The Interntionl Journl of Periodontics & Restortive Dentistry
835 A Step-y-Step Description of PDL-Medited Ridge Preservtion for Immedite Implnt Rehilittion in the Esthetic Region Miltidis E. Mitsis, DDS, MSc, PhD 1 Konstntinos D. Siormps, DDS 2 Eleni Kontsiotou-Siormp, DDS 2 /Hri Prsd, BS, MDT 3 Dvid Grer, DMD 4 /Georgios A. Kotskis, DDS 5 The im of this study ws to present in detil the clinicl steps of the rootmemrne technique. This technique comines the enefits of conventionl root sumergence vi intentionl mintennce of root frgment for ridge preservtion with those of immedite implnt plcement for functionl rehilittion of the treted site. A cse study of tooth dignosed with horizontl root frcture is used to illustrte this technique step y step. The clinicl ppliction of the root-memrne technique not only llowed for immedite plcement in site with compromised uccl plte ut lso fcilitted excellent clinicl stility of soft tissue contours during the 3 yers of follow-up. (Int J Periodontics Restortive Dent 2015;35:835 841. doi: 10.11607/prd.2148) 1 Adjunct Assistnt Professor, Deprtment of Periodontology & Implnt Dentistry, New York University College of Dentistry, New York, New York, USA; Privte Prctice, Athens, Greece. 2 Privte Prctice, Lriss, Greece. 3 Senior Reserch Scientist, Assistnt Director, Hrd Tissue Reserch Lortory, University of Minnesot, Minnepolis, Minnesot, USA. 4 Privte Prctice, Atlnt, Georgi, USA. 5 Assistnt Professor, Deprtment of Periodontics, University of Wshington, Settle, Wshington, USA. Correspondence to: Dr Georgios A. Kotskis, Assistnt Professor, Deprtment of Periodontics, University of Wshington, 1959 NE Pcific St, Box 357444, Settle, WA 98195-7444. Emil: kotskis@uw.edu 2015 y Quintessence Pulishing Co Inc. Extrction of tooth triggers cscde of events tht led to ridge resorption. 1 Even with the introduction of trumtic techniques for socket preservtion nd the dvncement of iomterils used in conjunction with these techniques, ridge resorption cn only e prtilly countered. 2,3 Prtil preservtion of the lveolr dimensions my e dequte for implnt plcement in posterior sites, ut esthetic implnt plcement in the mxillry nterior region remins elusive with conventionl tretment pproches. 4 In n ttempt to overcome this chllenge, reserchers hve revisited the pproches used for ridge preservtion y mintining the nturl ttchment pprtus of the tooth. 5 The ppliction of the root sumergence technique 5 ensures hrd nd consequently soft tissue dimensionl stility tht provides fvorle esthetics ut does not yield ny functionl enefit, s the re cn only e used s pontic site. Recently, novel pproch ws introduced wherey only portion of the root is retined nd susequently sumerged in proximity to n immeditely plced implnt. 6,7 This pproch serves dul purpose: the retined root frgment ids in the strtegic preservtion of tissues of the periodontium (root-memrne), while the immeditely plced implnt llows for the functionl Volume 35, Numer 6, 2015
836 Fig 1 Initil clinicl view showing the crck line t the cervicl mrgin of the right centrl incisor. rehilittion of the re. The first clinicl study reporting successful longitudinl outcomes of the rootmemrne technique ws recently pulished, instigting widespred clinicl use. 8 Results from Siormps et l showed excellent mediumnd long-term implnt survivl with no implnt filures recorded in lrge cohort of ptients. The sme study showed cliniclly insignificnt proximl crestl one loss of pproximtely 0.2 mm fter medin of 40 months. 8 As this study provides the only longitudinl dt currently ville on the clinicl use of the root-memrne technique, it hs shped the indictions for its use: dult helthy ptients, single mxillry teeth with no signs of moderte or severe periodontl disese (< 3 mm ttchment loss), nd no signs of cute inflmmtion. 8 Preceding this uspicious eginning for the clinicl ppliction of the root-memrne technique, severl niml studies supported the iologicl plusiility of osseointegrtion of implnts plced in proximity to retined root frgments. 7,9,10 In summry, the currently ville niml studies hve shown tht osseo/ dentointegrtion of implnts is fesile nd tht intentionl retention of uccl root frgment prevents osteoclstic remodeling nd consequent resorption of the uccl plte. 9,10 A common pttern seen in these studies is the formtion of new cementum on the internl dentinl surfces of the retined root frgment connected with minerlized tissue on the implnt surfce. 9 11 Schwrz et l pulished histologicl results of the integrtion of n implnt in the dentin of n unintentionlly retined root frgment, perfect exemplr of seminl yet serendipitous scientific dvncement. 11 The elorte histologicl nd immunohistochemicl nlysis provided in this study lends some insight into the iologicl sis of immedite implnt techniques, such s the root-memrne technique nd the socket-shield technique, tht re sed on PDL-medited ridge preservtion. 11 The uthors found tht following trum during implnt site preprtion, reprtive dentin ws formed on the exposed dentinl surfce of the retined frgment tht ridged the distnce etween the root frgment nd the implnt. 11 This minerlized tissue provided wht the uthors nmed dentointegrtion on the implnt-root interfce t pce equivlent to tht of osseointegrtion noted on the implnt-one interfce on the remining implnt surfces. 11 Bsed on the promising pulished dt in fvor of the use of this technique, the im of this rticle ws to demonstrte the technique for PDL-medited immedite implnt plcement on step-ystep sis nd to fcilitte the ppliction of this novel technique in clinicl prctice. Cse study A 37-yer-old femle ptient with noncontriutory medicl history presented for n emergency evlution in privte clinic with chief concern of pin following trum in the mxillry nterior region. The ptient ws nonsmoker nd hd no history of periodontl disese. Clinicl ssessment reveled horizontl frcture line in the cervicl region of the right mxillry centrl incisor (Fig 1). Both percussion nd cold testing yielded positive responses. The ptient s overll orl hygiene level ws very good (plque control record: 9%) with no sites hving proing depths greter thn 3 mm. The gingivl zenith of oth mxillry incisors ws t pproximtely the sme level, locted 0.5 mm coronlly to tht of the lterl incisors. A minor degree of supereruption of the involved centrl incisor ws noted. When the ptient ws sked out this finding she reported hving distem in dulthood tht eventully closed due to shifting of the teeth. The ptient requested tht recretion of the pre-existing distem e considered in the finl prosthetic restortion. Rdiogrphic ssessment reveled very good one levels round the neighoring teeth. A continuous rdiolucent horizontl The Interntionl Journl of Periodontics & Restortive Dentistry
837 Fig 2 Pnormic rdiogrph verifying the clinicl dignosis of horizontl root frcture. Fig 3 The diminished width of the uccl plte presented contrindiction for conventionl immedite implnt plcement. line ws visile t the level of the cementoenmel junction of the involved mxillry incisor consistent with the clinicl dignosis of horizontl root frcture (Fig 2). No signs of peripicl pthosis were noted. Further rdiogrphic ssessment vi cone en computed tomogrphy (CBCT) ws pursued to evlute the condition of the uccl plte of the hopeless tooth. Anlysis of the cross-sections reveled very thin uccl plte with width rnging from 0.2 to 0.7 mm (Fig 3). Alterntive tretment pln options for the replcement of the hopeless tooth were discussed with the ptient. The ptient requested to proceed with the lest invsive tretment option nd rejected the option of one grfting or djunctive use of iomterils to id in one regenertion. The ptient ws lso dmnt out receiving fixed interim restortion immeditely postsurgery. The proposed tretment pln included preservtion of the uccl portion of the root nd implnt plcement with immedite nonfunctionl loding. The ptient ccepted the tretment pln nd signed n informed consent. Surgicl procedure Implnt site preprtion Following dministrtion of locl nesthesi nd preopertive rinsing with 0.12% chlorhexidine, the frctured crown of the involved tooth ws removed with extrction forceps y exploiting the horizontl frcture (Fig 4). In cses where the crown cnnot e extrcted without dmging the root of the tooth, conventionl chmfer dimond ur is employed under copious irrigtion until the remining tooth structure is level with the gingivl mrgin (Fig 4). Cre should e given during reduction of the uccl spect of the root to ensure tht it is reduced sugingivlly ut remins 0.5 to 1 mm suprcrestlly. The retined suprcrestl frgment of the tooth functions s pillr tht supports the midfcil soft tissue vi ttchment of suprcrestl collgen fiers. Susequently, the implnt plcement procedure ws initited following the drilling sequence suggested y the implnt mnufcturer nd using the implnt drill through the long xis of the remining root. The drilling ws initited y engging the pltl spect of the root so tht the uccl spect would remin intct following preprtion of the implnt ed (Figs 5 nd 5). Prtil root extrction The gol fter enlrgement of the dentinotomy/osteotomy ws to hve n implnt housing composed of the mesil, distl, nd pltl ony wlls while the uccl wll ws occupied y the retined uccl spect of the root composed of thin lyer of dentin followed y cementum, periodontl ligment (PDL), nd undle one in n orofcil direction. To chieve this gol, conventionl dimond chmfer ur ws used to initite two indenttions prllel to the long xis of the root, Volume 35, Numer 6, 2015
838 Fig 4 Clinicl view of the remining root following removl of the frctured crown. Fig 4 In cses where the crown is not frctured ut the tooth is deemed nonrestorle (ie, sugingivl cries) chmfer dimond ur cn e used to seprte the crown. Fig 5 Preprtion of the osteotomy/ dentinotomy through the long xis of the root. Fig 5 The implnt drill must engge the pltl spect of the root similr to its positioning closer to the pltl ony wll during conventionl immedite implnt plcement. one t the mesiouccl line ngle of the hollowed root nd one on the distouccl. This seprted the remining root structure into uccl frgment nd frgment consisting of the proximl nd pltl spects of the root. The proximl-pltl root frgment ws esily retrieved with root tip forceps nd removed with cre to leve the uccl portion in situ (Figs 6 nd 6). Root-guided implnt plcement Following the selective retention of only the uccl portion of the root, the implnt plcement procedure ws initited. An importnt dvntge of this technique is the guidnce the root frgment provides for the idel prostheticlly driven positioning of the implnt. With the exception of cses with pre-existing severe mlpositioning of the tooth s crown, the root frgment successfully serves the purpose of surgicl guide tht functions in two distinct plnes: the long xis of the root frgment ids in the mesiodistl positioning of the drills, while the volume of the root frgment in the uccl portion fcilittes pproprite implnt positioning in the pltl two-thirds of the socket. Implnt selection included tpered implnt. The rtionle for selecting tpered implnt in conjunction with this technique is tht it follows the nturl contours of the mid- nd picl portion of the root nd llows for the retention of root frgment with enough thickness to ensure resistnce to frcture. The pth of the osteotomy should e such tht the implnt threds re in proximity to the dentinl surfce ut will not cuse unintentionl dislodgement of the retined root tip due to excessive insertion torque t the time of implnt plcement. A 4 11.5-mm tpered, self-threding implnt (AnyRidge, Meggen) ws plced in direct contct with the dentin of the retined root frgment. The implnt size ws such tht it would llow for the retention of root section with pproximtely 1 mm to 1.5 mm thickness (Figs 7 nd 7). The implnt ws plced with n implnt hndpiece t 20 rpm nd 40 Ncm torque. The tctile senstion during implnt insertion ws similr to tht of plcing n implnt in type 2 one. The Interntionl Journl of Periodontics & Restortive Dentistry
839 Fig 6 A chmfer dimond ur ws used to seprte the fcil root portion from the proximl nd pltl root surfces. Fig 6 Root tip forceps were used to remove the pltl root frgment tht ws esily detchle. Fig 7 Clinicl view of the implnt in situ. Note the proximity of the uccl portion of the root to the implnt. Fig 7 Idelly, uccl root frgment of pproximtely 1.5 mm should e retined to prevent frcture or dislodgement during implnt plcement. Immedite restortion nd postopertive regimen Upon implnt seting titnium temporry utment ws plced nd cement-retined provisionl restortion ws fricted using routine provisionliztion protocol. Following dpttion nd polishing of the provisionl, meticulous occlusl djustment ws performed using n rticulting pper to ensure nonfunctionl loding of the immeditely plced implnt (Fig 8). Postsurgicl instructions included ntiiotics (500 mg moxicillin every 8 hours for 1 week) nd nlgesic mediction (400 mg iuprofen per pin) s well s chlorhexidine 0.12% orl rinses. The ptient ws lso instructed to defer from tooth rushing or ny mechnicl trum in the re for 2 weeks. Follow-up ppointments were scheduled for 2 weeks, 4 weeks, nd 3 months. At the 3-month ppointment the provisionl prosthesis nd utment were removed nd the condition of the root ws cliniclly ssessed. The peri-implnt mucos hd completely covered the retined root nd ws ttched on the implnt (Fig 9). Proing round the implnt did not revel ny pockets greter thn 4 mm in depth. Plption of the uccl tissues did not cuse ny sujective symptoms to the ptient or revel ny signs of root displcement. The implnt ws therefore considered successful nd cliniclly stle, nd definitive ll-cermic restortion ws fricted nd cemented on custom utment s per routine clinicl protocols. 12 The ptient ws followed up nnully for 3 yers postloding. At the 3-yer clinicl evlution the tissue stility ws remrkle, with the gingivl zenith eing comprle to tht of the neighoring ntive centrl incisor nd the distl ppill completely filling the interdentl emrsure. In the mesil spect of the crown the midline distem ws reproduced sed on the ptient s demnd (Fig 10). In the rdiogrph, the root frgment remined clerly visile in contct with the implnt. Proximl one levels were stle in comprison to seline. No norml rections t the one-implnt interfce were noted (Fig 10). Volume 35, Numer 6, 2015
840 Fig 8 (left) Immeditely loded provisionl prosthesis restoring the distem sed on the ptient s preference. Fig 9 (right) Tissue contours t the finl impression ppointment. The retined root frgment ws fully sumerged under the soft tissue. Fig 10 Ptient s smile t the 3-yer follow-up ppointment. Note the excellent stility of the gingivl zenith point. Fig 10 Introrl rdiogrph of the implnt in proximity to the retined root frgment. Discussion The implnt rehilittion of single nterior mxillry edentulous site presents unique chllenge for the clinicin due to the esthetic significnce of this region. 13 Vrious interventions hve een recommended for chieving n esthetic soft tissue profile round single implnts. These include the use of iomterils, utogenous tissue grfts, dvnced surgicl techniques, nd comintions of these. 13 16 The fctor tht hs een shown to contriute most hevily to peri-implnt soft tissue esthetics is pproprite pltl positioning of the implnt fixture. 14 When implnt positioning is idel, the previously listed interventions for preservtion of the mid-fcil tissue profile remin equivocl. 14 The present clinicl study demonstrted in detil the rudimentry steps of novel technique for iologic preservtion of the tissue contours round single implnts in the esthetic zone. The root-memrne technique dicttes the plcement of n implnt in proximity to retined portion of the root of hopeless tooth. 8 The im of mintining the root frgment is preservtion of the lood nd cellulr supply tht stems from the PDL similr to the rootsumergence technique, 5 while the plcement of n implnt on the pltl spect of the socket llows for the functionl rehilittion of the site. Thus, the root-memrne technique nd similr techniques, such s the socket shield technique, cn e etter descried with the scientific term PDL-medited ridge preservtion for immedite implnt plcement. In ddition to the esthetic enefit of mintining the nturl tooth pprtus, it is the uthors opinion tht this technique ers psychologicl merit. Ptients re frequently devstted y the ide of tooth extrction, especilly in the esthetic region. The prtil mintennce of the root my prevent the psychologicl implictions of tooth extrction. In the cse exmple, tooth with intct periodontium ut poor prognosis due to horizontl root frcture ws successfully treted with PDL-medited immedite implnt plcement. The decresed width of the uccl plte tht ws noted in the preopertive CBCT scn would otherwise prevent immedite implnt plcement in this site. 17 Not only ws immedite The Interntionl Journl of Periodontics & Restortive Dentistry
841 plcement fesile with the use of the root-memrne technique, ut the soft tissue contours demonstrted excellent clinicl stility during the 3 yers of follow-up. In generl, PDL-medited immedite implnt plcement is reserved for cses tht fulfill certin criteri. The uthors crefully select cses tht include helthy dults who mintin good level of orl hygiene. Teeth with noticele gingivl recession or ttchment loss due to history of periodontl disese re not treted with this technique, s the preopertive tissue level will dictte the finl esthetic outcome. Additionlly, cses with cute inflmmtion ssocited with the root of the hopeless tooth re cler contrindiction for the use of PDL-medited immedite implnt plcement. Cses tht present with horizontl root frctures tht extend sucrestlly t the fcil spect of the root lso re not routinely treted with this technique, s the enefit of retention of the coronl spect of the root for ttchment of the soft tissue is eliminted in such cses. Conclusion The present cse study demonstrted the clinicl steps of n immedite implnt plcement technique tht is sed on iologic rtionle for preservtion of tissue contours round the immedite implnt. Excellent esthetic results cn e chieved under chllenging clinicl conditions using this technique with prtil preservtion of the nturl tooth pprtus during implnt plcement. However, the smll numer of longitudinl studies ville to evlute results of the root-memrne pproch nd its technique-sensitive nture should led clinicins to crefully select cses nd perform close follow-up. Acknowledgments The uthors wish to thnk Ms. Eugene Koumki for her exceptionl work in prepring the illustrtions of the root-memrne technique used in this rticle. The uthors reported no conflicts of interest relted to this study. References 1. Ashmn A. Ridge preservtion: Importnt uzzwords in dentistry. Gen Dent 2000;48:304 312. 2. Schropp L, Wenzel A, Kostopoulos L, Krring T. Bone heling nd soft tissue contour chnges following single-tooth extrction: A clinicl nd rdiogrphic 12-month prospective study. Int J Periodontics Restortive Dent 2003;23: 313 323. 3. Kotskis G, Slm M, Chrep V, Hinrichs J, Gillrd P. A rndomized, linded, controlled clinicl study of prticulte norgnic ovine one minerl nd clcium phosphosilicte putty one sustitutes for lveolr ridge preservtion. Int J Orl Mxillofc Implnts 2014;29:141 151. 4. Fvero G, Lng NP, Romnelli P, et l. A digitl evlution of lveolr ridge preservtion t implnts plced immeditely into extrction sockets: An experimentl study in the dog. Clin Orl Implnts Res 2015;26:102 108. 5. Slm M, Ishikw T, Slm H, Funto A, Grer D. Advntges of the root sumergence technique for pontic site development in esthetic implnt therpy. Int J Periodontics Restortive Dent 2007;27: 521 527. 6. Dvrpnh M, Szmukler-Moncler S. Unconventionl implnt tretment: I. Implnt plcement in contct with nkylosed root frgments. A series of five cse reports. Clin Orl Implnts Res 2009;20:851 856. 7. Hürzeler MB, Zuhr O, Schupch P, et l. The socket-shield technique: A proof-ofprinciple report. J Clin Periodontol 2010; 37:855 862. 8. Siormps K, Mitsis M, Kontsiotou-Siormp E, Grer D, Kotskis GA. Immedite implnt plcement in the esthetic zone utilizing the root-memrne technique: Clinicl results up to 5 yers post-loding. Int J Orl Mxillofc Implnts 2014;29: 1397 1405. 9. Buser D, Wrrer K, Krring T, Stich H. Titnium implnts with true periodontl ligment: An lterntive to osseointegrted implnts? Int J Orl Mxillofc Implnts 1990;5:113 116. 10. Bäumer D, Zuhr O, Reele S, et l. The socket-shield technique: First histologicl, clinicl, nd volumetricl oservtions fter seprtion of the uccl tooth segment pilot study. Clin Implnt Dent Relt Res 2015;17:71 82. 11. Schwrz F, Mihtovic F, Goluovic V, Becker J. Dentointegrtion of titnium implnt: A cse report. Orl Mxillofc Surg 2013;17:235 241. 12. Kroussis IK, Brägger U, Slvi GE, Bürgin W, Lng NP. Effect of implnt design on survivl nd success rtes of titnium orl implnts: A 10-yer prospective cohort study of the ITI Dentl Implnt System. Clin Orl Implnts Res 2004;15:8 17. 13. Grer DA, Slm MA, Slm H. Immedite totl tooth replcement. Compend Contin Educ Dent 2001;22: 210 216, 218. 14. Lin GH, Chn HL, Wng HL. Effects of currently ville surgicl nd restortive interventions on reducing midfcil mucosl recession of immeditely plced single-tooth implnts: A systemtic review. J Periodontol 2014;85:92 102. 15. Rungchrsseng K, Kn JY, Yoshino S, Morimoto T, Zimmermn G. Immedite implnt plcement nd provisionliztion with nd without connective tissue grft: An nlysis of fcil gingivl tissue thickness. Int J Periodontics Restortive Dent 2012;32:657 663. 16. Khzm N, Mttheos N, Roerts D, Bruce WL, Ivnovski S. Immedite plcement nd restortion of dentl implnts in the esthetic region: Clinicl cse series. J Esthet Restor Dent 2014;26:332 344. 17. Chen ST, Wilson TG Jr, Hämmerle CH. Immedite or erly plcement of implnts following tooth extrction: Review of iologic sis, clinicl procedures, nd outcomes. Int J Orl Mxillofc Implnts 2004;19(suppl):12 25. Volume 35, Numer 6, 2015