Full-Mouth Adhesive Rehabilitation of a Severely Eroded Dentition: The Three-Step Technique. Part 2.

Transcription

1 CLINICAL APPLICATION Puliction Full-Mouth Adhesive Rehilittion of Severely Eroded Dentition: The Three-Step Technique. Prt 2. Frncesc Vilti, MD, DMD, MSc Senior Lecturer, Dept of Fixed Prosthodontics nd Occlusion School of Dentl Medicine, University of Genev Switzerlnd Urs Christoph Belser, DMD, Prof Dr med dent Chirmn, Dept of Fixed Prosthodontics nd Occlusion School of Dentl Medicine, University of Genev Switzerlnd Correspondence to: Dr Frncesc Vilti University of Genev, Dept of Fixed Prosthodontics nd Occlusion, Rue Bthelemy-Menn 19, 1203 Genev, Switzerlnd; e-mil: 128

2 VAILATI/BELSER Puliction Astrct Trditionlly, full-mouth rehilittion sed on full-crown coverge hs een recommended tretment ptients ffected severe dentl erosion. Nowdys, thnks to improved dhesive techniques, the indictions crowns hve decresed nd more conservtive pproch my e proposed. Even though dhesive tretments simplify oth the clinicl nd lortory procedures, restoring such ptients still remins chllenge due to the gret mount of tooth destruction. To fcilitte the clinicin s tsk during the plnning nd execution of full-mouth dhesive rehilittion, n innovtive concept hs een developed: the three-step technique. Three lortory steps re lternted with three clinicl steps, llowing the clinicin nd the lortory technicin to constntly interct to chieve the most predictle esthetic nd functionl outcome. During the first step, n esthetic evlution is permed to estlish the position of the plne of occlusion. In the second step, the ptient s posterior qudrnts re restored t n incresed verticl dimension. Finlly, the third step reestlishes the nterior guidnce. Using the three-step technique, the clinicin cn trnsm full-mouth rehilittion into rehilittion individul qudrnts. The present rticle focuses on the second step, explining ll the lortory nd clinicl steps necessry to restore the posterior qudrnts with defined occlusl scheme t n incresed verticl dimension. A rief summry of the first step is lso included. (Eur J Esthet Dent 2008;3: ) 129

3 CLINICAL APPLICATION Puliction c Fig 1 ( to c) Clinicl views of 60-yer-old ptient ffected generlized dentl erosion. For yers the ptient suffered from gstric esophgel reflux. At this lte stge full-mouth rehilittion is inevitle. Despite the dvnced loss of tooth structure, ll teeth re still vitl. Trditionlly, full-mouth rehilittion hs een the recommended tretment ptients ffected generlized severe dentl erosion. However, restortive concept comprising full-crown coverge of lmost ll teeth nd extensive elective root cnl tretment my e too ggressive this generlly very young popultion of ptients. 1 3 With current improved dhesive techniques, the indictions crowns hve decresed nd more conservtive pproch my e proposed, to preserve tooth structure nd to postpone more invsive tretments until the ptient is older. 4 8 In order to test the hypothesis tht such concept cn predictly rech the specific tretment ojectives, clinicl tril testing fully dhesive pproch is underwy t the University of Genev. All ptients ffected generlized dvnced dentl erosion re systemticlly nd exclusively treted with dhesive techniques, using onlys the posterior region nd comintion of fcil onded porcelin restortions (BPRs) nd pltl composite restortions the nterior mxillry region. The gol of this prospective clinicl study is to evlute the longevity of dhesive rehilittions, ee proposing this tretment option s the new stndrd of cre. Despite the tendency dhesive modlities to rther simplify the involved clinicl nd lortory procedures, tretment of such ptients still remins chllenge ecuse of the significnt mount of tooth destruction (Fig 1). 130

4 VAILATI/BELSER Puliction Tle 1 The three-step technique Lortory Clinicl Mxillry vestiulr wxup Step 1: Esthetics Assessment of occlusl plne Posterior occlusl wxup Step 2: Posterior support Cretion of posterior occlusion t n incresed VDO Mxillry nterior pltl onlys Step 3: Anterior guidnce Reestlishment of finl nterior guidnce To fcilitte the clinicin s tsk during the plnning nd execution of full-mouth dhesive rehilittion, structured, innovtive concept hs een developed: the three-step technique (Tle 1). Three lortory steps re lternted three distinct clinicl steps, llowing the clinicin nd the lortory technicin to constntly interct nd thus to chieve the most predictle esthetic nd functionl outcome. The first step of the concept hs een previously descried in detil. 9 The present rticle focuses on the second step, explining ll the lortory nd clinicl steps necessry to restore the posterior qudrnts with defined occlusl scheme t n incresed verticl dimension. A rief summry of the first step is lso included. Full-mouth wxup: crucil or ritrry tool in the determintion of the plne of occlusion? Ptients ffected severe dentl erosion often present with n extremely dmged dentition, not infrequently mking clinicins hesitte to undertke such n ex- tended rehilittion. Trditionlly, one of the first steps consists of providing the lortory technicin with dignostic csts, nd requesting full-mouth wxup. A fullmouth wxup should guide the clinicin in plnning the tretment so tht the most esthetic nd functionl result is chieved respecting the principle of miniml invsiveness, ie, miniml tooth preprtion. Clinicins should relize, however, tht technicins will often ritrrily decide on numerous importnt dentl prmeters (eg, occlusl plne, incisl edge position) without seeing the ptients, nd with n often misleding lck of reference points (eg, djcent teeth). The fct tht the resulting finl rehilittions often do not reflect the initil full-mouth wxups confirms this sttement. In the uthors opinion, the most misjudged prmeter in full-mouth wxup is the position of the occlusl plne. In cse of full-mouth rehilittion t n incresed verticl dimension of occlusion (VDO), the gined interocclusl spce is generlly shred eqully etween the 131

5 CLINICAL APPLICATION Puliction mndiulr nd the mxillry posterior teeth, to minimize tooth preprtion in oth rches. However, such decision is completely ritrry, nd the repositioning of the occlusl plne t lower level thn the originl my led to compromised esthetic result. In order to chieve n optiml esthetic outcome, oth the mxillry incisl edges nd the occlusl plne should e in hrmony. In frontl, smiling view, the vestiulr cusps of the mxillry posterior teeth should follow the lower lip nd e locted more cerviclly thn the incisl edges of the nterior dentition. Otherwise, n unplesnt, reverse smile is generted. Thus, to determine the correct distriution of the interocclusl spce gined the increse of VDO, it is mndtory to determine first the optiml position of the mxillry incisl edges of the plnned finl restortions. In ptients where the mxillry nterior teeth cnnot e lengthened sufficiently on their incisl spect to compenste n excessively low occlusl plne, ll the spce otined hs to e used exclusively the restortion of the mndiulr posterior teeth, which in turn will require more ggressive tooth preprtion of the mxillry posterior teeth. Advnced generlized dentl erosion frequently leds to supreruption of oth the mxillry posterior sextnts nd the mndiulr nterior segment, cusing so-clled reverse smile (Fig 2). Logiclly, in these ptients, the position of the occlusl plne cnnot e further lowered, unless there is certitude tht the incisl edges of the mxillry nterior teeth will e sufficiently lengthened to correct the reverse smile. An dditionl prolem inherent to this prticulr type of ptient is tht they re used to perceiving themselves with smller teeth. As consequence, not ll of them will redily ccept hving their nterior teeth restored with dded incisl volume. Hence communiction with the ptient ecomes of prmount importnce to void esthetic misunderstndings. Bee strting the full-mouth rehilittion, it is recommended to determine to wht extent the ptient will ccept lengthening of the nterior mxillry teeth, so tht the finl esthetic outcome will e well defined nd the required mount of preprtion of the mxillry posterior teeth cn e ccurtely plnned. Step 1: Lortory nd clinic The first step of the three-step technique is conceived to gurntee tht oth the clinicin s nd the lortory technicin s vision of the plnned restortion is reflection of the ptient s true desires. With the introduction of the first clinicl step, the technicin will not complete potentilly incorrect full-mouth wxup. In fct, the first lortory step proposes to wx up only the vestiulr surfces of the mxillry teeth. At this stge, where much of the relevnt inmtion is still missing, it is not dvisle to invest time in more comprehensive wxup. Susequently, the inmtion represented the mxillry vestiulr wxup will e picked up mens of precise silicone key (Fig 3). The ptient is then scheduled clinicl ppointment where mxillry vestiulr mockup is directly fricted in the mouth (first clinicl step). The clinicin will lod the silicone key with tooth-colored utopolymerizing resin composite mteril nd position in the ptient s mouth. After its removl, ll vestiulr surfces of the mxillry teeth will e covered thin lyer of 132

6 VAILATI/BELSER Puliction c Fig 2 ( to c) An unplesent reverse smile is present when the position of the incisl edges of the mxillry nterior dentition is more cervicl thn the occlusl plne, s pprent in these three ptients ffected severe dentl erosion. c Fig 3 ( to c) First lortory step: Mxillry vestiulr wxup. The technicin is instructed to wx up only the vestiulr spect of the mxillry teeth. Neither the cingul nor the pltl cusps of the mxillry posterior teeth re included t this stge. A silicone key is then fricted nd will susequently e loded with tooth-colored resin composite mteril nd repositioned in the ptient s mouth the friction of mxillry mockup. c Fig 4 First clinicl step: Mxillry vestiulr mockup. Clinicl views ee () nd fter ( nd c) completion of the dignostic mockup. Mucogingivl surgery ws permed to cover the mrked gingivl recessions on the mxillry left cnine nd premolrs. e tht the mockup covers only the incisl edges nd the vestiulr cusps of the mxillry teeth. composite, reproducing the shpe defined the future restortions the lortory technicin. The descried, fully reversile reconstruction of the vestiulr cusps of the mxillry posterior teeth nd the incisl edges of the nterior teeth llows visuliztion of the future plne of occlusion. Additionl inmtion is lso otined, s explined in previous rticle, 9 most importntly the ptient s consensus regrding the plnned finl esthetic outcome (Figs 4 nd 5). After completion of the first step, either ml cceptnce the ptient is o- 133

7 CLINICAL APPLICATION Puliction c d Fig 5 ( to d) These photogrphs present the sme ptient s shown in Fig 4. Owing to the mxillry vestiulr mockup (), the orienttion of the future occlusl plne cn e visulized, nd the esthetic direction tken the technicin greed with the ptient. Generlly, ptients pprecite the plnned tretment ojective eing presented to them so clerly t n erly stge nd ee ny irreversile mesures hve een tken. tined, or new guidelines chnges re wrded to the technicin, who cn then progress with the complete wxup of the posterior qudrnts. Bee continuing ny further with the three-step technique, it is importnt to ddress two topics specificlly, which in the cse of full-mouth rehilittion re still controversil: centric reltion nd verticl dimension of occlusion. Centric reltion: centric occlusion dilemm In the presence of generlized dvnced dentl erosion, which often significntly ffects occlusl morphology in the posterior segments of the dentition s well s nterior guidnce, the clinicin fces the dilemm whether to restore the ptient in centric reltion (CR) or in mximum intercusption position (MIP). According to numerous clssic rticles pulished in the field of Gnthology, CR is recommended s the only cceptle position when it comes to full-mouth rehilittions, since it is considered the only reproducile one. This concept ws developed conventionl full-mouth rehilittions, when ll the teeth were going to e restored mens of full coverge (crowns or fixed dentl prostheses) nd when working ex- 134

8 VAILATI/BELSER Puliction Fig 6 Mounted study csts of sme ptient rticulted in MIP () nd in CR (), fter complete full mouth wxup. While the CR position cn e desirle in ptients with clss III molr occlusion, in ptients with clss II, s this prticulr ptient, it poses n occlusl dilemm. The future restortions on the nterior teeth would never e in contct (no nterior guidnce) unless unnturl oversized cingul were creted. e the excessive horizontl overlp () generted the comintion of the CR position nd the increse of VDO. tensively on oth rches t the sme time hd n elevted risk of losing ll intermxillry reference points. An dditionl rgument CR ws tht ptients treted under extended locl nesthesi were unle to collorte during the occlusl djustments. Currently, there is n incresing trend towrds minimizing the necessity complicted, time-consuming clinicl procedures on the one hnd, nd reducing the numer of full crown restortions on the other hnd, prticulrly when treting young ptients. Consequently, the new clinicl pproch (full-mouth dhesive rehilittion) the tretment of dvnced generlized erosion consists exclusively of posterior onlys nd nterior BPRs, nd is strtegiclly plnned in wy tht llows rehilittion of ptients qudrnt-wise insted of restoring oth dentl rches simultneously. In dynmic rehilittion process, where two key prmeters of functionl occlusion, ie, VDO nd interrch reltion, re constntly mintined the contrlterl side of the mouth, using CR s lndmrk reference of occlusion my not e so crucil. Furthermore, in cses of severe dentl erosion, the pltl spect of the mxillry teeth is often compromised; fter the enmel is lost, the exposed dentin is suject to ccelerted wer, which leds to pronounced concve morphology nd not infrequently to wekening nd frcture of the incisl edges. To stop the progression of the descried tooth destruction (erosion nd ttrition), the exposed remining dentin should e efficiently protected. Due to the supreruption of the nterior qudrnts, n increse of VDO is mndtory to restore the originl tooth m. However, in ptients with clss II molr occlusion, the comintion of incresed VDO nd CR position my set the nterior teeth significntly prt nd this cn led to n sence of nterior guidnce. 135

9 CLINICAL APPLICATION Puliction Since it is not recommended to sustntilly increse the incisl length of the mndiulr nterior teeth (generlly supererupted in cses of dvnced generlized dentl erosion), nterior contcts cn logiclly only e re-estlished incresing the size of the mxillry cingul. In fct, severl of the ptients ffected severe generlized erosion treted t our clinic presented clss II molr occlusion with mjor discrepncy etween MIP nd CR. Thus it ws preferred to restore their occlusion in MIP nd to estlish nterior contcts without the necessity of creting oversized mxillry cingul (Fig 6). Furthermore, to evlute if under the previously descried conditions nd strictly following the three-step technique the use of CR s the interrch reltionship of reference is not prerequisite, the decision ws mde to restore ll the ptients ffected severe erosion in MIP. From the preliminry dt collected so fr, no significnt dverse effects hve een encountered tht would question the choice of using MIP. The incresed VDO dilemm: how much nd how to test? In ptients ffected severe generlized erosion, the question of whether VDO hs eventully decresed during this pthologicl process is difficult to nswer, s severl compenstory mechnisms, eg, supereruption of the lveolr process, my hve occurred. It is lso cliniclly quite irrelevnt. An increse of VDO is lwys mndtory, in order to reduce the need sustntil tooth preprtion nd to void the necessity of elective endodontic tretments. However, ny increse of VDO should e miniml so it is tolerted the ptient, nd gurntees t the end of the rehilittion the preservtion or re-estlishment of functionl nterior interrch contcts required nterior guidnce. Furthermore, the new VDO should lwys e tested cliniclly, ee irreversile tretments egin, since it is selected ritrrily on the rticultor. In this context, trditionl nd fully reversile pproch consists of the use of n occlusl gurd, which requires complince of the ptient. However, considering the ctive lifestyle of most people, it is rther nïve to expect tht ptients will wer such n occlusl gurd 24 hours dy severl months. A more relistic pproch my e the use of interim restortions. In the cse of dhesive rehilittion, the dentl technicin could fricte provisionl composite onlys, which would susequently e onded to the teeth, including the pltl spects of the mxillry nterior dentition. There re severl disdvntges to this method, such s the ssocited dditionl l fees. Furthermore, it my in mny instnces not e truly reversile pproch, since it could require some tooth preprtion to ssure miniml thickness of the onlys. The third possiility clinicl testing of the fesiility of n ritrrily chosen increse of VDO is the use of direct composites. However, free-hnd direct composites re very time consuming, prticulrly if the clinicin ims to duplicte exctly the occlusl scheme determined wxup on the mounted study csts. It should e repeted tht not only the posterior, ut lso the nterior teeth should e involved in the tretment in order to increse the VDO nd to recrete dequte nterior guidnce. The respective result my e disppointing, especilly if the clinicin expects to position the mndile in CR nd to estlish simultneously stle 136

10 VAILATI/BELSER Puliction Fig 7 ( to c) Second lortory step: Posterior occlusl wxup. The lortory technicin wxes only the occlusl surfces of the premolrs nd the first molrs in ech posterior qudrnt of the mxillry nd mndiulr csts. Bsed on this wxup, four independent trnslucent silicone keys will e fricted. c occlusl contcts t the identicl VDO tht hd een previously selected on the rticultor, tsk tht is generlly considered lmost impossile. All the three of the ove techniques tht hve een proposed to test n increse of VDO hve some mjor drwcks. The dilemm of how to trnsfer efficiently nd correctly the new occlusion defined with the wxup remins. As consequence, the second step of the threestep technique proposes n esy nd reversile pproch to estlish new posterior support nd to test the dpttion of the ptient to this new VDO. This pproch, comining the dvntges of the ovementioned techniques, llows friction of fixed occlusl gurd, mde of splinted composite onlys, directly fricted in the mouth. Step 2: Lortory posterior occlusl wxup At the eginning of the tretment, the two mxillry nd mndiulr csts re mounted on semi-djustle rticultor with fceow in MIP. During the first step, the technicin permed vestiulr wxup on the mxillry cst, nd the position of the plne of occlusion ws susequently vlidted cliniclly. For ech ptient, the new VDO is decided ritrrily on the rticultor, tking into considertion the posterior teeth, where the mximum increse is desirle to mintin mximum of minerlized tissue, nd the 137

11 CLINICAL APPLICATION Puliction c d Fig 8 ( to d) Wxup modifictions ee the friction of the trnslucent silicone keys. It is necessry to remove the wx from the mxillry cnines, so tht the key will etter e dpted in the ptient s mouth (cnine s mesil stop). nterior teeth, which should not e set too fr prt to jeoprdize the recretion of nterior contcts nd the relted nterior guidnce. Once the increse of the VDO is estlished nd the plne of occlusion vlidted, it is esy the technicin to wx up completely the occlusl surfces of the posterior teeth. The second lortory step, however, proposes only to wx up the occlusl surfces of the two premolrs nd the first molr in ech sextnt (Fig 7). The pltl spect of the mxillry cnines my lso e wxed t this stge to etter select the cusp shpe nd inclintion in reltion to the occlusl scheme selected (eg, cnine guidnce or group function). In more complex cses (shllow future nterior guidnce), the technicin my e oligted to wx up ll the cingul of the mxillry nterior teeth s well, to verify the disclusion of the posterior qudrnts in protrusion. Generlly, there is no need to wx up the mndiulr nterior teeth, since they re often only minimlly ffected the erosion. At completion of the posterior occlusl wxup, the technicin will fricte ech qudrnt one key, mde of trnslucent silicone (Elite Trnsprent, Zhermck). These keys will e used in the second clinicl step introrlly to fricte direct composites, reproducing the wxup very closely. 138

12 VAILATI/BELSER Puliction c d Fig 9 ( to d) Introrl preprtion of posterior mxillry sextnt direct onding procedure: The two premolrs nd the first molrs ech posterior qudrnt re etched, nd priming nd onding gents re pplied. Cre is tken to isolte the djcent teeth with mtrices. Some modifictions of the wxup re susequently crried out to fcilitte the next clinicl step, ee producing the keys (Fig 8): The wx is crefully removed from the uccl nd the lingul surfces of the posterior teeth of the csts, so tht in turn ech key will e in close contct to the cervicl spect of the teeth in the ptient s mouth. As consequence, less excess resin composite my flow into the gingivl sulcus nd fewer introrl djustments will e necessry. The wx should lso e removed, if present, from the cnines, since they will serve s mesil stop to stilize the key introrlly. Step 2: Clinicl posterior interim composites The second clinicl step siclly consists of the friction of posterior composite onlys, directly permed in the ptient s mouth, thnks to the specil trnsprent keys duplicting the occlusl wxup. The two premolrs nd the first molrs of ech qudrnt re cid-etched, followed ppliction of primer nd ond (Optiond FL, Kerr) (Fig 9). In the uthors experience, even in cses of severe exposure of dentin, there is no need to nesthetize the ptient ee pplying the etching gent. The clinicin will then lod ech trnslucent key with composite, position it in the 139

13 CLINICAL APPLICATION Puliction Fig 10 ( nd ) Second clinicl step: interim posterior composite. The trnslucent silicone key, duplicting the occlusl wxup, is loded with resin composite nd positioned in the mouth. The key is well stilized the cnine nd the second molr (mesil nd distl stops). Owing to the trnslucency of the silicone, the composite cn e polymerized through the key. Fig 11 ( nd ) The posterior provisionl resin composite is esily nd quickly fricted, with miniml excess requiring removl. A composite shde tht is slightly different from the remining dentition should e selected to fcilitte the future removl of these provisionl restortions. e tht in this ptient the clinicin hs filled the interproximl spces with teflon to reduce excess resin composite in the emrsures. Fig 12 ( nd ) Since the second molrs re not restored with interim resin composite, they serve s vlule indiction of the increse of VDO, once the respective csts re rticulted. Fig 13 Even though the occlusl ccess to the interproximl res is locked the splinted posterior interim composites, the gingivl emrsures re still open to llow clening with Superfloss. 140

14 VAILATI/BELSER Puliction ptient s mouth, nd polymerize the composite through the key (Fig 10). Since the keys, mde of trnslucent silicone, re not s rigid s desired, it is crucil not to use too viscous resin composite (such s Tetric EvoCerm, Ivoclr Vivdent), or to lod the key excessively. To void distortion, the composite should e pre-wrmed, nd miniml quntity of mteril should e plced in the key, just enough the new volume of the occlusl surfces. At this stge, the second molrs re not included in the occlusl wxup, nor will they e restored with provisionl occlusl composite due to the following resons (Fig 12): to ssure the presence of stle distl occlusl stop ccurte positioning of the trnslucent keys during the friction of the posterior interim composites to cknowledge the fct tht three posterior teeth re considered sufficient to estlish stle posterior support in ech sextnt to hve reference indicting the mount of increse of VDO. Implementtion of this technique includes splinting the three posterior teeth involved, thus locking the occlusl ccess of two interproximl contcts res nd preventing the use of dentl floss. Adequte orl hygiene, however, is possile since the gingivl emrsures re kept open nd Superfloss cn e used with lterl pth of insertion (Fig 13). As stted ove, the originl models of the ptient re mounted in MIP nd the increse in VDO is decided on the rticultor. Despite the fct tht the rticultor's hinge xis is going to e different from the ptient's, in our experience it does not generte sufficiently different occlusl contcts on the composite resin to require the mounting of the csts in CR. Minor occlusl djustments should e expected implementing this technique, ut normlly, if the wxup is correctly permed, nd the keys ccurtely fricted nd positioned in the mouth, the time required the djustment is limited (Fig 14). In ddition, since there is normlly no need to nesthetize the ptient, control of the oc- Fig 14 ( nd ) A different ptient, ee nd fter the second step of the three-step technique. Miniml occlusl djustments re expected if the previous steps re permed correctly (eg, posterior occlusl wxup, trnslucent key friction, loding of the keys). e tht the composites do not extend to the cervicl third of the teeth, thnks to the respective modifictions of the wxup ee the key friction. The resulting visile trnsition step cn e smoothed with polishing ruer wheel. 141

15 CLINICAL APPLICATION Puliction c d Fig 15 ( to d) A 29-yer-old ptient ee nd fter the second clinicl step of the three-step technique. Even in cses of extensive dentine exposure, dentl nesthesi is not required during this step. Fig 16 ( nd ) Close-up view of the previous ptient. Existing mlgm restortions cn e removed (tooth 36) or left in plce nd covered with the interim resin composite (tooth 26). 142

16 VAILATI/BELSER Puliction cisl edge position, modifying the vestiulr cusps of the posterior provisionl composites. Finlly, their presence will fcilitte the occlusl djustments of the finl restortions plced in the opposite qudrnt. The lortory technicin could decide to fricte the ltter to the perfect m nd ll the occlusl djustments could e crried out on the opposite provisionl posterior composites. The second clinicl step hs een conceived to simplify the clinicin s work, without compromising the finl outcome of the full mouth rehilittion. In this cse, it ws decided not to ttempt to restore the nterior teeth with provisionl resin composite. In the uthors experience the increse of VDO is well tolerted (ecuse miniml) the ptients even when n nterior open ite is creted temporrily. Some speech impirments could e nticipted. However, ptients inmed ee tretment usully del very well with this prolem (Figs 17 to 19). Currently, there is no consensus of the time necessry to test the comt of the ptient with respect to new, incresed VDO, nd ech clinicin ppers to decide sed on personl opinion rther thn on clusion will e fcilitted nd consequently more ccurte. This fixed occlusl gurd hs the mjor dvntge tht the complince of the ptient is 100% in terms of testing the incresed VDO. Since no tooth preprtion is requested the friction of the posterior occlusl composites, the tretment cn e considered completely reversile; if signs nd/or symptoms of temporomndiulr dysfunction rise, the initil sttus could e re-estlished grinding off the occlusl composites. These composite onlys re ment to e provisionl, nd they will e replced (with finl composite or cermic onlys) fter the nterior qudrnts re definitely restored (step 3 of the three-step technique) (Fig 15). This is one of the resons tht the use of ruer dm is not vitl during this prticulr step, nd the removl of existing functioning restortions (eg, old mlgm restortions) is not strictly required. Another dvntge of these interim composites is their potentil modifiction. After, exmple, completion of the restortion of the mxillry nterior teeth, it is still possile to djust the position of the occlusl plne with respect to the new in Fig 17 ( nd ) Sme ptient s shown in Fig 12. After completion of the second clinicl step the ptient is restored t n incresed VDO (). e the slight nterior open ite tht hs een generted. 143

17 CLINICAL APPLICATION Puliction Fig 18 ( nd ) Another exmple of ptient ffected severe dentl erosion, restored ccording to the three-step technique. At this stge the posterior qudrnts (except the second molrs) were restored with interim posterior resin composite (second clinicl step). c d Fig 18 (c nd d) Frontl view t the new verticl dimension of occlusion shown in Fig 18. Normlly, ptients who were inmed eehnd del well with the resulting nterior open ite. Fig 19 Close-up view of the previous ptient s right side. Initil sttus () nd fter the second clinicl step (). The ptient underwent mucogingivl surgery, which reveled distinct clss V lesions, previously locted slightly sugingivlly. 144

18 VAILATI/BELSER Puliction scientific evidence. At the University of Genev, the protocol suggests witing one month. This is completely ritrry nd experimentl choice. Once the ptient feels comtle nd neither signs nor symptoms of temporomndiulr dysfunction pper, the cceptnce of the new VDO cn e confirmed, nd the third step (the cretion of the nterior guidnce) cn e undertken. If the clinicin is concerned out leving the ptient without nterior contcts nd thus without functionl nterior guidnce during the testing phse of the newly introduced, incresed VDO, the third step could e initited more rpidly. Finlly, the technicin will concentrte on the nterior teeth. Bsed on the degree of destruction, the pltl spect of the nterior teeth will e restored (direct or indirect resin composites), representing the third nd lst clinicl step of the three-step technique. At this point the ptient will e stle from point of view of occlusion. The only definitive restortions re the pltl reconstructions. The vestiulr/incisl spects of the nterior mxillry teeth, s well s the reminder of the posterior teeth, still need to e treted mens of permnent restortions. Conclusions The restortive therpy of dentl erosion should e sed on minimlly invsive pproch, even in the cse of extensive loss of tooth structure. Adhesive techniques cn help the clinicin in rehilitting this type of ptient in the most conservtive mnner. The three-step technique is structured pproch to chieve full-mouth dhesive rehilittion with the most predictle result, the miniml mount of tooth preprtion, nd the highest level of ptient cceptnce. The gol of this technique is to temporrily restore compromised dentition t new VDO, implementing directly onded posterior composite restortions. With stle posterior support, the nterior teeth cn susequently e restored esily, gin using exclusively dhesive techniques. Once the nterior contcts nd n nterior guidnce re re-estlished, the replcement of the posterior provisionl resin composites cn egin. Owing to the presence of the provisionl posterior composites, the fullmouth rehilittion cn e plnned ccording to qudrnt-wise pproch. Restoring ptient qudrnts hs enormous prcticl dvntges oth ptient nd clinicin, since fewer ppointments re necessry. Neither multiple nesthetic injections nor difficult full mouth impressions re required. Since the contrlterl prt of the mouth gurntees stle occlusion, ptients feel comtle throughout the whole ctive tretment phse up to the delivery of the finl restortions. In this rticle, the second step of the three-step technique hs een discussed in detil, including the friction of the directly onded provisionl posterior composites. Acknowledgments The uthors would like to thnk the lortory technicins nd cermists Alwin Schönenerger, Ptrick Schnider nd Sylvin Crciofo their enthusistic collortion nd meticulous execution of the lortory work presented in this rticle. 145

19 CLINICAL APPLICATION Puliction References 1. Kvour V, Kourtis SG, Zoidis P, Andritskis DP, Doukoudkis A. Full-mouth rehilittion of ptient with ulimi nervos. A cse report. Int 2005;36: Vn Roekel NB. Gstroesophgel reflux disese, tooth erosion, nd prosthodontic rehilittion: A clinicl report. J Prosthodont 2003;12: Bonill ED, Lun O. Orl rehilittion of ulimic ptient: cse report. Int 2001;32: Hyshi M, Shimizu K, Tkeshige F, Eisu S. Restortion of erosion ssocited with gstroesophgel reflux cused norexi nervos using cermic lminte veneers: cse report. Oper Dent 2007;32: Aziz K, Zieert AJ, Co D. Restoring erosion ssocited with gstroesophgel reflux using direct resins: cse report. Oper Dent 2005;30: Lussi A, Jeggi T, Schffner M. Prevention nd minimlly invsive tretment of erosions. Orl Helth Prev Dent 2004;2(Suppl 1): Sundrm G, Brtlett D, Wtson T. Bonding to nd protecting worn pltl surfces of teeth with dentine onding gents. J Orl Rehil 2004;31: Hstings JH. Conservtive restortion of function nd esthetics in ulimic ptient: cse report. Prct Periodontics Aesthet Dent 1996;8: Vilti F, Belser UC. Full mouth dhesive rehilittion of severely eroded dentition: the three step technique. Prt I. Eur J Esthet Dent 2008;1: Sturt CE, Golden IB. The History of Gnthology. CE Sturt Gntologicl Instruments. 1981;13 32, Grnger ER. Prcticl Procedures in Orl Rehilittion. Phildelphi: Lippincott, 1962: McCollum BB. Fundmentls involved in prescriing restortive dentl remedies. Dentl Items Interest,

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