Anders /ohansson, DDS, Or Odonl' Department of Restorative Dental Sciences College of Dentistry King Saud University Riyadh, Saudi Arabia

Ridwaan Omar, BSc, BDS, LDSRCS, MSc, FRACDS" Department of Dentistry Identification and Armed Forces Hospital Management of Wear Riyadh, Saudi Arabia

The etiology and treatment of occlusal tooth wear remain controversial. Longer tooth retention hy the aging population increases the likelihood that clinicians will be treating patients with worn dentitions, A careful approach to interventional clinical procedures is advocated but should not curtail definitive management of patients having identifiable and potent causative agents that produce a rapid deterioration of the dentition. This article descrihes the epidemiology and etiology of occlusal wear and presents a conservative approach to its management, int I Prosthodont 1994,7:506-516.

t is probable that the increasing incidence of nat- minimal interocclusal space are thus obvious, as I ural tooth retention into older age' will result in a are the irreversibility and radical nature of com- wider prevalence of severely worn dentition than monly practiced reconstructive techniques. previously has been seen. The resultant challenges The parameters for determining what constitutes in the clinical management of such patients have severe wear and when treatment should be carried aroused considerable professional interest con- out remain unclear. Controversies also center on cerning tooth wear. the relative importance of possible causative While there are numerous etiologic factors, agents and the indicated therapy, if any, for treat- effects, and/or other more abstract phenomena ing the worn dentition. associated with tooth wear, their interrelationships remain difficult to define.-' Some of the complexi- Epidemiology ties and sequelae of these factors are illustrated in Fig 1. There is a need for clinical techniques that While there seems to be no shortage of pub- assess whether tooth wear for a given individual is lished reports of anthropologie studies of tooth in the range of normal or pathologic, and that reli- wear in earlier populations,'-'" investigations ably measure the severity and rate of progression describing the contemporary epidemiologic status of such wear/ of tooth wear are seldom found. It may be that the When extensive wear occurs, it is frequently prevalence of extensive wear in contemporary localized to the anterior teeth, and often in only populations has been considered to be so low that one arch. Severe wear rarely affects all teeth to the epidemiologic investigations would be meaning- same degree^ (Figs 2a to 2c). Thus, the majority of less, at least for western populations. interventional procedures for worn dentitions However, certain nonwestern populations, for involve the restoration of only the anterior teeth. example Australian aborigines, Eskimos, and The clinical problems of short clinical crowns and Saudis, have been shown to exhibit significant tooth wear." '- Recent generations of these popula- tion groups, while showing predictably reduced 'Assistant Professor and Const: i tant. tooth wear with the transition from rural to urban "Postgraduate Clinicai Tutor and Consultant. lifestyles, nevertheless still experience a rate and a Reprint requests: Or Anders Johansson, Department of degree of wear that exceeds that of western popu- Restorative Dental Sciences. College of Dentistry, King Saud lations. It has been suggested, consequently, that University, P.O. Box 60169, Riyadh I ¡545, Saudi Arabia. the changing lifestyle accompanying urbanization

The [nlernational lournal of Proslhodonlic 506 Idenliíi calió n and Mana eniuf Tooth Wear

Fig 1 Sixty-five-year-old Swedish man witti an extremely Fig 2a Twenty-one-year-old heavily built Swedish sports- wom dentition. There is pronounced mandibular anterior wear man with extreme loss ot maxillary clinical height. He opposing the maxillary rnetal ceramic crown. The overall had previously ccnsumed cola daily tor 5 years, and had the reduced dimensions of the maxillary teeth indicate the com- habit of keeping the beverage in his mouth to better enjoy the bined effects of incisai, occlusal, and proximal wear. While taste betöre swallowing. In addition to the extremely short several possible etiologic factors were present, the increased clinical crowns, there is also considerable reduction cf functional loading on the anterior teeth following lost posterior meslodistal width. support is probably ot greatest importance. or "cultural development" reduces the potential for tooth wear,'^ and that the advanced wear that does occur in such populations is usually regarded as a variation from the norm.- Comparing the findings in various reports on tooth vyear frequently presents the problem of dif- fering assessment methods. Only the use of stan- dardized and unified evaluation techniques would permit absolute interpopulation comparisons. For example, many investigators use "exposed " as the one sign of obvious wear, and this is proba- Fig Zb Left buccal view of the same patient in the interous- pal position. The large interincisal space between maxillary bly the most consistent feature within the various and mandibular central incisors is indicative of loss of tooth grading criteria used. An epidemiologic study'-* substance by erosion reported that only 2% of 585 randomly selected Swedish adults aged 20 to 80 years had one or more teeth with extensive wear, while in those aged 20 to 29 years, 14% of examined teeth had marked enamel wear or dentinal exposure. In 717 randomly selected Swedes aged 20 to 80 years, 41% of individuals showed dentinal exposure, but in those aged 20 to 29 years the frequency was 20%." Another study reported a prevalence of only 6% of teeth with dentinal exposure in orthodonti- cally untreated subjects, although it should be noted that the age of all individuals in this sample was 19 years,'^ in contrast to these findings in Fig 2c Maxillary view of the same patient. The cham- western population samples, a similarly aged bers are visible througfi the thin remaining dentin on the cen- young adult (aged 19 to 25 years) Saudi population tra! incisors and the left lateral incisor. This is a sign of a rapid wear progression. With siower progression, puips would possessed a 45% frequency of dentinal exposure of rarely become involved since secondary dentin would have teeth examined (Table 1).'- Such an experience of had time to torm. wear in Saudis can probably be ascribed, in part, to the sandy and harsh desert environment in which they live.'' Ambient climatic and environ- mental factors may, therefore, play a role in the

7, Number 6, 1994 507 T lie Internation al of ProBthodontii nd ManagementolTooLhi We lo han Mon/On

Table 1 Prevalence of Tooth Wear of Young Adults in Some Recently Published Studies No. of Age Population Prevalence of Authors subjects (v! Country sample Wear cnteria vKorn teeth Hugosonetai(1988!" 100 20-29 Sweden Random Wear of enamel or into dentin in 14% single spots or wear ot dentin < 'h of crown height Dahletal (t989!'= 47 19 Norway Orthodontically Small areas of exposed dentin or 6% untreated OÖVIOUS tooth length reduction Fareed et al (1990)" 206 19-25 Saudi Arabia Dental students Wear into dentin or extensive wear 45%

ment, such as canine guidance, anterior guidance, or group function.'" Similarly, diet (ie, coarse and acidic substances], diseases (eg, gastric conditions, anorexia nervosa), salivary composition (ie, buffer capacity, secretion rate, and variations in calcium ion concentration!, and occupational environment (eg, airborne abrasives, acid) have been found to be associated with tooth wear.'''"'' Also, reduced occlusal tactile sensitivity, high occlusal force, and increased endurance time, all of which reflect muscle and functional proprioception, have been shown to be correlated to extensive wear.^* Extensive wear is also associated with age and gen- Fig 3 Fifty-one-year-old Saudi man exhibiting a uniformly der. It is more commonly seen in older individuals severely worn dentition. Almost all the teeth show extensive and is seldom seen in females.''-' wear into dentin and several into secondary dentin Such a ciinical picture is a common tinding among Saudis and can It is generally found that in botb arches anterior probably be ascribed to the fine ambient sand particles cf the teeth (and anterior tooth wear indices) exhibit sig- hot and dry desert terrain. nificantly greater wear than posterior teeth.-' The precise cause of the higher frequency of worn anterior teeth remains unclear. It is generally held wear experience of certain contemporary popula- that in earlier populations, the excessive wear of tions (Fig 3). However, in a young adult (aged 17 molars resulted mainly from a coarser diet and to 24 years! Indian population, wear was found to from the more vigorous maslicatory activity be less than in western equivalents. The minimal required. Wear of anterior teetb also results from wear experienced by this sample was speculated to nondietary functions such as holding and manipu- have been a result of the method of food prepara- lating.™ It can be speculated that in contemporary tion and ingestion.'° humans, wear-inducing factors are likely to affect the anterior teeth more than the posterior. For Etiology example, intrinsic acid and (which are common in modern humans! primarily affect the The terms , erosion, and are not anterior teeth, while the absence of a coarse diet is only implicit of particular mechanisms by which less likely to cause wear of the posterior teeth. loss of hard tooth structure occurs, but also of the Although epidemiologic studies have shed light presence of various etiologic factors associated on some of the factors associated with tooth wear, with such loss.'^ Furthermore, these mechanisms problems in clinical management remain, and tend to act concurrently, and progressive tooth therapy is largely empirical. The initial stages of wear appears to have a multifactoria! etiology.' tooth wear are immensely difficult to detect. An Specific factors that have been implicated as accurate differential diagnosis of early enamel being etiologic and/or associated with the pro- wear is particularly perplexing because of the sig- cesses of attrition, erosion, and abrasion include nificant number of potential causative agents and functional (ie, cbewing! or parafunctional habits the often concurrent presence of attrition, erosion (eg, bruxism) and patterns of mandibular move- and abrasion. This multifactoria) and multifaceted

The Internarründf Journal of 508 •7, NumherÈ, 1I3IÏ4 lohansson /Omar and Management of Tooth We

Table 2 Elements of the History to be Taken for Assessment of Tooth Wear Individuals With Tooth Wear Element Question History Personal data Age Sex Patient history is important in any investigation Occupationai environment Diet Type (eg, citrus fruits/coarse food) of individuals suffering from extensive tooth wear. Frequency ot daily intake Table 2 summarizes some of the relevant aspects Period ot oonsumption that must be examined and to which patient Beverages Type (eg, cola, fruil juices] Frequency ot flaiiy intake responses should be elicited. Possible wear-related Period of consumption factors, frequency, duration, and history should be Orotacial pain/masticatory function noted for each positive response. Onset Duration The dietary pattern is of special importance. The Parafunctional habits Type (eg, bfüxism, pen biting) type and intake frequency of acid-containing Frequency items, eg, citrus fruits, cola, and fruit juices, are Duration Type of brush particularly significant. It is also important to note Intensity and trequency the manner in which beverages are drunk. For Abrasivity of example, normal drinking, especially if the drink is Systemic diseases Diagnosis kept in the mouth for some time before swallow- Duration Medication ing, is likely to produce more erosive wear than if Subjective symptom(s) a drinking straw is used. Duration of wear The presence of diseases, such as gastritis, Treatment need ulcers, or alcoholism, and other factors that are associated with acid régurgitation, reflux, or vomit- ing must be investigated, Bruxism or other para- functional habits should also be evaluated. character of tooth wear adds to the complexity of However, most individuals with habits such as the phenomenon, as the mechanisms may occur at bruxism are unaware of these actions. The type of different times and in different combinations. toothbrush (ie, soft, medium, or hard), the intensity While clinicians traditionally have considered and duration of tooth brushing, and abrasivity of bruxism to be the major cau^e of extensive wear in toothpaste are important considerations. contemporary humans, this premise may be anec- Demands for esthetic and functional improve- dotal or even erroneous. In this regard, while a ments may not be common but need to be consid- correlation was shown to exist between the degree ered: esthetics could, in fact, be of subjective of wear and the presence of bruxism, the differ- importance in young patients. Patients should also ence in wear experiences of bruxers and nonbrux- be asked whether they have been exposed to a ers was minimal,'" Conversely, another study con- potentially wear-conducive environment earlier in ducted within a high-wear population-" showed a life. negative correlation between bruxism and wear, with nonbruxers possessing more wear than brux- Clinical Examination ers. Although a diagnosis of bruxism from anamnestic data, as in the aforementioned stud- Aspects of the clinical examination are summa- ies,'""' may be considered unreliable, the conclu- rized in Table 3, and should include impressions sion drawn subsequently has been corroborated, [n for diagnostic casts. These should be poured in a recent report on the relationship between the vacuum-mixed die stone to facilitate a detailed progression of enamel wear, the presence of brux- evaluation of wear features. Although wear usually ism, and the occlusal scheme, it was shown that can be assessed from the casts, dentinal or sec- wear was not significantly different with respect to ondary dentinal exposure, enamel texture, and non-bruxers, bruxers, or occlusal scheme within a other surface characteristics should be examined 1-year observation period.^' This supports the intraorally, Intraoral photographs can be of great aforementioned contention and further strengthens help, both for diagnosis and follow-up. the suggestion that bruxism may have been overes- Even though dysfunction of the stomatognathic timated as a causative factor in tooth wear. Other system is not especially pronounced in individuals etiologic influences are potentially as great or with tooth wear, a complete examination of static greater.-' and dynamic occlusal relationships and temporo- mandibular disorders {TMD) should be performed,-'^

Volume 7, Number 6,1994 509 al Journal of Proslhodontit Collection of stimulated saliva and an analysis of Table 3 Elements of the Clinical Examination for buffer capacity and rate of secretion may be neces- Individuals With Tooth Wear sary. This is especially indicated for patients sus- Element Procedure pected of having tooth substance ioss that is of ero- Study casts Poured in vacuum-mixed dit! 5tone sive origin, and/or a disease affecting the amount Intraoral photographs Anterior, posterior L/R, occiusal and quality of salivary secretion. Even though rest uiew U/L saliva would be the preferred lype, the difficulties of Examination of wear Wear facets: iocation, extension, teat u re s "matching" ot opposing tacett,, obtaining an adequate volume from patients having ditfuse/demarcated; enamei/dentin a reduced salivary secretion rate are evident. texture, ûentinal (secondary) exposure Grading of the From study casts, photographs Grading of Wear severity ot wear (inlraorai] Salivary anaiysis pH, secretion rate, butter capacity Assessment tor TMD Examination ot muscles, TMJ, An assessment of the severity, location, and and mandibular extent of worn teeth is best accomplished using a movements combined intraoral and diagnostic cast examina- tion. The evaluation of diafjnostic casts allows a more detailed assessment and a record. Use of the casts and a simple ordinal scale (Table 4) facilitates grading wear tooth by tooth (Fig 4), Intraexaminer Table 4 Ordinal Scale Used for Grading Severity and interexaminer reproducibilities have been of Occlusal Wear shown to be approximately 90%.-'" The appearance Grade Degree of occlusal wear of the enamel, which may indicate the presence of No visible facets in enamel; occlusai/incisal erosive wear (sbiny, silky, matte, etc), should be morphology intact assessed intraorally to detect signs of such loss. Marked wear tacets in enamel; occlusai/incisal Similarly, exposed secondary dentin can only be morphology altered Wear into dentin; dentin exposed occlusally/incisaily observed intraorally or from intraoral photographs. and/or adjacent tocth surface; occlusai/incisal Such photographs are of further value for future morphoiogy changed in shape with rieight comparisons. reduction of tooth Extensive wear into dentm; iarger dentin area To monitor the rate of progression of wear—the {>2 ntin'} exposed occlusaliy/incisally and/or most important aspect—another scale must be adjacent tooth surface; occlusai/incisal used. This scale (Table 5) facilitates an evaluation morphology totally lost locally cr generally; substantiai ioss of crown height of the changes in wear characteristics between ser- Wear into secondary dentin (verified by ial examinations. More sophisticated alternative photographs) methods for assessing rate of progression, using scanning electron microscopic methods, have been described,^' Using these methods, changes in enamel wear could be detected at only a few weeks' interval, in the future such techniques may Table 5 Scale Used for Scoring the Progression of be incorporated into clinical practice, but for the Occlusal Wear present tbey constitute a tremendous tool irn the Grade Progression of occlusal wear scientific study of tooth wear. 0 No visible change 1 Visible ctiange, such as increase of facet areas, without measurabie reduction o! tooth iength; Differential Diagnosis occlusai/incisal morphology changed in shape compared to the first examination Attrition 2 Measurable reduction of tcotii length, et mm 3 Marked reduction of tooth length, >t mm Pronounced attrition-related wear is commonly associated with parafunctional activity. Masticatory function may also lead to such wear, albeit to a lesser extent. It is likely that the minimally abrasive contact positions, predominantly between tbe influence of the modern refined diet allows the anterior antagonists (Fig 5), Such wear is usually effect of direct tooth-to-tooth contact in mastica- confined to the occlusal or incisai surfaces, but tion to be seen, A reliable sign of attritional wear is may also affect the buccal and palatal surfaces of extensive, sharply demarcated faceting, usually the maxillary and mandibular anterior teeth in matching the opposing arch facets in excursive deep vertical overlap relationships.

a[ of ProsthodontK 510 Volume 7, Number 6, Idemifiralioii ^nd Ma

Erosion

Erosive wear is caused by nonbacteriogenic acid-induced loss of the surface tooth structure. Dietary (acidic foodstuffs), intrinsic (acid régurgita- tion), and occupational (industrial chemical plants with ambient acid) sources of acid are well-known. The enamel will have lost its shiny appearance, taking on a matte sheen. As tooth substance loss progresses, islands of exposed dentin appear. The less clearly demarcated facets and olher morpho- Fig Í Cast poured in vacuum-mixed die stone obtained trom an irreversible hydrocolloid impression. Note the sharply logic features appear silky, smooth, and rounded, demarcated tacet on the second premolar corresponding to with frequent loss of normal surtace characteriza- grade 1 wear (Table 4), and the detinite "depressions" within tion. Restorations, especially occlusal amalgams, the buccai cusp tacet of the tirst premolar and mesiolingual cusp tacet of the tirst moiar, corresponding to grade 2 wear. appear as "outgrowths," because of the destruction Such "depressions" within a taoet area have been compared of the tooth structure surrounding the metallic with intraorai photographs under controlled conditions by the restoration. Generally, intrinsic acid affects the authors and are almost always ccntirmed as being an expo- palatal surfaces of maxillary anterior teeth, while sure of dentin. acid of extrinsic origin affects the dentition more randomiy: dietary and ambient acid normally affect the buccal, and to some extent, the occlusal and incisai areas; in this case, cervical "saucer"- type buccal defects may be present, usually referred to as "buccal erosion" (Fig 6). A typical and convincing sign of rapidly-progressing erosive wear is an absence of matching occlusal contacts with antagonists (see Fig 2b).

Abrasion

Fig 5 Forty-eight-year-old Swedisi^ man with a history cf Abrasion is usually caused by the intraoral use of bruxism. Note the matching worn anterior antagonists; aiso objects such as the toothbrush, often in com- note the fractures of the buccal enamel on the maxiilary lett bination with abrasive substances (eg, toothpaste, lateral incisor and canine and on the mandibuiar left tirst and second premoiars, signs of heavy bruxism. ash, salt). The most commonly cited effect of abra- sion is the V-shaped defect, which usually is ascribed to the use of an intensive horizontal brushing technique and an abrasive toothpaste. Thus, the abrasive defects are usually located on buccal surfaces and apical to the cementoenamel junction. FHabits involving other intraoral objects (eg, pipe smoking, tootbpick use, thread biting) cause defects on the incisai and occlusal surfaces as well. Cervical V-shaped dental defects are, however, sometimes subgingivally located beyond the influ- ence of "toothbrush abrasion." These defects have also been observed in horses and cows, as well as in individuals who seldom brush their teeth. This implies another, or possibly an additional, expla- nation for such defects." It has been suggested that Fig 6 Thirty-nine-year-old Swedish woman who had eaten a heavy stressing of the teeth (eg, extensive chewing large quantity of apples daily for the past several years. Note or bruxism) will result in strain microfractures the duii sheen cf the enamel and the buccal saucer-like along the buccal cementoenamel junction, pos- defects especiali/ on the maxiliary right canine and the mandihuiar left and right first premoiars, ail signs ot erosion. sibly making the area more prone to destruction AisOp the flat, demarcated, cen/ical areas on the mandibular (Fig 7).'-'' canines are a sign ot the initial stage ot buccal erosion.

Volume?, Number 6,1994 511 The Internaiional |oiima¡ of Pn lid Mariiïgcmcnl of Toolh We

Table 6 Characteristics of Different Wear Mechanisms Attrition Abrasion

Location Incisal/occlusai surfaces; Upper palatal surlaces; buccal Buccal surfaces; mainly al mainly anteriorly surfaces, mainly anteriorly cementoenamel jur'VÜon Severity Normally moderate: can Potentially very severe Normally mild; sometii" • ¡5 be severe moderate and seidti;: severe Topography Weli-defined tacets; sharp Occlusal contacts lost; the pulp V-shaped defects; more severe edges and angles; flaf surface may be visible; "saucer"-shaped in premolar/canine regions defects bucally and sometimes and less in the inciscr/ pa I ata I ly segments Well-defined defects; often Enamel/dentin texture Normal; shining facets Matte, siiky enamel; sometimes very thin enamel edges; iarge involving both enamel and areas of exposed dentin dentin Subjective complaints Seldom; sometimes esthetics Sensitivity Seldom; sensitivity, if extensive

Treatment

After the history has been established and the clinical examination and diagnosis completed, management should be directed toward elimination of etiologic factors. However, it may be difficult and sometimes hazardous to the patient to eradi- cate the causative factors. For example, preventing bruxing activity, treating gastrointestinal disorders causing acid régurgitation, or stopping frequent , as in cases of alcoholism or anorexia ner- vosa, can be extremely difficult. Consultation with the patient's physician, dietary counseling, prescrip- Fig 7 This 39-year-old Swedish woman brusties her teefh tion of medication, etc, must be fully explored in using a 'regular technique." Note the V-shaped defects on the the initial management of a patient's tooth wear. maxillary rjght premolars, first molar, and the mandibular right Salivary data should be viewed in the context of the first molar, as well as the relative absence of such defects on other teeth. Tbe extruded and lingual position of the maxiliary medical history and the clinical examination, and, posterior segment and its contact relationship with the tilted if indicated, the physician should further investigate molars may constitute excursive interferenoes and contnbute the patient's general health. to unfavorable ioading during function (or parafunction]. The lingual position of the segment may also decrease any abra- If bruxism is confirmed, a complete-coverage sjve effecf by the toothbrush. hard acrylic resin occlusal splint should be con- structed for nighttime use. However, it may be dif- ficult to motivate a patient in its long-term use, Diagnosis which would be necessary for the full benefit of the treatment to be realized. After the primary eti- Based on the history and the clinical examina- ology has been established and therapy initiated to tion, an attempt should he made to Identify the eliminate this element, esthetic and/or functional causative factors and the degree to which each demands may remain. When it is not possible to may contribute to the deterioration of the denti- determine the primary causative element, defini- fion. The relative contributions of attritional, abra- tive reconstructive therapy must be approached sive, and erosive effects on tooth wear should be cautiously. When a reconstructive phase is being evaluated (Table 6). Although such an assessment considered, the following guidelines are suggested. is subject fo diagnostic uncertainties, it is impor- tant for proper management of a worn dentition. Observation Phase The etiologic factors responsible for the observed condition may have long since ceased. Initially, the progression of wear should be carefully Although a combination of factors is usually monitored." Because wear normally progresses slowly, involved, in most cases the primary etiologic factor with patients seldom having either funaional or esthet- can be identified. Such an identification is important ic complaints, indications for major restorative work to for the choice of final treatment and for its prognosis. be routinely carried out are substantially reduced.

5Ï2 Volume 7, Number 6, 1994 Iohaii45on /Omar Idcnlidcatinn and Management oí Tootli Wear

Serial investigations should be performed, using preparation, clinical crown length may be ex- diagnostic casts at 6-to-12 month intervals tended. In any such procedure (viz, apically reposi- (depending on the perceived rate of progression! tioned flap, gingivectomy, electrosurgery, etc), con- and recordings compared. Based on an assessment sideration should be given to the maintenance of of the rate of wear (Table 5), it is possible to decide the biologic width for a favorable periodontal prog- whether intervention is necessary. Usually an inter- nosis,"" Flective devitalization of the pulp and im occlusal splint, especially if bruxism is con- endodontic treatment for the purpose of gaining firmed, can be provided. This affords some protec- intraradicular retention and/or space is not advised. tion while monitoring the progression of wear. These considerations apply particularly to heavy However, such an approach may also lead to an bruxism, in which the high risk of mechanical fail- underestimation of the progression. ure (eg, porcelain and connector fractures, cemen- When a dominant and active erosive influence tation failure, etc) should limit restorations to single has been implicated, rapid deterioration of tooth crowns. In this way, physiologic tooth mobility is structures may be expected and serial monitoring unrestrained, torquing forces are minimized, and is contraindicated. In such instances reconstruc- cementation failure can be easily detected. Also, a tive procedures, in conjunction with treating the complete-coverage occlusal splint should be con- causal element, should be initiated without delay structed to overlay the restored teelh, and the (see Fig 2c!. patient must be convinced about the benefit of its In instances of rapid (erosive) loss of tooth sub- regular use. stance from tbe palatal surfaces of maxillary Inasmuch as anterior teeth are usually the most incisors, adhesive techniques offer reliable means extensively involved, esthetic demands will likely for interim protection against ongoing insult.Use of outweigh functional needs, creating a restorative the acid etch technique for bonding direct or indi- dilemma. The problem of restoring worn anterior rect resin composite veneers, or ceramic veneers in teeth when little available interocclusal space the longer term, is now widely accepted.'" exists is apparent, and a poor prognosis is equally clear. A less radical alternative to complete Reconstructive Phase occlusal reconstruction is the combined forced intrusion of anterior teeth and supraeruption of When esthetics or function are substantialy com- posterior teeth. A procedure using an anterior promised, prosthodontic therapy is indicated. For cobalt-chromium splint or a resin-bonded cast many patients only the anterior segments will be palatal onlay has been presented."" Such an involved. These are the most commonly affected approach can greatly simplify treatment, obviating teeth, particularly with erosive wear; the complete the need for complete-coverage restoration of fre- dentition is rarely equally affected. Fixed restora- quently sound (albeit sometimes mildly worn! pos- tions should be designed as single units whenever terior teeth. The relapse of the anterior interoc- possible. Fixed partial dentures should be of mini- clusal space so gained has been shown to be negli- mal extension. Nevertheless, many restorations fail gible,"" Such a relatively conservative treatment as a result of stress concentration from differential modality is generally appropriate when severe wear and occlusal contacts." Splinting should be wear affects the anterior segments only and would avoided when possible, and it is not recommended also be appropriate in the younger patient with for confirmed bruxism patients.^ Similarly, splinting severe anterior wear (Figs 8a to 8d!. additional abutments to compensate for a short Space may also be gained when a large horizon- and poorly retentive primary abutment is con- tal discrepancy exists between the retruded contact traindicated. The chances of cementation failure, (RC! and intercuspal (IC) positions with little verti- rather than being reduced, will probably be as cal discrepancy. Occlusal adjustment of such RC great as that at the short abutment. interferences, although time-consuming, will pro- The geometric characteristics of tooth prepara- duce a significantly more distal ICP and provide tion should instead receive meticulous attention: adequate palatal space for complete-coverage extreme parallelism of axial walls including "step- anterior restorations.'•''•''''••" The authors have ping" of very sloped surfaces, boxes, grooves, and found that this modality maintains the original ver- pin holes are well-established features for maximiz- tical dimension and allows successful restoration ing the retention and resistance form of teeth to of an extensively worn anterior dentition. receive castings. When minimal tooth structure and After mounting diagnostic casts in RC on an an adverse pulp relationship preclude such auxil- articulator, a trial occlusal equilibration of the casts iary features from being incorporated into the is performed to the point of eliminating the vertical

Volume 7, Number 6, T994 5Í3 The Inlemational loLrnal of Prosthodortics lohanssori/Ois

Fig 8a Thirty-six-year-old year oid Swedisii sailor with a Fig 8b Cobait-chromium device incorporating retentive iong history of frequent citrus truit consumption. His maxiliary clasps and providing anterior tooth separation ot 2 mm. anterior teeth are extremely worn, with reduced buccolingual dimension and little avaiiabie space tor complete-cove rage restorations.

Fig Be After continuous use of the splint for 2 months, ade- Fig 8d Finai metal ceramic crowns in the maxillary anterior quate space has been created to place anterior crowns. segment postcementation. Although full intercuspation poste- rioriy is not yet evident, posterior contacts are present. Note that the previously ciasped first premolar has erupted into occiusion in the short period fcliowing discontinuation of the splint.

discrepancy and leaving a small space between the not necessarily lead to a decreased vertical dimen- maxillary and mandibular anterior teeth. Following sion: compensatory eruption generally maintains a diagnostic waxing producing smooth, concave, an adequate facial height,•^•"' anterior guiding features and, if planned for, evenly Increasing the vertical dimension is only neces- distributed posterior contacts for posterior restora- sary for patients in whom interocclusal space prob- tions as well, provisional restorations are fabri- lems or esthetic considerations are critical. cated, duplicating the diagnostic waxing. After a Considerable increases in occlusal vertical dimen- period of clinical adjustments of the provisional sion can be tolerated," and it is the authors' expe- restorations, impressions are made and casts of the rience as well as that of others' that there need be restorations are mounted on an articulator. A cus- no hesitation in increasing the vertical dimension tomized anterior guidance table is formed, from to attain the space required for restorative material. which the palatal surfaces (and posterior occlusal If any doubt exists, a removable occlusal splint or a surfaces, if necessary) of Ihe final restorations are trial partial denture can be provided. Should a subsequently fabricated. more critical appraisal of tolerance of the in- creased vertical dimension be necessary, provi- Generally, any reduced vertical dimension that sional fixed restorations may be placed," may result from wear should be maintained. In tbe absence of any functional problem, the patient's Conventional methods of determining the new ver- adapted "worn-in occlusion" need not be altered. tical dimension should be used. There are seidom any Increasing the vertical dimension according to adaptive problems in healthy individuals. However, a some predetermined "standard of normality" is not cautious approach is advocated with such procedures essential. It has been shown that tootb wear does for patients exhibiting signs or symptoms of TMD."

a I of PrD5lliodontii 514 • 7, Number 6, 7994 Ideniiiication and Management oí Tcotli Wear

Table 7 Elements of the Maintenance Examination References of Individuals With Tooth Wear Element Procedure 1. Haugeti LK, Biologicai and physiological changes in the aging dentillon, Inl Dent | 1 992;42:339-348, Clinical Retention 2. Carlsson CE, Ingen/all B, Occlusal variations and problems, Loose retainer in: Mohl N, Zarh C, Carlsson GE, Rugh JD (eds), A textbook Secondary caries Signs of further erosive loss 01 occlusion, London: Quintessence, 1988:209-212, Radiographs 3. Dahl BL, Carlsson CE, Ekfeldl A. Occlusal wear of teeth Signs of bruxism New wear facets and restorative materials. A review of classificalicn, etiol- Porcelain integrity ogy, mechanisms of wear, and some aspects of restorative Occlusal splint integrity procedures. Acta Odontol Scand I993;5I:299-311, Study casts and Scoring ot progression of wear 4. Johansson A, Haraldson T, Omar R, Kiliaridis S, Carisson intraoral photographs CE, A system for assessing ihe severity and progression of occlLsai tooth wear. J Oral Rehahil Í993;2O:1 25-1 31. 5. lohansson A, Haraidson T, Omar R, Kiliaridis 5, Carlsson CE. An investigation of some factors associated vtith occlusai tooth wear in a selected high-wear sample, Maintenance Phase Scand 1 Dent Res 1 993;1 01:407-41 5. 6. Creene OL, Ewing CN, Armelagos GJ, Dentition of Regular recall of patients is necessary for several mesolithic population from Wadi Haifa, Sudan, Am | Phys reasons. For example, a combination of short clin- Anlhropol 1 967;27:41-56, icai crowns, differential wear, and bruxism in- 7. Helm S, Prydso U, Assessment of age-al-death from mandibular molar attrition in medieval Danes, Scand J creases the risk of cementation failure. Similarly, DenI Res 1979;87:79-9O, erosion-induced wear may continue even in the B, Molnar S, Tooth wear and culture, A survey of toolh func- presence of teetb with complete-coverage crowns tion among some prehistoric populations. Curr Anthropol and can progress cervical to the restored tooth if 1972;13:511-526, causal factors have not been eliminated. Similarly, 9, Reinhardt CA, Relationships hetween attrition and lingual lilting in human teeth. Am J Phys Anthropol 1983;61: occlusal splint therapy may not be successful for 227-237. patients exhibiting combined attrition (bruxism) 10. Whittaker DK, Davies C, Brown M, , attrition and erosion. and temporo-mandibular joint changes in a Romano- Patients should be recalled at least annually; at Brilish population. | Oral Rehabil 1 9B5;1 2:407-419, 11. Molnar S, McKee ¡K, Molnar IM, Przybeck TR. Tooth wear this time, new diagnostic casts and photographs rates among contempoiary Australian aborigines, | Derit should be made, A careful clinical and radiograph- Res 1983;62:5G2-565, ie examination of abutments should be performed 12. Fareed K, Johansson A, Omar R, Prevalence and severity witb attention to secondary caries, failed retention, of occiusai toolh wear in a young Saudi population. Acta wear facets, porcelain integrity, etc (Table 7), Odontoi Scand 1 99O;48:279-285, 13. Davies TCH, Pedersen PO, The degree of attrition of the deciduous teeth and fitst permanent molars of primitive and Summary urbanized Greenland natives BrDertI 19SS;99:3S^3, 14. Hugoson A, Bergendal I", Ekt'pldt A, Helkimo M, Prev- aierice and severity of incisai and occlusal toolh wear in While wear of the dental hard tissues is a natural an aduit Swedish population. Acta Odontol Scand 1988; physiologic process with rare untoward effects, 46:2S5-265, instances of extensive wear have been docu- 15. Salonen L, Hellden L, Carlsson CE, Prevalence of signs mented in earlier populations, unlike certain non- and symptoms of dysfunction in the masticatory system: western populations, contemporary western popu- Ar epidemiologic study in an adult Swedish population, J Craniomandib Disord Facial Oral Pain 1990;4:241-2S0, lations rarely experience severe wear. This relative- 16. Dahl et, Krogstad BS, Ogaard B, Ecketsberg T, ly low prevalence of wear in the latter group can, Differences iri functional variabies, fillings, and tooth however, be expected to increase; it is the authors' wear in two groups of 19-year-old individuals. Acta contention that, even as this happens, the clini- Odontol Scand 1 989;47:35-40. cian's approach to definitive treatment must 17. Johansson A, Fareed K, Omar R, Analysis of possible fac- tors influencing the occurrence of occlusal tooth wear in remain cautious. a young Saudi population. Acta Odontol Scand 1991; 49:139-145, Acknowledgment 18. Abdullah A, Sherifudhin H, Omar R, lohansson A. Pievalence of occlusal tooth wear and its relationship to iateral and protrusive contact schemes in a young adult The authori express their sincere gratitude to Professor iridian popuiation. Acia Odontoi Scand 1 994,S2:202-210, Gunnar E, Carlsson, University oí Göteborg, Sweden, for his 19. Pindhorg II (edl. Pathoiugy of the Dental Hard Tissues. continuing interest in their work; his enthusiasm in reviewing Copenhagen: Munksgaard, 1970:312-332, this manuscript, together with his constructive criticism, are 20. Beyron HL. Occlusai changes m the aduit dentition, J Am what they have come to expect of him. Dent Assoc 1954;48:674-685,

olume7. Number 6, 1994 515 Ide ni I Deal I on and .Maiiagement ul Tootti Wear

21. Ekfeldt A. Incisai and occlusal wear and wear of some 36. Braem M, Lambrechts P, Vanherle C. Stress-induced cer- prosthodontic materials [PhD thesis]. Swed Dent | vical , J Prosthet Dent 1992:67:718-722. 1989;(5uppl 651:1-62. 37, Carlsson CE, Johansson A, Lundqvist S. Occlusal wear: A 22. Eccles |D, Jenkins WC. Dental erosiori arid diet, I Dent follow-up study of 18 subjects with extremely worn denti- 1974;2:153-159. tions. Acta Odontol Scand 1 965:43:83-90, 23. Helistrom I. Oral complications in ancrexia nervosa. 30. Noack Ml, Rouiet JF. Tooth-co I ou red inlays. Curr Opinion Scand | Dent Res 1977;8S:71-86. Dem 1991:1:171-178. 24. ]arvinen V, Meu'man |H, Hyvarinen H, Rylomaa I, 39. Wise MD. Occiusion and restorative dentistry. Br Dent ) Murtomaa H. Dental erosion and upper gastrointestinal dis- 1977:143:45-52. orders. Oral Surg Oral iMed Oral Pattiol 1988;65:39e-303. 40. Nevins M, Skurow HM, The intracrevicular restorative 25. Enbom L, Magniisson T, Wall G, Occlusal wear in rnineis, margin, the biologic width, and the maintenance of the gin- SwedDeniJ I986;IO:165-I7O. givai margin. Inl | Periodont Rest Dent 1 984:4:(3)30-49. 26. Linlicsalc E, Markkanen H, Dental erosions in lelation to 41. Block PL. Restorative margins and periodontal health: A lactovegetarian diet. Scand | Dent Res 1985;93:436-441. new look at an old perspective. ) Prosthet Dent 1987: 27. Mannerberg F. Saliva factcrs m cases cf ercsion. Odcntol 57:683-689, Rev 1963:14:156-166. 42. Dahl BL, Krogstad O, Karlsen K. An alternative treatment 2B. Ten Bruggen CHJ. Dental erosion in industry. Br | Ind Med in cases with advanced localized attrition. J Oral Rehabil 1968:25:249-266. 1975;3:209-214. 29. Johansson A. A cross-cultural study of occlusal tootli wear 43. Capp N|, Warren K, Restorative treatment of patients with [PhD thesisl. Swed Dent 1 1992:(suppl e6):1-59. extensive vertical overlap. Int J Pfosthodont 1991: 30. Varrela 1. Effects of attritive diet on craniofacial morpholo- 4:353-360. gy: A cephaiometric analysis of a Finnish skull sample. 44. Dahl BL, Krogstad 0. Long-term observations of an EurlOrthod 1990:12:219-223. increased occlusal face height obtained by a combined 31. Anderson GC, Pintado MR, Beyer |P, DeLcng R, Douglas orthodontic/prosthetic approach. | Oral Rehabil I9Ö5: WH. Ciinical enamel wear as reiated to bruxism and 12:173-176. occiusal scheme [abstract 1601). | Dem Res ]993;72:303. 45. Dawson PE, Vertical dimension. In: Dawson PE (ed). 32. Teaford MF, Tylenda CA. A new approach (o the snjdy of Evaluation, Diagnosis, and Treatment of Occlusal Treat- tooth wear. I Dent Res Í991;70:204-207. ment. St Louis: Mosby, 1 974:275-285, 33. Ott RW, Píoschel P. Zur Ätiolcgie des keilförmigen defek- 46. Turner KA, Missirlian DM. Restoration of the extremely tes. Ein funkicnsorientierter epidemiologischer und experi- worn dentition. J Prosthet Dent 1984:52:467-474. menteller beitrag. Dtsch Zahnarztl Z 1985;40:l 223-1 227, 47. Hylander WL. Morphologicai changes in human teeth and 34. Lee WC, Eakle WS. Possible role of tensile stress in the jaws in a high-attrition environment, in: Dahiberg AA, etiology of cervicai erosive iesions of teeth, | Prosthet Grabei TM (eds). Orofaciai Growth and Development. Dent 1984:52:374-380. Paris, The Hauge: Mcuton, 1977:301-330. 35. Bevenius ], L'Estrange P, Karlsson S, Carlsson CE. 48. Berry DC, Poole DFG. Attrition: Possible mechanisms of Idiopathíc cervical lesions: In vivo investigation by oral compensation. I Oral Rehabil 1976:3:201-206. microendoscopy and scanning electron microscopy. A 49. Garnick j, Ramfjord SP. Rest position. An electromyographic pilot study. I Oral Rehabil 1993:20:1-9. and clinical position. | Prosthet Dent 1962:12:895-911.

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