Summry Treting ptient with complex comintion of implnts nd prostheses requires good working reltionship etween dentist nd dentl technicin. A ptient cse is used to illustrte how, despite n initilly confusing sitution, lnced nd esthetic result cn e chieved with consistent ckwrd plnning, the ppliction of modern tretment methods nd the use of new frmework mteril. Indices Implnt prosthodontics, ckwrd plnning, CAD/CAM, three-dimensionl dignostic imging, metl-free denture, PEEK PEEK A new frmework mteril for metl-free prosthetic tretment Bernd Siewert, Helmut Rieger Medi interest keeps shifting to new topics, nd the sme is true of dentl prosthodontics, with exmples including ckwrd plnning, CAD/CAM, nvigted implntology, monolithic friction. The current focus is on vrious mterils which cn e processed using CAD/CAM ssisted friction. A multitude of oth procedures nd mteril vrints my e found in implnt prosthodontics, in prticulr. Frmeworks mde of non-precious metl lloys or titnium hve een the mterils of choice to dte, ut metl-free superstructures re now incresingly gining in importnce. For exmple, the high-performnce polymer polyetheretherketone (PEEK) is idelly suited for removle or conditionlly removle prosthesis. The mteril hs een used in industry for mny yers, nd hs lso proved its worth in vrious res of medicine. 1-3 PEEK is ioinert, tissue-friendly, cytotoxiclly sfe, does not conduct electricity nd is therml insultor. 2 To the uthors knowledge, the prtly crystlline high-performnce mteril PEEK, with its good mechnicl properties, low weight nd excellent chemicl stility, is winning over more nd more dentists nd dentl technicins. PEEK frmeworks mde from industrilly mnufctured lnks (e.g. Juvor Dentl Disc, Juvor Dentl Ltd., Lncshire, UK) cn now e fricted using CAD/CAM-ided techniques. Introduction 2 Quintessenz Zhntech 2013;39(10):2 11
Fig. 1 Pnormic X-ry of the seline sitution: edentulous mxill nd non-preservle residul teeth in the mndile. Fig. 2 Following implnttion: two implnts were inserted into the mxill nd four into the mndile. The mndiulr prosthesis ws retined during the heling period; this llowed the ptient to get used to the new sitution. Osseointegrtion of the implnts nd the optimum mterils re not the only fctors of successful outcome: considered nd coordinted working procedures should lso e included mong them. Long-term success will only e chieved if the criteri for the prosthesis re integrted into the overll implntologicl concept from the outset. In the uthors view, sort of hierrchy, in which the dentist lone rules supreme, is not stte of the rt. More thn ever, new technologies nd modern mteril designs require close working reltionship etween the tretment prtners. A comintion of promising criteri will e highlighted using the ptient cse documented elow: Considered tretment pln Optiml mteril Coopertion etween tretment prtners Cse report Bseline sitution Dentl tretment segment The 41-yer-old ptient presented t the prctice with his mouth in desperte stte. The mn s mxill ws edentulous. In the mndile, he showed decyed residul dentition with severe periodontl dmge nd correspondingly mrked loosening of the teeth. The pnormic X-ry (Fig. 1) showed severely trophied lveolr ridge in the mxill. It lso confirmed tht the teeth in the mxill were non-preservle. As result of the musculr compenstion due to yers of insufficient occlusl support, there ws pronounced fcil symmetry, mking it difficult to determine the centric reltion nd the midline. A considered, stepwise process ws required to solve this difficult nd initilly confusing cse. The pln ws to fit the ptient with implnt-supported prostheses. The first step consisted of stilising the sitution. A definitive restortion promising successful outcome could only e relised fter this. Following extrction of ll the teeth, the ptient ws provided with newly mde interim prosthesis for the lower jw, with his existing prosthesis incorported into the upper jw. The fitting of two implnts (luesky, redent, Senden) into the mxill followed fter three months. Regions with mximum one volume were chosen s the implnttion sites. A few weeks fter this, four implnts (luesky) were lso inserted into the mndile (Fig. 2). The ptient s interim prostheses were used during the four-month heling period. No chnges were mde to the upper jw prosthesis during this time, Quintessenz Zhntech 2013;39(10):2 11 3
Fig. 3 nd Tooth set-up ses with O-ring ttchments formed the sis for n X-ry templte (nd lter lso drilling templte) supported y the two implnts. s the implnts hd een inserted sugingivlly. The lower jw prosthesis ws pdded with soft gel (UfiGel SC, Voco, Cuxhven) in the ptient s mouth, the first time due to the one chnges tking plce while the extrction wounds heled, nd second time to protect the implnts. In the mxill, however, the two implnts could not gurntee dequte superstructure stility. Two dditionl implnts re therefore to e inserted t lter time. The templte-ssisted method ws selected to llow this to e undertken sfely nd without mjor surgery. A wx-up in the idel prosthetic sitution provided the sis. To stilise it, deep-drwn ses were fricted nd O-ring ttchments integrted into them. An X-ry templte (lso with O-ring ttchments) ws fshioned for the mxill, sed on the set-up of the teeth s verified in the ptient s mouth (Fig. 3). The ville implnts held the templte in plce during the three-dimensionl X-ry (DVT, Glileos compct, Siron, Bensheim) in the ptient s mouth (Fig. 3). Anlysis of the DVT dt set showed considerle discrepncy etween the height of the lveolr ridge nd the desired prosthetic sitution (Fig. 4 nd ). A removle solution ws unvoidle; consequently, one ugmenttion in the form of sinus lift in the mxill mde no sense. To provide the ptient with comfortle solution including dequte lip support, connecting r prosthesis supported y four implnts ws chosen for the definitive mxillry reconstruction. This removle denture fcilittes good prosthesis hygiene, nd ws to e of plte-less design. A fixed ridge, screw-retined nd thus conditionlly removle, seemed to e more dvntgeous for the mndile. The DICOM dt from the DVT imges were imported into the SKYPlnX (redent) plnning softwre, nd two dditionl implnts plced virtully into the optimum sites (Fig. 4c). The ntomiclly nd prostheticlly idel implnt positions were trnsferred to the drilling templte nd the implnts inserted into the jw y nvigted plcement. A circulr sclpel, which fits exctly into the guide holes of the drilling templte, ws pressed down gently to induce superficil leeding; the templte ws then removed to check whether the exit point lies within the kertinised mucos. This ws not the cse in the region of tooth 15, so tht stright incision 15 mm in length ws mde with the sclpel t the height of the pltl circumference nd the mucoperiostel flp opened out in the vestiulr direction. This type of intelligent incision is possile only 4 Quintessenz Zhntech 2013; 39(10):2 11
Fig. 4 Trnsverse section t the height of the left molr: lrge, pneumtised mxillry sinus nd pronounced trophy of the lveolr process _ Fig. 4 Trnsverse section t the height of the osseointegrted implnt in the region of tooth 12 with ll ttchment nd O- ring. c Fig. 4c Some things hve ecome indispensle: threedimensionl implnt plnning in the mxill. with drilling templte-ssisted procedure. When the implnttion is done freehnd, the incision is mde ritrrily in the centre of the lveolr ridge, which mkes trgeted soft tissue mngement impossile. Pressure on the inserted implnts during the heling period ws voided y grinding the underside of the interim prosthesis to the correct shpe. The O-ring ttchments tht were lredy in plce held the prosthesis securely in the mouth (Fig. 5). As is usul with this minimlly invsive procedure, the ptient hd no prolems or swellings fter the surgery. Seven months lter, the kertinised cuff t the implnt in the region of tooth 15 hd styed t optimum volume, n importnt fctor in the long-term success of the implnt. The volume ws considerly lower round implnt 24, which hd een inserted freehnd (see Fig. 6). Prosthetic tretment segment The optimum conditions for the strt of the restortive therpy were now in plce (Fig. 6 nd ). PEEK ws used s the frmework mteril oth for the connecting r in the mxill nd for the occlusl screw-retined ridge in the mndile. There were numer of resons for this decision: Avoidnce of glvnic element y using non-conducting mteril. High iocomptiility nd the excellent ehviour of soft tissue when in contct with pure, unfilled PEEK. Quintessenz Zhntech 2013;39(10):2 11 5
Fig. 5 The undersides of the interim prostheses were ground to shpe (mxill shown here) following insertion of the dditionl implnts. Fig. 6 nd Strt of the prosthetic tretment phse: optimum conditions for the reconstruction re pprent seven months fter insertion of the implnts Fig. 7 To ensure precise csting nd tension-free fit of the connecting r, the implnt posts were ttched inside the mouth using plstic splint. Fig. 8 Constructing the model: gingivl msk is essentil for indictions of this type. Optimum elsticity of the occlusl screw-retined mndiulr denture (Juvor Dentl Disc hs similr elsticity module to cncellous one). This compenstes for ny torsion in the mndiulr rce. High werer comfort due to low prosthesis weight. Virtully metl-free (only titnium utments). The veneers deliver good esthetic result. Comfortle ite for the ptient. Shock-soring properties to protect the implnts. Lck of tension is requirement with reconstructions of this type. To ensure it, the prosthesis ws cst following introrl splinting of the implnt posts nd using silicon in n open moulding try (Fig. 7). The mster models were fricted in the lortory; in this sort of work, the gum msk is gurntee for optimum shping of the underside of the denture (Fig. 8 und 9). The tooth set-up, lredy determined during the plnning phse, ws trnsferred to the mster models nd re-verified on the ptient. This ws necessry s the ptient s fcil muscles hd ecome visily relxed through wering the fixed full prostheses over the pst months (Fig. 10). The finl set-up of the teeth in the upper nd lower jws ws scnned in nd the STL dt imported into the softwre. The secondry structures could now e modelled virtully. Using the prosthesis teeth displyed y the softwre s sis, the structures were mde s delicte or s mssive s required. The option of displying the tooth set-up in the softwre enled ccurte modelling of the diminished crown shpes (Fig. 11 nd ). The ridge frmework for the mndile ws formed in such Frmework construction 6 Quintessenz Zhntech 2013;39(10):2 11
Fig. 9 nd The mster models used to mke the prosthetic reconstruction. A prosthesis supported with r ws to e constructed for the mxill. An occlusl screw-retined ridge ws plnned for the mndile Fig. 10 Verifying the positions of the teeth in the ptient s mouth. Not only esthetic, ut lso functionl nd phonetic spects were considered. Fig. 11 d Virtul representtion of the construction in the softwre (mndile). Fig. 12 to d Virtul construction of the secondry structures in the mxill sed on the tooth set-up. c d wy s to llow the prosthesis to e finished off with ese using the veneer concept (visio.lign, redent). The uthors lso used the softwre s trnsprent disply to model the mxillry frmework (Fig. 12 to d). The connecting r (primry prt) nd r clips (secondry prt) were designed nd mde t the sme time; this is nother dvntge conferred y the digitlly ssisted friction. The ses were moulded into fully ntomicl, convex shpe; the PEEK mteril ws to e in direct contct with the mucos. Quintessenz Zhntech 2013; 39(10):2 11 7
Fig. 13 nd The virtul structure ws relised using CAD/CAM-ssisted friction (PEEK, mteril lnk: Juvor Dentl Disc). Fig. 14. The frmeworks relised in PEEK. c Fig. 15 The dimensions of the frmeworks were checked with the silicon key (mndile shown here) Fig. 15 nd c Preprtions for lst wx try-in in the ptient s mouth. As is usul with CAD/CAM-ssisted friction, the design dt were trnsmitted to the milling mchine. The construction ws to e relised in PEEK; the lnks mnufctured industrilly for this purpose hold CE certifiction for definitive, conditionlly removle dentures (Fig. 13). Milling of the structures ws ccomplished without ny complictions (Fig. 13). The finished frmeworks were n identicl copy of the virtul templtes. Since the finl tooth set-up ws fixed with silicon key, it ws now possile to trnspose the sitution to the PEEK frmeworks (Fig. 14). Functionl spects ecome prticulrly significnt in the context of totl prostheses. For this reson, ite registrtion should tke plce efore the prosthesis is finished off definitively. This would lso e the idel time to review the esthetic criteri in the ptient s mouth once more. To do this, only the front teeth were set up in the mxill, while wx wlls were fitted in plce of the posterior teeth (Fig. 15 to c). After nother try-in, the exct ite sitution ws trnsposed into the rticultor (Fig. 16) nd the work completed. The frmework ws conditioned (primer, visio.link, redent) nd the reconstructions finished with veneers mde of high-performnce polymer (visio.lign) ccording to the wx try-in (Fig. 17 to 20). Among other things, close ttention ws pid to ensuring tht the undersides were given clen finish. Any rough res plce the long-term tretment Finishing
Fig. 16 After nother ite check, the prostheses were trnsferred ck to the rticultor nd the functionl reltionships precisely worked out. Fig. 17 Finishing the prostheses with veneers mde of PMMA (visio.lign, redent, Senden). Fig. 18 Checking the occlusl plne. Fig. 19 The finished mndiulr ridge on the PEEK frmework weighed only 12 grms. Fig. 19 Lingul view of the finished mndiulr ridge. Fig. 20 nd The primry r mde from PEEK nd the secondry structure for the mxill. results t risk. In the uthors opinion, the iocomptiility nd stility of PEEK in the mouth ensure tht no soft tissue impirments re likely if the finish is clen. Incorportion The occlusl screw-retined 12-unit ridge in the mndile weighed only 12 grms. The plte-less mxillry prosthesis (Fig. 21) lso impressed with its low weight. Tension-free fixtion of oth the r nd the ridge onto the implnt utments ws chieved (Fig. 22 to 25). 0 utments (luesky) were used in the mndile, long with titnium screw chnnels glued into the PEEK ridge frmework. The four implnt copies were glued on in the l. This ws possile in this cse, s the impression posts in the mouth were locked with composite nd the modelling plster ws seprted from the impression only fter the former hd stopped contrcting. When the r ws incorported into the ptient s mouth, tension-free fit ws confirmed (with the Sheffield Test). A miniml degree of cliniclly undetectle incongruence ws compensted for y the elsticity of the PEEK mteril, nd not trnsferred to the implnts or the one.
Fig. 21 First impression: this esthetic, light nd stle dentl prosthesis ws delivered to the prctice.. Fig. 22 nd 23 Tension-free fit of the r long with well-integrted mxillry prosthesis. Fig. 24 nd 25 A snug fit: the ridge in the lower jw ws secured to the implnts with occlusl screws. Fig. 26 The finl X-ry. The PEEK mteril used contins no rdiopque dditives (such s rium sulphte) nd is thus not visile on the follow-up pnormic X-ry. In the uthors view, this is mjor dvntge of this mteril. The milled PEEK r in the mxill ws lso glued to the utments in the lortory the implnt in the region of tooth 15 crries n dditionl post to compenste for the 35º-degree ngling (Fig. 26). The superstructure with the secondry prt mde of PEEK ws incorported into the ptient s mouth with good esthetic result nd snug fit. The running properties correspond to the sort of friction expected with conventionl connecting rs or glvno internl structures. Simple removl nd replcement, fcilitting good denture hygiene, were gurnteed. Two weeks fter the incorportion, the stisfied ptient consulted the prctice for finl check-up (Fig. 27 nd 28). Despite the difficult seline sitution, considered nd well-coordinted tretment concept mde it possile to relise reconstruction pproprite for the ptient. The 3D-guided plnning of the implnttion, s well s the CAD/CAM-ssisted friction of the prostheses provided vlule support. The PEEK mteril used is further contriution towrds longterm success. The mteril hs een trilled in implnts for medicl indictions for over ten yers (Inviio PEEK-Optim) nd its high iocomptiility hs een confirmed in severl clinicl trils. 1-4 Summry 10 Quintessenz Zhntech 2013;39(10):2 11
Fig. 27 The sitution two weeks fter incorportion of the dentl prosthesis. Fig. 28 The finl full-fce view shows visily stisfied ptient. PEEK hs lso proved its worth s frmework mteril in prosthetic dentistry. 5 Its low specific grvity, its one-like elsticity nd its toughness, comined with n lmost totl lck of mteril ftigue mke it n idel plyer in prosthodontics. The option of CAD/CAM-ssisted processing of PEEK gives rise to mny possiilities, oth from the ptient s nd the tretment tem s point of view. So fr, the mteril is restricted to removle nd conditionlly removle dentl prostheses. This mens tht the descried mteril cn e used to mke model-cst prostheses, secondry prts, superstructures for comined dentl reconstructions, screw-retined full crowns in estheticlly unimportnt res (posterior teeth) nd conditionlly removle, screwretined ridges. Acknowledgments The uthors thnks for the technicl relistion go to Mster Dentl Technicin Florin Rießenerger (CAD/ CAM specilist) nd Dentl Technicin Mrkus Smode (relistion of the veneers nd finishing). They would like to thnk the whole tem t Clínic Somosgus for their outstnding ptient cre. References 1. Aron R, Cutler AR, Squi Siddiqui MD, et l. Comprison of polyetheretherketone cges with femorl corticl one llogrft s single-piece interody spcer in trnsforminl lumr interody fusion. J Neurosurg 2006;5:534 539. 2. Cpps SG. PEEK Cges nd Spcers in Cervicl Spine Fusion Applictions. Spinl News Interntionl 2007;Septemer:4. 3. Celik SE, Kr A, Celik S. A Comprison of Chnges Over Time in Cervicl Forminl Height After Tricorticl Ilic Grft or Polyetheretherketone Cge Plcement Following Anterior Discectomy. J Neurosurg 2007;6:10 16. 4. Kurtz SM, Devine JN. PEEK iomterils in trum, orthopedic, nd spinl implnts. Biomter 2007;28:4845 4869. 5. Siewert B, Prr M. Eine neue Werkstoffklsse in der Zhnmedizin. PEEK ls Gerüstmteril ei 12-gliedrigen implnttgetrgenen Brücken. Z Zhnärztl Implntol 2013;29:148 159. Dr. Bernd Siewert Clle Aquilón, 2 Locl 7/8 28223 Pozuelo de Alrcón E-Mil: Siewert@dentl-med.com ZTM Helmut Rieger Am Bckofenwll 3 86153 Augsurg E-Mil: info@rieger-zhntechnik.de Quintessenz Zhntech 2013;39(10):2 11 11