16 Prevention nd mintennce J. L. Wickens 1 Awreness of hs incresed mong oth dentists nd ptients. This is, no dout, ecuse of the decline in cries rte nd the control of periodontl disese with the result tht mny more people remin prtilly or fully dentte into old ge. 1 The medi hve lso een influentil in rising ptients wreness of ppernce. These fctors hve led to shift in ptients demnds nd chnge in the prctice of dentistry. 2 Cries nd periodontl disese cn e controlled with pproprite eduction nd professionl support even in the older ptient. In contrst, the dentl profession does not seem to hve reched consensus on the ction needed in cses of. This current series of rticles hs rought together mny views on this topic. They ll hve one recurrent theme; tht prevention of is preferle to restortion. The ltter will often e extensive, expensive nd crries with it lifetime commitment to mintennce nd further restortive procedures. Effective prevention must involve: Ptient eduction Erly recognition Use of predictors Control of further. Prevention requires n understnding of the etiology nd recognition of erly signs nd symptoms. 3 Tooth surfce loss often hs complex chrcter mking it difficult to determine the etiologicl fctors responsile for dentl wer. This comined with non-specific signs nd symptoms hs resulted in slow pprecition of the disese ptterns y the profession nd ptients. The consequences re tht recognition is often so lte tht prevention lone is inpproprite. Terminology tends to confuse the issue further; terms in current use do not follow the common dentl pttern of descriing the physicl chrcteristics of the condition. Rther ll refer to the possile cuse (erosion, rsion, ttrition nd, more recently, frction) nd it follows tht cre my e directed t sole ttriuted etiologicl fctor, disregrding the common multi-fctoril nture of the condition. The description of the physicl effect, ie or tooth wer, encourges roder perspective. This results in less confusion over clssifiction, ccepting tht oth preventive mesures nd tretment hve common ground independent of the dominnt ttriutle cuse. 4 Prevention lso includes the identifiction of those individuls who my e t risk. There re indictors tht my e helpful. Tooth surfce loss my egin in the primry dentition. For given individul, there is evidence of link etween this nd in the permnent dentition. Nystrom et l. 5 found tht horizontl wer of the mxillry nterior teeth t 14 yers of ge, predicted well the continuing wer of these teeth t 18 yers of ge. Mximl nterior ite force, intke of low ph foodstuffs nd low gonil ngle correlted well with the totl wer re on the nterior teeth. These fetures, long with the knowledge tht the numer nd distriution of teeth with occlusl wer increse with ge, 6 would imply tht once wer egins, it is ongoing t stedy pce. The literture, though, does not support this. Tooth surfce loss cn occur in outs s hits nd morphologicl nd psychologicl sttes chnge. For instnce, Csh found tht ruxism in children generlly increses with ge through the mixed dentition nd then decreses. 7 A further compliction is tht while the dominnt etiologicl fctor my hve diminished, the tooth will hve een ltered to render it more susceptile to other fctors in tooth wer, such s erosion due to dietry cids. The dignosis is thus complex nd further highlights the need for comprehensive nd rodsed ptient eduction. Communiction is lso importnt in prevention of dvnced tooth wer. Creful questioning regrding ptients dietry, gstric or prfunctionl hits my indicte the resons for the stte of the dentition. Adults who report prfunctionl ctivity re known to hve more incisl nd occlusl thn those unwre of grinding hit. 8 It hs een suggested tht tooth grinding is motor disturnce tht is not limited to the mstictory muscles ut lso mnifests itself s generlly incresed ody movement. 9 Two etiologicl models hve een developed, the structurl model sed on the role plyed y mlocclusion or ltertions in mxillo-mndiulr reltions, while functionl model highlights the role of stress, emotionl tension nd personlity chrcteristics. 10 However, there is no cuse nd effect reltionship estlished in longitudinl studies to give ny predictive vlue to either of them. Therefore, the following groups should e Effective mintennce is necessry to minimise further tooth wer nd control other dentl disese. Restortive dentistry provided without such control is frequently unsuccessful. The Series Editors re Richrd Ietson nd Andrew Eder of the Estmn Dentl Institute for Orl Helth Cre Sciences nd the Estmn Dentl Hospitl 1 Consultnt in Restortive Dentistry, Estmn Dentl Hospitl nd Honorry Senior Lecturer, Estmn Dentl Institute for Orl Helth Cre Sciences, University of London, 256 Gry's Inn Rod WC1X 8LD British Dentl Journl 1999; 186: 371 376 BRITISH DENTAL JOURNAL, VOLUME 186, NO. 8, APRIL 24 1999 371
Fig. 1 nd 1 The loclised effects of retining primry tooth Fig. 2 to 2d Tooth wer presenting s cse of gross fcil symmetry c d considered t greter risk of. Those with history of: Tooth surfce loss s child Reported prfunctionl ctivity Hevy nterior ite force, possily relted to low gonil ngle Eting disorders, including the excessive intke of low ph everges Medicl disorders resulting in gstric reflux or voluntry vomiting. The ility to use such informtion depends on the ptient reporting spects of their own ehviour which they my not consider relevnt to their dentl prolems. Thus the teeth themselves my provide the first indiction of n norml hit or disese. Brtlett recently highlighted this when he showed tht 17 of the 26 ptients presenting with on the pltl spect of their upper nterior teeth hd unreported or undignosed dytime gstro-oesophgel reflux. 11 This illustrtes one of the fundmentl difficulties in predicting. Why prevent? The effects of re frequently not limited simply to wer of the teeth. It will lso ffect the surrounding structures. Teeth try to mintin functionl contct, oth occluslly nd interproximlly, 12 nd tend to move s they wer. Alveolr one nd the periodontl complex move with the tooth, such tht the congruity of the gingivl mrgin will often indicte where there hs een tooth movement. Figure 1 shows the loclised effect of retining n incresingly worn primry tooth, with the result tht the opposing nd djcent teeth hve encroched on the spce required for n esthetic or functionl replcement. Tretment for this dult hs een complicted y lck of erlier mngement of tooth wer. Wer cused y prfunctionl ctivity is frequently ccompnied y compenstory chnges in the dentition tht llow occlusl contcts nd function to e mintined. Tooth wer in the nterior segment of the mouth is often unsightly, driving the ptient to seek dentl dvice. It will very commonly hve een ccompnied y chnges in the occlusl reltionships which my hve functionl implictions nd complicte restortive procedures. Attempts re frequently mde to meet the esthetic demnds of ptients without due considertion of the functionl spects of worn teeth. This cn result in either filure of the restortions or wer of the opposing teeth due to inpproprite loding. Ptients my seek help only when gross chnges, such s fcil symmetry (fig. 2), hve tken plce. Investigtion of the ptient s mxillo-mndiulr reltionship in the retruded xis position reveled n underlying skeletl discrepncy of the dentl ses pro- 372 BRITISH DENTAL JOURNAL, VOLUME 186, NO. 8, APRIL 24 1999
ducing n edge-to-edge tooth reltionship. A functionl est fit hd een ssumed nd tooth wer hd resulted from prfunctionl ctivity in this position. Erlier recognition would perhps hve prevented compenstory tooth movement nd simplified corrective tretment. Prevention of further tooth wer idelly involves elimintion of the custive gent ut this simple ction is often impossile. A preventive regime with fetures common to ll cses cn e developed which ims to modify hits nd protect the remining tooth structure. This should include: Ptient eduction Dietry nd toothrushing dvice (technique nd timing of rushing) Fluoride (ptient nd/or professionl ppliction) dentifrice nd mouthwsh Creful monitoring of tooth structure (seril csts, photos nd the use of indices). 13 Further ctions my e prescried tht re specific to the dominnt etiologicl fctor. Prfunctionl ctivity, constnt or phsic in nture, will demnd the provision of protective occlusl splint. Detils of these pplinces were given in Prt 3. An integrted pproch with medicl collegues is recommended in cses of voluntry vomiting nd suspected gstro-oesophgel reflux. 14 Figure 3 shows the seril csts of young ldy produced for her in 1978, 1988 nd 1995. The csts llow much clerer ssessment of the extent of wer thn would hve een evident from n intr-orl exmintion. This technique, which is used insufficiently frequently, provides vlule evidence for judging the extent nd pce of tooth wer, the success of preventive mesures nd the need for restortive tretment to protect the remining tooth structure. The timing of restortive intervention cn e prolemticl. The conservtive plcement of plstic restortive mterils in erosion lesions (fig. 4) my e considered prt of preventive cre. In res not susceptile to high lods, they hve n excellent retention rte. 15 Signs nd symptoms from the teeth my indicte need for restortions ut my lso solely e evidence of ctive. However, the dentist must e lert to wer which cuses no symptoms nd ensure tht preventive regimes re estlished. Successful prevention, though, will e dependent on n pprecition y the ptient of the long-term enefits of such regimes. A tem pproch, using the hygienist to reinforce the modifiction in hits, will ssist with this difficult tsk of sustined motivtion. Without intervention, the numer nd distriution of teeth with incisl nd occlusl wer will increse with ge. 6 c Fig. 3 to 3d Seril csts recorded over period of 7 yers showing the vlue of using models to judge the extent of tooth wer The indictions for proceeding from prevention to intervention with restortions re: Symptoms nd signs ssocited with the tht cnnot e controlled through preventive regimes. These not only include pin nd sensitivity ut lso deteriortion in the ppernce of the teeth. The remining tooth structure requires protection. When filure to restore my led to the loss of the tooth or render lter restortion much more complicted. Fig. 4 nd 4 The plcement of plstic restortions in erosion lesions my e considered s prt of preventive cre d BRITISH DENTAL JOURNAL, VOLUME 186, NO. 8, APRIL 24 1999 373
Restortion of teeth with worn functionl surfces, presents three min difficulties: 1 The functionl reltionship of the teeth will hve chnged. The occlusl tle is widened ringing roder spect of the tooth into function, generting rod, flt occlusl contcts which lck stility. This ws discussed in detil in Prt 3 of the series. 2 Clinicl crown height is reduced. Retention nd resistnce form for conventionl crown preprtion will e compromised following dequte tooth removl to provide spce for the restortive mteril. 3 The qulity of the tooth structure, with exposure of lrge res of dentine, my limit the use of desirle, conservtive dhesive techniques. Mintennce of ptients with restored dentitions is necessry to prevent the prevention of further dmge The im is to mintin stility in the orl environment, given tht the originl etiologicl fctors re often incompletely controlled. A mintennce regime should hve the following chrcteristics: Development of n individul progrmme t the outset of tretment Use tem pproch to ensure complince Consider ll ptients to e high risk Consider providing protective occlusl splint for nocturnl wer fter restortion. Mintennce is n spect of cre tht is commonly overlooked ut cnnot e overstressed. The regime devised for ptient will e influenced y the degree of control of the Fig. 5 nd 5 Splint therpy used in cse of suspected prfunctionl ctivity etiologicl fctors tht resulted in the originl tooth wer nd y informtion gined from literture nd clinicl prctice on the pst performnce of restortions in similr circumstnces. Control of the etiologicl fctors Humn nture ensures tht ptient complies with requests to modify their hits for usully only limited period while under professionl review. Reviews should therefore e t intervls tht re sufficiently short to keep the ptient motivted. These need to e pproprite for the individul ptient nd the whole dentl tem should prticipte. It is unlikely tht ll the etiologicl fctors cusing the tooth wer will hve een identified nd controlled. For exmple, ptients who demonstrted prfunctionl ctivity t the time of initil presenttion should wer n occlusl splint post-restortively. In figure 5. the worn pltl surfces of the upper nterior teeth in this teenger hd een protected with dhesively retined metl ckings. Both the ptient nd clinicin were concerned tht the lower nterior teeth would e t risk of further wer; she ws provided with set of se-line csts nd hrd crylic mxillry gurd for night use. An nnul recll progrmme hs een considered pproprite for her. The dentist/hygienist tem is extremely importnt in the recll strtegy; the hygienist my see the ptient more regulrly nd cn lert the dentist to ovious lesions, chnges in tooth contour nd concerns expressed y the ptient. The survivl of restortions in the orl environment hs een widely investigted. Most commonly the performnce of the restortive mteril hs een ssessed nd this is often unrelted to the environment in which it ws employed. For instnce, secondry cries nd mrginl degrdtion re cited s the two most common resons for filure of restortions. 16 Precipitting fctors such s fcets, lck of clinicl crown height or the sustrte used for onding restortions, hve not een evluted. The literture indictes tht mlgm remins the mteril of choice for routine posterior restortions nd gold for more extensive ones; composite mterils should e limited to smll restortions with limited occlusl loding, 17 minly to stisfy ptients cosmetic demnds. Secondry cries, post-opertive sensitivity, frcture nd poor ntomicl form re common resons for filure of lrge posterior composites. Worn dentitions re frequently ptched nd repired with dhesively retined resins s the defects often do not lend themselves to conventionl cvity preprtion for mlgm. Deteriortion nd filure of such restortions cn contriute to loss of occlusl stility which is dded to y continued wer of the teeth. Figure 6 shows worn dentition tht hs een restored with indirect restortions in the 374 BRITISH DENTAL JOURNAL, VOLUME 186, NO. 8, APRIL 24 1999
PRACTICE e c d f Fig. 6 to 6f A worn dentition restored with indirect restortions in the posterior qudrnts posterior qudrnts. The occlusl environment t tht time provided pproprite nterior guidnce with posterior disclusion. While mxillry hrd crylic gurd ws provided post-restortively for night use, y the ptient s own dmission complince ws poor. The result hs een continued wer of the cnine teeth, with shllowing the nterior guidnce to such n extent tht the posterior teeth re in contct throughout lterl excursive movements. The gold restortions hve ecome worn nd occlusl stility hs een lost. This expensive restortive procedure hs een undermined y lck of complince with preventive regimes. It highlights the cre needed in mtching restortive tretment plns with the needs, wishes nd ilities of the ptient. Ptient involvement in the plnning of cre must e comprehensive nd the definitive tretment pln not mde efore thorough period of evlution hs een completed. The recll ppointment The routine t these visits should e: Listen Look Lern! Listen generl converstion with the ptient my indicte whether the originl etiologicl fctors in the tooth wer re under control. It is lso importnt to consider the ptient s views; for exmple if they think tht their splint is socil rrier, it my not e worn regulrly. Mjor life events my lso ffect the ility to crry out norml dily routines. Look intr-orl exmintion my support spects of the history. Comprison of the current sitution with the originl set of csts is impertive (fig. 3). These csts should e the property nd responsiility of the ptient. This encourges degree of ownership nd hopefully improves the ptient s interest in their condition. Indices for monitoring tooth wer hve een proposed y numer of uthors nd were discussed riefly in the first rticle in this series. These my e helpful ut the dynmic nture of the consequences of tooth wer still mkes ssessment difficult. Monitoring is demnding: frequency of re-evlution must e pproprite, not only to monitor preventive regimes, ut lso to e le to judge the need for nd timing of restortion. Once restored, further complictions cn rise. Mrginl deficiencies relted to ll indirectly fricted restortions re filled t cementtion with solule, permele cements, whether of cid-se or resin vriety. Detection of mrginl gps is often very difficult, especilly when mrgins re inccessile. 18 Their ssessment is sed on tctile cuity lone rther thn eing supported y visul inspection, s with supr-gingivl mrgins. Rdiogrphs provide n invlule djunct to this inspection. In well controlled cses, iologicl filures through cries nd periodontl disese will e rre ut continued wer of tooth or restortion my still occur. There remins considerle difficulty in controlling disese with multi-fctoril etiology nd vrying predominnt fetures. Symptoms to e ddressed t recll in reltion to continuing wer re: BRITISH DENTAL JOURNAL, VOLUME 186, NO. 8, APRIL 24 1999 375
1 Deprtment of Helth. An orl helth strtegy for Englnd. London; Deprtment of Helth, 1994. 2 Dentl Prctice Bord 1994-1995 nnul report. Estourne, 1995. 3 Milosevic A. Tooth wer: n etiologicl nd dignostic prolem. EurJ Prosthodont Rest Dent 1993; 1: 173-178. 4 Bder J, Levitch L, Shugrs D, Heymnn H, McClure F. How dentists clssified nd treted non crious cervicl lesions. J Am Dent Assoc 1993; 124: 46. 5 Nystrom M, Kononen M, Alluusu S, Evlhti M, Vrtiovr J. Development of horizontl tooth wer in mxillry nterior teeth from five to eighteen yers of ge. J Dent Res 1990; 69:1765-1770. 6 Hugoson A, Bergendl T, Ekfeldt A, Helkimo M. Prevelnce nd severity of incisl nd occlusl tooth wer in n dult Swedish popultion. Act Odontol Scnd 1988; 46: 255-265. 7 Csh R. Bruxism in children: review of the literture. J Pedodont 1988; 12: 107-127. 8 Ekfeldt A, Hugoson A, Bergendl T, Helkimo M. An individul tooth wer index nd n nlysis of fctors correlted to incisl nd occlusl tooth wer in n dult Swedish popultion. Act Odontol Scnd 1990; 48: 344-349. 9 Sjoholm T, Polo O, Alihnk A. Sleep movement in tooth grinders. J Crniomndi Disorders 1992; 6: 184-191. 10 Biondi M, Picrdi A. Temperomndiulr joint pin dysfunction syndrome nd ruxism: etiopthogenesis nd tretment from psychosomtic integrtive point of view. Psychotherpy & Psychosomtic 1993; 59: 84-98. 11 Brtlett D, Evns D, Smith B. Simultneous orl nd oesophgel ph mesurement fter reflux provoking mel. J Dent Res 1994; Spec Issue Ast 70. 12 Love W, Adms R. Tooth movement into edentulous res. J Prosthet Dent 1971; 25: 271-278. 13 Smith B, Knight J. An index for mesuring the wer of teeth. Br Dent J 1984; 156: 435-438. 14 Cown R, Stes C, Gross K, EllledgeD. Integrting dentl & medicl cre for chronic ulimi nervos ptient: cse report. Quintessence Int 1991; 22: 553-557. 15 Brndu H E, Ziemiecki T L, Chreneu G T. Restortion of cervicl contours on nonprepred teeth using glss ionomer cement: 4 fi yer report. J Am Dent Assoc 1984; 108: 782-783. 16 Rykke M. Dentl mterils for posterior restortions. Endod Dent Trumtol 1992; 8: 139-148. 17 Lundin S. Studies on posterior composite resins with specil reference to Clss II restortions. Swedish Dent J 1990; 73 (supplement). 18 Christenson G. Mrginl fit of gold inly cstings. J Prosthet Dent 1966; 16: 297-395. 19 Chdwick B, Dummer P. Fctors ffecting the dignostic qulity of itewing rdiogrphs: review. Br Dent J 1998; 184: 80-84. Fig. 7 A long cone rdiogrph of tooth 5 (35) pprently showing distl cvity; Fig. 7 A ite wing rdiogrph of the sme tooth confirming the clinicl finding of sound tissue Pin/sensitivity possily indicting tht tooth surfce loss is occurring fster thn ny reprtive mechnisms Shrp edges of tooth or restortion Frcture of tooth or restortive mteril Fcets on tooth or restortive mteril. Sensitivity nd shrp edges re commonly symptoms of rpid erosion, wheres frcture nd fcets re often indictors of continuing prfunctionl ctivity. Unfortuntely, the presence of these fetures is not lwys consistent nd therefore serve only s potentil indictors of the predominnt etiologicl fctor. Rdiogrphs The frequency with which these re tken nd the views used re, once gin, influenced y fetures of the specific cse. Frequency will relte to the perceived stility of the sitution nd the possile vlue to e gined from them. An verge intervl etween rdiogrphs would e 6 to 24 months ut they cn e tken t ny intervl when they will id either in monitoring or dignosis. The view tken must e pproprite: Bitewings: these will give informtion on the integrity of the tooth, restortion mrgins, nd one levels in the inter-proximl region. Long cone peripicls tken using prlleling technique : these provide peripicl informtion ut hve poorer definition of interproximl fetures t coronl level, eg cries. Accurte nd repetle views id dignosis. These cn only e otined using holder which supports the film nd guides the rdiogrphic em. 19 Orthopntomogrm: this provides generl view of the teeth nd jws ut is generlly of little use for specific tooth-relted dentl dignoses. When tooth hs een restored, dignosis of crious lesion from rdiogrph cn e very difficult, prticulrly where there re no clinicl signs or symptoms. Rdiogrphs cn e misleding nd dignosis must e mde from compound clinicl nd rdiogrphic informtion. Figure 7 shows long cone rdiogrph of tooth 5 (35) restored with gold cst retiner mny yers previously. There were no symptoms from this tooth. There ppered to e distl cervicl cries, however, no clinicl evidence for this could e found. A itewing view (fig. 7) showed the suspicious ppernce on the originl long cone peripicl ws shdow. Rdiogrphs form vlule dignostic id in the mintennce progrmme. The views tken nd the intervl etween rdiogrphs should e selected on the sis of the clinicl enefit tht will e derived. This pper hs descried the fetures of n effective mintennce progrmme. It comes in this series efore ppers which descrie restortive intervention. This reflects the importnce of the topic. Where the mintennce progrmme is ineffective, the restortive work defective or simply worn out, filure ecomes more likely. The next pper will descrie how such filures should e mnged nd wys in which their impct cn e lessened. This rticle is sed on presenttion t The Medicl Society of London on 10 My 1995 s prt of the Alph Omeg lecture progrmme. 376 BRITISH DENTAL JOURNAL, VOLUME 186, NO. 8, APRIL 24 1999