CLINICAL REPORT 215 Sr Tit-Pour, Anthony Roerts, Ro Hrrison, Iin Chpple Restortive plnning for hemisection surgery: technique report KEY WORDS hemisection, lortory stges, restortion Hemisection surgery involves the premeditted mputtion of one or more roots nd its overlying coronl structure to fcilitte prtil tooth retention. This cn e crried out in cses where multirooted tooth my hve its furction re, or one or more of its roots severely ffected periodontl disese, cries or periodontl-endodontic lesion. With pproprite cse selection nd pre-opertive plnning it is possile to ttin good esthetics, friendly environment for the periodontium nd good long-term prognosis. This report outlines technique where hemisected tooth my e restored without compromising its positionl reltionship to its utments nd minimising occlusl loding. Sr Tit-Pour Anthony Roerts Deprtment of Periodontology Ro Hrrison Iin LC Chpple Deprtment of Periodontology Tel: 0121 237 2807 Fx: 0121 237 2809 Emil: i.l.c.chpple@hm.c.uk Introduction The ultimte im of hemisection surgery is to slvge vile prt of the tooth to e used s prosthetic utment or for occlusl support. Fvourle predictors for crrying out hemisection surgery of multirooted tooth include dequte one support to mintin the sectioned helthy root, high furction level to reduce the mount of tooth tissue to e cut nd chieving supr-gingivl restortion mrgin (preventing encrochment upon the iologicl width) 1. A predictle endodontic tretment is lso of prmount importnce nd it is necessry to hve dequte residul coronl tooth tissue fter crown sectioning, cries removl, nd preprtion to provide dequte resistnce nd retention for the definitive restortion. As the hemisection procedure for tooth requires creful plnning nd execution of tretment, highly motivted ptient with good orl hygiene is prerequisite. If ll these criteri re met, hemisection surgery is n lterntive to extrction of the tooth nd its replcement with either dentl implnt or conventionl fixed/removle prosthesis.
216 Fig 1 Pre-opertive clinicl picture () nd cst model (), showing loss of ttchment of tooth 46 nd its high furction involvement. Fig 2 Peripicl of tooth 46, showing severely compromised distl root (tooth 44 ws extrcted prior to the clinicl photogrph). Fig 3 Peripicl of tooth 46 post endodontic therpy with mlgm restortion within the chmer nd the coronl portion of the root cnls (Nyyr core). Cse report The present report documents in n illustrtive mnner the pre-surgicl plnning nd the lortory stges involved in the interim nd definitive phses of restoring the remining root fter hemisection surgery of molr tooth. Dignosis nd cse selection The cse presented is of ptient in whom the tooth 46 hd distl root tht ws severely periodontlly compromised despite repeted ttempts t non-surgicl mngement. As it hd fvourle ntomy it ws chosen for hemisection, nd endodontic therpy of the tooth ws crried out to high stndrd. Following root cnl oturtion coronl sel is required to fcilitte susequent hemisection nd cn e provided plcing the coronl restortion within the pulp chmer s well s the coronl portion of the cnls (Nyyr core). Therefore if different clinicins re providing the endodontic therpy nd hemisection surgery, good communiction is needed to prepre the tooth endodonticlly for the hemisection procedure. Pre-surgicl plnning An lginte impression ws tken nd stone models (Plstex, pech die stone sed with Kffer D) were poured. The primry model ws duplicted using Duliplst thermo-reversile dupliction gel (Denturum, Ispringen, Germny). A mock surgicl procedure ws performed on the duplicted cst imitting the removl of the coronl distl portion of the tooth (Fig 4). The lortory technicin performed n idelised crown preprtion of the remining coronl prt, which represented the nticipted hemisection outcome (Fig 4). A temporry crown, either from indirect composite (3M ESPE Sinfony
217 Fig 4 Duplicted models, showing () lortory sectioned distl portion 46, nd () crown prepred mesil coronl portion. Fig 5 Lortory stges in the friction of the temporry composite crown. Reinforcement rion (3 mm Riond, THM, USA) nd indirect composite were used to construct the temporry crown, with distl extension, nd ter drop contcting the djcent tooth to prevent drift/tilting. The plcement of the reinforcement rion is shown in 5 nd 5, nd its incorportion within the temporry composite uild up in 5c nd 5d. c d shde A3), s with this cse, or in crylic (Pttern resin, e.g. Durly Dentl MFG, USA) is then constructed sed upon this idelised preprtion (Fig 5). It is essentil tht the mock crown preprtion is 'under'-prepred such tht smll spce remins t the time of fitting the crown. This tkes plce t the time of surgery, nd over-preprtion of the model would result in temporry crown tht did not fit the prepred tooth t the hemisection ppointment nd would require considerle chir-side djustment, which is undesirle t the surgicl ppointment. Fig 6 Definitive clinicl crown preprtion.
218 c Fig 7 Definitive restortive phse: the finl restortion ws fricted from gold (Cookson 620, type 4 lloy) with distl extension mking contct with djcent tooth. The clinicl hemisection procedure ws susequently crried out. This resulted in the division of coronl spect nd furction of the 46 nd extrction of the compromised root. Crown preprtion of the remining mesil crown ws lso undertken t the chir-side t the sme visit, nd prior to completion of the hemisection. Finl modifictions to the preprtion post-hemisection were performed whilst covering the extrction socket with sterile guze. The lortory-mde temporry, shown in Fig 5c, ws checked, relined nd djusted s necessry nd cemented with temporry cement, e.g. TempBond (Kerr Corportion, Ornge, CA, USA). It is importnt to provide stisfctory temporry restortion, with cceptle mrgins, occlusion nd in this cse with distl point contct with the djcent tooth. It my e necessry for the lortory mde temporry crowns to e relined with crylic t chir-side to provide etter mrginl fit nd retention. The interim restortion is then cemented with temporry cement for 3 months to llow soft tissue nd ony heling to occur. Once the definitive soft tissue contour hs een estlished, the finl crown preprtion (Fig 6) my e performed nd the finl restortion plced (Fig 7). Discussion Fig 8 Rdiogrph of the definitive restortive t 3-yer review ppointment. The present report provides step--step illustrted guide using, to our knowledge, previously unreported technique for the interim nd definitive restortion of tooth post-hemisection. The process requires good liison etween clinicins nd lortory. It is importnt to pln the procedure nd crry
219 out mock surgery on duplicted study models to ensure dequte tooth sustnce is ville posthemisection for restortion nd to pln for successful restortive tretment. The restortive plnning descried in the present cse offers severl dvntges. The premolr crown with distl 'ter drop' extension provides reduced occlusl tle, pproprite to the single remining root. By providing point contct with the djcent tooth it lso prevents drifting/tilting of the djcent tooth, which otherwise my result in occlusl dishrmony. It is importnt to er in mind tht postsurgery it my e necessry to wit up to 6 months for the mjority of the tissue remodelling to tke plce 2, prior to definitive indirect restortion. This is lengthy period, thus well-plnned interim restortion is essentil to offer n dequte coronl sel s well s cting s spce mintiner nd providing occlusl hrmony. The ter drop design lso provides dequte ccess for interdentl rushing to mintin periodontl helth. Summry The present cse demonstrtes novel restortive technique nd highlights the importnce of meticulous tretment plnning when prepring for hemisection surgery. It demonstrtes n uncomplicted method of plnning for the restortion of the hemisected molr tooth. The technique provides coronl sel post-root cnl therpy nd hemisection, s well s djcent tooth contct in oth the interim nd definitive phse in order to mintin occlusl hrmony. The occlusl design enhnces the long-term prognosis of the slvged tooth. References 1. Inger JS, Rose LF, Coslet JG. The 'iologic width': concept in periodontics nd restortive dentistry. Alph Omegn 1977;70:62 65. 2. Wise MD. Stility of gingivl crest fter surgery nd efore nterior crown plcement. J Prosthodont Dent 1985;53:20 23.