M,Bischof M. Short implants placed with orwithout grafting into atrophic sinuses: the5‐year results of a prospective randomizedcontrolled study. Clinical Oral ImplantsResearch. 2017;28(7):877-86.35. Ravidà A, Wang IC, Sammartino G, BarootchiS, Tattan M, Troiano G, Laino L, Marenzi G,Covani U, Wang HL. Prosthetic Rehabilitationof the Posterior Atrophic Maxilla, Short ( 6 mm) or Long ( 10 mm) Dental Implants?A Systematic Review, Meta-analysis, andTrial Sequential Analysis: Naples ConsensusReport Working Group A. Implant Dentistry.2019;28(6):590-602.36. Barone A, Santini S, Sbordone L, Crespi R,Covani U. A clinical study of the outcomes andcomplications associated with maxillary sinusaugmentation. Int J Oral Maxillofac Implants2006;21:815.37. Öncü E, Kaymaz E. Assessment of theeffectiveness of platelet rich fibrin in thetreatmentofSchneiderianmembraneperforation. Clinical Implant Dentistry andRelated Research. 2017;19(6):1009-14.Manipal Journal of Dental Sciences October 2020 Volume 5 Issue 221
the implant should be deferred by 4 - 6 months.8 Since the maxillary bone is a D3 and D4 bone, undersize the implant osteotomy site, protect the sinus membrane with a periosteal elevator to avoid the damage from the drills. Sinus membrane should be protected with a membrane. Implants are placed in the prepared osteotomy sites. There is diversified
